18Watt.com

In case of the use of the dedicated PCB I'd use a dumble style chassis. It's about 2" longer and 1" wider.

I'd prefer not to need another cab... I'm curious about the term dedicated PCB - are you referring to the board shown for the rectifier or the main PCB?
I did a quick search for dumble style chassis and there seem to be some options...I used to have a press brake years ago but maybe it's time to see if a hand brake could be used for chassis builds...

lavrgs wrote: ↑

Wed 03/24/21 12:29 pm

In case of the use of the dedicated PCB I'd use a dumble style chassis. It's about 2" longer and 1" wider.

I'd prefer not to need another cab... I'm curious about the term dedicated PCB - are you referring to the board shown for the rectifier or the main PCB?
I did a quick search for dumble style chassis and there seem to be some options...I used to have a press brake years ago but maybe it's time to see if a hand brake could be used for chassis builds...

I meant Josh’s tremolo TMB reverb PCB.
If the new chassis works out nice I'll be ordering more of those.
For 2mm aluminium a hand brake should be plenty ok.

Josh, do you ground your reverb jacks directly to the chassis?

Bieworm wrote: ↑

Thu 03/25/21 3:10 pm

Josh, do you ground your reverb jacks directly to the chassis?

I do. I haven't tested it compared to isolating them, but it has generally worked fine for me.

I do. I haven't tested it compared to isolating them, but it has generally worked fine for me.

Thanks! I'm gonna put a dwell control in the 36.. I did this on my 18 too.. on the back panel though

Bieworm wrote: ↑

Thu 03/25/21 3:24 pm

I do. I haven't tested it compared to isolating them, but it has generally worked fine for me.

Thanks! I'm gonna put a dwell control in the 36.. I did this on my 18 too.. on the back panel though

When I placed the amplifier's reverb input jack (low level output from the tank) directly onto the chassis, it hummed badly. I had to isolate that jack from the amplifier chassis and connect it to the same ground being used by the reverb tube. Just sayin'.

Jack

TriodeLuvr wrote: ↑

Thu 03/25/21 3:33 pm

Bieworm wrote: ↑

Thu 03/25/21 3:24 pm

I do. I haven't tested it compared to isolating them, but it has generally worked fine for me.

Thanks! I'm gonna put a dwell control in the 36.. I did this on my 18 too.. on the back panel though

When I placed the amplifier's reverb input jack (low level output from the tank) directly onto the chassis, it hummed badly. I had to isolate that jack from the amplifier chassis and connect it to the same ground being used by the reverb tube. Just sayin'.

Jack

I'll be putting the reverb RCA inputs on the back panel, so it's pretty easy to change the grounds

TriodeLuvr wrote: ↑

Thu 03/25/21 3:33 pm

When I placed the amplifier's reverb input jack (low level output from the tank) directly onto the chassis, it hummed badly. I had to isolate that jack from the amplifier chassis and connect it to the same ground being used by the reverb tube. Just sayin'.

I have done it both ways in the past, but IME there's been no difference. Of course there's plenty of variables in what affects the ground scheme and noise.

I may decide to do a test with this circuit at some point, but free time doesn't happen too often. Yes, for anybody with noise issues, they should be isolated.

Bieworm wrote: ↑

Thu 03/25/21 3:54 pm

I'll be putting the reverb RCA inputs on the back panel, so it's pretty easy to change the grounds

Is your back panel non-conductive? Mine are installed on the aluminum chassis, so I had to cut the hole slightly larger and install a shoulder washer. I was lucky to have a few of those left over from a previous project. IME, shoulder washers that fit Switchcraft phono jacks properly (and which don't have a huge outer diameter) aren't easy to find. The ones I have were samples from the manufacturer, but I think Mouser sells them now.

Jack

I use aluminium too

The jacks I use come with isolation washers:
I'll try them out on my next build and see if it makes a perceivable difference on this circuit.

Hey Josh, do you have the dimensions/ hole pattern for the pcb? Just out of curiosity

Bieworm wrote: ↑

Fri 03/26/21 9:04 am

Hey Josh, do you have the dimensions/ hole pattern for the pcb? Just out of curiosity

For you? Nah. But for anybody else that wants to use my PCBs, here's the mounting holes.

JMPGuitars wrote: ↑

Fri 03/26/21 10:23 am

Bieworm wrote: ↑

Fri 03/26/21 9:04 am

Hey Josh, do you have the dimensions/ hole pattern for the pcb? Just out of curiosity

For you? Nah. But for anybody else that wants to use my PCBs, here's the mounting holes.

PCB Mounting Holes.pdf

Lucky me then...you putting this out for other European readers

I finally got around to recording a demo of the 36W version with the PCB, and Mercury Magnetics transformers: https://youtu.be/L0p04n1pSio

Or here's the shorter instagram version: https://www.instagram.com/p/CQRGsyjgwzu/

The demo also includes the "2020 Special" JoshuWah pedal series.

Thanks,
Josh

Here.. one for the archives:

Time to build a couple more. Capacitors marked, and everything else is ready to go.

Thanks,
Josh

JMPGuitars wrote: ↑

Thu 10/28/21 4:57 pm

Time to build a couple more. Capacitors marked, and everything else is ready to go.

1.jpg

2.jpg

3.jpg


Thanks,
Josh

Way to go homie!!!

Fun!

Board 1 is done. I'll do board 2 tomorrow, then clean them up and take some real photos.

Though I do find the dramatic lighting on this cellphone pic pretty funny.