SSS - Nukular Warhead - Chassis are Finished

[txbluesboy]

I like the sound of the overdrive much better than the HRM clone I built.
The high filter is somewhat effective in that it will remove the icepicky highs but so far I can't hear any effect from the low filter, Ill probably play with some different values on these. It would probably help if I had some idea of what they are supposed to do!

[RJ Guitars]

Terry,

Very sweet work... you are a real pioneer. Congrats on getting it to this point, I'll be weeks if not months behind you.

I'm sure there is a lot to be learned from your work.

rj

[txbluesboy]

Thanks RJ, What is the vertical dimension on that head cabinet you had made?
Terry

[RJ Guitars]

Thanks RJ, What is the vertical dimension on that head cabinet you had made?
Terry

Terry, I'm away from the shop until next Wednesday and I don't have that drawing with me so we'll have to guess from the picture. Maybe Wawa will give us that dimension, he has that cabinet now.

The chassis is 26 inches long x 2.75 inches tall, so you can scale it and get pretty close. I know I made lots of room for tube clearance since 6550's might be an option, plus I added another inch and a half for the reverb tank. The wood is 5/8" thick Baltic Birch.

I'll start the guessing at 11.5 inches outside from top to bottom.

rj

[wawa]

The height of the cabinet with out feet is 11" and about 11.-3/4"" with the feet. length 27.5" , width 10"

[txbluesboy]

Thanks wawa!

[dr. who]

I am curious to how the SSS pi sounds with the OD. Does it sing and get dirty?

[RJ Guitars]

I've been working through my SSS schematic and layout creation process and I found this note in my archives:

The preamp is like the clean preamp of an Overdrive Special, with very similar tone circuitry. Some models use two EF86 pentodes (the first one configured as a triode) rather than a single 12AX7. The reverb topology is similar to that used in the Overdrive Reverb, with separate Send and Return controls. Some models have a tremolo with rate and modulation controls. Little information has surfaced about the high and low filter controls used on some models. The power amp uses a long-tailed pair phase inverter. Four 6550 tubes are driven by a 12BH7 operating as a direct-coupled cathode follower.

Does anybody recognize this? I'd like to give credit to the source and also verify that it's good info. Can anybody help out?

Thanks,

rj

[talbany]

ElectronAvalanche



Tony VVT

[Blindog]

The power amp uses a long-tailed pair phase inverter. Four 6550 tubes are driven by a 12BH7 operating as a direct-coupled cathode follower.
rj

Has anyone seen a schematic or could explain how to use the Ampeg CF circuit with just one 12BH7? Everything I've seen uses 2 12BH7's for the driver (SVT/V9) If that's ElectronAvalanch's quote, maybe he might chime in

Also, doesn't that arangement require a stout bias supply?

Mark

[briane]

Some models use two EF86 pentodes

I recall that was the silver alligator.

[thyx]

The power amp uses a long-tailed pair phase inverter. Four 6550 tubes are driven by a 12BH7 operating as a direct-coupled cathode follower.
rj

Has anyone seen a schematic or could explain how to use the Ampeg CF circuit with just one 12BH7? Everything I've seen uses 2 12BH7's for the driver (SVT/V9) If that's ElectronAvalanch's quote, maybe he might chime in

Also, doesn't that arangement require a stout bias supply?

Mark

I think the BH7 is used in the Ampeg...a 12AX7 is used in the SSS, which is why only a single tube is mentioned. I believe EA may have been thinking 12AX7, but wrote 12BH7 on accident. It's possible the SSS may also use a 5751 somewhere in the circuit, as well as some other tube substitutions in place of the standard 12AX7s. I think each SSS was a little different from the others.

[txbluesboy]

As far as I could figure, in the SVT there were two BH7s because there is an additional gain stage between the inverter ( Paraphase I think ) and the cathode follower stage. When you use a long tail pair inverter this extra gain stage is not needed.

[Blindog]

As far as I could figure, in the SVT there were two BH7s because there is an additional gain stage between the inverter ( Paraphase I think ) and the cathode follower stage. When you use a long tail pair inverter this extra gain stage is not needed.

Thanks for that explanation, it makes sense to me now. I don't no why I didn't see it...that svt schematic is a bit overwhelming though
Did you use a 12AX7 in your build? Also, what was your bias supply voltage?

Thanks,

Mark

[RJ Guitars]

I've created a first draft preamp schematic based on that note I put up earlier, apparently info given by Electron Avalanche. Thank you.

This schematic is nothing very original and uses the stock D-Lite values... thank you Norm/Brownnote for that work as well. I certainly expect tweaks to follow but I think the stock D'Lite values seem to be a great starting place for good tone.

The schematic is based upon a somewhat educated guess and placed up there for review... no statement of "This is how the SSS looks" is intended.

Thanks,

rj