This may be a bit of a long shot.

[Lee Unit]

as the title says, it probably is / will be. me and a guy i work with were thinking of making a gp-1000 as he has a hell of alot of expirience with electronics and wanted a Gp-1000 years and years ago as a kid, i was just wondering if anyone has any schematics or any other information regarding the circuit boards and components what so ever could you post them or let me know.
Thanks.

 

[Ben Johnson]

I just so happen to have some pics that might be helpful. I've never been able to find a schematic - I even bought Lee Jackson's Ultimate Bench Warrior book (Jackson said he would include a GP-1000 schematic in it...but it's not in there).

http://dl.dropbox.com/u/324863/GP1000.JPG

http://dl.dropbox.com/u/324863/GP1000_PCB_underside.JPG

You will have trouble making a clone without either a schematic or an actual GP-1000 to measure voltages with.

 

[predator2353]

Ahahaha.. it's all good that you show the board, but what about the elements ?

 

[johnnytophat]

Do you have a top view? or any other information about components?

 

[Ben Johnson]

Didn't notice I had two links to the same pic (re-check my post).

As far as components, the resistor values are obvious (color coded). Everything else not so much, as most of those parts will be obsolete nowadays. There are probably substitutions available, but as I said before, you won't have much luck without a schematic, or an original unit to make measurements with.

Also, FYI - the output transformers were custom made, so you won't likely find any off-the-shelf substitutes for that, unless your friend is able to wind one by hand. That's the main reason why I gave up on the idea of doing a clone (that, and I couldn't find a good 6-way rotary switch like the original).

It's a ton of work just sourcing the parts, and at the end of the day, you're better off finding a GP-1000 on ebay.

 

[johnnytophat]

There is no output transformer, just the torroidal power transformer, which can be substituted with a normal one. No OP TX because the output goes to a power amp normally. My idea has been for a while to put a GP-1000 in head form with a jcm-800 style power stage behind it. Been looking for schematics, waiting for Lee's book to come out, asked him about the GP-1000 II, still nothing so far. Reverse engineering may not be so hard, main problem I see is getting tone cap values right...

 

[Ben Johnson]

Sorry, I meant torroidal.

If you want to build a head, you can find the Metaltronix M1000 schematic here:

http://www.metaltronix.net/metaltronix-schematics.htm

The preamp section is supposed to be very similar to the GP-1000.

Whatever you end up doing, I'd love to hear about it.

 

[predator2353]

Reverse engineering at this case is difficult. If I don't have the circut diagram with the right elements then it's pretty fucked up to guess what they are. You coud only guess. That's the problem.

Sorry, I meant torroidal.

If you want to build a head, you can find the Metaltronix M1000 schematic here:

http://www.metaltronix.net/metaltronix-schematics.htm

The preamp section is supposed to be very similar to the GP-1000.

Whatever you end up doing, I'd love to hear about it.

Thank you

 

[Lee Unit]

Thanks for the picture, is the gp-1000 actually yours?