Josh's 18W Tremolo TMB Builds

[geoff 1965]

struggling with the resolution of the pics here! i can't see the value of the caps going to the pot and the phase inverter.

[JMPGuitars]

struggling with the resolution of the pics here! i can't see the value of the caps going to the pot and the phase inverter.

If I thought the values of stuff were that important, perhaps I would have provided higher res photos...and that's my last hint.

[geoff 1965]

yeah i know Josh,just trying to learn as much as possible i.e. values and reasons for using them.the idea is to work out what you've done rather than just copying and i'm finding it tricky! i'd like to see some more input from other members as well!

[Bieworm]

Josh.. this is what I can make out of your circuit. Looks like you reversed the circuit...

And for the record.. it sits before the fx loop

1602357134015313045882904929021.jpg

[JMPGuitars]

Josh.. this is what I can make out of your circuit. Looks like you reversed the circuit...

And for the record.. it sits before the fx loop

Not a bad attempt, but... Incorrect, on a lot of points. You are close enough with where the signal is sent to the reverb circuit, but from there, and the values, are not quite accurate yet. I'd ask a question, but that might be too big of a hint... I will tell you to look a lot closer at the pot. You're completely wrong with that. Darn. That was a hint.

[Bieworm]

Josh.. this is what I can make out of your circuit. Looks like you reversed the circuit...

And for the record.. it sits before the fx loop

Not a bad attempt, but... Incorrect, on a lot of points. You are close enough with where the signal is sent to the reverb circuit, but from there, and the values, are not quite accurate yet. I'd ask a question, but that might be too big of a hint... I will tell you to look a lot closer at the pot. You're completely wrong with that. Darn. That was a hint.

This is what I can make of it with the pics. Values I guessed based upon my schematic.
Maybe someone else has a better interpretation .. I'm too occupied by my new build.. lots and lots of dilemmas...
The relays circuit is pre assembled and it works just fine

[JMPGuitars]

This is what I can make of it with the pics. Values I guessed based upon my schematic.
Maybe someone else has a better interpretation .. I'm too occupied by my new build.. lots and lots of dilemmas...
The relays circuit is pre assembled and it works just fine

I get it if you're distracted, but the thing you're missing is fairly obvious if you look at enough of the photos.

[geoff 1965]

Josh can you confirm your cathode resistors,820R/2K2 or 1K2/1K5? I posted 2 schematics!
is the silver mica cap on the pot part of the switched bright?
talking of reverb my trusty boss me50 has developed a squeal on the spring reverb section,i’ve replaced the potentiometer but it’s still there so now i’ve got to trace the signal to see which IC’s,module and capacitors are involved,I hate working on PCB’s!

7249C3EE-80E4-4E85-9184-559919E49217.jpeg

[JMPGuitars]

Josh can you confirm your cathode resistors,820R/2K2 or 1K2/1K5? I posted 2 schematics!
is the silver mica cap on the pot part of the switched bright?

1k2, 1k5. Yup, good eye. And since you obviously know which pot is for the reverb, see if you can figure out what's happening.

[geoff 1965]

Thanks Josh

[Bieworm]

Another attempt...

20201015_081123.jpg

[JMPGuitars]

Another attempt...20201015_081123.jpg

Too much guessing, and not better than the last one. Look closer at the green wires coming off the reverb pot. Compare the photos with and without the board components and see if you can figure out the biggest thing you're missing.

[Bieworm]

Another attempt...20201015_081123.jpg

Too much guessing, and not better than the last one. Look closer at the green wires coming off the reverb pot. Compare the photos with and without the board components and see if you can figure out the biggest thing you're missing.

The wiper goes solely to 1 triode grid of the PI ? Does that mean the wet signal is out of phase with the dry signal? Is that the key?

[JMPGuitars]

The wiper goes solely to 1 triode grid of the PI ? Does that mean the wet signal is out of phase with the dry signal? Is that the key?

Ding ding ding! Now try and draw it, and I will share mine after you post it, and see how close you are to the actual schematic.

[JMPGuitars]

Here's a little more explanation:

Basically this reverb method is different than most (I've never seen it like this). I take the signal after the tone stack, but before the FX loop. Then the reverb circuit returns the signal to the unused half of the PI. This makes the reverb both out of phase with the guitar signal, and independently controlled really well. The reverb doesn't interact with the FX loop at all. Turning down the reverb volume all the way sends that half of the PI back to ground as it would be if nothing were connected to it. That part is thanks to the genius of ZP, and obviously his hidden love for reverb.

[geoff 1965]

Nicely explained Josh,thanks and yeah ZP’s “hidden love” is obvious in the way he kept out of the post!
well worked out bieworm!

[Bieworm]

Nicely explained Josh,thanks and yeah ZP’s “hidden love” is obvious in the way he kept out of the post!
well worked out bieworm!

Too bad this fun game is situating in the wrong period. I'm too busy and occupied with this imperial build.. drilling chassis, narrowing a combo shell,.. that takes a lot of thinking before execution

[Bieworm]

Here's a little more explanation:

Basically this reverb method is different than most (I've never seen it like this). I take the signal after the tone stack, but before the FX loop. Then the reverb circuit returns the signal to the unused half of the PI. This makes the reverb both out of phase with the guitar signal, and independently controlled really well. The reverb doesn't interact with the FX loop at all. Turning down the reverb volume all the way sends that half of the PI back to ground as it would be if nothing were connected to it. That part is thanks to the genius of ZP, and obviously his hidden love for reverb.

Maybe ZP 's amps all have had reverb all along

[JMPGuitars]

Too bad this fun game is situating in the wrong period. I'm too busy and occupied with this imperial build.. drilling chassis, narrowing a combo shell,.. that takes a lot of thinking before execution

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

[Bieworm]

Too bad this fun game is situating in the wrong period. I'm too busy and occupied with this imperial build.. drilling chassis, narrowing a combo shell,.. that takes a lot of thinking before execution

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