1: Quick question 6550/KT88 same amp - help please (11.39)
Posted by LD on 2000-12-02, 16:19:02 (170.253.240.1)
Due to unfortunate circumstances I have 3 KT88's that work and 3 6550's that work. My amps (Cary CAD-50M mkII)uses 2 KT88 or 6550. Can I use one KT88 and ONE 6550 in each amp? This is only temporary u .......

2: Re: KT88 for ASL Hurricane? (11.39)
Posted by MIchael Samra on 2005-11-08, 00:41:01 (66.188.56.2)
A 6550 is esentially a kt88 and even the curves are almost identical.You can always sub a kt88 for a 6550 but you cant always sub a 6550 for a kt88 becuase the plate voltage rating is slightly higher .......

3: VTV issue 19: 6550/KT88 Shoot-Out for Hi-Fi (11.29)
Posted by agattu on 2004-09-29, 21:53:07 (66.230.115.199)
Genelex KT88 (1969) was favorite followed in order by Tungsol 6550 (1963,grey plate, no holes), JJ KT88, Ei KT90, EH KT88, SED 6550, SED KT88, Philips/Sylvania 6550 (1970s)& Svetlana 6550 (tied), Valv .......

4: Different Tube? Same Tube? EH 6550/KT88, Sovtek 6550/KT88, Svet 6550/KT88 (11.16)
Posted by tvr2500m on 2003-09-12, 11:14:59 (209.6.113.23)
For current production KT88 and 6550 offerings, are these really differently rated/spec'd tubes or are they just the exactly the same internals with different labels? Looking at the EH 6550 and KT88 t .......

5: 6550 versus KT88 (11.00)
Posted by Mike Craig on 1999-11-10, 15:45:26 (12.73.167.149)
Can anyone tell me why someone would want to modify a Jolida 502 from a 6550 arrangement to a KT88? I guess I may be showing real ignorance here. Does the KT88 have advantages over the 6550? ::: TOPIC .......

6: Re: Why do KT88's sound like veiled mush to me? (10.54)
Posted by AbeCollins on 2006-02-26, 08:29:15 (67.176.116.152)
Again, in comparing SED 6550 vs SED KT88, I find the KT88 more lush or robust in the midrange. But the 6550 is tighter and better defined in the bass with more snap and overall more transparent throug .......

7: With tube you prefer for Maggie 1.6 (6550 or KT88) (10.54)
Posted by demetane on 2004-07-14, 19:52:24 (69.159.131.205)
Hi, What kind of tube you prefer to drive Magneplanars MG1.6. 6550 or KT88 Maggies will not play too flat with KT-88 ? I have compare 6550 to KT88 but not with Maggies. KT88 have more open mid but the .......

8: Re: 6550 vs kt88, is there a differnce? (10.40)
Posted by waterfall on 2000-06-09, 20:12:10 (38.27.199.53)
I can't comment about the specs either because I don't have a manuel either. My listening ear finds the kt88 to be a bit sweeter than the 6550, the 6550 might have a little more bass ( they also sound .......

9: RE: 6550/KT88's in Copland 505 (10.33)
Posted by edlin on 2007-12-13, 18:35:02 (75.153.175.89)
That is very interesting indeed! I vaguely recall it was my original dealer, that told me that the amp could only run 6550's and that it needed mod's to run KT88's. I have noticed these days that many .......

10: Re: Does KT88 output more power than 6550?(nt) (10.33)
Posted by Poul Kirk on 2002-01-01, 15:18:27 (203.59.171.196)
It is the other way round. 6550 tubes produce slightly higher output power than KT88's, about 5 to 8%. they also need a slightly higher Bias Voltage. 6550 also gives a more abrupt overload than KT88's .......

11: Re: 6550 Tubes for Doug A. (10.27)
Posted by AbeCollins on 2001-09-03, 23:36:41 (65.10.208.131)
You mentioned your KT88's vs the 6550's. I know this question has been asked a zillion times but what do you notice in the KT88's vs the 6550's? I have a CJ Premier 11a running pretty standard Svet 6 .......

12: 6550 vs. KT88 tubes (10.24)
Posted by Audioquest4life on 2008-10-01, 00:00:06 (139.139.83.70)
Ok, I know this is a vague question and their will be many answers, however, based upon the newer versions of the Gold Lion KT88's and others KT88 tubes such as from EH vs. the current 6550 tubes, whi .......

13: Re: Different Tube? Same Tube? EH 6550/KT88, Sovtek 6550/KT88, Svet 6550/KT88 (10.23)
Posted by Prokofief on 2003-09-12, 11:50:57 (68.134.162.202)
I have both the EH6550s and EHKT88s and they are definetly different tubes. .......

14: Please help with tube selection for Jolida 502 (10.22)
Posted by Driven on 2001-08-03, 23:38:59 (209.240.221.92)
Hello, I'm new to the tube world, and no very little in this area. I need to replace the tubes in my Jolida 502. I currently have Svetlana 6550's. From my reading I have made an assumption t .......

15: Re: Different Tube? Same Tube? EH 6550/KT88, Sovtek 6550/KT88, Svet 6550/KT88 (10.19)
Posted by tvr2500m on 2003-09-12, 14:43:51 (209.6.113.23)
Steve: This is more of what I'd like to know. I've got some of the datasheets for these tubes, but I haven't been able to find all of them. - SJ .......

16: Aronov monoblocks - change 6550's to KT88's? (10.14)
Posted by Spa317 on 2011-04-01, 22:55:16 (121.45.141.159)
Just picked up a pair of the monoblocks, with Svetlana 6550's in them. They sound real good, but I believe that you can also use KT88's in these amps. I like the midrange of the 6550's/amp, just wonde .......

17: RE: KT88/6550 (10.13)
Posted by tube_newbie on 2008-10-29, 02:29:44 (192.100.116.142)
Is it so that KT88 will last longer due to its ability to dissipate more power compared to 6550? If 6550 is more transitory then this means to me that KT88 would lack bass control? I would like to hav .......

18: Re: What's the difference btwn modern 6550 / KT88? (10.11)
Posted by DC on 2000-12-27, 17:22:32 (202.145.178.1)
I thought the 6550 is a beam pentode and KT88 a tetrode, no? I've not heard 6550 being billed as a poor man's KT88. But it doesn't surprise me considering the cost differences. -DC .......

19: Re: KT88's vs 6550's (10.02)
Posted by AbeCollins on 2002-06-29, 13:18:56 (12.252.106.56)
I think it really depends on the amp and personal preference. I can tell you that in my CJ Premier 11a, I prefer the sound of the 6550 tubes over the kt88's. The kt88's have a rich sweet sound but it' .......

20: RE: Can KT88's be used instead of 6550's? (9.97)
Posted by Kevin Deal on 2008-06-20, 11:56:12 (74.62.201.210)
What amp do you have and what brand 6550 are you using? The manufacturer of the tube has more to do with the sonics than the fact that it's a 6550 or a KT88. Just because a tube is a KT88 does not au .......

21: Re: Different Tube? Same Tube? EH 6550/KT88, Sovtek 6550/KT88, Svet 6550/KT88 (9.97)
Posted by Chuck Y on 2003-09-12, 11:40:57 (216.119.8.78)
Don't know about the Sovteks or EH's but I have a C logo Svet 6550 and KT 88 in front of me and I can see a bunch of differences in the construction - for starters look up in the area of the getters - .......

22: Re: EH 6550 with KT88 shaped bottles (9.96)
Posted by KIS on 2002-07-16, 01:11:27 (203.40.130.64)
Dear Uncle Ned I have just checked the current catalog from New Sensor's website which is the most accurate source - as they own both brands. There is no such thing as a EH KT88, only Sovtek KT88. I c .......

23: Re: KT88 in Audio Research amps (9.91)
Posted by DC on 2001-01-08, 17:55:58 (202.145.178.1)
I wrote a fax to AR and when I asked them if it were OK to use KT88 as posed to 6550, was given the statement: "OK, recommend Svetlana KT88, IF you can't find 6550" When asked about JJ/T KT88, said it .......

24: Re: 6550 and kt88 (9.88)
Posted by johnnybegood4 on 2001-03-18, 21:24:49 (209.185.214.213)
Having both of these tubes in my Jadis defy 7 for over a year I am fimilar with both. In general the 6550 has more slam and bass impact but lacks the clarity or musical purity of the kt88. The kt88 st .......

25: Re: current production tubes (9.87)
Posted by KIS on 2002-07-14, 11:28:20 (203.40.136.178)
Dear Newbee My amps needs 8x6550 valves aside. They are terribly expensive to retube or to borrow to try. I have used Sovtek KT88 and Sovtek 6550. I also tried the Chinese KT88 before. The Sovtek KT88 .......

26: KT88's vs 6550's (9.87)
Posted by goochmon on 2002-06-29, 12:15:44 (63.175.188.3)
I would like to here from those of you. Who prefer KT 88's over 6550's Also those of you who like 6550's over KT88's. Outside of power output what's the difference in sound. Thank Dave .......

27: Re: Different Tube? Same Tube? EH 6550/KT88, Sovtek 6550/KT88, Svet 6550/KT88 (9.85)
Posted by tvr2500m on 2003-09-12, 14:56:03 (209.6.113.23)
Well, that's what I'm seeing. the EH 6550s and KT88s I've got look like their internals are exactly the same. Now are they the same electrically? Nice enough tubes, just curious... .......

28: KT88/6550 (9.83)
Posted by tube_newbie on 2008-10-28, 12:53:09 (91.153.211.85)
I have Consonance Cyber 100 Signature integrated using 4*6550 (Electro Harmonics) power tubes. I have been looking for new tubes for my amp. What are the main differences between 6550 and KT88 tubes? .......

29: why 6550 over kt88 (9.82)
Posted by kenk on 2001-03-04, 12:51:51 (24.190.128.203)
I know there are manny comparisons in the archives, and this is not what i am after. I am looking to find out what the reason so many amp companies choose the 6550 over the k88. For example i belive t .......

30: Re: RCA 6550 (9.80)
Posted by evansjw on 2003-12-30, 12:37:16 (68.73.58.24)
A 6550 is very similar to a KT88. KT88 are a bit more rugged and have somewhat higher ratings. They will interchange but you will not get as much power out of the 6550. .......

31: Re: NOS 6550 vs Genalex KT88? (9.77)
Posted by TY on 2001-04-28, 09:56:53 (203.198.228.155)
Tung-sol 6550 is actually not bad for the MC275. But there is no way that it can sound better than the GEC KT88. And no other 6550/KT88 is remotely close to the sound quality of the Tung-sol and GEC. .......

32: Perhaps is the combo of the small tubes w/the power tubes..... (9.72)
Posted by Chuck Y on 2006-02-22, 17:04:42 (199.174.209.228)
Re SED 6550's and KT88's, I find the KT88's have a warmer mid bass and softer high end. The 6550 seems more balanced. Combine a soft/warm small tube with a KT88 and, depending on the amp, it could eas .......

33: Re: KT88 vs 6550C in Cary SLAM 100 (9.71)
Posted by excelit on 2002-01-15, 14:22:23 (63.27.109.228)
Hi, I'm not familiar with Cary products but in my setup the SVT6550C sounded more real on audiophile recording, but less forgiving on most commercial recordings. The SVT KT88 has more extension on bot .......

34: Re: Which Tubes deliver better bass performance? (9.69)
Posted by AbeCollins on 2003-06-24, 23:39:57 (12.252.236.227)
I believe Steve is correct and between the KT88 and 6550, I prefer the 6550 in my CJ tube amp. The KT88 is 'warmer' with more 'weight' in the midrange but the 6550 is more 'transparent' and more 'open .......

35: Re: Testing KT88/6550 by Hickok TV7 (9.61)
Posted by Jim McShane on 2000-12-25, 07:33:41 (209.247.38.218)
Look up KT88 and use those settings. For some reason the TV/* series testers never had a listing for 6550. The KT88 setting works fine for testing both KT88 and 6550 (KT90 also). It's on page 54 of pu .......

36: You are right, with the 6550 this KIT is very ( + Pic ) (9.60)
Posted by Steve P. on 2001-12-13, 03:20:43 (212.152.238.86)
good sounding. I tried this KIT with Ei KT90, JJ KT88 and Svetlana 6550 C's and GE 6550's. The midrange from the 6550's sounds best to me ans others. Maybe this is one of the reasons why the new KIT i .......

37: mixing 6550 and kt88 (9.59)
Posted by uncle mag on 2009-03-24, 15:24:46 (146.18.173.74)
would it cause any problems mixing kt88's and 6550's in the same amp? (vtl mb185's) the amps do accept kt88's or 6550's and have separate bias pots for each tube. i already have some old stock tungsol .......

38: are kt88, kt90 and 6550 inter-changeable? (9.59)
Posted by moose on 2001-01-29, 19:59:20 (152.163.207.54)
Are the KT88, KT 90 and 6550's all inter-changeable? I have a CJ amp, can I use the KT88 OR KT90 in place of my 6550's. thanks bill .......

39: Re: 6550/kt88 suggestion (9.57)
Posted by Michael P. on 2003-07-07, 15:08:00 (65.176.65.4)
I am still researching the same question. The new issue of Vacuum Tube Valley has extensive commentary on the 6550/KT88 tubes. Their blind test determined the Svet 6550 and JJ KT88 (of current product .......

40: RE: Reliablity of 6550 vs. KT88 (9.55)
Posted by JoKath on 2007-09-07, 13:03:29 (24.150.45.144)
My experience tells me the exact oppposite. I've seen more 6550 blown than any KT88. The difference is not so much in reliability as the way the tubes are used. The KT88 has much higher screen voltag .......

41: Re: Different Tube? Same Tube? EH 6550/KT88, Sovtek 6550/KT88, Svet 6550/KT88 (9.51)
Posted by Chingy on 2003-09-12, 12:23:48 (66.46.156.130)
It depends which EH 6550's you have. The ones made early 02 or before that had a tapered bottle. Also you would notice only four support posts. As of last fall though I have seen them and the bottle i .......

42: RE: Thanks Joe (9.51)
Posted by garf on 2015-06-04, 07:41:20 (86.187.137.159)
I did read your 6550 & KT88 reviews and was impressed that you rated the GL KT88 higher than the SED 6550. I also saw that you liked the Tung-Sol 6550 reissue but I wanted to hear the KT88 and am glad .......

43: Re: Groove Tubes KT88 (9.50)
Posted by Gary Kaufman on 2000-08-04, 09:33:34 (155.41.71.177)
For what it's worth, I like the TungSol 6550's more than any other KT88/6550 variant in my pair of Mcintosh Mc75's. I've compared them with GEC/GoldLion KT88's, GE6550A's, Sylvania 6550 and Tesla KT88 .......

44: Re: 6550 vs. KT88 (9.50)
Posted by Bobaroo on 2006-08-05, 04:47:46 (67.1.253.127)
Thanks for the responses, I think I may try the reissue TS when I need tubes. One further question, as long as the subject came up. What do you see as the pros & cons of 6550 and KT88. My understandin .......

45: I have in a 3/5 combo, FWIW (9.48)
Posted by Chuck Y on 2007-03-15, 19:46:03 (4.246.120.17)
Whether I liked the 6550 vs the KT88 (both SED's) depended a lot on the sonic's of my source. In my opinion the KT88 has a slightly enhanced upperbass which is a bit soft in comparison to the 6550 whi .......

46: Re: my favorites so far.... (9.46)
Posted by AbeCollins on 2006-05-29, 13:06:41 (67.176.116.152)
I liked the EH KT88's best in my ARC VT50 over the SED KT88's (or the factory SED 6550). A couple folks here on AA recommended them to me. In this particular amp, the EH KT88 seemed more open and tra .......

47: Re: Help with tube choice kt88/kt90/6550 which brand and price? (9.46)
Posted by Bryan F. on 1999-10-22, 05:44:51 (24.29.208.248)
>>> I saw someone say that the are not a direct plug in for 6550 in some amps. Not true. They have been re-designed for a long while now to have the same negative bias requirement and same Gm as 6550 .......

48: Re: VTL tube type from 6550 to KT-88 (9.45)
Posted by rlawry on 2001-09-18, 07:33:25 (165.121.119.212)
You should be able to replace the 6550's with the KT88's using the same bias setting. KT88's were originally designed by M-O Valve Company in the UK as their version of the Tung-Sol 6550. ::: TOPIC:: .......

49: KT88: does it sound like a 6550? (9.45)
Posted by banpuku on 2013-08-08, 14:15:07 (173.23.101.114)
I am considering the Decware Torii mono-blocks that use KT88 tubes. I am not familiar with the KT88 sound, but I am familiar with the ARC 6550 tube sound. I am not a big fan of ARC (my opinion only) a .......

50: Re: What's the difference btwn modern 6550 / KT88? (9.41)
Posted by Story on 2000-12-27, 11:18:53 (152.163.207.51)
there's not alot, they're both beam pentodes but they are constructed differently if one is talking about the original GEC kt88 design, which i feel is superior. I guess the 6550's came to be known as .......

51: Re: 6550 vs. KT88 (9.36)
Posted by Bobaroo on 2006-08-05, 15:18:56 (67.1.252.201)
aside from different tonal qualities in manufacturers, is there any reason a person should choose 6550 over KT88 or visa versa? I beleive I heard somwhere that the KT88 can handle higher plate voltage .......

52: Re: Tungsol 6550 vs. Svetlana KT88 (9.36)
Posted by Beam Tube on 2000-12-20, 14:50:07 (64.111.33.153)
Dear Bob: The Tung-Sol 6550 is the best version of this tube ever made; it is the standard of all 6550 power tubes. I have yet to try the Svetlana KT88's, but I really enjoy the Valve Art KT88's. Ple .......

53: Re: KT90 vs. KT88 (9.31)
Posted by rlawry@mindspring.com on 2002-01-02, 14:40:21 (209.86.218.169)
I have tried the following 6550/KT88/KT90 tubes in my AES DJH Superamp (p-p triode mode): Tung-Sol Black Plate 6550 Chinese KT88 Svetlana KT88 GEC KT88 Ei KT90 Yes, the KT90 seems to give the most out .......

54: Re: EH 6550 with KT88 shaped bottles (9.31)
Posted by Uncle Ned on 2002-07-15, 17:06:53 (64.109.231.108)
As much as we like Svet 6550, they are (I think) no longer in production. Any comments here? First I've heard of this...we don't have any problem getting them at all that I know of. Note that tubes a .......

55: 6550 vs. KT88 (9.31)
Posted by Bobaroo on 2006-08-06, 13:19:53 (67.1.252.80)
My amp can use either of these tubes, what are the pros & cons of each. I've heard that some KT88's have a better midrange than 6550's and the KT88 can handle higher plate voltages. I realize that ton .......

56: They are NOT always interchangable! (9.30)
Posted by Allen Wright on 2009-11-17, 02:56:58 (87.245.73.97)
They are similar, but NOT identical. Depends on the amp you want to use them in. The KT88 has a much high screen voltage rating, and if you use 6550's in a KT88 circuit they will work, but not for lon .......

57: RE: Kt88 Compare Please (9.30)
Posted by marlin on 2021-10-05, 05:31:54 (50.201.116.106)
I have never used Valve Art KT88's. I have tried TS 6550 and KT120, GL KT88, EH kt88, JJ KT77 and KT88 . My favorite are the GL tubes, second is TS KT120's. Least favorite were the 6550 and KT77. From .......

58: Can SF power 1,2, or 3 use EL34 tube instead 6550? (9.29)
Posted by Chris on 2001-03-23, 02:53:36 (203.117.33.23)
Have anyone try to use EL34 in place of 6550 in SF power 1, 2 or 3? However, SF says they only recommend 6550 and KT88. In theory, would most amps with 6550 can interchange safely with EL34. The KT88 .......

59: Re: KT88 vs 6550 (9.28)
Posted by tantra on 2006-11-08, 11:46:00 (149.142.139.20)
I swapped Svetlana 6550's for EH-KT88's in my C-J Premier 12 monoblocks. The bass is tighter and faster, but with less low-bass energy using the EH-KT88's. The mids are about the same with the EH-KT88 .......

60: Re: Different Tube? Same Tube? EH 6550/KT88, Sovtek 6550/KT88, Svet 6550/KT88 (9.28)
Posted by steve oda on 2003-09-12, 15:11:34 (66.214.160.49)
Steve, Hard to find factory data sheets on specific tubes and sub-types. Maybe in Russian??? But, the seller should know if the KT-88 he is selling can safely go into stock Marshall Major amps. If he .......

61: RE: SED "Winged C" 6550 vs. SED "Winged C" KT88 (9.26)
Posted by Nunki on 2011-10-24, 23:25:24 (79.196.186.98)
hello peter, in my gear (MC275 or welter ACPP60 monos) the 6550 C always is "the better KT88". KT88 C sounds too bright in my ear (...in my gear) and is lacking bass performance. these experiences hav .......

62: KT88 or 6550 which is better? (9.25)
Posted by Dan on 2001-04-21, 20:11:53 (64.111.73.55)
Hi! I have a pair of Dynaco Mark III power amps, and I know that they will take KT88 or 6550 on the outputs. Anyone have an opinion as to which tube is better for sonics or longevity? Also, any opinio .......

63: Re: Try GEC TT21, superb sound! (9.25)
Posted by jackk on 2001-09-04, 22:53:50 (210.241.238.35)
Yes! Simply connect pin 3 to the top cap of GEC TT21 and you can enjoy the best KT88/6550 sound in the world. By the way, I have tried JJ KT88,Svetlana KT88 and 6550,GE 6550 and some Chinese KT88s and .......

64: Why do KT88's sound like veiled mush to me? (9.24)
Posted by AbeCollins on 2006-02-22, 14:50:26 (67.176.116.152)
I've owned a few tube amps over the years and most of them work with either KT88 or 6550 tubes. In all of these amps including CJ Premier 11a, ARC VT100 mkII, ARC VT50, and Cary, I have always preferr .......

65: Re: How diff KT88 sounds like from Super TNT? (9.21)
Posted by wlee on 2005-07-06, 20:10:30 (202.156.2.130)
Tks Ron, but how is the KT 100 sound? I have a pair which was Golden Dragon label which I bought 12 uears ago, but hardly used. I think they are probably diff. I am confused as to if the new SED is th .......

66: Re: Different Tube? Same Tube? EH 6550/KT88, Sovtek 6550/KT88, Svet 6550/KT88 (9.19)
Posted by steve oda on 2003-09-12, 13:37:31 (66.214.160.49)
Steve, To know for sure----ask the seller if the "KT-88" can handle 700 VDC B+. As far as I know, that is the biggest difference, electrically, between the 6550 ans the KT-88. The 6550 is usually rate .......

67: RE: KT88 to replace 6550 (9.13)
Posted by ironbut on 2009-02-06, 10:04:00 (71.198.200.53)
I have a Premier 140 and it had the same warning about using KT88's in place of the stock 6550's. I've run nothing but KT88's in it for the last 6 years or so and never had a problem. I'm driving Magn .......

68: Re: Many KT88 ?'s (9.13)
Posted by ironbut on 2006-05-30, 19:45:34 (69.107.101.137)
I'm a real fan of the kt88eh too. I have them in my CJ Premier 140 and I just love them. I tried SED winged 6550, Tungsol reissue 6550, JJ kt88. I'm thinking of trying the pentlab gec copy kt88's but, .......

69: RE: 6550/KT88 for a lusher sound than EL34s? (9.12)
Posted by Pat S. on 2009-05-05, 14:08:47 (66.121.52.2)
I agree. Generally speaking, a 6550 or KT88 will provide greater power and frequency response, but with less midrange warmth and body. EL34's excell at midrange "lushness". Some complain of 6550/KT88' .......

70: Re: KT 88 - 6550 (9.12)
Posted by Graafman on 2002-01-25, 04:16:53 (198.142.218.191)
Hmm you can to some extent.Generally speaking the KT88 valve will produce more bass and general slam.On the downside I have found that the 6550 tubes produce much better mid to highs.My mate also has .......

71: In many respects the KT88 and 6550 are the same as noted below (9.12)
Posted by John PA on 2001-02-12, 11:23:47 (128.196.42.70)
I have talked to some very knoweldgable tube people who stated that the KT88 was the European answer to the 6550. I have switched back and forth over the years and have always preferred the 88's in tr .......

72: NOS 6550 vs Genalex KT88? (9.11)
Posted by J Z on 2001-04-26, 13:17:02 (12.2.142.7)
You know I wasn't impressed by Genalex KT88. What are your thoughts on GE or TungSol 6550 on MC275? I've tried Svetlana 6550 before. It made the amp sound more like EL34 on steroid but the tonal balan .......

73: Re: TS 6550 BP and Genelex KT88 and JJ KT88 (9.11)
Posted by Tubers on 2005-05-15, 04:51:51 (57.66.41.73)
Michael, I don't have BP TS 6550 but have 3-hole TS 6550 and GEC KT88 tubes. To my ear, the GEC KT88 have more body and power. They have more "drive" and "foundation" while the Tung-Sols are more subt .......

74: Re: Rogue M-120 Tube roll (9.10)
Posted by tvl59 on 2002-03-10, 18:19:07 (172.129.128.70)
Hi Dave, I have M120 Amps,I used to run Sovtek KT88 on them ,but last month I got 2 quads 6550 EH from Mark Obien and the tubes not break in yet ,but to me 6550 EH sound better than Sovtek KT88 I also .......

75: RE: 6550 vs. KT88 tubes (9.08)
Posted by ironbut on 2008-10-01, 17:58:20 (71.198.205.99)
I have a CJ Premeir 140 and have also been using KT88EH's for the last few years. I've rolled JJ KT88, SED KT88, Winged C 6550, reissue Tungsol 6550 but have yet to try the Penta Labs KT88 or the new .......

76: One Bad 6550 (9.08)
Posted by NicktheKnife on 2021-01-09, 14:51:48 (99.7.22.145)
I have a Jolida Fushion 3502P power amp. It can use either EL34's or KT6550's. I wanted to try the 6550's but only have three (one went bad) I used with my old Rogue 88. The manual says that I can use .......

77: Re: Amperex 6550 vs. Svetlana KT88. What are the sonic difference? (9.07)
Posted by Norwegian wood on 2001-09-25, 09:48:27 (193.216.43.108)
I believe KT88 will give u 15-20% more power than 6550, not less. So says Sonic Frontiers..... I think I have read that Amperex never made a 6550 too, They may be fake..... .......

78: Re: EL34, 6550 or KT88 (9.07)
Posted by Ray Moth on 2007-03-26, 20:03:17 (203.27.21.96)
6550 and KT88 are beam tetrodes. They are very similar and usually interchangeable in most applications, although KT88 has a slight edge in terms of output power. EL34 is a pentode, with less availabl .......

79: Re: 6550's vs KT88's (again!) - bass (9.04)
Posted by mmhifi on 2006-08-27, 12:42:30 (80.178.148.115)
I am sorry but JJ KT88 are anything but bass shy. JJ and KT90Ei are the best in this area actually and I tried virtually all KT88/6550 in two different amps. It's also in any way not lean. Seems your .......

80: Re: 6550/KT88 bias (9.04)
Posted by beermanpete@socal.rr.com on 2006-01-10, 19:39:47 (66.75.81.92)
Set the bias at the same setting as the EL34. However it is possible that the adjustment range is not great enough to accomodate the 6550/KT88. This will be evident by not being able to get the bias l .......

81: Re: Kt88 6550 el34 (9.02)
Posted by story on 2000-12-11, 19:17:11 (205.188.199.179)
word is that the tesla and svet's are true kt88 design, the sov is a 6550. .......

82: Try searching the Tubes Asylum archives..... (9.02)
Posted by agattu on 2001-03-04, 16:11:35 (209.193.50.196)
there are over 250 messages regarding 6550 vs. KT88. Search for "kt88 AND 6550" .......

83: Re: Amperex 6550 vs. Svetlana KT88. What are the sonic difference? (9.02)
Posted by J on 2001-09-25, 14:23:09 (24.102.232.199)
I too think that the KT88's make more power than the 6550..but I haven't compared them..I did compare Yugo EI KT90's vs 6550's and the KT90's where a big improvement for my power starved speakers. ::: .......

84: Re: Which will perform better in Triode mode - KT88 or 6550 and why? (nt) (9.01)
Posted by Chris O on 2003-12-01, 12:58:26 (158.52.254.238)
Unless you are talking about GEC, KT88 and 6550 are essentially the same tube with different packaging. The ratings on KT88s are pushed more than the 6550. The big difference is the addition of some c .......

85: Re: why 6550 over kt88 (9.01)
Posted by Minuteman on 2001-03-06, 06:22:10 (64.12.96.108)
>Did you ever come across all modern amp come shipped with engrived >based NOS WE274A, NOS (not the re-issue) WE300B or any NOS Gold >Lion? Not even from Audio Note Japan! The manufacturer is generall .......

86: Re: KT88 vs. KT90 vs. 6550 (9.00)
Posted by jmset315 on 2005-12-21, 15:42:49 (162.119.232.102)
I have 2 Jolidas using EH KT88 and SED KT88. In my system, both of them are the clear winner. SED gives more mid-freq lush & sweetness while EH KT88 has a little bright and straightforward tonal quali .......

87: Sylvania 6550 tubes with Cary SLI-80 (9.00)
Posted by akolegov on 2014-10-05, 11:37:17 (93.174.93.145)
I am wondering what I should expect from Sylvania 6550 output tubes with Cary SLI-80 integrated amplifier? I purchased it new 11 years ago, and so far I have used vintage TS 6550, GEC KT88's, various .......

88: Hickok 539 tester data for EL34/Kt66 &6550/KT88 ? (8.99)
Posted by Rick R on 2005-12-11, 14:51:24 (71.108.166.26)
I am trying to find appropriate test settings for my Hickok 539A for EL34/Kt66 &6550/KT88 tubes. The only thing I have found in a search is a suggestions for 6550's for using: KT88/6550 - Voltage 6.3 .......

89: 6550 question (8.96)
Posted by quiros.javier7 on 2010-08-28, 17:42:18 (112.198.64.100)
Hello! I have a question concerning 6550's.I have an old ARC Classic 60 with RCA cleartop 6CG7's and GE 6550's.Since the cost of the GE's keeps rising,I started thinking about acquiring a set of suita .......

90: RE: Can KT88's be used instead of 6550's? (8.96)
Posted by Chuck Y on 2008-06-20, 14:19:20 (4.246.240.85)
Some amps can accomodate both 6550's and KT88 but some can't (I have a KT90/6550 amp and the manufacturer specifically recommends against it - the one time I tried I blew a tube and a resister in the .......

91: RE: My ARC D70 Mk II needs to be retubed, SED 6550C or Shuggies KT88Z? (8.95)
Posted by geraldm121 on 2011-07-26, 14:29:10 (24.151.10.123)
I have both an old ARC D75 and a CA30 Integrated that both use 6550's and have had the best luck both sonically and reliability wise with 6550's rather than KT88's and of those the SED and Tungsol new .......

92: Who is who in the 6550/KT88 world?? New production (8.95)
Posted by Balle Clorin on 2008-06-23, 15:09:30 (80.202.44.212)
I mean with all the re-issueing I can not keep track of who is who anymore 6550, is Sovtek=Electo-harmonic=Tung-Sol= same russian factory? KT88, is Sovtek=Gold Lion==Electoharmonics= ??? And could eve .......

93: Re: 6550 and kt88 (8.94)
Posted by jay2 on 2001-03-18, 22:04:02 (209.236.30.8)
In my opinion, in my amp, (Cary sli80), the svetKT88 is a little better than the 6550c in every parameter. As for the bass, the 6550 seems less defined than the Kt88. .......

94: RE: Antique Sound Lab aq1001dt KT88 & 6550 recommendations (8.94)
Posted by JoKath on 2007-06-05, 13:15:12 (24.36.0.132)
The Valve Art KT88's are excellent in these amps. Replacing with 6550's can result in a sound with more body, but much less refined. I find the 88's to be slightly better overall. Cost wise KT88's an .......

95: Which is faster TS 6550 or Svet 6550? (8.92)
Posted by excelit on 2004-08-24, 18:56:13 (198.81.26.7)
've been using the Svetlana 6550 and Svetlana Kt88 on my CJ Premier 11a. I find the KT88 generally more tonally refined than the 6550 specially on female vocals where the kt88 sounds more organic. Lat .......

96: Re: EH 6550 with KT88 shaped bottles (8.91)
Posted by Uncle Ned on 2002-07-16, 20:51:37 (64.109.231.65)
I have just checked the current catalog from New Sensor's website which is the most accurate source The New Sensor dealer flyer I have is more accurate, but that's not completely accurate either.Act .......

97: KT88/90 in place of 6550? (8.91)
Posted by AbeCollins on 2001-06-22, 21:37:53 (65.10.208.131)
I'm relatively new to tube gear and was wondering if I can use the KT88 or KT90 in my CJ Premier 11a w/o any problems? Will I be able to correctly bias them using the LED bias indicators on this amp? .......

98: Reliablity of 6550 vs. KT88 (8.90)
Posted by Michael O on 2007-09-07, 11:49:18 (136.165.113.7)
Hi. A friend of mine was told by a tech. that the 6550 was more reliable than the KT88. I am not certain that is the case. My friend has a Rogue M 120 and one Penta Labs KT88 (solid plate) went bad. .......

99: Re: KT88's vs 6550's (8.90)
Posted by excelit on 2002-06-29, 13:16:40 (63.212.130.161)
I prefer the kt88 in my system. Compared to the 6550 the kt88 is more extended in both frequency range with a more defined bass but less bass fullness. In the midrange, it is thicker which lends more .......

100: RE: Another KT88/6550 thread (8.90)
Posted by Freo-1 on 2011-09-17, 16:55:55 (24.62.56.61)
Excellent post, SJ. Having been at this for a long time myself, it's safe to say that this is very much a subjective set of judgments. So, if a group of people do or do not care for the Sonics from a .......

101: Re: suggestions about the GEC KT88 (8.86)
Posted by Quirites on 2003-08-15, 05:37:45 (219.76.64.2)
Would have to say the GEC KT88 does sound better than the Svets but not THAT much better and it does depend on your personal preference sound preference. Just as an example, if you like a clear fast/r .......

102: Re: One difference is the sound, :^) . . (8.85)
Posted by agattu on 2003-03-25, 18:57:10 (209.112.212.139)
You can substitute the 6550 for the KT88 without harming the Rogue 88. While I slight prefer the Svetlana KT88, the Electro Harmonix 6550 is an excellent tube and is reasonably priced. I also believe .......

103: KT88 in Audio Research amps (8.85)
Posted by DC on 2001-01-07, 22:30:26 (202.145.178.1)
Hi, I'm wondering if KT88 tubes will make AR amps sound better than its original 6550s? Is the sonic gain worth the price of, say, Svetlana KT88 over Svetlana 6550? Has anyone tried the replacement an .......

104: Re: KT88 vs. KT 90? (8.85)
Posted by rlawry on 2002-11-28, 08:35:17 (209.179.50.13)
I am not one of those enamored with the sound of the Ei KT90. There was a Chinese knockoff, the KT99, but I have not heard it. I had an Audio Electronic Supply AE-25 DJH Superamp, which runs the tubes .......

105: Re: Rogue tube Question (8.85)
Posted by Alung on 2004-04-25, 19:16:06 (172.152.118.191)
Stock they came with either Sovtek KT88's or 6550's. I had both and did not really care for the 6550's. The Sovtek KT88 were really very nice sounding KT88's I felt. The first upgrade KT88's offered b .......

106: KT88 vs. 6550 (8.84)
Posted by Michael P. on 2003-03-22, 18:07:10 (12.208.167.181)
The application is for Quicksilver V4's. I have been told the EH 6550 or Svetlana KT88 are the right tubes for these amps. Does anyone have experience with either? .......

107: Any they have listed will be fine. (8.84)
Posted by Chris O on 2011-12-19, 17:41:09 (98.66.61.86)
6550 and KT88 are basically interchangeable, don't overlook the 6550. I would spring the extra few bucks and get the TungSol 6550 reissue. .......

108: Re: Why do KT88's sound like veiled mush to me? (8.82)
Posted by AbeCollins on 2006-02-22, 15:25:01 (67.176.116.152)
In all cases I was comparing Svetlana C logo (or is that SED now) to the same brand/logo 6550. I'll give those KT88's a longer try maybe tomorrow. I've been playing the amp with my 6550's quite a lot .......

109: Re: Rogue M150s. SED winged C, 6550 or KT88? (8.82)
Posted by The Killer Piglet on 2005-11-04, 12:53:38 (12.42.142.168)
On the same amps, I have tried EH KT88, GE 6550A, Svet 6550C (winged logo), and EH 6550's. I prefer them in the order I list them, with the EH 6550's trailing well behind the others. It was a year ago .......

110: Tungsol 6550 vs. Svetlana KT88 (8.81)
Posted by Phantom on 2000-12-17, 22:02:45 (172.147.148.82)
Is Tungsol 6550 much better than Svetlana KT88 or about the same? To my ears the Svetlana is very good even against Genalex KT88. .......

111: Re: Power Tubes: 6550 vs. KT88 (8.81)
Posted by Tromatic on 2003-01-19, 22:28:05 (216.99.209.139)
Check this out. A search can help lower your cholesterol, enhance vitality and it's free! .......

112: Re: KT88 - best replacement for cheap chinese ones? (8.79)
Posted by lampa on 2001-02-26, 22:49:54 (63.25.170.106)
Sylvania 6550 is inexpensive and beat all Sovtek and Svetlana 6550/KT88 in my amps of course GEC TT21 is the best of the best. Joe .......

113: He can't be talking about T-S 6550 or GEC KT88... (8.79)
Posted by CDnull on 2002-03-19, 14:03:06 (168.99.166.2)
because in most circuits they will prove superior. I have tried the Russian 6550 and KT88, and the E. European ones, and they do not sound as good as the above mentioned heralded tubes. .......

114: Sound of EL34, KT88, 6550, etc. ??? (8.79)
Posted by greg7 on 2003-05-22, 10:29:44 (24.196.191.154)
I've been considering switching to tubes for a while. Can I get a general overview of how the common PP tubes sound -- el34, el84, kt88, 6550, etc. ? My impression is: el34 -- warm mids, not the great .......

115: RE: Another KT88/6550 thread (8.77)
Posted by Freo-1 on 2011-09-08, 14:03:28 (24.62.56.61)
Mike, I respect your opinion, and while I also think the black plate TS 6550 is a killer tube, with the amp my buddy made, the EAT KT88 was the best performer of the various 6550/KT88's we tried (by a .......

116: question about 6550's (8.77)
Posted by Andy_G on 2007-01-27, 17:27:08 (202.7.166.170)
I can get the following from my down-under supplier at reasonable price. Sovtec 6550-WE Svetlana 6550-SV-PL Electroharmonix 6550-EH What are the characteristics of each these tubes? Is there any notic .......

117: Re: 6550 vs KT88 in VT130SE (8.76)
Posted by Wino on 2001-11-30, 15:05:39 (209.204.186.114)
Am not familiar w/the amp, but while Sovtek KT88's have been the hot setup for many people, among currently-manufactured tubes, the new Electro Harmonix 6550 is killer in at least some applications. : .......

118: Re: KT88 or Tungsol 6550 (8.73)
Posted by rlawry on 2002-02-09, 09:15:04 (165.121.124.208)
I have run GEC KT88's and Tung-Sol black plate 6550's in my AES DJH Superamp, and both are great-sounding tubes. The 6550 is a little leaner in the mids, deeper, tighter, more detailed bass, more deta .......

119: That's not my topic of choice but... (8.73)
Posted by AbeCollins on 2008-12-16, 15:25:44 (67.177.242.32)
I'm sure there are some NOS 6550 that sound incredible but in comparing cheap Russian or Chinese 6550/KT88 vs same cheap range of EL34 tubes, lets just say that I LIKE EL34's much better. And I've had .......

120: Re: KT88 vs 6550C in Cary SLAM 100 (8.72)
Posted by rlawry on 2002-01-16, 07:18:17 (165.121.112.207)
I have tried Svetlana KT88's, Tung-Sol Black Plate 6550's, and GEC KT88's in my triode-connected AES DJH Superamp. I would agree that the 6550's are leaner, quicker, more detailed, more extended at th .......

121: 6550/KT88's in Copland 505 (8.71)
Posted by edlin on 2007-12-12, 15:53:16 (198.53.20.102)
I'm not sure if this is true or not, but I've heard from a few other 505 "experts" that the 505 amp can not run KT88's without extensive circuit modifications. It was offered to me once, a few years a .......

122: Svetlana KT88: next best upgrade? Tung-Sol 6550? (8.71)
Posted by MM on 2002-11-17, 18:15:51 (66.245.49.124)
If I want more resolution, air and smoother high than SV KT88, is Tung-Sol 6550 the next best upgrade for my vintage MC275? I've tried SV 6550 and Ei KT90. They are not my cup of tea. BTW, where can I .......

123: Re: UL 6550 (8.70)
Posted by Gary Kaufman on 2000-11-12, 15:55:26 (24.218.120.21)
Dynaco used a 4300 ohm primary on their A431 output transformer that was used for the Mark III (6550 or KT88 PP) amplifier. Acrosound specified the TO-330 for KT88/6550 use in fixed bias (3000 ohm pri .......

124: RE: Reissue Gold Lions KT-66 (8.70)
Posted by Freo-1 on 2008-10-07, 19:34:44 (76.24.96.48)
While I agree that the GL KT88 is a good sounding tube (and I do not have sufficient exposure to the original KT88), I DO know that the upper mids and HF on the GL KT88 is a bit hard. I also know they .......

125: Re: Reliability - Rogue Audio Cronus (8.68)
Posted by agattu on 2005-09-22, 19:44:37 (209.112.185.97)
I'm using Tungsol 6550 w/solid grey plates. My favorite current production 6550/KT88 is EH KT88. .......

126: 6550/KT88 bias (8.68)
Posted by Kajtsu on 2006-01-07, 09:55:06 (83.102.22.23)
What is the bias voltage (mv) on 6550 and KT88? .......

127: Mcintosh MC2102 - 6550 or KT88 (8.67)
Posted by Sea Monster on 2009-04-27, 09:06:44 (218.103.133.89)
What are the differences between using 6550 and KT88 in the MC2102? What will you use? .......

128: Svet KT88 vs 6550 (8.67)
Posted by MM on 2002-02-07, 11:01:55 (172.168.169.230)
I have experience with both. Svet 6550 didn't sound right out of the box. It sounded too dark, rolled off and lacking air. Burned-in for another 50 hrs but it still sounded the same. Upgraded to Svet .......

129: Re: Hickock 539s can test KT88 but not 6550?? (8.66)
Posted by Sherlock on 2003-08-14, 21:27:22 (67.160.69.90)
On my 752A the KT88 and 6550 test with the same setup... .......

130: RE: Genelex KT88 vs T-S 6550 (8.66)
Posted by Shakey on 2009-02-18, 06:46:53 (69.114.117.250)
Mike, have you compared the re-issue GL KT88's to the re-issue T-S 6550's? .......

131: 6550, KT88, or KT90, which to use? (8.66)
Posted by audioman on 2006-10-02, 19:46:44 (70.27.140.88)
OK, you own an amp that can take 6550's, KT88's or KT90's. First off, which is the best " sounding " tube? Secondly, is there a good sounding KT90 out there. I hvae heard people like the KT88 for soun .......

132: RE: 6550/KT88 Recommendations (8.65)
Posted by TubeAcolyte on 2015-01-10, 07:24:47 (99.241.53.36)
In terms of available product that's within a fair budget, I'd look at the Gold Lion KT88, or the Shuguang KT88SC (see Pref Series KT88 from TubeStore, same thing). In terms of 6550 types, I'm not sur .......

133: Re: ebay #1202320843 Mullard KT88 (8.65)
Posted by TY on 2000-12-19, 18:35:47 (210.24.135.105)
Mullard labelled KT88 exist and they are all OEM from GEC. Chinese KT88 generally have the same GT type bottle as the GEC ones and look more like the real thing compare to that 6550 on eBay. The earli .......

134: Do all 6550 power tube amp support KT88 ?? (8.64)
Posted by cktc on 2001-02-12, 01:32:59 (158.132.12.74)
Hi, I bought used ARC Classic 30 amp and it come with Tesla KT88 tube. It sounds good and I don't have any intention of replacing them. But a tube dealer told me that ARC amp must match with 6550 tube .......

135: Re: EL34 for 6550 swap? (8.64)
Posted by jackcpsu on 2002-03-18, 11:26:58 (130.207.57.195)
It depends on the design of the amp. For my Cary SLI 80 Signature, I can use both 6550/KT88 and EL34. In my system, 6550/KT88 is more textured, full bodied and has better sound stage and bass. But, E .......

136: 6550 vs KT88 in VT130SE (8.64)
Posted by stash on 2001-11-30, 07:35:26 (141.236.81.73)
Could someone give me an idea of what to expect in an ARC VT130SE if the standard 6550 are changed for KT88's? Thanks, Brian .......

137: KT88 vs 6550 (8.64)
Posted by bluesbuff on 2006-11-05, 20:05:29 (64.66.114.54)
What are the main differences in sound between the KT88 and the 6550 tubes? What are some of your experiences with each type? Thanks,Bluesbuff .......

138: Re: sed 6550c vs kt88 (8.64)
Posted by ratbbb2@optonline.net on 2005-04-04, 19:06:31 (67.85.66.234)
I cant vouch for the Cary As I don't own or have I ever spent any real time with one but I feel that in both my Quicksilver and the current resident Rogues the 6550 is a much smoother with lush mids a .......

139: RE: +1 on the PentaLabs KT88SC (8.64)
Posted by sherod on 2017-04-03, 18:37:08 (24.242.118.226)
Doug's Tubes stocks two versions of the Ruby tube, the KT88-STR, which is the Shuguang Kt88-98, three holes and the KT88V-STR which have the solid plates and is his current substitute for the Penta KT .......

140: Re: el34/6550/kt88: seeking forwards presentation without excessive bass (8.63)
Posted by Chuck Y on 2004-11-18, 06:03:35 (209.165.34.70)
Tesla NOS E34L's (don't know about the new JJ's) Svetlana 6550's EH KT88's .......

141: Frequent Topic: use the search function-if you contemplate.... (8.62)
Posted by CDnull on 2000-12-30, 11:29:02 (172.158.234.29)
KT88 use, the Svetlana is better than its 6550 brother. If you can use EL34 I would check them out for sure. I like them better than the 6550/KT88 type. .......

142: KT88 / 6550 Alternative to EH (8.61)
Posted by petercapo on 2013-01-12, 19:48:06 (71.174.16.163)
I have a set of EH KT88 that have a bit of a bite to them, maybe even just a bit shrill / glassy at times. Although I do really like these EH, sometimes a change might be nice. Any recommendations fo .......

143: Re: one thing, though (8.59)
Posted by g on 2003-11-29, 08:10:17 (66.227.182.117)
Totally. I have backed off on my criticism of the Svetlana KT88 a bit because I was getting charred from the responses.... I still think it is OK in some amps but overall I find the Svetlana KT88 a bi .......

144: Re: Rogue M150s. SED winged C, 6550 or KT88? (8.58)
Posted by wlee on 2005-11-04, 11:15:17 (202.156.6.68)
hi Jim, I like your no nonsense style, tks! I am happy that I try the EI KT90 after listening to you. Yes it has very nice tone. I will try them against both the old and new TS 6550, and the Genelex K .......

145: Re: 6550C vs KT88 (8.58)
Posted by Jerry O on 2000-09-11, 10:08:14 (12.13.238.140)
It's difficult to make generalities regarding the "house sound" of 6550's vs KT88's. Amp brands and designs can effect the sound as much or more. But, there is a fairly significant electrical consider .......

146: Re: VTV 6550/KT88 shoot out (8.57)
Posted by Sherlock on 2003-06-03, 21:52:47 (63.228.100.71)
Interesting...they wrote an article in issue number 6 about KT88 and 6550 "Power Kings"......being popular tubes I figure they want to sell more magazines. .......

147: Re: KT88 vs 6550C in Cary SLAM 100 (8.56)
Posted by AbeCollins on 2002-01-15, 18:17:10 (12.252.106.56)
I have to disagree with the comment about the 6550's being like a 13" B&W TV vs a 40" Sony XBR for the KT88's. At least in my CJ Premier 11a tube amp, I find the 6550's to be more "natural" sounding. .......

148: KT88 vs 6550 on Quad forty monoblocks (8.55)
Posted by zuo2000 on 2006-07-28, 09:36:15 (221.220.61.37)
hi, all, i have these pair of Quad forty monoblocks, they have two pair of KT88 on each of them. my question is, can i replace those KT88 with 6550? is this done before? what are the changes made? is .......

149: RE: Compare the Red Lion KT88 with the GE6550A please (8.55)
Posted by nick-seattle on 2013-10-22, 20:45:33 (50.135.222.141)
I tried practically every 6550 and KT88 tube that exists. It all depends on the music you like. For dynamic type of music with lots of bass, KT88 is the way to go - that's where Genalex really shines. .......

150: Re: opinions on shugang kt88-98 vs gekt88... (8.54)
Posted by ARC on 2006-08-05, 11:54:28 (68.74.138.31)
The GEC copy is a better sounding tube, and certainly closer in sound to an old stock tube; they actually have more of a 1960s TungSol 6550 sound than a vinatage GEC KT88 sound (that's a GOOD thing, I .......

151: Re: KT-88 vs KT-90 vs 6550 (8.52)
Posted by BillC on 2001-02-25, 23:22:48 (208.191.24.87)
I am talking about the situation: the best 6550 VS. the best KT88!!!! Here's what you wrote in the original post: "Personally find that the 6550 is not as good as either KT88 or KT90." Point out exa .......

152: RE: KT88/6550 (8.52)
Posted by Diode on 2008-10-28, 13:20:49 (66.162.49.101)
"I have been told that KT88 is more like a transistor?" In my opinion it's the other way around... although the 6550 has excellent clarity, to my ears the tube lacks in tonal colors and sounds more .......

153: Re: GE 6550 Vs Svet KT-88. Very surprised at the outcome! (8.52)
Posted by Rsedillo on 2001-11-13, 19:26:30 (64.12.101.184)
Just put in quad of new Valve Art KT88 in my AirTight ATM-2. Very smooth, like Blaster felt about his 6550. And there new, most of members here love the Tung Sol 6550 and Gec-Generex KT88. Have both .......

154: Re: I like the 6550 (8.51)
Posted by twisty on 2004-11-18, 09:41:24 (207.163.1.200)
Thanks. For my needs, are they the best of both worlds: 1) Forwardness of KT88 2) Bass level of EL34 3) Midrange naturalness of EL34 I think I'm narrowed down to EH KT88 vs. Svetlana 6550. ::: TOPIC:: .......

155: Re: KT88/6550 versus KT90? your real world opinions please (8.51)
Posted by rlawry on 2002-01-22, 09:21:42 (209.86.216.56)
I have posted this before, but I have compared Chinese, Svetlana, and GEC KT88's, Tung-Sol Black Plate 6550's, and Ei KT90's in my AES DJH Superamp, which runs the tube plates at 495 volts in triode m .......

156: Re: KT88 vs. KT 90? (8.51)
Posted by DevoX on 2002-11-27, 20:37:15 (204.26.92.113)
The general consensus is that the KT90 is a fantastic tube. Myself, I have never tried the KT88's but, from what I've read both here and on other sites, the KT90 is more similar to a 6550 (generally s .......

157: Re: 6550c tubes (8.51)
Posted by Jareb on 2002-05-05, 06:43:03 (64.12.105.177)
KP, I've used both the Svet 6550's and KT88's in my McIntosh 275re. The 6550's have good base punch and in my system the KT88's seem a little more lively on top- both very good tubes for the money. I .......

158: RE: JJ KT88 to ??? (8.51)
Posted by tubemaze on 2020-08-09, 03:54:52 (73.104.7.17)
I would start with KT88 Genelex, definitely a better choice if an amp takes KT88/6550. I didn't find that KT77 would roll off on the bottom, but it could seam that way just because it produces less po .......

159: Re: okay tube gurus... (8.50)
Posted by rlawry on 2002-03-28, 08:22:23 (165.121.113.144)
I haven't heard the Tesla/KR KT88, but have tried the Svetlana, JJ, GEC KT88 and the Black Plate Tung-Sol 6550 in my AES DJH Superamp. To my ears, and for the money, I would go with the T-S 6550. The .......

160: Re: Tung Sol 6550 (8.48)
Posted by rlawry on 2002-04-26, 07:33:53 (165.121.112.30)
I agree with the other posts that there seem to be a lot more T-S 6550's around for sale, and at less than half the price of the GEC KT88. The GEC KT88 has its charms, but considering the price of the .......

161: RE: Electro-Harmonix 6550-KT88 (8.47)
Posted by TubeAcolyte on 2015-10-05, 18:01:02 (99.241.205.115)
I have experience with both. They're different. The glass may be the same, but the internals are not. In the end, they're really similar by spec. Teeeechnically, the KT88 is supposed to have a pretty .......

162: RE: GEC KT88 review & a couple of questions (8.47)
Posted by S54B32 on 2013-10-09, 20:15:02 (111.252.134.27)
Hi! I have the same view of vintage GEC KT88 with you, I had used them on my Jadis JA30 since 2000 and my feeling still remain, I had tried many 6550/KT88 included Tungsol 6550 black plate/no hole/wit .......

163: Re: el34/6550/kt88: seeking forwards presentation without excessive bass (8.46)
Posted by twisty on 2004-11-18, 09:37:14 (207.163.1.200)
What to expect: Tesla EL34: More forward than the Svetlana EL34? Svetlana 6550: Split the difference? Forwardness of the KT88, sweetness of the EL34, without the bass boom/level of the KT88? EH KT88: .......

164: Re: EL34 or 6550. no way you can substitute the kt88's (8.46)
Posted by roberts@bandstand productions on 1999-12-20, 15:57:01 (208.149.44.186)
Correct me if I am wrong , but if you read c a r e f u l l y , I did not say anything about using the KT88's insted of the EL34's read, read, read!!!!! and thanks tom s for understanding. You want a f .......

165: RE: Another KT88/6550 thread (8.45)
Posted by Freo-1 on 2011-09-07, 14:00:41 (24.62.56.61)
Mikey, Can't argue about NOS 6550 Black Plates. They were/are a awesome tube. Having said that, they have dried up, and what's left is worse that roulette. The old TS tubes had a tendency to go gassy .......

166: Re: Audio Research 6550 vs KT88 and tube brands (8.45)
Posted by tantra on 2007-03-12, 11:12:05 (149.142.139.20)
I had similar experience with Conrad-Johnson Premier 12 amps. Significant overall improvement, especially smoother and more extended highs, when I switched from Svet 6550's to EH-KT88's. The EH-KT88's .......

167: EH 6550 vs Svetlana SV6550C (8.44)
Posted by KIS on 2002-12-11, 13:24:37 (203.40.133.174)
The best currently in production 6550 I have tried is the Svetlana. I am curious to find out if anyone at AA has tried the new EH 6550. How does the new EH 6550 sound like? The EH 6550 and the EH KT88 .......

168: RE: KT88 (8.44)
Posted by tantra on 2007-07-27, 12:01:55 (149.142.139.20)
I replaced the Svet 6550's in my C-J premier 12's with EH-KT88's. Very happy with the result. Clean, extended highs. Midrange is glorious, but no better than with the 6550's. The bass is tight and fas .......

169: Re: KT88 tube recommendations (8.44)
Posted by tube Tom on 2006-10-22, 18:22:40 (70.96.108.123)
I have tried 2 KT88's (EH, VA) & 1 quad 6550 (VA). IMHO the KT88 EH was a little polite & lacked hi end, the VA KT88 has slightly more extended hi's. I'm now running, in a pair of Quicksilver Mini Mit .......

170: kt88's (8.43)
Posted by dennie on 2002-06-25, 16:34:27 (65.58.36.220)
anyone know anything about electroharmonix making a kt88? I am aware of their 6550, but, I understand they have just introduced a kt88. thank you .......

171: Can KT88's be used instead of 6550's? (8.43)
Posted by PhiloTFarnsworth on 2008-06-20, 11:22:43 (68.44.201.215)
Have a 6550 based power amp. Enjoy the bass control and sense of "power" of the 6550's but miss the "midrange magic" of my previous El34 based amp. It has been suggested that I substitute KT88's for t .......

172: 6550 or KT88 on ARC? (8.43)
Posted by Finn Magne on 2002-02-22, 04:52:09 (130.67.153.82)
I'm a happy owner of a Audio Research VT-100 mk.2 amp. But: have anyone tried to switch tubes from 6550 to KT88 on this amp? What is the differences in sound? .......

173: Re: Tung Sol 6550 vs Phillips 6550 (8.43)
Posted by rlawry on 2005-02-05, 20:09:29 (66.81.254.115)
Yup, had a quad of 70's GEC KT88's. Maybe the earlier versions sound better, but I was disappointed with mine. Smooth with a big soundstage and lots of midrange warmth, but lacked resolution, especial .......

174: Re: best tube integrate (8.41)
Posted by MIchael Samra on 2005-10-05, 11:00:28 (66.188.56.2)
Mac Your going to hear all kinds of opinions here and I know most are sincere.I personally like the kt88/6550 best for cost / performance ratio of the tubes you mentioned. The 6l6gc is my favorite ov .......

175: I know this is 'beat to death'....KT88 KT90 6550 (8.41)
Posted by Jimmy on 2005-08-12, 08:14:38 (69.179.57.149)
These tubes change a lot, thus archives are not always up to date. KT88, KT88-98, etc What is a good new manufacture tube of the 6550 KT88 KT90 family of tubes that is accurate & clean sounding. I do .......

176: Re: Help with tube choice kt88/kt90/6550 which brand and price? (8.39)
Posted by Bryan F. on 1999-10-21, 22:25:35 (24.29.208.248)
The KT90 isn't a direct plug-in replacement in "all" amplifiers. He forgot to mention Tesla KT88's and Sventlana 6550's on his wish list. .......

177: Re: EL34 or 6550. 2 watt output difference, which would have more musical qualities? (8.38)
Posted by A Question Please on 1999-12-20, 14:52:14 (205.188.199.195)
Are saying that I can use a EL34 or 6550 or KT88 or KT90 in my mono amps (Rogue M120's - self-biasing - came with KT88's) with NO problems????????? Just plug em' in and GO???? .......

178: Re: current production tubes (8.38)
Posted by lampa on 2002-07-14, 19:36:37 (67.82.9.117)
Well somebody liked red wine others liked red one.My list from the best : TungSol 6550,GEC TT21,Sylvania 6550,Richardson US made KT88,very early Golden Dragon KT88 ( GEC use them in thier boxes after .......

179: RE: Perhaps then (8.38)
Posted by Freo-1 on 2011-09-06, 17:09:26 (24.62.56.61)
You're taking this just a (bit) too seriously. You are looking for slights that are simply not there. No right or wrong answers here, just a subjective set of observations that are slightly different, .......

180: Re: Help with 6550 (8.37)
Posted by Aurum on 2004-04-22, 04:56:37 (61.68.190.109)
Try the Svet 6550, if you specially want a 6550. Other than that I would go for the EH KT88 or EI KT 90 regards Ian .......

181: RE: That's right, it's not clickable... (8.36)
Posted by Joe Appierto on 2014-10-06, 04:33:58 (69.248.131.226)
I'm using Chrome on a PC and for me, that isn't an active link, it's a hypertext address which needs to be copied and pasted into a new window to access the page. Maybe with a different browser and/or .......

182: Difference in output from KT88 to EL34, 6550 and 6L6 (8.35)
Posted by gary.m on 2005-02-20, 04:52:51 (68.236.3.187)
I have a Cary Rocket 88r and looking to try some different output tubes. What is the difference in output switching from KT88 to EL34, 6550 and 6L6. My amp currently puts out 30 watts triode with the .......

183: Re: Tung Sol 6550 vs Phillips 6550 (8.35)
Posted by b9ronaldo on 2005-02-05, 21:14:29 (210.186.172.89)
Early 1970 or late 1970? Well match? I'd tried old slyvania 6550, Tungsol with or without holes 6550, after try GEC TT21 and KT88, never go back! May be it suit my system, .......

184: Re: JJ KT88 Tubes (8.34)
Posted by rlawry on 2005-02-03, 16:57:02 (66.81.105.21)
I had a quad of these in my AES DJH Superamp running in triode mode and they were nothing special. The bass was OK and soundstage was pretty good, but the midrange was slow and syrupy and the top was .......

185: Re: Do all 6550 power tube amp support KT88 ?? (8.34)
Posted by Dick on 2001-02-14, 19:45:01 (64.12.103.47)
Use either. Anode and screen voltage ratings are the only thing to watch. Later GE6550A were 42W. Early KT88 were only 35W. I`m using Svet 6550C which they say will replace any 6550 type and they are .......

186: Re: EL34 better suited for triode than 6550 or KT88? (8.34)
Posted by Response34 on 2004-03-12, 07:29:15 (152.163.252.5)
Without reading the the responses to this thread, I will give my personal opinion. I hope it falls in line with the rest. For a triode operation, not SET, I actually find the 6550/KT88 to perform be .......

187: Crank up the B+ and play with the idle current!!! (8.34)
Posted by TomWh on 2006-02-22, 18:39:53 (63.18.120.164)
I actually like KT88 better than the 6550's I have heard. But I would say if you want to make a big leap forward use 845's, even at lower voltages. You can use the 6550's and kt88's to drive them, but .......

188: KT88 vs 6550 Tubes for Rogue M150 (8.33)
Posted by tricon_dave on 2005-04-27, 04:33:57 (168.182.1.254)
My M150's came with EH 6550 output tubes from the factory. I have had them for about a year and they sound very good. This is my first tube amp, and I am still learning as I go. My local dealer tells .......

189: EH 6550 vs Svet 6550 (8.31)
Posted by KIS on 2002-07-14, 10:44:16 (203.40.136.178)
Dear Chris Just to clarify your post. Is Svet 6550 still in production? Many runours said that they are no longer being made. Judging from their prices, they are getting more expensive - which support .......

190: Re: KT88's vs 6550's (8.30)
Posted by Cut-Throat on 2002-06-29, 15:46:10 (198.81.17.56)
I have a quad of EH 6550 in my AE-25 amp that I preferred over the KT88 Svetlana. More detail and dynamics. Cut-Throat .......

191: Power Tubes: 6550 vs. KT88 (8.30)
Posted by HJS on 2003-01-19, 20:16:13 (24.46.212.31)
I'd like get some opinions on power tubes. What are the distinguishing sonic characteristics between 6550 vs. KT88? What about the difference between the the manufacturers? .......

192: Antique Sound Lab aq1001dt KT88 & 6550 recommendations (8.30)
Posted by amansker on 2007-06-05, 09:44:40 (71.136.80.195)
I'm a tube newbie. Had an ARC Classic 60 for years, but never did any maintenance, just ran it every day. Just purchased a used ASL AQ1001DT with stock JJ KT88 and 12AU7 tubes. Speakers are Nelson Ree .......

193: Re: KT88's vs 6550's (8.29)
Posted by rlawry on 2002-06-29, 15:24:26 (209.86.221.108)
I have tried Tung-Sol black plate and Philips ECG 6550's in my AES DJH Superamp. Also GEC, Svetlana, Chinese, Tesla, and JJ KT88's. I prefer the 6550, as it is more detailed, has better dynamics, more .......

194: 6550 vs kt88, is there a differnce? (8.29)
Posted by kenk on 2000-06-09, 15:32:00 (24.189.248.250)
i was wondering since the 6550's ant kt88's are interchangeable in most amps (i stress MOST) what the main differnce is, technically and sound wise. I would look up the specs in a manual, but i dont h .......

195: Difference between KT88 and 6550? (8.29)
Posted by Ubetit on 2001-04-15, 20:58:58 (12.87.133.77)
I am getting ready to re-tube an amp and I haven't been able to find out what the basic difference is between the 6550 and kt88 tube types. Will the output wattage be the same? - Rich .......

196: Anyone know the settings for KT88/6550 on a TV-2/B (8.28)
Posted by tvr2500m on 2004-06-20, 21:35:16 (65.78.8.202)
Hello good folk of the Tubes Asylum. Would anyone happen to know, and be willing to share with me, the KT88/6550 settings on the TV-2/B? Thanks, - SJ .......

197: Re: 6550/KT88 bias (8.28)
Posted by Kajtsu on 2006-01-10, 05:56:12 (83.102.22.130)
I have Cayin A-50T and it uses normally EL34 tubes with 0,30-0,35 biasvoltage. I´d like to test 6550 or KT88 tubes but what is right bias for them. .......

198: Re: Yes I am, just because it will annoy those who don't get it (8.28)
Posted by doctorjohn on 2000-12-12, 19:14:20 (137.189.4.1)
Joe: I don't mind strong opinions. They are as valid as mild ones. But I do wonder about your MkIII experience. As a Dynaco fan myself, and as a lover of ST70, I am also a lover of the MkIII. Mine cam .......

199: Re: KT88 vs. 6550 (8.27)
Posted by hydropower on 2003-03-23, 10:14:51 (24.161.75.68)
I also own the V4's and prefer EH KT88's to the Svetlana KT88's. Both were better than the stock chinese, which sounded flat to me. The Svetlana and the EH mids & highs are similar while the EH offere .......

200: TV/7 settings for 7868, KT66 and KT88 tubes (8.27)
Posted by waldenpuddle on 2004-11-06, 17:14:16 (63.207.13.56)
Howdy, CAn someone please post the correct settings for 7868 KT66 and KT88 tubes on a TV-7/U tester? (If the KT88 is different from the 6550, then I would need the 6550 as well.) I had them written do .......

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