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Proton 1100 Pre-Amplifier not working

I have multiple bad capacitors that I need to replace.  According to a local audio repair shop, my muting relay circuit is also bad.  They said the parts were not locally available.  Does anyone know how I could go about getting one?  Is it possible to bypass this relay with a switch, and manually activate the switch after powering on the amp?
Thanks in advance for any help!

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  • tjalbrecht Feb 02, 2009

    No parts have been replaced yet, just diagnosed a little.  The capacitors show physical damage.  I would like to replace those, and try it out, but I am worried I will just blow whatever ones I install.

    Is there a logical process to follow besides replacing parts and turning it on?

  • tjalbrecht Feb 02, 2009

    I am in the Minneapolis, MN area.  Thanks for your help.

  • lwpdx1 Apr 01, 2009

    I have an AA1150 which did have a similar problem with the relays. The contacts were dirty. I popped the top off the relay and rubbed a piece of paper between the contacts to clean them. I'm sure this isn't a final fix but it works for now.


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The probability of a relay going bad is remote. This relay is part of the protection circuit and will not turn on if there are problems detected. If you can detail the parts that have been replaced, I may e able to determine the reason for the relay failure. Realize that some internal measurements may be required as well.


Posted on Feb 02, 2009

  • ABRsvcs Feb 02, 2009

    Yes there is a procedure, but it is rather involved and too much for this type of interaction. Where are you located? Perhaps I can recommend a shop. Unless there is a specific Ic for your unit (and I doubt it!) there is no reason for parts not being available. If the exact replacement is no longer made, there are substitutes that will work as well without any degradation in performance.



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