ManhattanUp
Active Member
Greetings!
I'm looking to put a little love, time and $ into my MC2125. It appears to be working well enough though I note two anomalies: one (minor I think) is that the Watts position on the left meter doesn't seem to be working at all and second that it appears to be putting out much less power (as measured in DB using a pink noise test signal) than my recently refurbed MC2105. It's running with the faders all the way open while the MC2105 is set about 2-3 o'clock for equivalent SPL. OK, possibly that's a red herring but I figured it's worth putting out there as another variable. Mostly I am guessing that at it's age, some of it's parts could use replacement and I enjoy these projects.
I have already read through a number of relevant threads on work performed by other MC2125 owners and have begun putting together a parts list for the refurb, though I need some help with the caps. However, I see two possible workflows in front of me and wanted to get some opinions from folks wiser and smarter than me before doing anything. I want to do this right and efficiently. So…
Workflow #1 would simply entail shotgunning parts. To me that means replacing caps, pre-driver, driver, and output transistors, as well as the emitter resistors. It's a simple and straightforward approach which possibly replaces components that might otherwise be working just fine. On the positive side, it minimizes the number of times I'm inside mucking about inside with tools and soldering iron. On the downside, I might be missing some other less obvious details that need addressing.
Workflow #2 would entail spending time tracing and measuring signal through the left and right circuit pathways, looking for weak and/or failed components and only replacing these. I would likely need some assistance interpreting my results as well. The risk of this approach, if I had to hazard a guess, is that as weak/failed components are replaced, they may in turn put new stress on marginal down-circuit components that precipitates their failure and necessitates replacement. So I'm possibly having to perform multiple "surgeries" where in Workflow #1, I'm in and, hopefully, out once or twice at most. On the plus side, I'm catching more details and possibly replacing some less obviously important parts.
That's it. Looking forward to your input on this…
Michael
I'm looking to put a little love, time and $ into my MC2125. It appears to be working well enough though I note two anomalies: one (minor I think) is that the Watts position on the left meter doesn't seem to be working at all and second that it appears to be putting out much less power (as measured in DB using a pink noise test signal) than my recently refurbed MC2105. It's running with the faders all the way open while the MC2105 is set about 2-3 o'clock for equivalent SPL. OK, possibly that's a red herring but I figured it's worth putting out there as another variable. Mostly I am guessing that at it's age, some of it's parts could use replacement and I enjoy these projects.
I have already read through a number of relevant threads on work performed by other MC2125 owners and have begun putting together a parts list for the refurb, though I need some help with the caps. However, I see two possible workflows in front of me and wanted to get some opinions from folks wiser and smarter than me before doing anything. I want to do this right and efficiently. So…
Workflow #1 would simply entail shotgunning parts. To me that means replacing caps, pre-driver, driver, and output transistors, as well as the emitter resistors. It's a simple and straightforward approach which possibly replaces components that might otherwise be working just fine. On the positive side, it minimizes the number of times I'm inside mucking about inside with tools and soldering iron. On the downside, I might be missing some other less obvious details that need addressing.
Workflow #2 would entail spending time tracing and measuring signal through the left and right circuit pathways, looking for weak and/or failed components and only replacing these. I would likely need some assistance interpreting my results as well. The risk of this approach, if I had to hazard a guess, is that as weak/failed components are replaced, they may in turn put new stress on marginal down-circuit components that precipitates their failure and necessitates replacement. So I'm possibly having to perform multiple "surgeries" where in Workflow #1, I'm in and, hopefully, out once or twice at most. On the plus side, I'm catching more details and possibly replacing some less obviously important parts.
That's it. Looking forward to your input on this…
Michael