New ReleaSSSes

[passfan]

I have the owners blessing so here are the rest of the pics.

[passfan]

If he wants to take credit for sharing he can. I can only post 5 at a time as they are high res.

[passfan]

And the next group.

[passfan]

ditto

[passfan]

ditto

[passfan]

And ditto

[passfan]

And the last group. Guys this is about as good as I get. It would take me forever to scheme out by looking at pictures with my dyslexic self. I think most here are after a new design and not necessarily looking to clone Nick's version, which does not have the CF after the PI. We should be able to get it done now. If not, then maybe never.

[David Root]

Thanx passfan, good to have all that detail in hi-res. I will look those over more carefully later tonite!

Tom, the Surgistor has a different name these days. Yes it's a thermistor, but GE calls them inrush current limiters now. For once that seems like truth in advertizing.

I'm using the CL-70 on my SSS build. I did that because I originally had a toroidal PT, which has a much higher inrush current than an EI design, so I figured I should have it in there. See attachment.

10thtx, thanx again for rev. 4!

[Max]

Looks like a 250K mid pot and 500K bass pot, which differs from both SSS schematics recently posted here.

Just to avoid confusion:

The SSS schematic showing some ODS and ODR "modules" posted in this thread as being the schematic of SSS #004 and showing a "250K mid pot and 500K bass pot" calls its tonestack-module a "2gen classic tonestack" .

IMO this is contradictional:

The tonestack, which is usually called the "classic" tonestack here, and that's found in the transition generation and 4th generation ODS amps, is the one shown in this layout: http://ampgarage.com/forum/viewtopic.php?t=12872.

But the tonestack of a 2nd generation ODS amp, which I once proposed to call the "pre-classic" tonestack, is the one shown in this layout: http://ampgarage.com/forum/viewtopic.php?t=12870

Driver tube of SSS #001:

AFAIK Alexander Dumble usually specified a 7025 phase inverter and a 7025 driver for the 100W SSSs with such a phase inverter / driver configuration. But of course #001 might be an exception. As you'll know, you'll find a 12AU7 / 12BH7 configuration in some of his 100W amps, too (Odyssey e.g.) The tubes Alexander Dumble specified for (at least most of) 70ies and early eighties amps will usually be written (engraved) on the amp chassis.

Cheers,

Max

[10thTx]

I think the LNFB from V2A to V1B and from V1B to V1A should both originate from the plate, rather than from the grid, on V2A, and out of nowhere, from V1B

IF this is regarding the #002, I am going to need some help here, please. I am having trouble envisioning this. Even a hand drawn correction would be useful & I can edit the SCH version again for #5 revision.

No problems with the bias supply I came up with though. I used a 20mA 120VAC source, a BR34 bridge rectifier and a 47uF 250V cap on the raw driver cathode bias and another 47uF 100V on the driver grid bias. I inserted a 56K resistor ahead of the standard HAD 10K bias pot/22K tail and get minus 175 to 180V raw bias. With 310V on the driver plates I get minus 44.3V on the cathodes and minus 45.8V on the driver grids.

I am presuming this is for the "reported" #004, and that I should leave the #002 as is currently? Can you confirm this as correct, please?

Since we now have two SSS type schematics, maybe it would be helpful to reference which one we're refering to. I will try to help with #002 only.


With respect, 10thtx

[David Root]

Since #001 is now published, admittedly with a few kinks to it, here's my contribution to the overall discussion. Remember this layout does NOT include the reverb or tremelo from the original.

This is obviously not the "proper" HAD-approved layout with multiple over the tube socket boards. I didn't have room for that in this chassis, which is one of Allyn's "Gromet 60" chassis.

So I simply inserted the LNFB and inductor components into an ODS layout and added the driver bias supply on the end of the board, which was something of a cosmic happenstance in that the board was exactly long enough!

[David Root]

10thtx, sorry for muddying the waters.

My comment about the LNFB refers to the #001 schematic, which I had previously thought was #004, and not to the #002 hand sketches.

Yes you are right about my bias comment, it also refers to #001 which I had thought was #004.

[David Root]

Thanx again Max, I am sure you are right about 7025 drivers and phase inverters on these 100W amps.

Is this chassis #001? This pic has been around for a while I think. It's a high contrast lo-definition pic and the tube stamped names are real hard to read. I'm not sure it is #001 but with the reverb, CF mixers and tremelo I think #001 must have had eight pre tubes. This one looks like it might have eight noval tubes though.

The bottom four look like 12AX7A, the upper four, left to right, 7025, 7247 (?), 6267, 6267. If I read the last two right they are EF86s!

[LeftyStrat]

Thanx again Max, I am sure you are right about 7025 drivers and phase inverters on these 100W amps.

Is this chassis #001? This pic has been around for a while I think. It's a high contrast lo-definition pic and the tube stamped names are real hard to read. I'm not sure it is #001 but with the reverb, CF mixers and tremelo I think #001 must have had eight pre tubes. This one looks like it might have eight noval tubes though.

The bottom four look like 12AX7A, the upper four, left to right, 7025, 7247 (?), 6267, 6267. If I read the last two right they are EF86s!

This definitely looks like the master chassis. Perhaps different models were built on this same chassis.

The gut shot that I tried to enhance would certainly fit this chassis.

[David Root]

Reason I think this is a 100W model is because of the small size of the OT.