Dumbleland update (was SSS) :D

[Runaway J]

Is a layout or schematic of ODR #17 available?
I'd be very interested.
Thanks.

[tomrasdf]

Oops! I mean # 13. In the file section.

[dr. who]

It was confirmed to me by someone who serviced a TR sterling recently, that the filters are placed between the volume and master. The hi filter is placed directly after the volume before re-entering the other half of the tube. He was very friendly until I asked him where the lo filter was placed; either before the tube or after, and he told me that he wasn't going to just give me all of the information to "copy-cat" the amp, so he said that I'll just have to figure it out by myself. There are only two places that the lo-filter could be located, either directly after the hi-filter, or directly before the master volume pot. I imagine that they are setup like a tonestack.
Hope this helps guys.

-to get this information I had to contact an owner of a TR sterling and ask who they used to service their amp, only mildly alluding to own one and contacted the tech and played dumb asking what the filters do. He was nice until he percieved that I was asing too specific of information. At least I got us a lot closer to knowing how the filters act and where they are placed.

[dr. who]

I would like to know if the sss had the same type of reverb as the odsr- Andy Fuchs said that the odsr had-
"a reverb driver, a reverb return amp, and a reverb/dry mix amp circuit"

[dr. who]

Any news?

[dr. who]

Sweet IC is on the case with me...
http://ampgarage.com/forum/download/file.php?id=7885

[Max]

I would like to know if the sss had the same type of reverb as the odsr- Andy Fuchs said that the odsr had-
"a reverb driver, a reverb return amp, and a reverb/dry mix amp circuit"

Hi Dr. Who,

as far as I remember the reverb circuit in the SSS is not the same one as in the odsr.

All the best

Max

[Roe]

The ones I have seen are around 500 on the plates, high 490's on the screens.

Depends on the SSS Some have twin Iron, some have Ampeg Iron, Some have Sunn/Dynaco Iron.

if the SSS does not use ultralinear taps, but run 500v into a 2k OT (ala Twin or SVT) doesn't this mean that its a 100w amp rather than a 150w amp?

[thyx]

if the SSS does not use ultralinear taps, but run 500v into a 2k OT (ala Twin or SVT) doesn't this mean that its a 100w amp rather than a 150w amp?

Depends on the output tubes. 6L6 SSS amps will be closer to 100W...6550 SSS amps will be closer to 150W. If the OT trannies chosen have the proper impedences and current capability for the voltage and tubes as used, they aren't going to be the determining factor for power output. Most SSS amps are the 6550 type...only a few early ones used the 6L6.

[Roe]

if the SSS does not use ultralinear taps, but run 500v into a 2k OT (ala Twin or SVT) doesn't this mean that its a 100w amp rather than a 150w amp?

Depends on the output tubes. 6L6 SSS amps will be closer to 100W...6550 SSS amps will be closer to 150W. If the OT trannies chosen have the proper impedences and current capability for the voltage and tubes as used, they aren't going to be the determining factor for power output. Most SSS amps are the 6550 type...only a few early ones used the 6L6.

well, going from 6l6GCs to 6550s is not going to give 50w extra with 500v and a 2k Z. perhaps it will give 20w, but not 50w.

[David Root]

HAD's 150W 4x6550 SSSs have been measured at 137W clean output. KT88s might do a little better?

[paulster]

Does anybody know (and is prepared to divulge) which output transformers were used in the 4x6550 SSS amps? I've got a non-SSS build in mind that I'd like to use a quad of 6550s in the output stage so I'm interested to know what off-the-shelf transformers that will be happy at 150W are available to use as an experimentation starting point.

[David Root]

This new Triad transformer archive www.triadtransformers.com is proving very useful. I was in it trying to figure out which PT HAD would have used, and in the 79/80 catalog, page 12, under combined plate & filament I find model R-25A, 400-0-400, 500 mA DC, 6.3V 8A, 5V 6 A, weight 19 lbs.

Look at the PT in Dumbleland #009, below. No doubt he used the same one in his 6550 SSS.

Above it is the OT from the same amp. Schumacher 606108, probably '71 or '81. Anyone recognize the 28-1312 part no. above the EIA code?

[Max]

No doubt he used the same one in his 6550 SSS.

Hi David,

so you doubt what Brandon posted here: http://ampgarage.com/forum/viewtopic.php?p=56161#56161 ?

Cheers,

Max

[Roe]

what's the specs of the Schumacher 606108?