high gain lee jackson gp 1000

[Gorhrut]

just found out i do still have radio stations coming thru. squealing is gone for sure tho, so thats good.

its no longer coming in when i touch the volume pot shaft, thats why i missed it.

happens when i touch the shaft of treble pot (pulled/or pushed in) and the mid shift pot shaft. all others are fine.

when i touch either pot shaft with one hand and then touch the chassis it goes away. if i put my whole hand on the chassis this thing is dead silent but the more i take off, the more rf comes back.

this makes me think grounding issues. how bout u guys?

[Rune]

So did everything you did, Gorhrut. And still noise...
Tested another set of tubes. Sovtek and they caused Squeeling that wasn't there with Groove Tubes??? And still the noise. Grounding issue then?
Could rule out guitars, I've tested 5 different guitars on the amp, most of them with different pickups and setup. Still the same.... Could it be that it is a power issue too?

[Cameron]

now that mods are done i tried the same test and squealing is gone. tried everything to recreate the squeal but couldnt do it. (guess thats a good sign) and no radio stations. only thing is a moderately loud hum that was there before. i didnt use shielded cable cuz i didnt have any on hand but ill switch it out when i do and see if that helps.

Congrats man! Great job. My guess is that (some of the) hum is coming from the heaters. This can be addressed with lead dress of said wires. On page 4, Rune posted some gut shots, they're the brown twisted together ones on the tube sockets. If yours look like this, they could be tidied up a bit for sure! Not saying that's a guarantee, but it certainly wouldn't hurt.

For the plate resistor....... put one end of the resistor on the socket...run a wire to the resistor from the circuit board....this wire does not need to be shielded...
When you get some shielded wire ...you should be able to get it sounding better.

Um, you may want to exercise a little caution if you do this one... This is the B+ supply, and I'm not sure how fast the pre discharges its voltage after power down. Just be mindful that there may be some residual juice there, check with a multimeter (DC) to confirm.

Also, if you hang a resistor off the socket, and connect a wire from the other side of the resistor to where the supply comes off the board, it'd be in your best interest to cover this exposed area of wire with heat shrink. (Hell, some black tape will do, temporarily.) You don't want to accidentally touch it when the amp is on, and you don't want it touching anything like the chassis or other components when it's live, either.

Cameron, that clip sounded not too bad at all!

It will happen at some point I've gotton shocked enough to not even flinch when I do now...... I think Gorhrut knows that stuff....Rune ...he might get shocked

All this is to get it working and find out the problems these guys are having..... of coerce ...once the circuit is fixed .. it will get cleaned up before the preamp is put back together and used.

Its just a waist to use heat shrink when you are just trying to find where a problem is......Just watch you're self ....if thats where it stays.....then of coerce ...you would put heat shrink.

It really wont help the hum to clean up the filament wires..... go read this... the part on DC bias on heater wires
http://www.rru.com/~meo/Guitar/Amps/Kal ... s/hum.html
Doing that should get rid of the hum. You can't make an amp that runs on the tubes we have these days...without doing this.

[Rune]

Did you listen to the clip I posted Cameron? Heard any noise like that before?

[Cameron]

Thanks for sharing, Mark. The other day I hacked the Lee Pre in an ODS type, and it was just kinda ok. Concerning your Deluxe, it looks like you split the plate load on the 3rd stage for the purpose of snubbing the B+ side, but took the coupler off the plate? Also, is that a small ceramic across the bias feeds?? I'm gonna give this one a shot. Dig the clip.

Yes I left some stuff as it was so...the last tube has its own b+ supply..V2 A&B. The coupling cap is there on the last stage ..its like the schematic.
The 39pf in the bias ..was in there already ...I don't think it would make difference..in or out...its just left over from previous madness.

[Cameron]

Did you listen to the clip I posted Cameron? Heard any noise like that before?

I don't here a noise ?? Is it the low end you are talking about?? or is it in the hi end ... describe it.

[Rune]

It is the low end trail. Like a little buzzy/scratchy delay. Very annoying.

[Meat&Beer]

It will happen at some point I've gotton shocked enough to not even flinch when I do now...... I think Gorhrut knows that stuff....Rune ...he might get shocked

Same here, thought it's been a while since it's happened... It's funny, people that work on amps are thankful when they grab 120v, instead of something else... Same thing when I burn myself on the iron. No reaction out of me anymore, hah!

Yes, DC elevation helps, I'm aware of that. It's just that the heater wires were all untwisted and willy nilly in Rune's pic, tidying up is a quick and easy thing to try. (Not to mention good practice)

Hey Rune, you said you've tried different guitars, how about a different speaker cabinet? That really sounded like something rattling/vibrating to me. I could be wrong, it's a recording and I'm not in the room.

[Cameron]

just found out i do still have radio stations coming thru. squealing is gone for sure tho, so thats good.

its no longer coming in when i touch the volume pot shaft, thats why i missed it.

happens when i touch the shaft of treble pot (pulled/or pushed in) and the mid shift pot shaft. all others are fine.

when i touch either pot shaft with one hand and then touch the chassis it goes away. if i put my whole hand on the chassis this thing is dead silent but the more i take off, the more rf comes back.

this makes me think grounding issues. how bout u guys?

Check to see if the treble pot is loose ...the body of the treble pot should get its ground through the faceplate.

[Gorhrut]

Check to see if the treble pot is loose ...the body of the treble pot should get its ground through the faceplate.

none of the pots have any wiggle in them at all. i dont crank the nuts down or anything but i have them fairly secure.

[Rune]

Tried with 4 different speaker cabinets (1 is the effects loop of a combo).
Marshall 1960B
Marshall M412A
Marshall 1936
Randall GT75 G3 combo

Would a panel oven in the same powerstrip/circuit cause any noise like that?

Clone got really tidy heater wires....

[Cameron]

It will happen at some point I've gotton shocked enough to not even flinch when I do now...... I think Gorhrut knows that stuff....Rune ...he might get shocked

Same here, thought it's been a while since it's happened... It's funny, people that work on amps are thankful when they grab 120v, instead of something else... Same thing when I burn myself on the iron. No reaction out of me anymore, hah!

Yes, DC elevation helps, I'm aware of that. It's just that the heater wires were all untwisted and willy nilly in Rune's pic, tidying up is a quick and easy thing to try. (Not to mention good practice)

Hey Rune, you said you've tried different guitars, how about a different speaker cabinet? That really sounded like something rattling/vibrating to me. I could be wrong, it's a recording and I'm not in the room.

You don't want to be thankfull to get shocked by 120vAC ...thats the one that could kill you. I would rather be shocked by 600vDC then 120AC.

[Gorhrut]

Tried with 4 different speaker cabinets (1 is the effects loop of a combo).
Marshall 1960B
Marshall M412A
Marshall 1936
Randall GT75 G3 combo

Would a panel oven in the same powerstrip/circuit cause any noise like that?

Clone got really tidy heater wires....

only one way to know.....try it on another circuit.

[Jana]

iPhone sample.

[Rune]

I guess I have to try tomorrow, but my other amps don't act like that so I guess it must be something else.