Plz Help i think iv'e just distroyed my amp

[Rixsta]

My zen 4 has been running fine until i just turned it on and i get a very load buzzzzzz.
it sounds like 50hz and it slowly fades away when i turn the amp off...

well it was working ok or perfect even, the transformer was a bit warm but thats all. and im running it bias at 1.5 amp

It's a zen 4 penultimate and it effects both channels dam it id only just today got it working and was enjoying the qualty and realising how bad mp3 actualy sounds too..

I do have one theory and that is i might of had a bad rca/phono connector on the input maybe the earth is faulty on it and cause the input transistor to blow..

[wuffwaff]

Rixsta,

do you use a shared power supply for the two channels? If so it sounds like a cap has gone.

William

[Rixsta]

theres two seperate windings on my toroidal transformer i have 1 rectifier on each and one cap on each rectifier

i think thats basicly a shared transformer

if i charge up a new good cap and put it onto the amp alone i will find out right?

[wuffwaff]

but do you use this supply for both channels?

If so check the caps and the wiring to the caps, if you´ve got an scope you should see a large ripple on one of the two caps (or on both)

William

[Rixsta]

but do you use this supply for both channels?

Yes

i have no scope but i will replace the cap's or one of them one channel at a time.
the cap's are different so i dont see why they would both go at the same time unlss the transformer killed them or too much power was drawn from the PS

[Rixsta]

Ok i know im only a ammiture at electronics but i just hocked up a 20v power supply to it and when i touch the ground of the speaker outs it buzzez. as if they were the inputs to the amp

[Panelhead]

Originally posted by Rixsta
Ok i know im only a ammiture at electronics but i just hocked up a 20v power supply to it and when i touch the ground of the speaker outs it buzzez. as if they were the inputs to the amp

Sounds like a grounding issue. Check all your solder joints and pull on wires to verify good connections.
If you used the Passdiy boards, check solder connections. It takes a 40 watt iron to make good connections on some of the ground plane pads.

George

[Rixsta]

thanks

Iv'e just fond out my amp is ok it's my graphic eq thats gone wrong makinmg a badd hummm

cheers