SSS - Nukular Warhead - Chassis are Finished

[txbluesboy]

Hey blindog, I am using an AX7 in the LTP inverter and an AT7 in the cathode follower. I have one of the London Power ' Raw Bias Auxillary supply ' boards on my build for the bias supply since the PT I used didn't have bias taps. I believe my max bias voltage is around -60 volts. For the plate voltage on the cathode followers I added a 1K resistor to the dropping string after the screen node. For my preamp I used the ODS-101 non HRM with 100K plates and skyline EQ. Im still loving it by the way. Dr who asked if it could sing and get dirty, I can't really answer this yet as I'm still messing with the settings on the OD section. My feeling so far is that it can sing but I don't know just how dirty it will get. It has really nice single note seperation even when in overdrive.

[dr. who]

I wonder what all is in common with the 150w ODS and the 150w SSS.

[txbluesboy]

Maybe just use overdrive tube for reverb and add filters?

[Blindog]

Hey blindog, I am using an AX7 in the LTP inverter and an AT7 in the cathode follower. I have one of the London Power ' Raw Bias Auxillary supply ' boards on my build for the bias supply since the PT I used didn't have bias taps. I believe my max bias voltage is around -60 volts. For the plate voltage on the cathode followers I added a 1K resistor to the dropping string after the screen node. For my preamp I used the ODS-101 non HRM with 100K plates and skyline EQ. Im still loving it by the way. Dr who asked if it could sing and get dirty, I can't really answer this yet as I'm still messing with the settings on the OD section. My feeling so far is that it can sing but I don't know just how dirty it will get. It has really nice single note seperation even when in overdrive.

Thanks for the info. My build is going in this KMD chassis. It's already got a 4X6550 output section, and I'm having Ken Watts build me a generic turret/eyelet board that will match the old preamp pc board spacing. I'll mount the tube sockets to the board.. I'm piecing together my schematic, and I pretty much have it fleshed out, just need to do the step filters. I'll try and put it up when I get done. I'm more or less sticking to the same layout as yours with no od and adding reverb.

MArk

[txbluesboy]

Looks like a great project, good luck!! I think my high filter scheme is pretty close, still working on the low filter however.
Terry

[thyx]

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

That's pretty close to what I've got...I used a diff value for the grid stopper on V1b and 100k/1.5k for plate/cathode resistors on both stages...no bypass cap on the bass control.

[txbluesboy]

I also used 100K plates and 1.5K cathode resistors. I just mentioned this in a PM but think I'll mention it here too. When Funk was more talkative about the SSS he described a Fender Twin conversion to SSS styling as "Use a low plate skyline clean section into an AB 763 reverb, ditch the tremelo and use that socket for the PI. Use the PI socket for an Ampeg style driver section".

[txbluesboy]

Also RJ, it looks like you have got one of the 22 meg resistors shorted out on V2b's feedback loop.

[RJ Guitars]

Also RJ, it looks like you have got one of the 22 meg resistors shorted out on V2b's feedback loop.

Yup - I sure did. It's fixed now, thanks Terry!

[mauiboy81]

Hey Guys, nice builds!

So what exactly does the ampeg style driver do? I can guess but it would be great to know for sure.

How much different would the amp be without the driver?

Thanks

Nick

[dave g]

When the output tubes are driven hard, they can draw enough grid current to introduce a fair amount of distortion in the PI. The Ampeg driver circuit reduces this distortion by acting as a buffer between the PI and output tubes, providing all the needed grid current without loading down the PI.

I think it contributes fairly heavily to the sound of the SSS.

[dr. who]

Thanks for the info Dave...Does anyone know if the SSS is exactly like the ampeg or have some changes to values been made to the PI?

[Roe]

If you guys can settle on a SSS type circuit (and layout) that works well, I'm temped to build one

[txbluesboy]

If we can settle on one that everyone agrees is correct, I'll build another one myself, however I was to impatient to wait for that. I really like the way my first effort turned out though!

[RJ Guitars]

Hey Guys,

I created a block diagram showing how I see the SSS pieces... this is based on discussions here on the AGF and the limited amount of info that I've collected on this amp. If anyone knows what I need to modify to make this more accurate, I'd be appreciative to if you'd share with us.

Once I have an accurate block diagram I'll use that to create a schematic.

Thanks in advance for your kind and helpful comments.

rj