[bg4533]

I have a Teac AL700P digital amp that I am in the middle of modding.

So far I have:
-Removed center channel board
-Replaced the 1000uF/35V electrolytic on the amp board with a 1500uF Panasonic FC
-Removed potentiometer board and RCAs
-Added Cardas GRFA RCAs
-Wired RCAs directly to amp board
-Replaced the coupling caps on the amp board with 47uF Blackgate NX

I currently have a little problem.  When a source is hooked up to the amp I get a turn on pop.  When no source is connected I do not get the pop.  I put in the unmodded board and soldered the RCAs to it and same problem.  The problem seems to be related to the removal of the pot board.  Does anyone have any ideas about how to get rid of the pop?

I have only tested the amp with cheap speakers.  I have been afraid of testing it with nice ones.

While I am at it are there any other mods I should do to the amp?

[Wayne1]

47 uf is far too large. 4.7 uf is plenty big.

The Teac should not have any turn on pop as there is a delay between power on and when the relay engages.

There is 2.5 volts coming out of the Tripath chip into the coupling caps. Some of that "pop" may be from the far too large coupling cap charging up.

Run the RCAs to the input of the amp boards on the bottom of the main board.

[bg4533]

I tried the stock amp board (from the center channel, no mods besides direct wiring the RCAs) and still got the turn on pop.  It doesn't seem to be related to the coupling caps.  The 47uF caps were what I had around so I used them.

[Wayne1]

Have you measured the DC offset? There are two small pots on the amp boards that might have gotten moved while you were taking things in and out.

Try to get DC down to a couple of millivolts.