I have a Kenwood C2 preamp that isnt outputting any energy from the four small wires (white, yellow, black, red) of transformer to power supply circuit. Jumping the switch did nothing. Part number is L01-2776-05 Nothing found on ebay. Is there a toroidal or another center-tap transformer that could be accommodated? There is plenty of space for a toroidal.
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It looks like you need a 13v secondary and a 22v secondary - ideally from one transformer, but may need to use two. 12.6v filament transformers are easy to find. What current do you need from the 22 v secondary?
I looked up the schematic and service manual. It looks like what you need is +20v and -20v for almost all of the circuitry, the + and - 12v for the headphone amplifier and a headphone relay. Look at the block diagram in the attachment. Total power usage for the whole preamp is listed as only 12w, so it might be easiest to just focus on building a small PS to provide voltages you need.
Good ideas Ben, appreciate you looking at schematic.
I was leaning towards two transformers. I thought a dual 12+24 transformer would be easy to find for this application, but it’s not.
A custom split rail PS would give me an opportunity to put in something regulated.
I was leaning towards two transformers. I thought a dual 12+24 transformer would be easy to find for this application, but it’s not.
A custom split rail PS would give me an opportunity to put in something regulated.
Back on this...I misstated, I have a C1 not C2.
I need a recommendation on an adjustable regulator for the B+ of the 27VCD power supply I need to create.
My thoughts for the positive rail is to use this LDO regulator but I dont see one for neg polarity. Maybe there is something out there that can do both?
Here is snippet from the C1
I need a recommendation on an adjustable regulator for the B+ of the 27VCD power supply I need to create.
My thoughts for the positive rail is to use this LDO regulator but I dont see one for neg polarity. Maybe there is something out there that can do both?
Here is snippet from the C1
I attached a 24VAC transformer to pins 10,11, bypassed R64,65 and got +17/-17VDC. Close enough I may say.
Now I need to figure out how to incorporate the relay drive into the new regulated 12V supply I created.
Now I need to figure out how to incorporate the relay drive into the new regulated 12V supply I created.
It turns out I need the +-27v to power the phono amp, im going to have to shop for a larger transformer with at least a 40VAC secondary.
Would 40VCT @ 0.188amp provide enough current?
https://www.mouser.com/ProductDetail/Triad-Magnetics/F-157XP?qs=%2BfhPKvh1fqN%2BnKbbXY3bGg==
https://www.mouser.com/ProductDetail/Triad-Magnetics/F-157XP?qs=%2BfhPKvh1fqN%2BnKbbXY3bGg==