This is an easy to do replacement for the CP-50 raw power supply. Get yourself a Power-One, Model MAP110-4001 from Allied Electronics, or from a surplus house if you have one in your area that has lots of supplies around. I was able to get mine as new/surplus the other day for 25.00 new in the box! If you can't get one from surplus they're 120 dollars new from Allied. It is a switching type supply which is more efficient than the old toroid based unit anyway and very tightly regulated. I reccommend mounting this outside the CP-50 although it may fit on the right hand rack ear where the old supply sat. I just feel its better tog et the AC out of a high gain piece of gear altogether. Just feed it in though the white molex on the CP-50 backplane the same way the old supply fed in.
I did some testing with the 50's original supply before wiring in the new Power-One unit for more measuremants. They are as follows.

In a normal run of the mill 50 with all stock cards the voltages measured as follows.......
24 Volt Line was 27.85 Volts
12 Volt Line was 11.29 Volts
-12 Volt Line was -10.68 Volts
In this case the CP-50 plays back just fine although the DC rails are a bit off from what they should really be. This Dolby supply had recently been completely overhauled. New diodes, and all new low ESR electrolytic caps. This supply had several hundred hours on it at this point.

Now here is the clinker.....
Throw in a Cat 113C, a pair of Cat 280T's and a new 108C preamp card. and here's what happens.......

24 Volt Line is now 27.35 Volts
12 Volt Line is now 11.04 Volts
-12 Volt Line is now 10.49 Volts
The unit stopped playing at this point as the supply sags to low to operate all these hungry cards. The voltage LED's on the 113C card also appeared unevenly lit as though things were sagging a bit in the rail department.

With the new supply hooked in place of the old one, all three voltages measured with in .05 volts of where they are supposed to be. +24, +12 and -12 volts.
Am going to do some other measurements if I ever have time and add some film bypass caps to the rails on the backplane as well. I don't know at this point if the new supply will help better any of the other CP-50 specs, although the fader card and other related cards will be less likely to clip as soon as they would with the old supply so high quality SR playback will probably benefit. The S/N ratio might be just a tad better too but probably not by much. After a day of operation the new supply runs only luke warm. Its a 110 watt supply so its pretty over rated for the job at hand. There's plenty of reserve for running other accessories such as remote faders, or mag preamps.
Since this is my home unit I'll post more on this later this week after doing some listening tests and other measurements.
Mark @ Home

 |  IP: Logged

Here is a link to the PDF spec sheet that I should have included in the above posting. http://216.147.54.136/resources/products/datasheet/map110.pdf

 |  IP: Logged

 |  IP: Logged

It has been 2923 days since the last post.

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged