My take on the SSS Updated: the beast is alive VIDEO(S) NEW

[ElectronAvalanche]

So I was able to work on the amp a bit.

Finished the octal holes in the chassis with a punch, drilled the holes for the controls on the back and finished the main board, FET board, Rectifier and Relais supply board.

Since the toner transfer method did not work out as planned, I had to handdraw the layout onto the copper-side of the PCBs using a Eddie 300 pen. Etching worked ok, I used chemical "tin" to coat the copper and then applied some solder to make the traces real beefy

I started to populate the main board yesterday and it is coming along nicely, although a tight fit.

I will post a revised layout/schemo once the amp is working. The PS board needs to be done.

Some open questions remain:

1. do I put two preamp sockets in front of the main board? Do I then have to use DC heaters for these two?
2. I want to implement a bias pot, so I will use a 120k resistor with a 10-20k bias pot to ground to be at least able to set the bias in a narrow range
3. will the inductor pick up any hum by the filaments?

Electron

[mhartman]

Go with two of the preamp tubes up-front -- that will be more true to the originals.

Mike

[ElectronAvalanche]

Just a quick follow up.

Got the boards all etched, main board is populated. All pots and switches installed as well as tube sockets.

Next steps:

Wire up 6VDC circuit for relay. Rock/Jazz-Deep-Switches, Pots with ground-bus. Tube sockets wiring (heaters), grounds, FET board wiring, Main-board, PS boards, install Transformers....

I have a few questions for you guys:

Is the 0.22 uF from the 6A grid as in the hand-drawn schematic of 002 legit? This should give quite a dampening in highs/high mids. I have the option to do this on the main board.

Is the 100kA Volume pot correct?

Having troubles to locate 7 position rotary switches here in Germany. I only get 6 position switches which makes them 5 switching, so one position will have to left blank. Any source for a 7 position rotary? Which values for the high/low filters are best to be left out?

Is the CF-driver a 12X7 or 12BH7 in the 002?

There is a mistake in the layout labeling showing 2x0.22uF in the CF section. These should be 0.1uF as per 002 schematic. I will remove all typos/errors once the amp is running/final.

Electron

[talbany]

Dominick

The Volume control should be a 1M not a 100k
I would leave off the .01 on the high and the 39K on the low(I believe this is the one that gives the deepest bass)..I never use these settings..
For the CF I would use either a 7025 or a 12AT7...Anything below a 70% gain feels more like a bass amp than a guitar amp to me..Also the amp seems to breathe sustain better with a higher gain tube in that spot..YMMV but that's what I recommend..

Looks good so far..
Best of luck!

Tony

[mhartman]

Dominick

The Volume control should be a 1M not a 100k
I would leave off the .01 on the high and the 39K on the low(I believe this is the one that gives the deepest bass)..I never use these settings..
For the CF I would use either a 7025 or a 12AT7...Anything below a 70% gain feels more like a bass amp than a guitar amp to me..Also the amp seems to breathe sustain better with a higher gain tube in that spot..YMMV but that's what I recommend..

Looks good so far..
Best of luck!

Tony

+1. Dumble used 7025 drivers in the original SSS amps. Just don't use a new production Tung Sol, they don't do well here. I like JJs in this position.

[ElectronAvalanche]

Dominick

The Volume control should be a 1M not a 100k
I would leave off the .01 on the high and the 39K on the low(I believe this is the one that gives the deepest bass)..I never use these settings..
For the CF I would use either a 7025 or a 12AT7...Anything below a 70% gain feels more like a bass amp than a guitar amp to me..Also the amp seems to breathe sustain better with a higher gain tube in that spot..YMMV but that's what I recommend..

Looks good so far..
Best of luck!

Tony

Hi Tony,

thanks for your reply. So the 100kB is a typo in the naddrawn!

I will leave the 0.01 and the 39k off the filters and try a 7025 in the CF position.

My question about the 0.2 uF on the PI was a brain-fart on my side

Thanks again,

@Mike: thank you for the tip on the CF tube. Will try a 7025 in that position.

Electron

[ElectronAvalanche]

Work on the amp has progressed. Will post some pics tonight.

I have a question concerning the grounding of the internal Dumbleator (dlator):

The Dlator will be fed by a trimmer (1Mlog) replacing the Master as in the 002 schematic. Return of the Loop will be Recover Input (see attached Dlator schematic), overall Master will be the 250K "Return" Level of the Dlatr for the whole amp.

Currently I have planned to do the grounding of the Dlator as follows:
27k of first triode and 1.3k/47uF combo going to ground plane that feds all cathodes of preamp as well as 1Mlog Master trimmer. There will be one wire to the chassis ground near input jack (isolated input jack). PS caps of preamp and Dlator share ground plane on PS board.

Now here is the question:

shall I use isolated Send/Return Jacks and run a wire from these to preamp ground plane? Or could I get away with non-isolated jacks? Anyone with experience on internal Dlator grounding? I searched the board, but did not find too much info on that unfortunately.

Or use non-isolated Send/Return jacks, but separate Dlator 17k and 1.3k/47uF ground from preamp grounds and run them to ground on jacks?

Thanks in advance,

Electron

[ElectronAvalanche]

Some more pics of the progress

[aflynt]

FWIW, I grounded both sides of my integrated D-Lator, master voltage divider and send in my #102 clone to the return jack. I also ran a separate filter for the D-Lator tube that was grounded to the same place the PI filters go. I used non-isolated jacks. I haven't had any hum issues, but I do power all my pedals in the loop off of my amp's relay supply.

-Aaron

[talbany]

Deleted

[ElectronAvalanche]

So the 002 is slowly progressing.

I have one question concerning the CF mixing stage. In the handdrawn 002 schematic the cathode resistor of V2B and V3B are 1k each. 001 and the cleaned up schematic show 100k resistors there. What is the correct value? A 1k shouldn't really work too well as a cathode resistor for a CF.

I know that reducing the CF cathode resistor from 100k to 83k or even 47k will increase compression, but 1K seems way too low.

Thanks in advance,

Electron

[ElectronAvalanche]

FWIW, I grounded both sides of my integrated D-Lator, master voltage divider and send in my #102 clone to the return jack. I also ran a separate filter for the D-Lator tube that was grounded to the same place the PI filters go. I used non-isolated jacks. I haven't had any hum issues, but I do power all my pedals in the loop off of my amp's relay supply.

-Aaron

Hi Aaron,

thanks for your tipp. I have decided to have the send/return jacks isolated from the chassis. Will see how that works out.

Thank you,

Electron

[ElectronAvalanche]

So, fired the amp for the first time:

Voltages are in the expected range, then some smoke from the Relay PS board, one of the Voltage regulator legs was slightly touching ground, so one of the FWB diodes died. Fixed that, all fine, but had to swap the OT primaries due to oscillation.

First impressions:

great, no..... fantastic sound! Clean to die for.... very musical...

Filters work nicely, maybe I have the rotary switches wired up wrong, but higher settings of the filters filter out highs/lows. Probably a misconception on my behalf. So turning the filters clockwise filters out frequencies. A lot of different sounds available from the filters, really nice.

The bright cap (250pF) on the volume seems way over the top. One odd thing is with the bright on, when turning up the mid above 3 o'clock I get reduction in volume. Either parasitic oscillation or something else.

The FET board is not working yet unfortunately. I get some 14V on the FET but no sound. Need to check that.

I have a DLator instead of the Reverb. Have not yet checked a Pedal in the Dlator, but am loving the possibilties of shaping the sound with the Dlatr Send / Return Gain pots. Need to change the Bright cap on the Master (acutally the real Return of the Dlator) since 22pF is too low to make a difference.

I get some 40mA per tube with two output tubes running. Need to install the new set of 4 and see what I get. Will report back with voltages (have them written down).

I currently have 270k between the filters and will experiment with a 270k in parallel to the one installed. I think it was Sergio that wrote that the 270k robbed to much signal.

Once the amp is really finished I will update the layout for the mainboard.

All in all this is really a complex amp to build, but seems to be worth the effort.

As said, first impression is great. Will be back with more. Atteched some pics for you.

Thanks to all the kind ampgarage members who published the 002 schematics, thanks to Mike and Aaron for being an inspiration and to Sergio and all others for info/help.

Electron

[mhartman]

Nice work! Your build looks great. I can't wait to hear it.

[Aaron]

Nice work! Your build looks great. I can't wait to hear it.

I'll second that. Very nicely done. I like the idea of the set and forget master.

Now what's it going to be covered in?

Aaron