Quad 44 - problems with used preamplifier

Hi, to all
I have bought used on ebay an QUAD 44 preamplifier. I have found the filter on the push-button of ignition is broken. I ask to you if it's necessary and with what I can replace such member.
The slot where it is present the input phono do not sound on the left channel, but moving the card on an other slot this works correctly. I suspect that the problem is on central board therefore
I have replaced all the condensers on the central motherboard with new condensers that have same capacitance but advanced tension.
After some minutes of operation all led begin to ignite itself and to extinguish and feels a metallic noise like if the relè of the commutation of the incomes were activated and deactivated. There is someone that can gives some suggestion to me on what to control and like?
Thanks.
 

dizt3mp3r

Member
2011-07-13 10:25 pm
I know it is an old thread but if you have a Quad 44 that is operating on one channel check the four or five TL07n opamps on the switching board. There is an electrolytic cap sitting directly next to one of the op amps and if it has spilled it's guts over the opamp it could have damaged the adjacent op amp. This is what happened on a Quad 44 I recently repaired. Replacement of the opamps is a good thing to do in any case, inserting gold plated sockets in place of the old opamps so you can upgrade in the future to OPA627s. BB 134s did suffice for the moment to make it sound very sweet indeed.