On Jul 3, 8:18 am, "Arfa Daily" wrote:
"Meat Plow" wrote in message

...

On Tue, 03 Jul 2007 08:28:35 +0000, Arfa Daily wrote:

"Eeyore" wrote in message
...

Arfa Daily wrote:

"Eeyore" wrote
ll wrote:

I recently installed a transformer (12VAC, 2Amp) in a musical
instrument amplifier (rated at 10 Watts RMS), and when I test it
with
a variety of input sources (guitars, keyboards, different cables),
for
about 30 seconds, the amplifier produces a nice healthy volume
level,
and then, consistently, the volume just drops about 50%. For some
reason, this problem sounds like it might be heat-related. Has
anyone
else experienced this?

Are you by any chance sine wave testing it for those 30 seconds ?

I took it he wasn't, as he says that "when I test it with a variety of
input
*sources* ... " and then specifically mentions guitars and keyboards.

I was a bit dozy at the time.

I've seen that effect though.

Graham

Likewise. I often deliberately test group amps with a 400Hz tone for a
few
minutes, just to get the output stages thoroughly thrashed up to
temperature.

I made a looped test CD with me playing some leads, licks and riffs on my
Les Paul through my Boss GT-6 just to test guitar amps.

You should send me the files !!

Arfa


Yes, guitars, lots of guitars (a variety) were used to test the amp.
The tx was an exact replacement. It seems we have narrowed this down
to heat-related.