Master Volume in an Express

[rooster]

I have the sound clip to match this photo that I will post, but right now I thought I would share the picture of the LarMar MV's sound file on my DAW as it is turned up from '0' to '10' in ten increments. (The '0' position is not audible through the amp - instead you will hear me standing in the room playing my electric guitar acoustically - and you will need some good headphones or speakers to hear the first pass, it is very quiet.) The number '5' position is 12 o'clock, BTW. The wave shows two different passes playing two different repeated phrases.

This is using a LINEAR taper pot.

Here's the sound bite added of my Express with the LarMar MV using a LINEAR taper pot. (I elected to only present the second wave file that is shown in the pic, BTW, it's simpler.) There is no compression or limiting or effects added, just the guitar (Strat) straight in. This is a somewhat difficult recording to present accurately because there is no compression or limiting, but it has to be done this way - no compression or limiting - to show the various levels. I'm not exactly sure that an MP3 does not skew the levels a bit anyway, but you should get a pretty good idea of what the lineal pot is doing.

[Trainlover]

Excuse me for sounding stupid but does this wave form prove or show anything? Can you explain? I thought at first it would be an audio file...

[JoeCon]

Trainlover

I think he's showing the linear pot waveform. It continues to get larger in a linear fashions as the control is raised. So at 5/10 the waveform is at 50%.

An audio/log taper would be lower at 50% and then swing up at 7 thru 10.

See numbers 1 and 2 on the graph...audio is way lower than linear at 50%.

[donzoid]

I don't remember which I put in my Express LarMar (Linear, or Log) but after 5 months of gigging it, and going to 6v6 to tame it (quite nice for clubs really) I have "sussed out" 2 things:

first, the larmar is only good for taking the edge off. I no longer use it if I don't have to (just sits there full up) OR I use it trimmed only 10% of rotation AND in combination with an Airbrake (no more n 2 clicks since the last click is bypass that means two steps of atten.)

Did i mention this is the loudest darn 28 watt amp I or half dozen other club players I know have ever heard? Nyuk Nyuk...

You would I think have much better luck with a HotPlate or Airbrake for tone. I do, with either the 6v6 or the el34's. But I want to try a VVR!

[martin manning]

Do you have a cut control on your Express? I find that it can compensate for the tone loss when the LarMar is dialed down. This is odd but it seems to work.

[donzoid]

I don't, but I need to try one...and/or presonance but after your experiences (and others) with trying both, I delayed it.

Now I have it back on the bench troubleshooting some weird tonal changes (as it heats up over 3 hrs in a club, but that's fodder for a whole different thread) so once that is root caused I may just put one in!

[M Fowler]

I have some troubles with Martin's cool Express modded version but I still really enjoy the amp. One of these days I need to reread the presonance info in the threads and get the amp more stable.

But it doesn't go crazy all the time.