Depth mod gurus

[FourT6and2]

That makes more sense. But wouldnt changing the dropping resistor values effect V1 and V2 as well?

Yes. See above.

 

[RedPlated]

Changing voltage at the PI alters voltages the from that point all the way down to V1. Raising voltage at the droppers will require adjusting plate resistor values up if you wish to have voltages remain constant at each stage in relation to what they were before raising PI voltage.

As far as the slope, you just need to change it and use your ears to determine if it does what you want. Clarity, string separation and reduction of low mids come with raising the value. However, there is a trade off and you change the Q of the mid structure, which may or or may not be to your preference. I believe Diezel uses 39k in the VH4. I’ve also seen some Cameron mods with 39k. Both still using a 500pf treble cap.

You check the PI voltage at the point where the red arrow is in this photo. You adjust the large resistors just prior to allow more or less voltage through. Paralleling a resistor on top of one of them is common practice. Use a good 3w metal film. You don’t want a 1/2 or 1w resistor here. There is potentially upwards of 450-500+vdc coming from the screen supply.

 

[tlp1234]

I tend to hate amps with all one kind though. I don’t like wizards with all orange drops, and I don’t like old Marshall’s with all original spragues. You need both for an amp to sound good. Where and what value is where it gets challenging.

Thank for posting this, forgive me for editing out a lot of your thought. I just wanted to bring part of it to whit.

I've always wondered if the all orange drop thing on my Wizards was intentional because the designer actually knew exactly what this would sound like, or because he didn't wish to fine tune things any further by mixing different types in different positions. Of course that curiousity could apply to other amps too.

I love my Wizards and not criticizing, just wondering about the possibilities.

All of this makes me also consider trying it myself, but not sure if I have the patience at the present.

And too.......everytime I look at this craftsmanship, I cannot bring myself to take a soldering iron to it.

 

[FourT6and2]

Thank for posting this, forgive me for editing out a lot of your thought. I just wanted to bring part of it to whit.

I've always wondered if the all orange drop thing on my Wizards was intentional because the designer actually knew exactly what this would sound like, or because he didn't wish to fine tune things any further by mixing different types in different positions. Of course that curiousity could apply to other amps too.

I love my Wizards and not criticizing, just wondering about the possibilities.

All of this makes me also consider trying it myself, but not sure if I have the patience at the present.

And too.......everytime I look at this craftsmanship, I cannot bring myself to take a soldering iron to it.

Like this?

 

[glpg80]

Like this?

Yep - you get it too. I use WIMA, vishay, panasonic, sprague, and sozo. It’s all personal preference but their location matters. Can you name out the brands used? Some I don’t even recognize.

 

[psychodave]

A bunch of us learned to use different caps. I didn’t just use whatever I had on hand.

 

[RedPlated]

The Wima MKS caps are great for cathode bypass. That's what I use a lot.

 

[Arcturus]

Try temporarily replacing the 220k resistor with a one meg pot and dial in the tone you like. Then replace the meg pot with the resister closest to the value on the pot.