SSS with OD/FET/Filters

[valveandsound]

Hello all,

Several months ago, I got curious and drafted together a schemo for a somewhat ambitious design:

SSS derived, with the post cathode voltage driver based on Martin Mannings ideas (thanks Martin!)

Also, tweaked High and low filters as per Martin Manning.

Preamp is similar to JM Sig amp with low plate OD setup.

Ive never been super happy with the Dumble FET preamp - But i do love the Echoplex EP3 one, which is somewhat similar. So i will use it in it's place.


The biggest thing im not 100% sure of is the negative voltage driver and bias setup for the Post PI cathode follower. Any eagle eyed viewers please let me know if there is a glaringly terrible error in the schemo. I'd like to hammer out the details and put together a layout.

[martin manning]

Looks like you have drawn the bipolar CF driver power supply and bias balance circuit I posted here: https://ampgarage.com/forum/viewtopic.p ... 882&hilit=
Looks right to me. The bipolar supply has been used a couple of times by others; not sure if anyone has built the bias-balance. I have validated it with a sim, though, so it should be fine.

Looks like a great project!

[Mr. dB]

This is the "all of the above" model. Everything and kitchen sink. Soup and salad.

[beasleybodyshop]

Thanks for weighing in Martin! I know there is some little details like how the filters are going to sound in OD mode, but good to know I've got the post PI driver down pat.

Regarding the filters, I've decided that I will likely have a bypass switch/relay, might set it up so that the filters dis-engage when OD mode is switched in.

Also going to use DC heaters on the first 2 tubes.

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[dreric]

I've built Martin's driver and the standard Dumble driver. I like Martin's better.

Impressive project, Are you planning on doing a layout?

Eric

[beasleybodyshop]

Eventually Eric. It's going to be a pretty epic task but should be fun.

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[Guy77]

I am also interested in seeing how this turns out for you!
Excited to see your findings and results.

Cheers

Guy