My latest TPA3106D1 40W mono boards

[theAnonymous1]

The thing that really amazes me about these boards is how cool they stay. The inductors don't heat up at all and the entire board only gets slightly warm when playing near full volume for long periods of time.

These are my favorite pair so far. I've given up on the TPA3122D2; it requires extra circuitry for bridging and just isn't as good in many respects. It was fun experimenting with it though.

[Pano]

Very interesting. Did you make those, or are they eval boards you got from TI? (the logo)

[theAnonymous1]

Hi Pano,

I made these myself. I "borrowed" the TI logo from one of their PDFs using a PDF editor. I hope they don't mind.

I'm glad you popped into this thread though. I was thinking of letting someone else audition these so I can get a second opinion on how they perform. Interested?

[Pano]

Yes, I'd love to. Right now tho I'm not running a passive crossover, so can really only listen to them from about 500Hz up (horns) or 500Hz down (Altec woofers) Not sure if that meets your needs. Oh wait, I do have some nice floor standers that could test them.

Nice work on the PCB. I thought it looked home made, but the nice TI logo on the corner had me confused.

[von.ah]

Jeebus, those are small! Quite an awesome little build. How do you think they sound compared to other lower-powered class D amps you've used?
Edit: yikes, those THD+N plots from the TI datasheet don't exactly look stellar... At least to this noob.

[theAnonymous1]

Originally Posted by panomaniac

Yes, I'd love to.

Great, just PM me your addy then. Give me about a week or so so I can find an enclosure to put them in so they are easier to handle

Originally Posted by von.ah

How do you think they sound compared to other lower-powered class D amps you've used?

Heh, that's what I need Pano for.

I can only tell when there is some obvious flaw in the sound. I can pick out things like lack of bass (or lack of control), high noise floor, extreme sibilance, and high levels of distortion. Things like "resolution" and "soundstage" just get lost in my brain somewhere.

All in all, I think these sound great. Definitely no lack of bass, and with the lowest two gain settings the noise floor seems lower than the "T-Amps" I have.

Originally Posted by von.ah

yikes, those THD+N plots from the TI datasheet don't exactly look stellar... At least to this noob.

THD is more complicated than just a number. You can't say an amp will sound bad just by the THD specs. Go look at the THD numbers for tube amps.

[theAnonymous1]

I forgot to mention the DC offset on these is also considerably lower than most of the small Tripath amps (without offset adjustment). One has 5mV and the other 9mV.

[von.ah]

Originally Posted by theAnonymous1

THD is more complicated than just a number. You can't say an amp will sound bad just by the THD specs. Go look at the THD numbers for tube amps.

Right, I get that. Since we don't know what type of THD or N is influencing the plot most, we can't make assumptions on how that might relate to "sound." People tend to "like" tube distortion, whereas the output devices in these sorts of chips are tiny FETs, right?
But just as a quick apples to pears comparison, looking at the long time favorite TA2020, the TPA seems a bit wacky in the THD+N/frequency plot.
Just an observation.

Regardless, I admire your work.

[theAnonymous1]

Yeah, it is a strange curve.

Anywho, not trying to claim this is some uber Hi-Fi T-Amp killer. Just another option (for me at least).

It is what it is; a budget, low powered, "fast food" packaged, class-d amp. Sometimes I really onjoy a good burger and fries though.

[von.ah]

Well put.
The small and simple form factor is certainly an advantage. These would be great for powered speakers.
Cheers.