formula sound

[formulafan]

Good evening too you all, I have a much loved formula sound PM90 mixer in need of attention . This unit was loaned some time ago ,and when returned it was broken ,the mixer was run on a bad generator and damaged the psu 4 . I rang Formula Sound and after a brief consult the problem was solved , a bad humm. I replaced all the voltage regulators and problem solved. for about 4 months . So I decided to change all the regulators again in case 1 was damaged and also all the smoothing caps . all worked perfect for about 2 months now the humm is back again, this is the strange thing it takes about 2/3 hours of use before it happens then it gets worse as the night goes on . I have used the unit with different amps , decks even speakers, I have changed all the leads pat tested the mains cables everything I can think off and still no joy. I am going to change out the 15 in4004 diodes next just to see. I rang Formula Sound again and rightly so the suggested I send the whole unit back to them for a repair job , but I feel it my be more than its worth, I just don't want to admit defeat. I use the machine 2/3 a week in different venues and until now it has never let me down in over 20 years of service, apart from pots fader's etc any help would be greatly appreciated. I have used many mixers but I must say it has the richest sound through any system .

Regard and thanks in advance

Formula Fan

[djmatthill]

Hi there ,

 

Not sure what the issue is ,, BUT ,, if you think it could be a PSU problem

 

it just so happens that I have a couple of PM90 external PSU`s up for sale

if you are interested .

 

 

Matt

[formulafan]

Cheers Matt sorry for the late reply I am working weekends for the last while and didn't get much of a chance to reply.

how much are you looking for the formula sound psu4