express and master volume

[riscado]

So I tried adding a master volume for an express circuit I built, and decided to look in Ken's trainwreck pages, I used the circuit with the single 1Meg pot, due to the lack of 500k dual pots in my stash. When I tried it, the pot doesn't seem to attenuate a lot it's either full output, or almost completely cut. I though I'd change the taper, still no luck, I don't want to use a lower value like 250k as that will mean there will always be some attenuation unless I remove the pot from the circuit, any ideas?

thanks

[Blind Lemon]

Are you using the Phase Inverter Gain (PIG)? I put one on my last Rocket and it is very effective with good range. You might want to revisit the installation and make sure its wired correctly. With that one meg pot you ought to be getting good range.

You might post a picture.........

BL

[M Fowler]

I will attack some ceriatone has to offer.

Mark

[riscado]

Hi blind lemon, this is the circuit I'm using, everything wired quite correctly:

http://angela.com/images/t24.jpg

Fowler I intend to use the regular single pot circuit rather than the dual ganged pot one, that said, I dislike ceriatone's offering, to put it in other words, I'm not a big fan of their products. I'm familiar with that kind of circuit, thanks anyway.

[M Fowler]

Only trying to help.

Mark

[riscado]

my answer might have come across as harsh... sorry didn't mean to.

[bluegate]

I have two PPIMV installed in my Express clone.
Both come from the Trainwreck pages.
The first is a Type 2, this one is always on.
The second is a Type 3, this one can be switched on/off with a pedal.
When I want Cleaner sounds or play Lead, I use the first set at max level for the gig.
When I want a crunchy sound for chords, I engage the second MV set softer so that
I don't overpower the rest of the band.
Works great.

I'm building a better version of my first Express clone and it will have the same PPIMV's.
Very happy with both.

[sliberty]

Another option that some like very much (including me) is Dana's Variable Voltage Regulator. It is a sort of power scaling add on that works well with Express amps (probably Liverpools too, but I never built one). It consists of a small board and a dual pot which can either be mounted on the board, or not. I have one in my UniWreck, and really like the results.

[Structo]

I just recently installed the same MV in a little 6V6 amp.

It's called a cross line MV.

I experience the same thing with mine.
Very little range of dynamics.
There is hardly any low volume before it jumps up to almost full.

I think it is the nature of the beast concerning that style MV.

[jjman]

One could use or make a "no load" type pot for the Type 3 crossline MV. When set on max volume it could be "invisible" as with a no load tone pot on a guitar. Not hard to convert a normal one to no load.

I'm using Type 1 dual type which sounds very good on my pseudo-Express, but the Type 3 should solve my problem with losing my output-tremolo when the MV is down.

[Structo]

I tried making a no load pot for the type 3 crossline.

I must have done something wrong and it didn't work after I scraped the carbon off the end of the trace.

I may have done it wrong or done the wrong end of it.....

Here is a different view of the type that Mark posted.

It may be easier to visualize with this drawing.

[riscado]

it's funny to some people, and remember we are talking about the same amp here... the 1MG pot type circuit sounds very nice and works properly, to other people (myself included) there is not midle ground, it's either muffled and cut or full output. I know mine is wired properly. So more than looking for an alternative, I'm trying to understand why it behaves the way it does.