Hiwatt CS-30

[passfan]

If you need the schematic for the studio stage i have it.

PM sent James, thanks.

[KT66]

The poster at the vintage amp forum sent me the PDF of the schem that was posted earlier .

[passfan]

The poster at the vintage amp forum sent me the PDF of the schem that was posted earlier .

Many thanks Ryan. The voltages will help immensely.

[passfan]

IT'S ALIVE !!!!!

Just as I remembered it from years ago. I changed the screen grid resistors to 1K. I got tired of seeing the screens glow brighter with every note and quite frankly the extra fizz it created is just not needed with this circuit. I plugged a 12ay7 in V1 just to calm it down a tad and was forced to use a couple of .022's in the stack as I am out of .047's. She also cleans up quite well with the guitar volume without losing much volume , which is a plus in my book. I have some small buzzing issues but some of that is fluorescent lighting and I used some older stock multicaps which may be acting up. These things will not be a problem in a permanent build. Right now it's a point to point mess but oh what a sound. This would be a great bedroom amp for those who love searing leads up high on the neck. Got to go play.

[passfan]

Here is some porn for those who like to peep. I changed back to a 12ax7 on the input as the ay got too fizzy. Went to old stock GE longplates and it made a pleasant difference. I now have my control settings marked.

[passfan]

Changed the tone stack to the traditional Hiwatt stack after discovering that is how the lead 30 was set up. Saw it in some online picks of the Lead 30 guts. I have to admit the amp came to life and the tone response is tons better.

[passfan]

If you need the schematic for the studio stage i have it.

I'd like to take you up on that James. It would be good to see how they're doing it now. passfan1@verizon.net

[andrew]

James, could I have a look also? Thanks. dwmclemore@knology.net

[2651amp]

Was it confirmed that this is the lead 20?
I originally posted the amp schematic.
If anyone would like more info on the amp
let me know.
The pcb version has a lot of problems.

[passfan]

Was it confirmed that this is the lead 20?
I originally posted the amp schematic.
If anyone would like more info on the amp
let me know.
The pcb version has a lot of problems.

Here is a link to the culmination of my efforts.
http://ampgarage.com/forum/viewtopic.ph ... highlight=

[passfan]

Finally acquired a combo version of this amp and I’m currently restoring it. Here is the traced layout and values so far in case anyone needs them.

[andrew]

Great work passfan and thanks for sharing!

[passfan]

So , continuing my documentation I discovered a couple of errors. In drawing out the circuit I realized it is almost a perfect match for the 80’s “lead” preamp at the mhuss site. Instead of the dual input go to a single one with no grid and couple it to the gain pot with a 1n cap. 220k on the plate and 1.5k cathode bypassed with 150uf. A couple of slightly different values for feedback through the presence which I will note when I finish the complete schematic.
I do plan to use my select choice for when I rebuild the circuit. 1watt resistors and mustards along with lead dressing and different grids on the output tubes. Also 1ohms to ground on the cathodes and a bias pot as well for the output and a vvr for the whole amp. I love these things wide open.

[passfan]

Here is my handrawn schematic