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Re: Josh's 18W Tremolo TMB Builds
Posted: Sat 10/10/20 1:14 pm
by 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.
Re: Josh's 18W Tremolo TMB Builds
Posted: Sat 10/10/20 1:17 pm
by JMPGuitars
geoff 1965 wrote: ↑Sat 10/10/20 1:14 pm
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.
Re: Josh's 18W Tremolo TMB Builds
Posted: Sat 10/10/20 1:26 pm
by 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!
Re: Josh's 18W Tremolo TMB Builds
Posted: Sat 10/10/20 2:13 pm
by 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
Re: Josh's 18W Tremolo TMB Builds
Posted: Sat 10/10/20 4:24 pm
by JMPGuitars
Bieworm wrote: ↑Sat 10/10/20 2:13 pm
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.
Re: Josh's 18W Tremolo TMB Builds
Posted: Sun 10/11/20 2:39 am
by Bieworm
JMPGuitars wrote: ↑Sat 10/10/20 4:24 pm
Bieworm wrote: ↑Sat 10/10/20 2:13 pm
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
Re: Josh's 18W Tremolo TMB Builds
Posted: Sun 10/11/20 8:09 am
by JMPGuitars
Bieworm wrote: ↑Sun 10/11/20 2:39 am
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.
Re: Josh's 18W Tremolo TMB Builds
Posted: Sun 10/11/20 10:43 am
by 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
Re: Josh's 18W Tremolo TMB Builds
Posted: Sun 10/11/20 12:27 pm
by JMPGuitars
geoff 1965 wrote: ↑Sun 10/11/20 10:43 am
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.
Re: Josh's 18W Tremolo TMB Builds
Posted: Sun 10/11/20 12:33 pm
by geoff 1965
Thanks Josh
Re: Josh's 18W Tremolo TMB Builds
Posted: Thu 10/15/20 1:07 am
by Bieworm
Another attempt...
20201015_081123.jpg
Re: Josh's 18W Tremolo TMB Builds
Posted: Thu 10/15/20 6:09 am
by JMPGuitars
Bieworm wrote: ↑Thu 10/15/20 1:07 am
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.
Re: Josh's 18W Tremolo TMB Builds
Posted: Thu 10/15/20 11:20 am
by Bieworm
JMPGuitars wrote: ↑Thu 10/15/20 6:09 am
Bieworm wrote: ↑Thu 10/15/20 1:07 am
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?
Re: Josh's 18W Tremolo TMB Builds
Posted: Thu 10/15/20 2:06 pm
by JMPGuitars
Bieworm wrote: ↑Thu 10/15/20 11:20 am
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.
Re: Josh's 18W Tremolo TMB Builds
Posted: Fri 10/16/20 9:58 pm
by 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.
Re: Josh's 18W Tremolo TMB Builds
Posted: Fri 10/16/20 10:28 pm
by 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!
Re: Josh's 18W Tremolo TMB Builds
Posted: Sat 10/17/20 1:23 am
by Bieworm
geoff 1965 wrote: ↑Fri 10/16/20 10:28 pm
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
Re: Josh's 18W Tremolo TMB Builds
Posted: Sat 10/17/20 3:16 am
by Bieworm
JMPGuitars wrote: ↑Fri 10/16/20 9:58 pm
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
Re: Josh's 18W Tremolo TMB Builds
Posted: Sat 10/17/20 7:42 am
by JMPGuitars
Bieworm wrote: ↑Sat 10/17/20 1:23 am
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.
Re: Josh's 18W Tremolo TMB Builds
Posted: Sat 10/17/20 9:10 am
by Bieworm
JMPGuitars wrote: ↑Sat 10/17/20 7:42 am
Bieworm wrote: ↑Sat 10/17/20 1:23 am
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
