V2 lead dress questions?

[greiswig]

Got a couple of questions about the V2 lead dress that, it seems to be universally acknowledged, is part of the "Dumble tone."

1. In the pictures I've seen, it looks like the plate lead of V2b is run parallel to *both* the cathode leads from V2. This seems counterintuitive...why aren't the plate and cathode leads from each half of the tube run parallel?

2. Why does this dress rule apply only to V2, and not to V1?

Thanks, and Happy New Year!!

[Structo]

This has been puzzling me as well.

[markmalin]

Got a couple of questions about the V2 lead dress that, it seems to be universally acknowledged, is part of the "Dumble tone."

1. In the pictures I've seen, it looks like the plate lead of V2b is run parallel to *both* the cathode leads from V2. This seems counterintuitive...why aren't the plate and cathode leads from each half of the tube run parallel?

In general don't you want to never run plates and cathodes next to each other (parallel)? I thought it was OK to cross them, but not run them next to each other. But I must have that wrong...

[jurgen]

On at least a few amps it was both V1 and V2

[jurgen]

and

[Structo]

That's what I was thinking that I had seen it on V1 and V2 but not the PI.

You think this is something you have to chopstick to get the best placement or just run them close to each other and button it up?

[greiswig]

Thanks for the responses. But still no explanation as to why the plate lead from V2a isn't run parallel to the cathode lead from that side? It seems oddly asymmetrical.

[markmalin]

interesting. Looks like a sheilded input jack. Why twist the wires going to the tone stack??

[Normster]

interesting. Looks like a sheilded input jack. Why twist the wires going to the tone stack??

Solid core wire (especially teflon) tends to rattle and can even be microphonic. Twisting or bundling the wires stiffens things up so they don't rattle around in the chassis. It also keeps things tidy.

[Bob-I]

I've done some experimenting with the cathode/plate leads. I don't know why but the OD tightens up, especally on the bottom end when these leads are close together. On V1 it doesn't seem to matter, at least to my ears.

[markmalin]

interesting. Looks like a sheilded input jack. Why twist the wires going to the tone stack??

Solid core wire (especially teflon) tends to rattle and can even be microphonic. Twisting or bundling the wires stiffens things up so they don't rattle around in the chassis. It also keeps things tidy.

VERY interesting. Thanks, Normster.

Mark.

[Structo]

interesting. Looks like a sheilded input jack. Why twist the wires going to the tone stack??

Solid core wire (especially teflon) tends to rattle and can even be microphonic. Twisting or bundling the wires stiffens things up so they don't rattle around in the chassis. It also keeps things tidy.

Also Norm, doesn't twisting wires especially those with ac content offer some noise cancelling or shielding effects? Isn't that why we twist ac heater wires?

[greiswig]

1. In the pictures I've seen, it looks like the plate lead of V2b is run parallel to *both* the cathode leads from V2. This seems counterintuitive...why aren't the plate and cathode leads from each half of the tube run parallel?

2. Why does this dress rule (EDIT: generally) apply only to V2, and not to V1?

Thanks, and Happy New Year!!

Other than finding out that some HAD amps *did* have this same lead dress on V1, it seems that this is still a mystery! C'mon...I'll be someone (dogears, Gil?) knows these answers!

[groovtubin]

1. In the pictures I've seen, it looks like the plate lead of V2b is run parallel to *both* the cathode leads from V2. This seems counterintuitive...why aren't the plate and cathode leads from each half of the tube run parallel?

2. Why does this dress rule (EDIT: generally) apply only to V2, and not to V1?

Thanks, and Happy New Year!!

Other than finding out that some HAD amps *did* have this same lead dress on V1, it seems that this is still a mystery! C'mon...I'll be someone (dogears, Gil?) knows these answers!

Acoording to HAD, via the cow palace interview, this gets into circuit constants, where moving a wire a millimeter or whatever, changes sound. I`d put my $$ on the fact of a positive lead lying next to a neg lead, thro in some natural RFI interaction, a tad of inter-distortion modulation, Kharma, and luck, and there ya have it. Allan at Carol-Ann learned this at school ( from what he says) Moving a output transformer in right situation can have affect as well on tone, inducing an oscillation if leads are in right place. When i built for ELECTRIC AMP ( Matamp/Orange thingy) the OT leads would FLIPPIN OSCILLATE if NOT bound tightly to chassis, it was NUTS..drove me bats, proving that there IS a relationship for wires and chassis even if you can`t see it!!

[greiswig]

Yes, but why leave the V2a plate lead off by it's lonesome? Why isn't the lead dress symmetrical between the halves of the tube?