My take on an SSS

[crbowman]

One thing I've noticed on your layout is that the plates on your PI cathode follower are connected to each other, but not to a B+ node. The SSS schematic appears to have it connected to the screen grid node.


Again though, great work, and thanks!

[mhartman]

One thing I've noticed on your layout is that the plates on your PI cathode follower are connected to each other, but not to a B+ node. The SSS schematic appears to have it connected to the screen grid node.


Again though, great work, and thanks!

Thanks man. Good eye. Yes, there should be (and there is on my amp) a connection from the CF plates to pin 6 of the first power tube. I'll revise when I get a moment.

[Dr d]

Once again, great work! Looking at the layout I can't see a grid stopper on V1b or a 220k to ground off pin7 V2b reverb return. Is this as you built it? Also, do you mind me asking which reverb tank you used? Very interesting thread. Thanks.

[ATL Strat]

Cool!

[mhartman]

Once again, great work! Looking at the layout I can't see a grid stopper on V1b or a 220k to ground off pin7 V2b reverb return. Is this as you built it? Also, do you mind me asking which reverb tank you used? Very interesting thread. Thanks.

Thanks D. On the reverb return, yes there should be a 220k to ground from the reverb return jack signal to ground. I did this at the RCA jack, not the tube socket. I'll get this updated on the layout. I'm using a Fender Twin Reverb style tank currently. I may upgrade to a 3 spring tank though. Any Fender style tank should be fine.

Regarding the grid stopper on V1b, I did a lot of alligator clipping to experiment here. I tried 220k, 220K/470pf, 68k and no grid stopper (like the SSS02 original schem). None of the combinations were bad, but I went with no grid stopper for maximum clarity/openness. I'm not experiencing any problems without the grid stopper in place. I have seen some SSS clones using an unbypassed 220k here (but I don't know if those clones were based on original circuits).

[edit] I will note that it is obvious from the SSS01 pic that SSS01 has a 68k grid stopper of V1b. SSS02 does not appear to have a grid stopper on V1b (based on the hand written schem and the picture (which is too fuzzy to be conclusive).

[Dr d]

Thanks......that is great info. Another question!! How do you think this amp differs from your previous project which sounded wonderful as well?

[mhartman]

Thanks......that is great info. Another question!! How do you think this amp differs from your previous project which sounded wonderful as well?

Thank you. They are similar amps in layout, but are very different due to voltages, filtering, negative feedback levels, etc. the JM style amp is "looser", "browner" and "friendlier". The SSS is brutally honest...and much more like tapping into a hifi amp. I'm not sure if that makes sense, but those are my initial impressions.

BTW, I added some info to my post above about the V1b grid stopper.

[Dr d]

Thats an interesting comparison....thank you!

[Max]

I'm not sure how close I am

There are many different versions of original SSS amps with many different voices. I've attached a clip IMO demonstrating - at least to some extent - why "singer" is a part of the name.

but I am happy with the sound

And isn't exactly this what building musical instruments for personal use is all about?

Have Fun!

Cheers,

Max

[mhartman]

Thank you Max! I have read and re-read all of your posts regarding the SSS amps (and the big Dumble amps in the same "family"). I really appreciate your contributions. That clip is the one that I've using as a benchmark as I tweak the components/configuration in my amp. In doing so, I've realized that I have neither Dumble's skills nor LC's chops, but I'm having fun with it!

[mhartman]

For anyone following this one who might be interested, here's a short sound clip at medium volume. This is the amp as it exists based on the layout that I updated yesterday (in the first post). Again, please excuse the poor playing and recording -- I wish that there was some easy way to capture the actual sound/feel of the amp (but I guess that would put recording engineers out of business)!

[fltundra]

For anyone following this one who might be interested, here's a short sound clip at medium volume. This is the amp as it exists based on the layout that I updated yesterday (in the first post). Again, please excuse the poor playing and recording -- I wish that there was some easy way to capture the actual sound/feel of the amp (but I guess that would put recording engineers out of business)!

Very nice!

[Colossal]

For anyone following this one who might be interested, here's a short sound clip at medium volume.

Sounds great! Very SRVish! Very clear, articulate, and bouncy, but so smooth!

I wish that there was some easy way to capture the actual sound/feel of the amp (but I guess that would put recording engineers out of business)!

The economy has already seen to that.

[M Fowler]

Don't know how I missed this thread, great job

[David Root]

I missed it because I was in hospital when it started. mhartman we all owe you for this one, thank you!!

Last year I built an SSS off Bill Dunham's 004 schematic, which turned out to be 001 instead. Left out the reverb and crammed the rest into one of Allyn's Trainwreck chassis.

I didn't finish the filters because I've had continuing health problems the last 9 months, but did use the proper direct bias from driver cathodes, which as you observed is what makes the SSS what it is. I believe this is because that biasing method forces the amp to operate in class AB2, although I don't recall why. That accounts for how loud these beasts can be and the phenomenally defined and extended bass. I used a 12BZ7 driver.

So now I must get off my butt and clean this one up!!