Randall preamp schematic added in my site

[Marcos - Munky]

Take a look, it's very interesting. I made a layout for it, but after finish it and start to draw it in my PC, I noticed that I used the wrong pinout, so I need to redraw it. It will be in my site later.

[space_ryerson]

Looks great! Let me know how it goes when you build it.

[space_ryerson]

Edit: ack! double post demon.

[rubberlips]

what the addresss??

[Marcos - Munky]

Click in"My site" in my signature.

[John G]

Marcos, I have a hand drawn schem of the GA 80 and is almost identical. It uses the same circuit topology as the all valve schem in the Pittman book (If you can read it) They just scaled down the voltages and component values to suit the FETs. The pre amp voltage on the GA 80 was derived of the +40 volt rail and was 30v. I have the schem of the clean(er) ch if you want it. Also the power amp. The reverb schem I didn't get.
John G

[Marcos - Munky]

The schematic that I have is for the complete RG80 and RG100 (preamp, reverb and power amp). If you are interested in it, do a search for a topic where I asked for Randall schematics (a week ago), there's a link for the schematic.

[Johan]

I think you have an error in your schematic...the last stage. it's drawn so the output is taken from the powersupply ( ? ). should be from the resistorside of that FET instead, I believe..other  than that, great work..

Johan

[Rob Strand]

I thought the clipping diodes across the FET output looked a little odd too (but they still could be OK) - do they go on the other side of the 10k?

[Marcos - Munky]

Thanks, Johan. I corrected the error. About the clipping diodes, they're OK. I just drew them different to the amp schematic, but is the same connection.