600w Pure Sine inverter recommendations?

[dannyg1]

I was told that there were a number of electronics geeks here, on the electric guitars forum. I'm shopping for a quality 600w pure sine inverter and I've narrowed my choices down to these:

Power Bright APS600-12
Samlex PST600W-12
Samlex SA-600
Go Power GP-SW600-12 (Same as Samlex SA)

Two used outliers:

Exeltech x1100
Magnum CSW1012

I'd like an inverter that operates at 12v, ideally with an input voltage range of 10-16v (9.5v would be nice but I don't ever see that) and a temp controlled fan. An adjustable output voltage (110-120v) would be nice too.
Anything I should be looking at?

[printer2]

Find out what the voltage is internally in your amp (24V?) and feed it directly from two batteries in series. Why switch the voltage up for the amp to switch it down again with both losses from the conversion going up as heat?

[dannyg1]

How would this be connected? Before the transformer taps? Have you done this? Any photos, possibly? What kind of performance changes do you get out of the amp?

Thanks for your insight.

[printer2]

Haven't done it, just have an electronic background. The speaker in the Loudbox (from your post in the Acoustic Amplification thread) is 4 ohms (from another thread quoting Fishman on the amp's speaker), and a 24V switching amp will make the 90W. I can not find a schematic of the amp online so I am only guessing at the circuit and voltage. Your best bet is finding someone with a reasonable amount of electronic knowledge pop the top and measure the power supply voltage. If it is a switching power amp then I can see using two smaller batteries in series (rather than 12V at 10A, 24V at 5A, as an example).

If they are using older technology of analog transistors or the like then the amp will be running at higher voltages and it would not be worth the effort. If the metal chassis of the amp does not get hot when using it I would guess they are using a switching amplifier. Sorry I can't be of any more help.

[dannyg1]

Thanks for sharing the idea. I can access the power amp section directly in my Loudbox 100. When I get it back, I'll measure the voltage coming off the power supply and get back. Do I need an ultra high quality voltmeter to accurately read this? It will be DC and I only have a cheap meter.

[printer2]

No, any meter will do.