Josh's 18W Tremolo TMB Builds

[JMPGuitars]

I hear ya. Plus, when I release the docs you might want to build that version, and that might also take up time.

You can read my mind

No worries, the people relying on you to get me to release the docs can wait.

Maybe somebody else wants to give it a shot?

[Bieworm]

I hear ya. Plus, when I release the docs you might want to build that version, and that might also take up time.

You can read my mind

No worries, the people relying on you to get me to release the docs can wait.

Maybe somebody else wants to give it a shot?

Still strange that an apprentice like me discovered the key ingredient... admitted you gave a big hint about them green wires. So the schematic should include the unused half of the PI tube. So on a normal 18W the reverb would be injected on that same half, opposite of the fx loop injection?

[JMPGuitars]

Still strange that an apprentice like me discovered the key ingredient... admitted you gave a big hint about them green wires. So the schematic should include the unused half of the PI tube. So on a normal 18W the reverb would be injected on that same half, opposite of the fx loop injection?

Yeah, I had to give a few big hints, but you did get it.

On a 2 channel amp that uses each half of the PI for each separate channel, you obviously have to choose which channel gets reverb and stick to that channel (similar to the FX loop). I think there are some methods that may work to apply it to both, but I don't usually build 2 channel amps, so I haven't done any research on that (and I assume relays or something ugly might be needed). I like to keep things relatively simple, and make the one channel I use awesome.

[Bieworm]

Still strange that an apprentice like me discovered the key ingredient... admitted you gave a big hint about them green wires. So the schematic should include the unused half of the PI tube. So on a normal 18W the reverb would be injected on that same half, opposite of the fx loop injection?

Yeah, I had to give a few big hints, but you did get it.

On a 2 channel amp that uses each half of the PI for each separate channel, you obviously have to choose which channel gets reverb and stick to that channel (similar to the FX loop). I think there are some methods that may work to apply it to both, but I don't usually build 2 channel amps, so I haven't done any research on that (and I assume relays or something ugly might be needed). I like to keep things relatively simple, and make the one channel I use awesome.

I'm using them ugly relays right now on my new build. It's a 2 channel, 1 input amp. At first I only wanted to build the drive channel, but I thought maybe that clean channel might come in handy sometime. Or when I don't like the amp and decide to sell it there are more people to be adressed with a 2 channel amp. There are relatively few people like us that use OD all the time.

[JMPGuitars]

I'm using them ugly relays right now on my new build. It's a 2 channel, 1 input amp. At first I only wanted to build the drive channel, but I thought maybe that clean channel might come in handy sometime. Or when I don't like the amp and decide to sell it there are more people to be adressed with a 2 channel amp. There are relatively few people like us that use OD all the time.

I don't use OD all the time, but I have it on tap all the time.

[JMPGuitars]

Still strange that an apprentice like me discovered the key ingredient... admitted you gave a big hint about them green wires. So the schematic should include the unused half of the PI tube. So on a normal 18W the reverb would be injected on that same half, opposite of the fx loop injection?

You gonna try and figure this out?

[Bieworm]

Still strange that an apprentice like me discovered the key ingredient... admitted you gave a big hint about them green wires. So the schematic should include the unused half of the PI tube. So on a normal 18W the reverb would be injected on that same half, opposite of the fx loop injection?

You gonna try and figure this out?

I will for sure! Very very soon

[Bieworm]

Here it izzz

16037918515658660587150660163073.jpg

[JMPGuitars]

Here it izzz

Not a bad attempt!

Now go compare it to the real thing: viewtopic.php?f=25&t=25550

[geoff 1965]

I love it! that was a good attempt by bieworm, see what you mean by less tone sucking resistors compared to the other 1 tube schematics,thank’s for posting this Josh.

[Bieworm]

Here it izzz

Not a bad attempt!

Now go compare it to the real thing: viewtopic.php?f=25&t=25550

finally!!! It differs on some values...but generally I got it right. That's a relief...
The 220k resistor at pin 7 is there for the function of the switch with the bright cap?

[JMPGuitars]

finally!!! It differs on some values...but generally I got it right. That's a relief...
The 220k resistor at pin 7 is there for the function of the switch with the bright cap?

You also reversed the reverb in/out jacks. I'm not sure why you added a capacitor to ground on the pot? Maybe the bright cap tricked you? I have it directly connected to the switched pot.

The 220K is required with or without the bright cap (and/or switch). Overall though, a great attempt, especially for somebody who couldn't read schematics not so long ago.

That reminds me. I still haven't tested the bright switch on my combo. I'll remember eventually. I'm not getting any younger.

[Bieworm]

I might be older than you. From 75. Who is the old fart?
True about the reading of schematics. Now it's all I read... i learned that layouts are just building guides for component placement and proportions. Thanks for always being a PITA about that. The use of more braincells keep the Alzheimer away for now ..

[JMPGuitars]

I might be older than you. From 75. Who is the old fart?
True about the reading of schematics. Now it's all I read... i learned that layouts are just building guides for component placement and proportions. Thanks for always being a PITA about that. The use of more braincells keep the Alzheimer away for now ..

Wow, you are older; I was born in 78. You're wicked old!

[JMPGuitars]

I love it! that was a good attempt by bieworm, see what you mean by less tone sucking resistors compared to the other 1 tube schematics,thank’s for posting this Josh.

No problem. I know you've been waiting a long time.

I also like the return of the reverb signal being independent. I think it has a thicker tone, and doesn't effect or get effected by the FX loop.

I've not tried it, but it would be interesting to run a good reverb pedal through the FX loop and see what it sounds like together.

Thanks,
Josh

[geoff 1965]

i've only got one spare triode on my 6V6 amp and the turret board is pretty full! so i'm looking into using that triode as a FX loop buffer or a parallel input on the TMB channel. but my next build i will allow for the extra components to use your reverb circuit,keep us posted with your reverb/FX tests,thanks Josh.

[Bieworm]

I love it! that was a good attempt by bieworm, see what you mean by less tone sucking resistors compared to the other 1 tube schematics,thank’s for posting this Josh.

No problem. I know you've been waiting a long time.

I also like the return of the reverb signal being independent. I think it has a thicker tone, and doesn't effect or get effected by the FX loop.

I've not tried it, but it would be interesting to run a good reverb pedal through the FX loop and see what it sounds like together.

Thanks,
Josh

Poor ZP... you are almost running an 18W through an army of reverb

[JMPGuitars]

Poor ZP... you are almost running an 18W through an army of reverb

LOL! I wasn't actually gonna bother doing the experiment, it was just a curiosity. But since you mention it, I think I have at least 2 reverb pedals. I could run two pedals through the FX loop, and run the tube reverb high. Now that would be hilarious. "This underwater jazz song is dedicated to ZP."

[Bieworm]

Poor ZP... you are almost running an 18W through an army of reverb

LOL! I wasn't actually gonna bother doing the experiment, it was just a curiosity. But since you mention it, I think I have at least 2 reverb pedals. I could run two pedals through the FX loop, and run the tube reverb high. Now that would be hilarious. "This underwater jazz song is dedicated to ZP."

As a counteract he would go play his amps very very dry in the middle of the Sahara desert. ( on a 4x12 closed back cab filled with sand, baffle flat on the ground)

[geoff 1965]

Easy on ZP lads! Sahara desert!!? we all know he’s the Buddha of guitar amps and sits floating on a cloud on top of a high mountain in Canada.