[RE-wrenches] Sound Equipment Inverter

[Dave Angelini Offgrid Solar]

The work I did on this back in the day, when I was into this kind of thing
was setting AC voltage for the amps. Marshall and other really nice
sounding guitar amps need a specific AC voltage to sound great and get good
tube life. I can't remember the voltages exactly but they are out there to
find in a search. Bands that are touring, bias the tubes at say 117vac and
then run them on stage from an adjustable supply. I used the Xantrex config
tool to set XW's for the exact output Vac under typical loading. This was
to replace an existing Japanese company that built stage power supplies.
They had got very expensive and were hard to find and get support. I never
noticed any big noise difference from the grid vs XW supply but the sound
quality was noticeable to me when the voltage was right. That was a fun job
but really bad hours!

Still not getting over losing Eddie Van Halen. He was a master at great
sound and nothing between the guitar and his amps but a cable or RF
transmitter. He also made his own guitars and amps, even when he could
afford to hire it. He used all 10 fingers in his neck tapping techniques.


Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail offgridsolar at sti.net
text 209 813 0060

On Thu, 22 Oct 2020 16:42:03 -0600, Ray <ray at solarray.com> wrote:
> Hi All;
> 
> I've just had an inquiry on building a portable sound stage and 
> recording setup.  Traditionally we've always used Exeltech, as they've 
> had the cleanest output, with background buzz on tube amps being lower 
> than grid power.  Modsine were horrible, Old Trace SWs were pretty 
> intolerable, Magnum's were usable, but still noticeably more buzz than 
> grid.  I think THD is roughly associated with the background buzz, but 
> there might be certain harmonics that are particularly problematic.  I 
> haven't gotten into looking at the separate harmonics relative to what 
> induces the most noise in these old vacuum tube circuits.
> 
> This is a 48 v application that also needs a built in charger with 
> transfer switching.  Exeltech does not appear to have anything in that 
> department.  Any other choices?  How are Samlex?
> 
> As always, thanks in advance for your time and expertise,