Conrad Johnson MV55 again - and Hi from a newb

[Dunney]

Hi all from a UK Midlands newb.
I'm new to this forum but I'm hoping someone here may be able to help me.

The DC power supply in my CJ MV-55 has got fried.
I know nothing about tube gear repairs so I dropped it in with a fairly local vintage valve gear repairer. He's told me whats wrong but needs a schematic in order to be able to identify the replacement parts that are required and fix it.

Does anyone here know where I might be able to find and download a copy?

I'd really a[ppreciate any help you can give. This amp is/was my pride and joy and I really dont want to countenance the possibility that I may have to 'bin it' for want of a circuit diagram.

Thanks in advance,

Chris Dunne

 

[vinylkid58]

Hey Chris, why not contact CJ directly and ask them for a schematic. As this is an older amp, I'm sure they would oblige if you plead your case.

jeff

 

[Dunney]

Hi Vinylkid58,
Well, I took your suggestion and contacted CJ direct.
24 hours later and, Hey Presto, I now have a schematic.
I was very sceptical but there's no accounting for the kindness of others when you're in a jam.

Thanks to CJ and to you mate,
Chris 🙂

 

[Caonguyendang]

Hi,
I am sorry for steal the thread, but I don't have permission to start a new thread yet. Here is my question: My Conrad Johnson MV55 is having a left fuse blown out. Before that happened, I heard a distortion on the tweeter of the left speaker. When I looked at the amp, I see one of my power tube was so bright, it looked blue instead of red. I am ordering the replacement fuse for the amp. Should I change the tube and fuse and continue to hookup my speakers or should I bring the amp to a tech for checking up? Was the amp damaged inside or it is just the bad tube?
Thanks for your help.
Calvin

 

[kevinkr]

Could be a bad tube or it could be a component failure in the amp that caused the tube to go bad. In this case a visit to a tech might be best.

 

[Caonguyendang]

Thanks Kevinkr.
I am trying to locate a local technician to check my amp up. Is there any serious damage if i try to do a run test by replacing the fuse and tube before bring it to the tech?
Calvin

 

[azazello]

Caonguyengang, You have PM.

 

[Triodethom]

The channel fuses are plate fuses they are speced close to running current . one or both of the output tube is drawing excess current . Time to test the tubes. Check the tubes before replacing the expensive fuses . It should not damage amp . However do not waste the fuse.

 

[Caonguyendang]

Thanks everyone. The technician called me yesterday. The amp only had a bad tube and it made the fuse blown up. I already ordered the fuses (very costly, $57 for 10 including shipping). I love the sound of mv55. What other conrad johnson amp will give me more power with the same warm sound? Can a premier 11A replace mv55?
Happy Thanks Giving to you all.
Calvin