Footswitch pedal cable induced volume reduction

[WhopperPlate]

Update: haven’t relocated relay led wires , but I did install dual conductor shielded grid wires to the power tubes

Whereas the new found clarity and stability is ideal to my ears, the sonic effect remains with the Pedal connected. Interesting though , before it was annoying , now it’s actually pleasant lol.

At least the tail chasing invariably improves the amp as I search for and apply possible remedies

[WhopperPlate]

Update:

1) attempted to float relay power supply on the dedicated 6.3vac tap just to see anything . Noisy and buzzy as I expected , but noticed that the footswitch inserted practically eliminated all the noise , and removing the foot-switch cables shield from ground brought it mostly back.

I couldn’t help but think there was a mistaken ground connection and meticulously check every point in the system. Nothing out of the ordinary .

For reference, the disconnected cat5 cable open ends total capacitance reads 3700pf to ground with shield grounded , 2700pf with the shield removed from ground

2) I installed a fitted shield plate to cover all the toggle switches and footswitch connectors . While the polished stainless steel wall looked clean it didn’t benefit anything per se.

3) I removed the whole CAT5 cable from the chassis, and disconnected power to the relays and LEDs. The effect still remained, and important to note that this is regardless of inserting guitar at the input or effects loop return. Both do this . at this point there is not any relay wires anywhere near the remaining circuitry and it still interacts, nor is it being powered or connected to ground….

…and the effect remains…

*cue theme to twilight zone

I am officially stumped and stupid

[Reeltarded]

Hold short. I'm thinking.

I don't like twisted pairs of solid wires anyhow.

Cute story. I was like 14 and a friend borrowed my Phase 90. He took out a screwdriver to see what battery it had to buy a spare.

It didn't have a battery. It operated.

You can say it's bullshit, but I was there. heheh

[WhopperPlate]

Hold short. I'm thinking.

I don't like twisted pairs of solid wires anyhow.

Cute story. I was like 14 and a friend borrowed my Phase 90. He took out a screwdriver to see what battery it had to buy a spare.

It didn't have a battery. It operated.

You can say it's bullshit, but I was there. heheh

I good friend of mine (Greg Langrish RIP) told me a story of how he was cleaning his parents garage and he kept hearing a toy clown laughing on repeat . He thought , “god , shut that thing up” and found it in the bottom of a crate . He opened it up to take the batteries out…there were no batteries …and it was still laughing …

He proceeded to immediately lock it inside a box and drive to the nearest bridge to toss it away for good into a local water stream .

When he had returned home from the drive …the dolls shoe was in the driveway …

IMG_2741.jpeg

[Reeltarded]

I drank coffee. I never planned to sleep again.

Clowns are hateful, even if it's your grandmother handing out candy to kids. Especially.

[sluckey]

My name is Talky Tina...

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[WhopperPlate]

My name is Talky Tina...

Talky_Tina.gif

Oh perfect synchronicity, I forgot about that episode! Bravo

[Reeltarded]

My name is Talky Tina...

Talky_Tina.gif

I accidently clicked like. Stop that.

Speaking of tile cutting.. does anyone know how to get clown blood out of spandex?

[WhopperPlate]

Update:

Here’s is what I have done since last post:

1) replaced old RG58 mesh shielded conductors with modern RG59 double mesh and foil shielded conductors. Foil wrapped all the way to the end of conductor for maximum coverage and protection . A little bit of nail polish at each end to help prevent someone from carelessly bending a lead and shorting conductor to the shield. . 12 conductors total.

2) rewired preamp tone controls with twisted bundle that’s ground wire wrapped for extra shielding .

3) wrapped Wire bundle leading to doghouse with grounded lead. I had previously mistakingly assumed this would prove negligible to the layout . I was wrong.

4) most of the long shielded leads that were running on the chassis floor are now elevated further away from high current and high voltage paths, including the master volume input and output and PI input.

Happy to say that the mystery induction problem has almost completely subsided . If anything there is a light amount of compression left over that no longer clamps the signal and affect the amplifier headroom . Very very subtle . practically indiscernible.

I will also report that the amp now has much better overall tonality and clarity . I would say it now behaves like a different amplifier . All of the changes yielded a tighter and far more dynamic tone that increased the headroom dramatically. It now feels and sounds similar to the vintage blackface twin reverb I just finished repairing for a client , which is easy to play, with a nice stiff fundamental tone , bold clean and crystal clear.

This whole journey has me pondering a lot about the ab763 layout and the later silver face vs blackface wiring and how much more unstable those silver faces could be with the haphazard and careless lead dress. They often were forced to shield everything and add stabilizing components to various parts of the circuitry as they crammed in the additions over the years . Self evidently I have experienced similar issues . Whereas I felt my lead dress was definitely well done and far neater in comparison to those rats nests , the issues still proved real. Small changes add up.

Moral of story: Careful consideration of lead dress and observing the methods of the classic platforms generally deliver desired results .