Mini-As almost alive

[winslow]

If I wasn't missing 1 value of resistor, the Mini-As would be up and running tonight. I'm so sad. Got them built with the 1 amp bias resistors in, but that will probably get changed once the amps are making music and I'm certain they are operating properly.

I do have to give a big thanks to the guys who made the Mini-A- Nelson, Grey, Jason, and Brian. Those boards are slick and was pretty fun to put together. Probably took 3 hours to do both amp boards.

Anyways, finally off to bed dreaming about high biased single ended class A amps.

[safetyman]

Winslow, are you using this in your ride? Any chance of pics? You should have dual700 and dingaling do an amp shoot out. Most interested to know your developments.

[winslow]

They will be going to ID for a listen when they are done...actually a few people want to take a listen.

[winslow]

The power supply that I measured doing +/- 18 is going +/- 25 tonight, and she's set to be biased at 1 amp, but I'm getting .03 amps across the bias resistor.

[mpmarino]

Originally posted by winslow
The power supply that I measured doing +/- 18 is going +/- 25 tonight, and she's set to be biased at 1 amp, but I'm getting .03 amps across the bias resistor.

Are you running it at +-25 or +-18? .. +-25 is way too high for a mini. I doubt the devices could get rid of the heat. Bias is measured by checking voltage across a source resistor and using ohms law. example: .5v measured / .5r resistor = 1A bias <or> .62v measured / .47r resistor = 1.319A.

good luck..don't give up if you have problems, it's well worth it.

Marc

[winslow]

Right now it's +/- 25 under load. She sounds sweet...very sweet, not like any solid state amp I've heard. Has a good turn on pop too.

Yuck...now I gota figure out a way to get the voltage down...or build a bigger amp.

[winslow]

One side has nearly 14 volts, other side has .55 volts. So, .55 volts divided by .475 ohms gets me 1.15 amps. That makes me feel better. Now just have to figure out what do do about that voltage.

The power supply is from a car amp that I had laying around since this was going in the car. Have to find out if she's regulated or not.

Damn, she's hot...glad I didn't go full bias off the bat...and glad I have larger heatsink wanting to get drilled and tapped.

[Stones]

Originally posted by winslow
Right now it's +/- 25 under load. She sounds sweet...very sweet, not like any solid state amp I've heard. Has a good turn on pop too.

Yuck...now I gota figure out a way to get the voltage down...or build a bigger amp.

You could scale it up to an A30

[safetyman]

yeah, don't give up. Get it going right and go kick a$$ at the shows and give TRU's Class A a run for his money.

Mr. Nelson Pass, any chance of a Class A car audio amp? I meant a DIY project.

[mpmarino]

Originally posted by winslow
One side has nearly 14 volts, other side has .55 volts. So, .55 volts divided by .475 ohms gets me 1.15 amps. That makes me feel better. Now just have to figure out what do do about that voltage.

Do you mean that you have 14v across a source resistor? if so...

If so,sumpins wrong. Any DC at the output?