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toolkit 27th November 2006 03:31 PM

SI T-amp - bad hiss in one channel
Just got one and powered it up, but there's a really bad hiss in the left channel. The music is there behind the hiss though so it's not a complete channel failure.

I've resoldered the input jack as one of the legs looked really badly done, no change. Some of the other soldering looks dodgy too.

Any ideas if there's an obvious component that could be the cause of this hiss?


toolkit 28th November 2006 04:09 PM

Oh great, and now the one channel that works is cutting out :xeye:

I'd heard there were quality issues.

Another one now on order, let's hope this one works. At least I can use the duffer for test-fitting if I get round to re-boxing it.

v-bro 29th November 2006 08:56 PM

Ther ARE quality issues, read the thread here:

But I had a similar problem on an AMP32 build from (very similar kind of chip, very very similar) the bias capacitor needed changing...overheated it with soldering I guess, funny the SMD parts all went well on the eight AMP32 kits I've built so far....Great alternative by the way, the chip seems to be able to handle a lot more abuse.

But all my T-amps from sonic impact died (had three of them babies:bawling: :bawling: :bawling: :bawling: :bawling: :bawling: )

Here's some pictures of my AMP32 builds (just scroll down....)

toolkit 29th November 2006 10:12 PM

Well, if I like the Tripath sound, I will either rebox the T-amp with some mods (got some Soniq caps for the input on order anyway) or combine that with an AMP6 build or buy an autocostruire kit anyway as they seem to last a bit better!

v-bro 29th November 2006 10:30 PM

Autocostruire is quite a good bet, I have an MC4x100 they sell. A very nice four channel amp with plenty of power and very good sound.
Don't know about the Fenice though... probably a very fine amp too...

But I am very very satisfied with the quality of the cheapest amp (amp32) and have just ordered the 12V version of AMP9 which is also four channel (sharing the same chip as the MC4x100) This amp delivers a lot more current than the TA2020 based amps (AMP6) and has only a couple of relatively large surface mount components ("little component count and pretty easy to build") funny it only costs 49 EUR.

The TAA4100A chip has proven itself to me to be virtually indestructible.
Shorted it accidentally a lot of times (use in car, cable between chair...:cannotbe: ) and used it on SLA batteries, NiCD, SMPS, tranny (MC4x100 has rectifier on board) connected it to ESLs...(TAA4100A can handle very tough loads)..

Pano 30th November 2006 12:15 AM

It does seem to be very easy to kill the inputs of the Sonic Impact. :dead: Don't know why....

I have a whole drawer full of dead ones that I hope to call "Lazarus" some day. ;)

v-bro 30th November 2006 12:28 AM

Me too!

I still have them, and must say I liked the sound quite well. Especially after some modifications, but the AMP32 (maybe due to the inductors, which appear very nice to me...) sounds better out of the box ("from the workbench")...

The TA2020 chip seems fine to me (I think it's the same chip package as the TAA4100A, not?) if higher power requirements or bi-amping are not one your wishlist..

I chose the versatility of the TAA4100A based amp...

I once read the TA2024 chip has problems (called internal fuses, how useless if they don't self-recover...) I'm curious if anyone knows where this information can be read again...I forgot....

v-bro 30th November 2006 12:47 AM

2 Attachment(s)
And I do find the board layout of Jan's amps (41hz) very nice (much space for good input caps, on AMP32 even the choice between smd and trough-hole types).

I have a hunch the reliability of Jan's amps is more than good...I made a couple of small mistakes during the builds which would probably have killed an SI-amp several times...(good protection circuitry in both TA2021B and TAA4100A, almost no need for Jan to sell them separately)...

Jan has good eye for detail and has presented himself as quite a nice guy sofar...(very quick email response also, good support, his own forum, soon a picture gallery.....)

And last but not least, looooooowww price!

Stick your hands out of your sleeves diyers and build!

:smash: :smash: :smash: :smash: :smash: :smash: :smash: :smash:

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