Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: DummyLoad on August 26, 2012, 05:36:34 pm
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here's a (another?) spin on the x-press SE. another forum member mentioned that they mated the x-press preamp to an SE output stage. here's my take on that idea.
cool little amp. not running the 6L6GC too hard as i want compatibility with 5881/6L6GB as well. calculator tells me the 6L6 plate in this amp is dissipating just under 19W. amp has more headroom than i expected. dime it and it's a demon. C10 can go either way - amp is bright enough to not need it. yup, using 6AV6s - they're cheap and i'm cheap + i can't stand to not use a triode & i'm not a fan of tremelo.
about that 125FSE - yes it's overkill - it's dwarfs the PT - i used what i had on-hand. the 125ESE would be a better match. the choke (L1) is a hammond 193H.
--DL
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Nice work, thanks for sharing!
I've decided my next project is actually building a breadboard. I get all these ideas from you guys; might's well have an easy and cheap(er) way to try 'em out!
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Please tell us about the tonestack.
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Please tell us about the tonestack.
ripped off from t-wreck x-press schematics floating around the on www. don't care for it too much, working on a replacement.
--DL
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Hi DL, Would you say that the 6av6 is a close match to half 12ax7??
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a close match to half 12ax7??
timbo, it is 1/2 12ax7. similar sonics as well. another 1/2 12AX7 7-pin variant is the 6DR4 which is quite rare.
when our AV dept. was scrapping out all of the old repair parts, they passed on a box of about 50-60 7-pin ceramic sockets to me. needless to say, i've been doing a bit of experimenting and building with 6AV6/6AT6 lately, saving my 12AX7 stash for HI-FI tinkering and personal amp repairs.
should anyone else have interest in fiddling with 7-pin valves, the 6AB4 is 1/2 of 12AT7, the 6AT6 is 1/2 of 5751, and the 6C4 is 1/2 of 12AU7. there are others but those aforementioned are common still and available at reasonable cost; for time being.... :-\
regards,
--DL
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Thanks DL , got a similar thing,only requiring half 12ax7.
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this sounds much, much, better... attached schema updates.
--DL
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Many Thanks for sharing :thumbsup:
K
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this variant is a lot of fun... :icon_biggrin: again, this was built with parts i had laying around and the OT is overkill - you could use 125ESE.
finally! experiments with the 5879... :think1:
cheers!
--DL
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a 5879 tube as V3, nice implementation
this was built with parts i had laying around and the OT is overkill
Just curious, which OT did you used ?
K
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... i've been doing a bit of experimenting and building with 6AV6/6AT6 lately, saving my 12AX7 stash for HI-FI tinkering and personal amp repairs.
should anyone else have interest in fiddling with 7-pin valves, the 6AB4 is 1/2 of 12AT7, the 6AT6 is 1/2 of 5751, and the 6C4 is 1/2 of 12AU7. there are others but those aforementioned are common still and available at reasonable cost; for time being.... :-\
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You should just pass those 6AV6's and 6AT6's on to me! I use them in my Standel build... (Scrapped a channel that would never see use, and didn't need both halves of a 12AX7).
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a 5879 tube as V3, nice implementation
this was built with parts i had laying around and the OT is overkill
Just curious, which OT did you used ?
K
KL, i used the 125FSE. i have a pair of 125ESE on order. PT i plan to use is the hammond 270/370DX.
--DL
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You should just pass those 6AV6's and 6AT6's on to me! I use them in my Standel build... (Scrapped a channel that would never see use, and didn't need both halves of a 12AX7).
love 'em. great tube; so much versatility and flexibility. you can mix and match based on single stages not just in pairs. more hassle building, as each triode requires a socket and the only other down is increased chassis area required.
i have a few i can pass our way, but not a whole lot, i'm re-stocking... :icon_biggrin:
http://www.piexx.com/index.php?main_page=product_info&cPath=10&products_id=41 (http://www.piexx.com/index.php?main_page=product_info&cPath=10&products_id=41)
they claim to have 4K plus - price is decent too... i have 20 on the way, i'll let you know how the transaction goes. the 1AD4 look tempting too at 14bits each; might make a decent all pentode stomp box or front-end to a low-volt low-watt tube amp. filament power could be a pain...
regards,
--DL