high gain lee jackson gp 1000

[Jana]

So far, so good.

There are way too many gain stages on the last filter node. At a minimum, I would put both sections of V1 on a new, filtered node of the B+.

[Gorhrut]

[img2478]http://i.imgur.com/UXYLtKe.jpg[/img]


initial mock up of the last schematic i posted. not all connections shown and some things not totally in place(tubes, pots)

how'd i do for my first ever layout?

[billyz]

You can start doing mine

[Cameron]

[img2176]http://i.imgur.com/KN9oPrz.jpg[/img]


is this looking better?


i had the two masters on there because they were on the original. not really needed. stereo was the big buzz word at the time so lee jackson did this setup to sell it off as stereo amp

There you go... much better. Ill see if I can find some of my old schematic and notes. There are a few small things missing but it is basically there.

[Cameron]

Oh forget what I said about distoetion being on first tube, it is on the second, but need to open my 88 to draw a new schematic, turns out the one I had for GPSP is wrong too. No wonder it's noisy when parts are totally messed up. Most of the resistors are messed up on the tubestages or simply not added at all. This schematic sucks, written by german amatures and my famous by that Jon Woodworm guy from Bodom forum.

Want proof, okay then tell me where R200,201 and why R207 is an ouput resistor and nowhere near the distortion then. I believe R202 should be connected to distortion, but I only got these old unclear pics to study at the moment.....

You're saying the distortion/OD/P2 is between the 3rd and 4th stages?

R200,201 are virtual center taps for the heater winding, if that is indeed the case and have nothing to do with the signal path. However, they could be grounded anywhere, and this may provided clues. Wherever they meet, this a ground point. Can you tell where they are grounded?

These resistors are around the tube sockets.

[Cameron]

Also..... go look at the Fender Concert II amp ....a lot of answers there.

[Rune]

Ah I see them thanks for clarifying that. Anyways R17 is not connected to C4, it goes to ground and master(s). And no distortion is till not connected to R207. It's either R202/R203/R204...

[Cameron]

Ah I see them thanks for clarifying that. Anyways R17 is not connected to C4, it goes to ground and master(s). And no distortion is till not connected to R207. It's either R202/R203/R204...

Again... go look at the Concert amp then add the last gain stage that the Concert doesn't have ...thats it ...your done......it will also show you how the distortion gain pot is wired up. Its the 3m pot..If I remember right its a 1m in the preamp. If you are not going to put the clean in...use the 3m ...it will give you more range to get a cleaner sound..if you want that.

[Gorhrut]

[img2178]http://i.imgur.com/4emOa17.jpg[/img]

how's this if i decide to have it switchable again? i dont understand why the relay was there in the first place....

so if i understand this correctly, when pushed in, this removes v2a+b from the circuit and goes straight to v3a+b.

when pulled, this brings v2a+b in to the circuit.

is this correct?

[Cameron]

I just did this so you can see what I'm saying about the Concert.

[Cameron]

[img2178]http://i.imgur.com/4emOa17.jpg[/img]

how's this if i decide to have it switchable again? i dont understand why the relay was there in the first place....

so if i understand this correctly, when pushed in, this removes v2a+b from the circuit and goes straight to v3a+b.

when pulled, this brings v2a+b in to the circuit.

is this correct?

Go look at the Dumble schematics to get a clear idea of how the switching works .....its kind of the same...switching out the last two gain stages....but yes that looks right.

[Gorhrut]

so that schematic of the concert would be straight OD right? no switching to clean?

[Gorhrut]

i discovered part of what was confusing me there. r17 does not attach to p100 it definitely goes to ground.

so, p100 basically is a volume control into the next stage?

[Cameron]

so that schematic of the concert would be straight OD right? no switching to clean?

Yes.
I would add the separate clean channel if you are building it.

[Cameron]

i discovered part of what was confusing me there. r17 does not attach to p100 it definitely goes to ground.

so, p100 basically is a volume control into the next stage?

Again the Concert has the answers.
P100 would be your master for the gain channel ...P100 is also the trimpot on the circuit board or sometimes added to the back. The master before the buffer is the preamp output level.