modified or pure sine wave power supply

[pbiagi]

Hello,

I may run a 5E3 Fender Deluxe (plus other audio equip.) self-built amp from a solar battery..

Would I require a pure sine wave inverter or would a modified sine wave inverter work?
I'm guessing there could be a consequence to the supply transformer, but I'm really not sure.
Pure sine wave inverters are harder to find and more expensive, so I'll get a modified if that works.. But no sense in doing that if it's going to cause problems..

Thanks in advance

[Steve Conner]

The amp should run fine off a mod sine, however it's likely to buzz a lot worse than it would on a pure sine wave.

What the inverter industry call a "modified sine wave" is really a square wave with some bites out of it to give it the same peak-to-RMS ratio as a real sine wave. Only a marketing guy could use the word "sine wave" anywhere near it. Being basically a square wave, it contains a lot of high frequency harmonics that can bleed through into your audio.

[pbiagi]

Thanks Steve. I think I'll pass on the square wave buzz then.
Do you have any links for a pure sine wave inverter, 300 - 800 Watts, maybe doing 120 and 220 V.. and of course for a reasonable price?

[Steve Conner]

There are dozens of pure sine wave inverters available, you'll have to do your own research there. One example would be the AC Master range from Mastervolt, these are made in Holland so will be cheaper than American ones if you live in Europe.

AC Master | Mastervolt. The world‘s leading brand in maritime, mobile and solar energy solutions.

Note you have to order the 120 or 240 version, and can't switch it later.

Exeltech have the reputation of making the purest pure sine wave inverter in existence:
Exeltech is a manufacturer of premium power inverters, BBS, rack systems, and grid-tie systems

Of course you will pay for this purity in cost and reduced efficiency...

Other ideas:
Use a mod sine inverter with one of those old-fashioned "Constant voltage transformer" power conditioners. (I don't think they're manufactured any more, but check Ebay) I believe they do a reasonable job of converting the input waveform to a sinewave, as well as their original purpose of regulating the voltage. They should be able to convert from 240 to 120 too, if you find the right one.

Find a pure sine wave computer UPS, rip out the warning beeper, and connect it to your solar batteries. Usually cheap/free, but less efficient than a dedicated inverter and may need extra cooling to run continuously.