Need a help: Mark Levinson No26.

[anubiz84]

Hello...

I got a ML No26 without the PLS 226 from one of my uncles. In here in Sri Lanka we do not have a Mark Levinson dealer or service center. So I made my own power supply for it. my input voltage per channel is +18V 0V -18V. and for the relays, its 12V. Pre-amplifier is working now. But I need to know the factory input voltage for this. Please let me know if anyone knows.

Even though it sounds one resistor got burn. I am attaching a picture & you guys can find the resistor marked in RED. Please let me know the value of the resistor & the function of that resistor in the main output board.

I am very new to this Hi Fi stuffs. So need a hand to sort the thing out. Thanks Alot.

Regards,
A. Perera.

 

[orthoefer]

This might be of some assistance: DIY forum link

 

[anubiz84]

Thanks. I am going to improve my supply according to that diagram. Thanks again. Resistor burn issue remain. Can anyone assist?

 

[stellavox]

As the link shows, the power supply only sent rectified/filtered voltage to the preamp. The regulator is in the left center of the picture. Look for the 6 jumpers going up to the input board, they are +,- and common and should be +/-18 volts, adjusted by the 1K pots near the jumpers. Adding in 6 or 7 volts of "headroom", The outboard supply should be +/- 24-25 volts or so.

Believe the resistor in question is 10 ohms. Could have overheated because of a bad electrolytic nearby. Replace ANY brown-cased "RDE" electrolytics you see inside - all prone to failure.

Charles

 

[anubiz84]

Hi Charles...

Thanks for the information. I replaced 10 Ohm half watt resistor. But that one also started to burn after some time. I did a voltage test after that. I checked the voltage between two soldering points of that resistor. It was 0.3V when it cold. Then I checked it again after running for one hour. The reading was 18.2V. Do have any thing to say about that?

 

[anubiz84]

FYI, I did the above voltage test after removing the resistor

 

[stellavox]

I have two of these units to work on - will try to figure out what the resistor does. Just to be sure we're talking the right one (on my units it is soldered on the bottom side of the board) - what other components is it connected between?

Charles

 

[anubiz84]

My unit is Mark Levinson No26. (NOT No26S). YES, that resistor soldered on the bottom side. The thing is Charles, My unit sounds perfectly alright. Only thing I am not getting any effect by Stereo/ Mono switch. I checked, now its on Stereo mode.