t-amp stealth mod problem - no sound output at all...

[stephanko]

Well, did the stealth mod and put the t-amp in another case. The only problem: nothing coming out. No music, no hiss, no squeal, no nothing.

Power seems ok (light comes on, chip warms up)
C3 and C4 bridges seem ok.

Any idea where to look and what to check for?

Thanks.........

[Saturnus]

Proper shorting and removal of board components.

Correct phase if you use electrolytic capacitors.

Try removing the caps, and connect inputs directly to source.

Ensure source outputs a signal.

If none of that helps I'm at a loss.

[Pano]

Originally posted by Saturnus
Try removing the caps, and connect inputs directly to source.

Do NOT do this! The Tripath inputs are biased at 2.5V. You must have the input caps in place.

All the other advice above is good. Let us know what you found. Also, see your email.

[Saturnus]

Originally posted by panomaniac


Do NOT do this! The Tripath inputs are biased at 2.5V. You must have the input caps in place.

Yeah, I should have mentioned "briefly". Mine didn't take any damage when I did it at least. Maybe just luck.

[stephanko]

a first few answers:

- input caps are MKPs, no polarity
- iPod (source) output works fine
- removed R01, R02
- bridged C3, C4
- replaced C10 w/ Panasonic FM 1000uF/16V

- have a look at the sample picture R02/C3 for my 'craftsmanship'

[Davet]

Did you replace the stock SI volume control?

If so, make sure that you wire the VR exactly as shown in the diagram. Insure that the last two wires coming from the board to the VR are not conencted if you replaced the VR.

If these wires are connected to the new VR as grounds - you will be shorting the input to ground. Thus no sound. Check the comnnections to your VR closely.

The Tripath chip is very resilient. Once you correct the problem it will make music.

[stephanko]

Yes, I did replace the pot with an Alps. Forgot to mention this earlier.

And yes, the two last wires of the ribbon cable (opposite end to the switch wires) are not connected to anything. Right now, they are just hanging in the air.

Any more ideas?

[Pano]

Looking at your photo it is possible that your cap bridges are not good. With the amp on, touch each bridge with the tip of your finger. Do you get a hum or buzz in the speakers?

If you can not get your fingers in there, use a small bit of bare wire. The idea is to couple the noise picked up by your body into the circuit.

[cpemma]

Originally posted by panomaniac
Looking at your photo it is possible that your cap bridges are not good.

I found it far easier to bridge the cap gaps with a bit of tinned wire; just hold in place with a knife edge and touch with the iron.

[Davet]

Did you add RCAs for the inputs directly to the Alps VR as in the diagram?

If so check what Panomaniac suggest (bridges) first. Then check the grounds with a multimeter to insure there is continuity from inputs to VR. VR to PCB. Input to speaker outputs.

As an aside are the small caps still there for the speaker outputs?

At one point I had not replaced mine at the outputs and I got no sound through my test piezo tweeters.