Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: burt_toast on October 08, 2011, 06:44:06 am
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ok, if you thought my last posts were moronic - just wait.
since i'm gonna have my friend Randy at http://www.vintageamprepair.com (http://www.vintageamprepair.com) fix my Traynor YBA1, having my plexified BF bandmaster will be a little redundant. gulp, here goes:
provided i can fabricate a way to change the octal sockets to 9 pin (no, i can't afford the adapters), is it possible to lower my B+ enough to run a 4 x el84 psuedo-ac30 power section, or would i have to change my PT altogether? the bandmaster OT seems like it might work for this (4k pri ?), although it only has the one 4 ohm out. and yes, there are four octal cutouts in the chassis (2 unused, of course).
dumb idea, i know, but along with plexis, ac30s are my favorite sounds (actually bought/lugged home a '63 from London in the 80's - why did i ever get rid of that?? single dumbest move EVER - ah, youth...)
thoughts? rotten tomatoes?
ps, the sound clip of me (Scott Gorsuch) on Randy's site IS my bandmaster thru a leslie 125
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You can use a VVR and set it permanently at around 325v on the plates. If you're doing the AC30 thing, then it would be cathode biased. However, you'd be dropping quite a bit of voltage to make this work.
http://www.el34world.com/Forum/index.php?topic=6899.0 (http://www.el34world.com/Forum/index.php?topic=6899.0)
I would not personally do that. I'd get the correct PT instead. You'd be needing to pretty much gut the amp to convert it. Since you're doing ALOT of work anyway ......... do it correctly.
With respect, Tubenit
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does VVR stand for variable voltage regulator or something? the fact that i have to ask that should probably disqualify me from even DOING the mod.
yep, i ran the bandmaster cathode-biased for a while and liked it, not sure why i changed it back. it currently has a vox-style cut knob with no NFB. i wont even start this till i get the YBA-1 back and deem it Marshallier than the bandmaster.
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does VVR stand for variable voltage regulator or something? the fact that i have to ask that should probably disqualify me from even DOING the mod.
yep, i ran the bandmaster cathode-biased for a while and liked it, not sure why i changed it back. it currently has a vox-style cut knob with no NFB. i wont even start this till i get the YBA-1 back and deem it Marshallier than the bandmaster.
IMO, you're getting to where you're doing enough to the amp that it would make sense to start from scratch building the amp you actually want. Since apparently you don't want a BF Bandmaster but a lot of other people do, I would actually restore it to stock and sell it for enough to build 1 or 2 amps from scratch, where you won't be hampered by an existing design that doesn't suit your taste.
Chris
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I would restore it as well. I had a virgin untouched 1962 Blonde Bandmaster 6G7A here 2 months ago and the customer wanted me to Plexifi it
I said no way man. The amp is what it is and sounds very good with spice added. He finally agreed
This is that amp below
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IMO, you're getting to where you're doing enough to the amp that it would make sense to start from scratch building the amp you actually want. Since apparently you don't want a BF Bandmaster but a lot of other people do, I would actually restore it to stock and sell it for enough to build 1 or 2 amps from scratch
yeah... well, heh... it's a 66' bf. bought it for $180 in '88 - changed it into (more or less) a JCM800 in '90 (then retro-plexed a few years ago)- broke the front spot-welds and straightened the front panel (in of the angled F-style), and built an ac30-style 2x12 combo w/ top-mount controls. i don't even HAVE the original head box any longer. i'll never sell it, because no one would BUY it. restockifying is not an option.
i know what you must be thinking... sorry
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Im guilty of many alterations myself. Too late now
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i know what you must be thinking... sorry
It hurts my very soul. :cry:
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Come on BB, it's just a Fender!!!
Yer pal Jim :icon_biggrin:
+2 on 'Nits comment. Save and buy the tranny you need to do it right. Less is better when you are debugging. Good luck!
Jim
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thanks Jim,
yeah, that bandmaster has been my main amp for a long time, in bars from coast to coast (still sounds amazing, poor thing). i think i just get excited seeing what you guys are capable of here, and wanna change everything. i should probably sit on my hands, and lurk/learn for a while.
this forum is truly a gold mine!
kirk out,
scott