Does adding a master volume control hinder tone?

[zzmoore]

Re: Does adding a master volume control hinder tone?

It's a simple blend circuit. Whenever you blend the positive signal with the negative signal coming out of the phase inverter, there will be some cancellation. The more of one signal you blend with the other. When they're fully blended - nothing is being sent to the power section. Whatever signal you don't introduce for cancellation (via variable resistance) just goes to its respective valve(s). Your volume is at "0" when .......

Oh Boy.....this confusion was completely of my own making...Total Tunnel Vision on my part.
Whenever somebody says Master Volume, i automatically think of the Typical/Traditional... MV/Gain/Volume type of control, with a single pot that sets up some kind of grounded Voltage Divider. You can the imagine the disaster of using that type of control, with One Pot, after the PI. I was stuck in my own mud.
Your examples up there ^^^^^^^ are very well said BTW.
Thanks

 

[Darg1911]

Re: Does adding a master volume control hinder tone?

The crossline MV is interesting, first single pot PPIMV I've seen. Although the page you linked to says that the type-2 (dual ganged 100K pot) is the most transparent.

The LarMar is a type 2 with resistors installed at the pot to act as fail safe grid leak resistors in the event the pot craps out.

He goes on to explain ... "I recommend a 100KL dual gang pot when the original grid leak resistors are 100K. For amps with 220k grid leaks like most Fenders I recommend a dual gang 220KA pot like this. Another option is placing two 1.8M resistors in parallel with a 250KA dual gang's pots. Solder the resistors across both pot's--center terminal to input terminal (left terminal above). This will improve the pot's taper and drop the pot's max resistance from 250k to 220k. The "Lar Mar" MV is simply a Type-2 MV using 2.2M resistors added to a 250KA dual gang pot. The 1.8M or 2.2M resistors will lessen pot scratchiness and act as a backup path for the bias voltage in case the pot fails."

 

[Falloffthebonetone]

Re: Does adding a master volume control hinder tone?

If it was installed by someone else, then there's no way of knowing what was done without taking a look inside. I'd just try it out if possible and if the amps sounds good - go with it. A master volume shouldn't make a great amp sound bad/removing a master volume shouldn't make a bad amp sound great. A great amp is still a great amp no matter what. I'd argue that anything that prevents an amp from being fully driven, which is just about every type of master volume circuit, is a drag, but you could always make it switchable. Just remember to turn the channel volume down before switching it out.

Yeah that's pretty much the plan. I put money down on it to hold it til I get to try it out. I've shot out a few V4s in another store closer to me so I know what they're supposed to sound like. I found it cheaper than anything else around here so it was tempting enough to give it a shot. Worst case scenario: it sounds terrible, I get refunded and the search continues. I just never knew how adding a knob could change so much. Even if I did pick it up and it wasn't good I don't see anything stopping me from switching it like you said.