SSS002 build log

[timrobertson100]

Hi folks,

I thought I'd share the process of my SSS002 build, using the PCB/chassis bought from member Erwin following his collaboration with Ryan (here and thetonegeek on youtube).
Thanks for looking, feel free to ask questions or for measurements, and if you spot anything wrong along the way please say.

I used the BOM for Mouser, and I shared a European BOM in Ryan's project.

I have some Mercury Vibrolux 35W transformers kicking around that I plan to use but am already torn if I should go all in and build a 100W to use as a reference for future lower-powered builds. If I go 35W I'll build it stock, modify the bias circuitry, adjust dropping resistors for pre-amp voltages, and then presume I may need to tweak the gains around the PI section, and maybe reduce the filtering. If anyone's gone down the rabbit hole of a lower-powered SSS-style already and has the experience to share, I'm interested to learn.

So far: drilled for the pilot light/smaller transformer/reverb transformer, replaced dented end bell on PT, scrapped off powder coating for grounded areas, dry-fitted some parts. I'm using 15mm standoffs and looks like it may get tight in some spots.
I have various fuse holders, but only the smallest diameter ones fit this chassis (one on my BOM is no good). You do need the long switchcraft jack sockets - the standard short ones are too short. I scratched the face-plate when scrapping the powder coat and regretted not taping it up earlier with decorator's tape.

[erwin_ve]

Looking good Tim!

The powdercoating is a one of those things that is solved in the new batch of chassis. The entire inside is not coated. The scratch possibly can be fixed with a strong solvent as long as it's not too deep and no lettering is damaged.
Using longer standoffs is definitely a good choice. I think you dont want the heater wires induce their 50Hz in the pcb traces.

Erwin

[timrobertson100]

Thanks, Erwin

I notice on your build you scrapped powder coating on the reverb RCA jacks and it looks like you use isolated sockets but then ground at the chassis on the RCA here (could be a trick of the photo):
https://ampgarage.com/forum/download/fi ... &mode=view

I see Ryan grounds his reverb at the star by the input jack. Can you please confirm you have no issues grounding here? I'm ordering some missing parts, and not sure if I should get isolated RCA sockets too as I only have un-isolated ones here.

Thanks

[erwin_ve]

Tim,

Those RCA jacks with chassis grounding were not not working well and caused grounding problems due to the RCA construction. I replaced them and grounded them at the star ground at the input jack.

Erwin

[timrobertson100]

Thanks, Erwin. Glad I asked.
I've found I have some but they all have thing plastic "lips" that won't work well in this nice thick chassis. Do you recall the specific ones you bought, please?

[erwin_ve]

Thanks, Erwin. Glad I asked.
I've found I have some but they all have thing plastic "lips" that won't work well in this nice thick chassis. Do you recall the specific ones you bought, please?

Sorry I dont know, old surplus probably.

[Richard1001]

I used non-isolated RCA connectors. No hum issues either. I did use the RCA sockets to ground the reverb driver side of the board (12AT7) together with the shield of the wire coming from the send pot. The 12AX7 small signal side of the board is wired to the preamp ground bus.

[timrobertson100]

Thanks Richard

[timrobertson100]

High filter day. Lot's of photos of complete ones, so I thought I'd share some of how I built mine (hope it is correct).
Soldering iron on 350C, and I tried to solder quickly as I've damaged a filter cap before with too much heat. 3 croc clips and an elastic band helped a lot.
I left the two outside ones until last, and worked from 150pF to 5100pF, using the 150pF leg as the common connection.

[ChopSauce]

Lovely...

I'm a bit sorry I can't comment beyond that but never cease to be amazed by this kind of builds...

[dreric]

Nice work of the caps.

A word of advise, triple check for shorts BEFORE mounting the switch and AFTER mounting. On my second SSS build I had tiniest short in there, took hours to find it.

[rccolgan]

Looking good, Tim! Thank you for your BOM contributions on GitHub. Love the collaboration!

[timrobertson100]

Thanks ChopSauce, Dreric (that is a good tip!), Ryan

Board night tonight. It is such a pleasure working on these PCBs having been using turrets for my previous builds.
A simple tip for those of us new to PCB: low components on first (resistors, diodes), flip it over and solder on the back, then higher parts, flip and solder etc as this makes it easy to seat components nicely.

Too late to test the drop capacitor orientation so they'll go in later this week.

I populated the FET board with the values printed on the PCB, not the layout. I didn't pay all that much attention to handling the FET with care other than to touch the radiator first to discharge static.
I'll take some time later to check the FET bias before installing using the recommended method.

IMG_0891.jpeg

[erwin_ve]

Looking neat Tim,

One observation: the entrance resistors 2x 68k: you can replace them with the 2x 68k (carbon film Beyschlag) I sent you. The ones you have there are metal oxide 2w and are a bit overkill on that position.

On the power supply filter board you can tie the ground together on the last 3 nodes: this is fixed in the new revision of the boards.

Erwin

[timrobertson100]

Thanks Erwin - I appreciate you looking

Those are 2W but they are Koa Speer Carbon Films, not metal oxide. I'll swap them out anyway.

I must admit I find it hard to identify resistor types visually (these look like metal oxide to me too for example) and had I assumed the NOS ones you sent were carbon comp based on appearance - I didn't want to pester you with silly questions. Are they all carbon film, please, as there may be values that can fill the other holes I'm missing?