Calling Rockstah - 1959 HW to 12xxx series spec

[rockstah]

You're sure it's not just the conversion to mp3 that's making the high end grating? It's never an ideal way to go, although mp3's are an internet necessity.

i know what yer talking about Andy but i dint think so. i bet when he hits a open g chord he hears that same sound going on. shhhhanggggg, Rob describes it as cymbal crash. i was just think he made need to up the screens filtering some but i want to hear what these mods do first.

[vkaxeman]

Here are the most recent pictures. The only thing that has changed is the 50/50 caps I just put on the V3PI and Mains.

76 pictures of the Chassis
http://www.putfile.com/vkaxeman/images/171176

Yeah good way to describe it Cymbal Crash, like your standing right next to the drummer. Kills your ears!

[rockstah]

move the neg feedback wire from the speaker jack to the resistor far away from v3. pull it up and over to the right. its okay if it up in the air just move it away from v3.

also did u at one point remove the wires to the output tubes?
are the wires going to pin 5 of the out tubes twisted? it looks like they could be twisted more together going to the tubes.

[vkaxeman]

then lift the wire off of pin 2 of v2 and put a 220k resistor on pin2 and reconnect the wire to the end of the resistor. leads as short as possible.
(it has been discussed about a similar mod on v3 - i am clear on it and i want the resistor on v2 , pin 2 ) make a clip.
Mark

To confirm: Unsolder/remove the input/grid (green wire) from V2, pin 2. Solder one end of a 220k resistor to V2 Pin 2. Then solder the wire that I removed to the other end of the 220k resistor. Make leads as short as possible. This correct?

V2

[vkaxeman]

move the neg feedback wire from the speaker jack to the resistor far away from v3. pull it up and over to the right. its okay if it up in the air just move it away from v3.

Just moved it away from V3 and closer towards V4 and pulled it up away from the chassis.

also did u at one point remove the wires to the output tubes?
are the wires going to pin 5 of the out tubes twisted? it looks like they could be twisted more together going to the tubes.

The only wires I removed and replaced were on Pin 2 and 7 of V7 when I put in the Dual Tap. I have not touched any other wires on the output tubes. It's as stock.

[rockstah]

then lift the wire off of pin 2 of v2 and put a 220k resistor on pin2 and reconnect the wire to the end of the resistor. leads as short as possible.
(it has been discussed about a similar mod on v3 - i am clear on it and i want the resistor on v2 , pin 2 ) make a clip.
Mark

To confirm: Unsolder/remove the input/grid (green wire) from V2, pin 2. Solder one end of a 220k resistor to V2 Pin 2. Then solder the wire that I removed to the other end of the 220k resistor. Make leads as short as possible. This correct?

V2

correct.

also make the wire from the impedence switch to the speaker jack shorter. its ok if it has tiny bit of slack, yours has too much slack.

u want to move the neg feeback wire away from v3 - up in the air and to the right.

the wires to pin 5 of the output tubes should be twisted together. dont over due it..about 3/4 inch between twists as much as you can towards the two differnet pin 5's. they should cross and not run parrallel to any of the OT wires as much as possible.

[vkaxeman]

the wires to pin 5 of the output tubes should be twisted together. dont over due it..about 3/4 inch between twists as much as you can towards the two differnet pin 5's. they should cross and not run parrallel to any of the OT wires as much as possible.

To confirm: The blue wire on V5 pin 5 and the Green wire on V6 pin 5 that come from under the turret board need to be twisted together and not run parrallel to the OT wires.. Correct?

[rockstah]

the wires to pin 5 of the output tubes should be twisted together. dont over due it..about 3/4 inch between twists as much as you can towards the two differnet pin 5's. they should cross and not run parrallel to any of the OT wires as much as possible.

To confirm: The blue wire on V5 pin 5 and the Green wire on V6 pin 5 that come from under the turret board need to be twisted together and not run parrallel to the OT wires.. Correct?

correct amundo!

[vkaxeman]

Got IT! THanks!
Firing up the iron and Going back in!

[rockstah]

my pleasure. dont forget to drain that amp!

[vkaxeman]

my pleasure. dont forget to drain that amp!

That's the first thing I always do. And I double check with a meter and then when the can caps are reading in the millivolts, I connect alligators direct to ground and leave em there so they can't recharge while I'm working on it. Thanks for the reminder though!

You might say I'm a little paranoid of the ZAP!

[rockstah]

its a good thing to be aware of. not a good thing to have your ass kicked around the room by your amp.

[vkaxeman]

Sorry for the delay. Had something Saturday Night and Sunday that I had to take care of. Picked up the resistor today and hope to have parts in and MP3's posted by tomorrow evening. I wish I could build/modify amps all day long / every day. Now that would be cool.

[rockstah]

it sure would be kewl huh?

[vkaxeman]

Put the Mains Filtering back to 32u and the V3 PI Filtering back to 16u


Moved the feedback wire up and away from V3 and shortened black wire on impedance switch.


Replaced .0022 V1b coupling cap with .022


Unsoldered the leads that go to Pin 5 of V5 and V6 and pulled them back from under the turret board, attempted to twist them and feed them back under a couple of times but they are to short to reach with twists in them. And they will still run parallell with the OT wires. Will have to replace them with new longer wires.
One came off the Turret while trying to stretch it under the turret board to make it reach:


Where can I buy different color wire at a reasonable price that I can use in my amp to replace / add wiring as needed?