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Did you clean the controls or scope to see where the signal stops before you gut it?
mike@itx
New Member
I am going to clean controls with Deoxit, just downloaded service manual going to trace signal to pinpoint the problem. I think replacing all the 40+ year old lytics will be good, what do you think?
MACKIE1975
Super Member
Fix the issue then recap
kevzep
Its all about the Music
Fix the issue before doing anything else to the unit.
It could be anything from an intermittent switch, balance pot, volume pot, some connection somewhere, I am not sure if the C32 has them, but Mc like to use Jfets for muting, so could be that, usually not too difficult to find this sort of fault...
It could be anything from an intermittent switch, balance pot, volume pot, some connection somewhere, I am not sure if the C32 has them, but Mc like to use Jfets for muting, so could be that, usually not too difficult to find this sort of fault...
I agree with others, if you have schematics and scope or signal tracer and average skills it is very easy to trace signal and find where is lost. Print or follow block diagram and you can easilly find where and on which board signal is lost. Fix that and then restore it.
Sure, capacitors should be changed, switches and pots cleaned and all solder points checked. But first, try to fix problem.
I would leave all opamps original. If you change them, it will not be the same preamp as original. Will it be better if you change opamps - it depends. I preffer as original as can be, but this is just my opinion. Any newer (and perhaps better) models have different design and schematics and are using 'newer and better' parts. This model was in production for couple of years and was made as best as can be. This is why I preffer originality.
Look at many threads about this preamp.
Sure, capacitors should be changed, switches and pots cleaned and all solder points checked. But first, try to fix problem.
I would leave all opamps original. If you change them, it will not be the same preamp as original. Will it be better if you change opamps - it depends. I preffer as original as can be, but this is just my opinion. Any newer (and perhaps better) models have different design and schematics and are using 'newer and better' parts. This model was in production for couple of years and was made as best as can be. This is why I preffer originality.
Look at many threads about this preamp.
mike@itx
New Member
I went ahead and recapped unit along with new cables sounds great!
Had a noisy transistor on tone board @1500Khz right channel.. fixed with a new Motorola MPSA14.
Replaced NE5534N's with NE5534AN's
Waiting for a new glass front from Mac.
Reflowed all molex type headers and RCA connectors on the I/O boards
Had a noisy transistor on tone board @1500Khz right channel.. fixed with a new Motorola MPSA14.
Replaced NE5534N's with NE5534AN's
Waiting for a new glass front from Mac.
Reflowed all molex type headers and RCA connectors on the I/O boards
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Looks like you did a great job, congrats.
I always liked the MC2205 also, just a great workhorse that looks all McIntosh.
Regarding replacement glass, did you look for NOS elsewhere? Some of the usual McIntosh dealers/repair shops have them and the older glass has the correct gold that lights up green, new ones from McIntosh do not.
I always liked the MC2205 also, just a great workhorse that looks all McIntosh.
Regarding replacement glass, did you look for NOS elsewhere? Some of the usual McIntosh dealers/repair shops have them and the older glass has the correct gold that lights up green, new ones from McIntosh do not.
mike@itx
New Member
HelloJeff.
Thanks!
I did not realize the difference on the glass, I will look to see if I can find an older NOS with the correct gold.
Mike
Best of luck Mike, it seems to matter more to some of us than to others, wish they'd make it like original though!
Excellent recap as this was NEEDED, I find it a common theme in this form when I had Recap my "3" 4100's... why are you doing this? I would also look into replacing the
Ribbon Cables as to a clause of noise which the ribbon cables will delaminate. When I also Recapped a C32, a Audiokarma member sold a kit on FleaBay "McIntosh C32 Preamp Flat Ribbon Cable Kit".
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I'm afraid to ask, what happened to the glass?