Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Misc Schematics and Layouts => Topic started by: eldredjames on May 28, 2017, 11:31:35 pm
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Has anyone built a tweed overdrive special but added reverb to it? Preferable with a bypass switch? :w2: :w2: I think that is what I would want to build next.
Yes I have built projects before but I am a computer programmer by trade and designing circuits like some of you do is beyond my skill set.
Thanks,
Jim Barnhart
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Looks like a Glaswerks Super Overdrive II would fill the bill, but they don't sell kits. Hmmm.
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I built a Tweed Overdrive Special and added an active FX loop to it.
Adding reverb should be relatively easy. Here is a DRAFT example that I've not built using a 6BM8 tube. I have built numerous amps using a 12AX7 "one tube reverb" that worked well to my satisfaction.
One tube reverb info: http://el34world.com/Forum/index.php?topic=7957.0 (http://el34world.com/Forum/index.php?topic=7957.0)
Since the TOS is somewhat higher gain, I would lean towards using an active FX loop and delay instead of adding reverb.
soundbit for TOS: http://www.soundclick.com/html5/v3/player.cfm?type=single&songid=9488477&q=hi&newref=1 (http://www.soundclick.com/html5/v3/player.cfm?type=single&songid=9488477&q=hi&newref=1)
With respect, Tubenit
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Thanks Tubenit, this is exactly what I was looking for.
Jim
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I would make one change to this. I would have RV be between the switch (clean/OD) and the 100k resistor and then RV2 be where it shows already on the schematic.
You can also change that 100k resistor between the insertion points of RV and RV2 to a higher value IF needed such as 150k -330k range. That's something you can experiment with if you need to.
With respect, Tubenit
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I've got 95% of the parts collected. But first, some questions.
V7 i presume, is a rectifier. Yes? What is an SS plug? What rectifier?
There is a choke shown between the A and B voltage takeoffs. It says 3H. Will 4H work as well? Finally, does it matter which way you hook up the choke?
Thanks all. I'm getting excited about this build.
Jim :m8
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Yes, the schematic shows a solid state rectifer plug in. However, you can use a GZ34 if you wish.
No, there isn't a set way to hook up the choke to my knowledge. Not sure about the Henries ratings? You'll have to research that or ask someone.
with respect, Tubenit
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A 4H choke will work just fine.
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Thanks Tubenit and Sluckey! Time to layout my cap board and reverb board.
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IF you are comfortable building a TOS with a 12AX7 one tube reverb (which is the only kind of one tube reverb that I've built & I've been happy with them), then there is already a schematic and layout drawn up right here:
http://el34world.com/Forum/index.php?topic=9812.0 (http://el34world.com/Forum/index.php?topic=9812.0)
Just check for ERRORS and compare schematic with layout. IF there is a discrepency, go with the schematic.
I personally would build a FX instead of reverb (& have option of reverb or delay pedals), but both sound good.
With respect, Tubenit
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Thanks Again Tubenit!
That layout is new to me. I already have a board from Mr Hoffman for the TOS, so I plan on adding a separate reverb board. Looks like I can excise the reverb section out for the board I have yet to start, or a good jumping off point.
You're right, of course, I could go with the reverb effects pedal. Hmm, I'll ponder that for awhile.
Thanks,
Jim
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Since you already have the TOS Hoffman board, you can simply use terminal strips on both side of a tube. Or build a small reverb or FX board.