Question about adding caps with this bright switch

[Reeltarded]

About 5 concepts from now you will be looking at the amp and it will be afraid of what you are thinking.

[cap217]

I want to just understand why he modded it this way. He charges a good amount for his work and is one of the leading vox techs out there. There must be a reason but I cant get in contact with him to get an answer.

[Reeltarded]

Careful with questions. I had paid $1000 and more to all the names in the big 80's to basically swap tube positions and change a resistor.

There is no magic except what you can find.

[starlite22]

Hello RT

Thanks very much for the link. I been looking for something like this.

Gday

http://www.muzique.com/schem/filter.htm

There is a place to look at the cutoff of simple filter networks.

[iknowjohnny]

To add to what reeltarded has already said, and he's spot on, note that these are the kinds of changes that can VERY easily be misinterpreted as a positive change but when in fact you may later realize just the opposite. You are opening up a huge can of worms, and my best advice is put any changes you do if possible on a switch so you can A/B them over the course of a good week or more till your ears hear the absolute truth. Otherwise you will be going back and fourth with this forever, each time believing that latest change back is best. been there done that so many times is a blur. But this is truly the area where fine tuning can make important improvements. The hard part is recognizing which way is best, and thats near impossible to be sure of till any change has been A/B'd many times and the ear is dead familiar with the difference. Otherwise you can never be sure it's the best it can be to your ear. It's fun chasing the magic tho, it's a addiction i can't seem to stop even when my amp sounds like pure gold !

[Masco]

I want to just understand why he modded it this way. He charges a good amount for his work and is one of the leading vox techs out there. There must be a reason but I cant get in contact with him to get an answer.

Lyle modded it that way to make the normal channel more versatile. The stock normal channel circuit Vox used in this particular HW model included the JMI AC-30 "treble" variant which was an option introduced in the mid-late '60's. This new model HW has this variant put on a switch that throws in the 220p at the volume pot, where the original AC-30s had both 330k/220p "treble" components hard wired at the volume pot(non-switchable). Lyle swaps the 220p for a 68p for less brightness and uses a pull volume switch and mini toggle to do a few things: 1. completely bypass both "treble" components (330k/220p); 2. select between two different coupling capacitor values off the plate of the normal pre; and 3. route the normal channel to be mixed(via 220k on board) to the same side of the PI as the top boost channel for out of phase operation when channels are linked. I'm sure a lot of thought was put into his mods.
I personally prefer the original JMI normal channel. Triode> .047uF> 500ka volume> phase inverter. Simple, glorious and pedal friendly. I would try this first to see if you like it.