[mega]

I posted this on the amp forums, but i guess this is a better place to post this...so here it goes.

I had a PPA going for sale for a while, but recently, i checked up on it just to make sure it was still in working order, but now something's wrong.

I made sure everything was plugged in, and everything was intact. When i play music, the sound is VERY distant...i can turn the volume knob up almost to max, and it sounds like the music is barley playing..

The L/R inputs on the back are kinda loose...not that they are coming out of the sockets or anything..but they aren't tight, and when i pull on them lightly, they seem very springy, as if as though they were to pop out.

I dunno whats wrong, so im asking you guys. I gotta sell this either way..broken or not..as i need some dough!

 

[enemigo]

Is there any noise in the amp? Like sparkling if you tap on the amp, pull the wires, fiddle with the volumecontrol or simply plays loud? Or is the volume just low without any distortion?

Tried different headphones? Does the amp smell? Some components smell when broken.

I haven't built the PPA myself yet, so I'm not really sure, just some ideas to get it started.

Knut

 

[mega]

Quote:

Originally Posted by enemigo Is there any noise in the amp? Like sparkling if you tap on the amp, pull the wires, fiddle with the volumecontrol or simply plays loud? Or is the volume just low without any distortion? Tried different headphones? Does the amp smell? Some components smell when broken. I haven't built the PPA myself yet, so I'm not really sure, just some ideas to get it started. Knut

Nope, i didn't hear any noise in the amp. No smell either. The volume is REALLY low and i wouldn't say the sound is distorted, but it sounds very distant and very thin and lifless, along with the very low volume. Everything seems fine with the amp physically, except with the loose input jacks on the back..

 

[bg4533]

Do you have a multimeter? If so start measuring. Check DC offset and the power on the opamp rails. Also check for continuity at all the plugs and places wires go it.

Are all the opamps seated correctly?

My guess is a ground is bad somewhere. Could be anywhere though.

Did you build this? I am guessing not. If you don't know how to solder and don't have a multimeter it is likely best just to send it to someone else to fix. That is unless you want to learn of course.

 

[Earwax]

When jacks are loose like that they can start spinning around as you plug/unplug cables. Too much movement and the wire connections inside can break. If you feel like opening up the amp you may be able to see something amiss pretty easily.

 

[mega]

Quote:

Originally Posted by bg4533 Do you have a multimeter? If so start measuring. Check DC offset and the power on the opamp rails. Also check for continuity at all the plugs and places wires go it. Are all the opamps seated correctly? My guess is a ground is bad somewhere. Could be anywhere though. Did you build this? I am guessing not. If you don't know how to solder and don't have a multimeter it is likely best just to send it to someone else to fix. That is unless you want to learn of course.

I don't have a multimeter, nor do i know how to solder anything..im not into the DIY

Well, Mister X built this amp for me, but some of you may know the history behind this amp...the guuy who had the amp replaced the original op-amps with the 627/637's, so he may have messed something up..

Is this something that might be easy to fix? Cause if it is, i would take a look at it to see if i could fix it myself...but if its something too complicated, then im not gonna even bother..like i said before, i have no knowledge on fixing/building amps.

 

[MisterX]

I will be more then happy to take a look at it.....

 

[mega]

Well just to get updated...

I opened up the PPA and the screws connected to the inputs on the back were a bit loose, so i tightened them up and popped everything back into place....nothing else seemed out of the ordinary.

Well, i tried my A900's with the PPA, and it seems as though it works fine with them...but when i tired my HD-650's, the same problem happened...very low volumes/thin sound even at max voulume.

Also, when i play my a900's with the PPA for a little while, the drivers get pretty warm....i can feel the heat when i wear them too.

Hope that helps some more....BTW, Mister X, i emailed you, but you didn't answer back...

 

[Pars]

Drivers in the headphones getting warm? Sounds like a DC offset problem (i.e., something is wrong in the amp).

DO NOT use any of your good phones to listen to this! Higer impedence phones like Senns, etc. are somewhat resilient to DC offset, but low impedence cans like Grados would get toasted by this.

Arrange to have MisterX look at it... he's a good guy and will take care of it for you properly.

 

[MisterX]

Quote:

Mister X, i emailed you, but you didn't answer back...

Yes I did.

 

[MisterX]

Anybody else see what the problem was?

 

[PeterR]

 

[steinchen]

no OpAmp for the ground channel ?

 

[Edwood]

Quote:

Originally Posted by MisterX Anybody else see what the problem was?

ROFLMFAO!!!!!

-Ed

 

[MisterX]

Yea... that was my first thought.
Then I remembered all of the nonsense Mega went through recovering this amp from a troll so I was not all that surprised to see said troll returned it like that.
Luckily none of the buffers were cooked.