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Tubes Asylum: Ah ! the famous "Six busy Sevens" ! by Bambi B Questions about tubes and gear that glows. FAQ |
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In Reply to: What abouit 6BZ7 ? posted by Capt. Z on July 18, 2006 at 02:34:23:
Capt. Z.,Actually, I don't know the 6BZ7 or 6BQ7A types. As I've had to deal with some new types recently, I checked into the duncanamps tube data page on Triode Electronics:
http://tdsl.duncanamps.com/show.php?des=6BZ7
- and learned almost nothing except the pinout appears the same, but the Va of the 6922 is 90 while the 6BZ7 is 150. It appears the 6BZ7 and 6BQ7A are not listed as direct substitutes for 6DJ7- (perhaps you mean 6DJ8) or 6922. The two types seem electrically different in some ways,..
On Ebay there are a pile for sale at very modest prices:,
http://search.ebay.com/search/search.dll?from=R40&satitle=6bz7
-so if it works electrically in your headphone amp- and good ones were made, it might be interesting -these are $4 tubes rather than the $35 you might spend for a good 6922.
I bought a McIntosh MR67 recently and it has some types not used very often so I could buy NOS Telefunken, Mullard or Amperex for very reasonable prices- thanks to their not being commonly used. When a Telefunken anything is $10 NOS in the box- it's very comforting in one way- and disconcerting to learn that there will never be anymore of that type made! Even though I may not keep the MR67, I already have at least 2 NOS of any type that isn't made any longer.
I'm always a bit nervous about types and substitutions- I've never heard of the 6BZ7 as a substitute for 6922- and over the 20+ years I've been fussing with the 6DJ8 family, I've heard of people looking for any alternative that will allow them to use something else- preferably less expensive- 7DJ8s, PCC88s had a fad, and people often ask if the 6FQ7 will go.
The preamp tube fad now seems to be the 5751 substitute for 12AX7.
I would make sure- ask the maker - what tubes the preamp can use. Some kinds of gear- and their makers- seem to be more flexible than others for substitutions.
Cheers,
Bambi B
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Topic - Valvo ECC88 & Amperex 7308 - Snegrah 20:56:53 07/16/06 ( 19)
- The thing about Joe's tube page - Sigmund 09:13:04 07/17/06 ( 1)
- Furthur...the part number means little. 6DJ8 vs 7308, 6550 vs KT88, etc - Kevin Deal 15:09:32 07/18/06 ( 0)
The 6DJ8 family - Bambi B 06:56:00 07/17/06 ( 13)
- So since it's all synergistic - what about for MF X10d? - bartc 04:21:13 07/18/06 ( 2)
- The 6DJ8 is difficult but choices can be made easier - Bambi B 10:59:20 07/18/06 ( 1)
- Re: The 6DJ8 is difficult but choices can be made easier - bone43 16:44:36 07/20/06 ( 0)
Re: The 6DJ8 family - Len_ 18:10:27 07/17/06 ( 2)
- Careful consideration is still neceassry - Bambi B 18:28:51 07/17/06 ( 1)
- Re: Careful consideration is still neceassry - Len_ 19:23:01 07/17/06 ( 0)
Re: The 6DJ8 family - Doc B. 08:33:43 07/17/06 ( 6)
- Re: The 6DJ8 family - Bambi B 16:16:13 07/17/06 ( 5)
- Re: The 6DJ8 family - Doc B. 20:37:52 07/17/06 ( 4)
- Three great 6DJ8 testers: ARC SP10, SP8, D115 - Bambi B 23:10:19 07/17/06 ( 3)
- What abouit 6BZ7 ? - Capt. Z 02:34:23 07/18/06 ( 2)
- Ah ! the famous "Six busy Sevens" ! - Bambi B 07/18/06 08:03:10 07/18/06 ( 1)
- Re: Ah ! the famous "Six busy Sevens" 6DJ8 - Capt. Z 08:46:03 07/18/06 ( 0)
Re: Maybe - Ron Oehlert 23:12:14 07/16/06 ( 0)
Re: No - Ron Oehlert 23:04:26 07/16/06 ( 0)