Noise om my modified SI T-amp

[Plydsen]

Hi Audioguys!

I've just completed modifying my new SI T-amp - adding premium terminals and RCA's and connected it to my Elna/MiniMelf attenuator. I changed from batteries to a 12V/2Amp PSU. I followed pretty much the mods sugested by David Holgate of TNT (www.tnt-audio.com).
The amp is working "fine" but it is incredible noisy. I should say that 1/3 of the signal is pure and steady "white" noise, and it is present whether I have my audiosource running or not.

Can anyone help my out on this one?

Best regards,

Plydsen

 

[Mick_F]

This is definitely not normal. Did you have such a high noise level also before you modded the amp?

Mick

 

[BWRX]

can you try hooking up a different source? if so, see if the noise is still present.

 

[Plydsen]

Hej Mick

Unfortunately I didn't try the amp before the mods. I guess I was to eager getting the magic... Quite a mistake.

Plydsen

 

[audio1st]

Have you tried it with a different power supply, say a 12v car battery?

 

[Plydsen]

BWRX and Barry -

Unfortunately... Noise on all sources - also using a 12V batterypac

I've ran through another check without finding any anomalities - may I conclude that this little thing let me down in the first place?

Plydsen

 

[Mick_F]

may I conclude that this little thing let me down in the first place?

That would not be too surprising. When I first bought the SI I ordered two and only one worked.

Mick

 

[BWRX]

I have an AMP3 and also had some noise problems - a white noise type sound similar to what you described. Jan pointed out that the noise may be due to a bad solder joint at the biascap pin on the chip or around one of the 0.1uF decoupling caps. The biascap pin on the TA2024 is pin 16. Pin 1 is the pin closest to the triangular corner on the chip and pin 16 is the third pin up from that side of the chip. Check that joint and go over it with your soldering iron and any other solder joints that may look really dull or lumpy. My AMP3's noise was greatly reduced when I resoldered the biascap pin and redid some of the 0.1uF joints.

 

[Plydsen]

Mick and BWRX and Barry!

Thanks for your various contributions...

I ran carefully over the joints with my solderion with no improvements whatsoever....

So I must admit that I just ordered an Amp6 by 41hz.com and committed the SI to the dustbin... still, the Class-D is a fun and affordable hobby.

Thanks for you time and efford,

Plydsen

 

[BWRX]

Sorry to hear you couldn't get the amp working.

So I must admit that I just ordered an Amp6 by 41hz.com and committed the SI to the dustbin... still, the Class-D is a fun and affordable hobby.

Good to hear that it didn't discourage you from joining the tripath party

If the AMP6 sounds anything like the AMP3 you made a wise purchase!

 

[zanash]

I've been tweaking my T-amps and had something similar......Check the routing of your wireing, my problem was a hard wired component was too near to the board ....just bent it out by a couple or 5mm and now sounds fine [ as quiet as its twin !] but good advice in checking your solder joints.