Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Jonny Beck on January 03, 2020, 09:39:53 am
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I bought this thing for the dual output tube circuit (6V6/EL84) and the hot gain structure...
The clean tones are so so on both but the overdriven 6V6 side... well it's so bad that I'm thinkin' maybe I should try replacing the 6V6's . The EL84's when pushed are usable, but the 6V6's ? whew :sad2:, just awful, like high/mid shallow distortion that quits and reverts to clean prematurely.(I guess a sound clip may be in order at some point)... Also maybe a fresh 12AX7 in v1 would help (?) BTW I've tried different speakers and that ain't it. Anyways, I ain't so wealthy I can buy output tubes willy nilly so I thought I'd run it by y'all to get an opinion other than me own. Oh, also I bought it used from GC and though it was really mint it's also maybe 10 or 12 years old so who knows the status of the tubes :w2: ...but no noise/no hum.
Thanx in advance and cheers
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The reason I buy from Guitar Center, when I do, is the return policy. Never had any issues with them as long as it's within the return cycle.
I believe the Egnater designer, owner, is a forum member. Seems I've seen his posts here before.
silverfox.
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This is from an old thread here on the forum
https://el34world.com/charts/Schematics/files/Egnater/Egnater_rebel_20.pdf (https://el34world.com/charts/Schematics/files/Egnater/Egnater_rebel_20.pdf)
if you do a search, here on the forum, using rebel 20, you'll find some thread that talk about it in some way
Franco
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Have you checked the bias on those 6V6 tubes?
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Thanx so much everyone...
Guilty of being lazy about checking bias...
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From what I can tell from the schematic for that amp, it appears everything is the same from preamp to LTPI going into each pair of tubes. In other words, the EL84 and 6V6 pairs share everything the same up to the biasing.
With respect, Tubenit
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I've find also a version of the schematic with components values instead of only components designation numbers
Here attached the .pdf file (look down on this post)
(the .pdf is more readable than the following .jpg image)
(https://i.imgur.com/gGQ6Bzg.jpg)
Franco
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fwiw
I've brought a couple bad from failed, the consciences with my guitar amp test group, none of them bonded well with the amp, but the 2 harp guys in the mix they likey lots joe
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I've find also a version of the schematic with components values instead of only components designation numbers
Here attached the .pdf file (look down on this post)
(the .pdf is more readable than the following .jpg image)
(https://i.imgur.com/gGQ6Bzg.jpg)
Franco
Thanks for the PDF with values
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Thanx so much, kids and special thanx to Kagliostro for the pdf...
As fate would have it, I left the poor beast on for 2 or 3 hrs. and from the acquired 'hum' I thimk she may've popped a filter so along with opening it up for that hopefully I can improve the tone... (?)
I've been getting into my '68 Princeton RI and that thing is so sweet... My Tele's LOVE it and the feedback with hollows and semi hollows is choice. Has anyone ever REALLY improved on the tone from 5E3's and AB763's, etc. ??? Cheerios, all