I am looking for help on the Palette unit in the Cello system. The internal power supply is putting out + and - 25 VDC and I think it should be + and - 15 VDC.
I do not have a schematic and do not know where to get one.
Any help would be appreciated!
I do not have a schematic and do not know where to get one.
Any help would be appreciated!
Please do not hack on this rare and expensive equipment without a proper schematic and parts list.
It is extremely unlikely that the power supply somehow changed its output voltage on both polarities.
Quote from paper: "Both the left channel and the right channel are operated from ±22 V"
It is extremely unlikely that the power supply somehow changed its output voltage on both polarities.
Quote from paper: "Both the left channel and the right channel are operated from ±22 V"
I have been working on this Cello equipment for years without schematics (the manuals do not exist, thank you Cello and Mark Levinson). Now I will have to attempt to make my own schematic by looking at the power supply board. I am not a "hack". I have kept 4 power amps, the preamp, and the Palette going for 20+ years and my cousin doesn't want new equipment.
For whatever it might help... I've seen Cello components, including the Palette, at George Meyer in West LA. I'm pretty sure they repair them in there.
You might ask them.
https://www.georgemeyer-av.com/
You might ask them.
https://www.georgemeyer-av.com/
I appreciate your contact information. The schematics and info you posted has IC's in it and there are none in the unit I have. Just a really large amount of transistors for what it does. They are all running in Class A and like everything else Cello, they produce heat. Each mono power amp consumes 400 watts with no signal. They heat his living room!
From the paper: "This design used a large number of integrated circuit op amps. Cello wanted to achieve the best possible performance and avoid any possible criticism of its op amps. They replaced the important signal processing op amps with their own proprietary discrete component op amps, greatly increasing the manufacturing cost. The final production circuit, aside from the op amp design, was simplified somewhat in order to use fewer op amps."
These schematics for a different but related product may also be of some use.
These schematics for a different but related product may also be of some use.
