[Madcat05]

I hooked up my pimeta and when I turned it on I get the right channel but no left. Along with there not being a left channel, after about 10-15 sec the sound fades out and I get a crackling noise and then the sound fades out.

unfortunalty I don't have a DMM right now so I can't do a real test.

Anyhelp? Thanks.

 

[eyevancsu]

Is your pimeta cased up? If you mix the input and output grounds on your pimeta (like using a metal case), it will cause the sound to fade out after a few seconds, and cause your tle2426 to overheat (scald your fingers).

This may not apply to you, but it happened to me a while back.

 

[Madcat05]

no it isn't cased yet, it is sitting on my wood desk. wood wouldn't affect the amp would it?

 

[tangent]

If you've soldered jacks onto the cables running to the board, desolder them and use alligator jumpers to attach the cables. You may have damaged one of the connectors with your soldering iron, which can make chips overheat and shut down; that's what your symptom sounds like to me.

Any other tests I'd want you to do will require a meter.

 

[Madcat05]

Well I regrounded the inputs and I'm getting both channels now.

But in both channels there is crackling and its as loud as the music.

 

[tangent]

Go over all the connections. If your input jacks' soldering wasn't good enough, other joints may be bad, too.

Are any of the chips getting hot?

 

[Madcat05]

nope, no chips are hot. they are are all cool.

should the buffers be flush with the sockets? Because mine are slightly raised. I don't think I pushed them in all the way.

 

[Madcat05]

Well I'm not gettting any crackling anymore. But I still can't get the left channel.

EDIT: The AD8620 is getting hot when the amp is on now.

 

[tangent]

Quote:

I don't think I pushed them in all the way.

Push firmly down on them. If they go down farther, they weren't in all the way. If they don't move, they're in.

Quote:

The AD8620 is getting hot when the amp is on now.

It's oscillating or damaged. Swap in another dual op-amp to figure out which.

 

[Madcat05]

Can I push the buffers while they are soldered to the sockets?

Is the OPA627 or the OPA637 dual? And I don't have any browndog adapters either.

And what does oscillating mean again?

 

[tangent]

Quote:

Can I push the buffers while they are soldered to the sockets?

If they're soldered, contact is as good as it's going to get.

Quote:

Is the OPA627 or the OPA637 dual?

It's quicker for you to ask that and wait for an answer than to read the datasheet and find out?

Quote:

what does oscillating mean again?

The Search button is your friend.

 

[Madcat05]

Ok I'll search next time. I contacted my supplier of the opamps to see if they were working when he had them.

When I first turned on the power I didn't know how far to puch down on the opamps. So they were just sitting on the sockets, then I pushed them in while the amp was on. This could probably affect them right? And if could the AD8610 isn't getting hot.

 

[tangent]

Quote:

I contacted my supplier of the opamps to see if they were working when he had them.

That's helpful to know, but not conclusive. There are many ways to kill a chip, and it can happen at any stage after your supplier pulled them out of their test rig.

Quote:

This could probably affect them right?

Possible, but I wouldn't bet on it. Usually when a chip isn't fully inserted, it just doesn't work.

Can you go down to Radio Shack and pick up a TL082 to test with? It'll run you $2.

 

[Madcat05]

Ya I can get a TL082 today.

 

[Madcat05]

I didn't find any TLO82s at Radioshack. I also put a OPA637 in and I get only the right channel. I also have to turn the volume up all the way to hear it.