Got another rebuilt Carver C-9 Sonic Hologram Unit. Updated power supply, and two TI 4136 op-amps replaced with sockets for simple changing in the future. $280
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Well thank you. A few folks from this site do appreciate what it actually takes remake or rebuild a unit to make it the best that can be. I have been doing these C-9 units so many years, I can't imagine how many that have been rebuilt over the years. never did this for money, and that's good because I mostly break even.
Tell me a bit about your system. That way I may be able to advise you better. Funny thing is, I don't really remember where this unit didn't show potential in a system. That, and the fact that it can be disengaged with a button if a certain recording doesn't require/benefit from it. I am easy to work with. Just go to US Audio Mart and see my feedback. I use '4krow' there and the unit is listed at this time on that site.
Regards, Greg
Tell me a bit about your system. That way I may be able to advise you better. Funny thing is, I don't really remember where this unit didn't show potential in a system. That, and the fact that it can be disengaged with a button if a certain recording doesn't require/benefit from it. I am easy to work with. Just go to US Audio Mart and see my feedback. I use '4krow' there and the unit is listed at this time on that site.
Regards, Greg
I suppose that it would be good if I mention some of the things that are done for this rebuild. As so often is the case, a power supply can be improved for performance or output. I tried to improve both by replacing the original transformer with a larger unit that was easily capable of supplying current to some of the more hungry integrated circuits out there. For example, if you were to use a 2134opa (in concert with a brown Dog adapter because of the original pinout being different than most), you will quickly find that 2134opa wants much more current than the original 4136opa. Along with that, I chose to replace the original IN4004 diodes with faster recovery Vishay SF4007. Along with that, there is now an easy opportunity to bypass each diode with a .1 multilayer ceramic dip capacitor, which will reject RFI. And since we are all in there taking everything apart, it is also easy to slip on some ferrite beads coming from the transformer's secondary windings that are connected to the circuit board via wiring instead of a circuit board mounted transformer, which was originally the case.
Moving on, RCA jacks are now chassis mounted instead of circuit board mounting (yah, I don't prefer board mounting for some components). Manley Labs RCA jacks are the only ones that I have tried over the years that are consistently better than the originals. This is an important aspect for audio components, since the signal voltages are very small (1-2 volts at best).
Not stopping there, it has always made sense to me to add a couple of damping sheets to help make the unit have more solid feel and also not transmit any vibrations coming from outside sources to other possible sensitive components. Enough for today. I just wanted to get across the amount of effort that it takes to update and possibly improve these units for many more decades of service.
Moving on, RCA jacks are now chassis mounted instead of circuit board mounting (yah, I don't prefer board mounting for some components). Manley Labs RCA jacks are the only ones that I have tried over the years that are consistently better than the originals. This is an important aspect for audio components, since the signal voltages are very small (1-2 volts at best).
Not stopping there, it has always made sense to me to add a couple of damping sheets to help make the unit have more solid feel and also not transmit any vibrations coming from outside sources to other possible sensitive components. Enough for today. I just wanted to get across the amount of effort that it takes to update and possibly improve these units for many more decades of service.