I'd like to hear from other users of this chip. I have a Tripath demo board, EB-TAA4100 and there is a good deal of hiss that is noticeable from 2' feet away.
I am curious if this is an artifact of the early Tripath demo board design, a potentially bad chip, or an innate chararacteristic of the chip itself? As there are a few designs out now using it, what has your experience been in this regard as to hiss?
I am curious if this is an artifact of the early Tripath demo board design, a potentially bad chip, or an innate chararacteristic of the chip itself? As there are a few designs out now using it, what has your experience been in this regard as to hiss?
I am using Jan's AMP9 and there is no hiss at all. In fact, it's very quite.
What type of power are you using?
What type of power are you using?
Is it in a case? How about isolated from chassis with shielded inputs?
I don't know about the Ref board but Jan's have a .01uf speaker output to ground, to cut down on EMI. How about the ref board?
It sounds like a grounding or EMI problem somewhere?
I don't know about the Ref board but Jan's have a .01uf speaker output to ground, to cut down on EMI. How about the ref board?
It sounds like a grounding or EMI problem somewhere?
Bearman said:
It has hiss both in & out of a metal case that is grounded. Currently it is out of the case as it did not make a difference when it was in. The noise is a constant "ssssssssssssssssssssssssssss". It is reasonably masked when music is playing but clearly audible on quiet passages.
The eval board appears to be a close implementation of the reference design shown on the device data sheet.
There is a .01uF across the speaker output as the last stage in the output filter. There is no .01uF cap to ground. That is easy to implement & I will try that & see if there is improvement.
What is good to know is that this seems unusual to those familar with the TAA4100 chip. That gives me hope that the "problem" here is unique to this demo board and not the Tripath reference design.
Bearman said:
Nothing I can see at least.
Put a .01uF to ground from each speaker positive, no difference.
Shorted inputs, no difference.
Increased supply capacitance from 22KuF to 69KuF, no difference.
Check the solder joints on the biascap pin of the chip. Also check the solder joints of the cap connected to that pin. Reflow those and see if that helps.
BWRX said:
Will do!
And to everyone who has been offering suggestions as to what might cause this, thank you!
I appreciate it very much.
What voltage are you driving it?
It is exactly what happened in one channel of a SI T-amp I owned before it broke down (chip was damaged).
Unfortunately the chip just went up in price...
It is exactly what happened in one channel of a SI T-amp I owned before it broke down (chip was damaged).
Unfortunately the chip just went up in price...
I second Brian. Bad or no bias cap will cause hiss.
There was a whole bunch of Fenice boards that shipped that way last year.
Hsssssss......
There was a whole bunch of Fenice boards that shipped that way last year.
Hsssssss......
panomaniac said:
I reflowed but no difference. The bias cap is an SMT. I don't have any at hand so I think I will pull it and lap solder a lead type to the pads & see if there is any change.
I'm am betting there won't be and believe the issue may be either a bad TAA4100 or inherent issue in the demo board. The set early as I got it from Tripath right after the TAA4100 was released.
Is it a TAA4100 or TAA4100A? I read the version without 'A' became obsolete after they discovered there were problems with it.
Will try to find back the info...Kinda forgotten the issues of the problems, all the chips I used were 'A' version...
Will try to find back the info...Kinda forgotten the issues of the problems, all the chips I used were 'A' version...
Here's a link that proofs the version without 'A' became obsolete...
From the manufacturer's site.
From the manufacturer's site.
v-bro said:
v-bro, I think you nailed it!
I do indeed have the TAA4100 & not the TAA4100A.
They appear pin-for-pin compatible so I think I need to swap in the "A" version.
v-bro said:
Next week I am going to try & get one in the USA. If that doesn't work I'll likely be ordering something from 41hz anyway and I'll tag it along with that. In either case I'll post the results here once I get the TAA4100 swapped for the TAA4100A.
I bought a couple of AMP32's from Jan (really nice guy by the way) and I'm very satisfied with the quality, can advise this one to anybody!
They're so cute and small, must be the smallest amplifier in the world producing this kind of power...
They sound a bit more intense than the Audiodigit MC4x100 (using TAA4100A chip), the latter seems to sound more subtle. The AMP32 though appears as if it produces more detail and more powerfull bass (upto a certain level)...I guess the AMP32 mates very well with simple small speakers and therefore is excellent for portable use or high quality small systems. Or offcourse at home with reasonably high eff. speakers. The Audiodigit (have used this amp much longer) never gave me any listening fatigue on the other hand (surprised me a lot! Class D with ESLs!).
Too bad I can't connect the ESLs to the AMP32, it won't handle the impedance....But if I use my bookshelves (placed on to of the 10" woofer TL's I own the AMP32 really amazes....😱
They're so cute and small, must be the smallest amplifier in the world producing this kind of power...
They sound a bit more intense than the Audiodigit MC4x100 (using TAA4100A chip), the latter seems to sound more subtle. The AMP32 though appears as if it produces more detail and more powerfull bass (upto a certain level)...I guess the AMP32 mates very well with simple small speakers and therefore is excellent for portable use or high quality small systems. Or offcourse at home with reasonably high eff. speakers. The Audiodigit (have used this amp much longer) never gave me any listening fatigue on the other hand (surprised me a lot! Class D with ESLs!).
Too bad I can't connect the ESLs to the AMP32, it won't handle the impedance....But if I use my bookshelves (placed on to of the 10" woofer TL's I own the AMP32 really amazes....😱
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