Rectifier substitutions in Pilot SA-260...

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Posted by Interstage Tranny (A) on February 27, 2012 at 14:21:38

In Reply to: RE: 12bh7 substitution in pilot sa 260 posted by Tom Bavis on February 27, 2012 at 08:14:14:

There is a sonic difference with each type of rectifier. With 5U4s, drawing that 6A of 5V filament does help to cause that power tranny to run hot after a few hours. Changing to 5V4s or 5AR4/GZ34s or 5R4s will only draw 4A off the 5V fil winding; definitely cooler running.

With 5U4s as the "standard" sound, changing to 5AR4s or even 5V4s, will undoubtedly yield more bass oomph and possibly even more bass detail, but at the expense of midrange sweetness. 5R4s will undoubtedly yield sweeter mids(the sweetest of these three types) and less bass than these other choices. The voltage drop is significant enough to change sound character and the tube type is also contributing to this change in sound character. These sonic results are typical...

Also, something else to consider: Two different brands or two differently testing tubes of the same type will not necessarily have the exact same voltage output ! I can take two good testing 5V4s and their voltages might be differing on the same circuit. With parallel rectifiers that are not split internally, this might cause problems. It's a rare two rectifier tube amp that splits the tube internally in circuit. Matching tubes might be best.

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Follow Ups Full Thread

Topic - 12bh7 substitution in pilot sa 260 - pennyford 07:59:20 02/26/12 (14)

RE: 12bh7 substitution in pilot sa 260 - pennyford 18:23:23 03/3/12 (0)

RE: 12bh7 substitution in pilot sa 260 - Eli Duttman 18:06:38 02/27/12 (0)

RE: 12bh7 substitution in pilot sa 260 - Cleantimestream 11:06:11 02/26/12 (11)

RE: 12bh7 substitution in pilot sa 260 - pennyford 18:57:32 02/26/12 (10)

RE: 12bh7 substitution in pilot sa 260 - Cleantimestream 00:13:40 02/27/12 (5)

RE: 12bh7 substitution in pilot sa 260 - pennyford 04:48:51 02/27/12 (4)

RE: 12bh7 substitution in pilot sa 260 - Neff 20:29:12 02/27/12 (0)

RE: 12bh7 substitution in pilot sa 260 - Tom Bavis 08:14:14 02/27/12 (2)

Rectifier substitutions in Pilot SA-260... - Interstage Tranny 02/27/1214:21:38 02/27/12 (1)

RE: Rectifier substitutions in Pilot SA-260... - Eli Duttman 17:26:20 02/27/12 (0)

RE: 12bh7 substitution in pilot sa 260 - Eli Duttman 19:10:59 02/26/12 (3)

I think the answer is yes - Tre' 10:06:08 02/27/12 (2)

I think the answer is ? - Interstage Tranny 14:04:19 02/27/12 (1)

I messed up, again - Tre' 16:07:42 02/27/12 (0)

Follow Ups

Rectifier substitutions in Pilot SA-260... - Interstage Tranny 02/27/1214:21:38 02/27/12 (1)

RE: Rectifier substitutions in Pilot SA-260... - Eli Duttman 17:26:20 02/27/12 (0)

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