...no need for overheat protection because the heat sink only gets lukewarm under normal conditions.TheMG said:Nice use of a thermostat for overheat protection, SubSoniks.
Despite the hiss, that is not audible at listening position with my speakers, the sound is really great, very dynamic but smooth with strong bass and 3d soundstage.
I tried different power supplies...from a IBM Thinkpad SMPS (16V, 5A) to a MeanWell 24V SMPS 100W, all sound good.
I think you will not get more amp for the buck elsewhere.
Happy listening
Pieroh
I fitted the thermal switch to be on the safe side and partly because I had it handy and also as they are being used flat out for PA work with the limiters on the xover protecting against clipping.
One thing to note that I think has been mentioned earlier is that these amp modules don't come with heat sink paste so the chip may be getting hotter than the temperature of the heat sink might suggest, I have put some on.
When I get a moment I will attach a K type thermocouple and measure the temps.
The amp did sound very nice at the party last weekend and surprisingly loud.
Jake
One thing to note that I think has been mentioned earlier is that these amp modules don't come with heat sink paste so the chip may be getting hotter than the temperature of the heat sink might suggest, I have put some on.
When I get a moment I will attach a K type thermocouple and measure the temps.
The amp did sound very nice at the party last weekend and surprisingly loud.
Jake
On my board there was a gap between the heat sink and the chip. The 2 screws holding the chip to the heat sink were bending the board to pull the chip up to the heat sink. I filed the mounting posts to drop the heat sink and then applied some arctic silver.
I don't know if it helped the temp or not cause I was just snooping under the heat sink when I noticed it.
I don't know if it helped the temp or not cause I was just snooping under the heat sink when I noticed it.
Forgive me if I am telling you old news but these amps are not available any more,which is bad news for me as I wanted to order another two.
I am awaiting a reply to an email asking them if they have any plans to sell a similar amp.
Maybe they read the "hiss" discussions and decided to develop a new version,although from what I can gather,they sold ,not produced the amp in this thread.
Paul
I am awaiting a reply to an email asking them if they have any plans to sell a similar amp.
Maybe they read the "hiss" discussions and decided to develop a new version,although from what I can gather,they sold ,not produced the amp in this thread.
Paul
Yes, that is interesting. I would have brought more of the 4*100 amps if it wasn't for the hiss. After many a vain attempt at dealing with the hiss I gave up and Instead ended up building 3 of the by-far-superior 41hz Amp9 kits. That was a lot of work though. I hope they do produce a similar unit for around the same cost without the hiss. I would certainly be purchasing.
Has anyone tried running the outputs single-ended like for tweeters requiring less power in active speakers setup. Just connect the positive output to speaker via capacitor, and from speaker to ground (not to the negative output)? Kind of unbridge the amp. I guess that might also help removing some hiss.
Yes, I guess some cap is needed anyway as the output is at 1/2 Vss I think, because this is a single supply amp.
You could as well have the cap functioning as 1st degree xover. For an example if you use a waveguide like in Zaph's Waveguide TMM (Zaph|Audio) you could use just a 3.9 uF cap for the tweeter and nothing else. For the woofer(s) then you could build an active (or passive line level) xover simulating the needed response (http://www.zaphaudio.com/WaveguideTMM-perfection-FR-woofers-tweeter.gif) which looks like a 12 db/oct @ 2kHz LP. You don't need two woofers / amp channels (used like Zaph did in his passive xover design), just use a single woofer and implement an active (well, you have to buffer the passive filter anyway) variable baffle-step compensation circuit like this:
http://sound.westhost.com/bafflestep.htm
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I have one AA-AB009 (v1.1) and there's a few aspects that I think are worth to share:
+ the sound is good for the price of the board
- the daughter board AA-AB123 cannot be removed properly
"Fortunately" in my case only the top components tend to die
- the TK-2050 are... sensitive, kind of hard to solder
They tend to blow up easily and their main failure mode is "short Vcc to Vdd".
- I'm pretty sure that some components are under-rated for reliable operation
I don't know whether the TK-2050 also blow up in other systems.
In this thread I saw different kinds of daughter boards, they must have evolved...
+ the sound is good for the price of the board
- the daughter board AA-AB123 cannot be removed properly
"Fortunately" in my case only the top components tend to die
- the TK-2050 are... sensitive, kind of hard to solder
They tend to blow up easily and their main failure mode is "short Vcc to Vdd".
- I'm pretty sure that some components are under-rated for reliable operation
I don't know whether the TK-2050 also blow up in other systems.
In this thread I saw different kinds of daughter boards, they must have evolved...
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