Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dwp on June 12, 2010, 07:19:37 pm
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So I have the EF86 Channel in front of typical 5F6A Build. I was with two sets of input jacks, introducing the EF86 channel at the V-2 pin 2 so I get the benefit of 5F6A Tonestack. This I like.
Now, I want a little more aggressive Lead Channel via EF86, Relay, one set of inputs only. Does this look correct for relay and insertion?
Forgive my longhandle sketch, and then reducing to upload went alittle worse. Hope you can read.
Thanks in advance, dwp
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Again I apologize for the poor drawing. I have it wired this way and it seems I have an overall drop in output power on normal. Switched in the OD is alittle grainy. I'm going to move the in/out on the relay to the other side of the 270K's in the morning, not sure if I need a cap there as well. I figured I would be overly brite if anything, currently it is not. More later, will get back to the .sch practice.....
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I came, I conquered, lessons learned. Too much gain on tap to make a usefull stomp lead channel. Sure, can turn the pot down, to 3.......
Am going to revert back to all three channels bridged at V2-2, use the relay to switch the input jacks from 5F6A to EF86. The only way to get the color out of the EF86, in my opinion.......
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if too much gain, put in a trim pot to dial it back. I did that with this:
by adding an EF86 stage that is alternate to a 12ax7 1/2 triode stage.
trim pot cuts voltage about 50% or 60% as I have set with this amp.
works great. pentode feel for sure.
http://www.dougcircuits.com/EF86.html (http://www.dougcircuits.com/EF86.html)