Search found 17 matches

by 4thtimeaudiophile
Mon May 22, 2023 8:54 pm
Forum: Troubleshooting/problems/manuals/schematics
Topic: MV45 running too hot
Replies: 7
Views: 5987

Re: MV45 running too hot

I forgot about the ground loop possibility. Even though the MV45 uses a 2 wire power cord, there could still be something wrong there. So, there is no connection to the AC mains service ground on the chassis. However, I could have an imbalance on the two legs of my AC mains. There could be some DC o...
by 4thtimeaudiophile
Mon May 22, 2023 8:10 pm
Forum: Troubleshooting/problems/manuals/schematics
Topic: MV45 running too hot
Replies: 7
Views: 5987

MV45 running too hot

I know that the MV45 will run hot because it is a tube amp. But.....everything gets hot including the chassis. It is more than just warm to the touch. The EL34's are good and they hold bias as well. There is some mechanical hum which I attribute to transformer delamination, due to its age. It sounds...
by 4thtimeaudiophile
Thu Mar 02, 2023 8:00 am
Forum: Amplifiers
Topic: MV60 transformer hum
Replies: 34
Views: 2202

Re: MV60 transformer hum

I may have a schematic for this. Otherwise, there may be one available here on this forum. I will see what I can find out. You have the "SE" version. So, there is a slight difference between your amp and mine. I quick suggestion, if you have not done so already, is to take the bottom cover...
by 4thtimeaudiophile
Sat Jan 21, 2023 7:59 am
Forum: Amplifiers
Topic: MV60 transformer hum
Replies: 34
Views: 2202

Re: MV60 transformer hum

I am not sure if I am hearing the dull thump as you describe it. I am hearing something as the power supply fades into oblivion. Whatever it is, I don't seem to be bothered by it. Like most of us, at some point in our years of listening, we have heard much worse come out of our amps. This is not lim...
by 4thtimeaudiophile
Thu Jan 19, 2023 12:02 pm
Forum: Amplifiers
Topic: MV60 transformer hum
Replies: 34
Views: 2202

Re: MV60 transformer hum

I have never removed the rear transformer cover on the MV60 as there really never was a need to. Even though I have a mid-range hearing loss, being a discriminating listener has taken me in the direction of listening for nuances (except for my wife's voice, which is not a nuance). At my last job, we...
by 4thtimeaudiophile
Thu Jan 19, 2023 8:41 am
Forum: Amplifiers
Topic: MV60 transformer hum
Replies: 34
Views: 2202

Re: MV60 transformer hum

Good idea with the plastic washers. I know that I have something like that. They could be teflon or delrin. There are other materials that I could try. My concern is that it may cause an alignment problem with the two allen head screws that connect the cage to the front panel on the left side.
by 4thtimeaudiophile
Wed Jan 18, 2023 9:16 pm
Forum: Amplifiers
Topic: MV60 transformer hum
Replies: 34
Views: 2202

Re: MV60 transformer hum

I removed the tube cage and the hum went away. I re-installed it and tightened it down good. There is just a bit of hum but you have to really listen for it. Thanks to everyone's input, I have a lot more insight into these types of problems.
by 4thtimeaudiophile
Wed Jan 18, 2023 6:56 pm
Forum: Amplifiers
Topic: MV60 transformer hum
Replies: 34
Views: 2202

Re: MV60 transformer hum

Thanks for the good advice. I will work on tightening the screws. I just hope that the transformers are not beginning to delaminate.
by 4thtimeaudiophile
Wed Jan 18, 2023 12:15 pm
Forum: Amplifiers
Topic: MV60 transformer hum
Replies: 34
Views: 2202

MV60 transformer hum

I am getting some "mechanical" hum from the transformers in my MV60 power amp. I have the identical issue with my MV45. I resolved it, sort of, by removing the cage on the MV45 and running it with the tubes exposed. Since the MV45 is my "backup" power amp, it does not get used re...
by 4thtimeaudiophile
Mon Dec 06, 2021 9:33 pm
Forum: Non-CJ Products-Audio
Topic: Do any of you kind folks have experience with the Oddwatt Audio Forewatt?
Replies: 3
Views: 260

Do any of you kind folks have experience with the Oddwatt Audio Forewatt?

Just to give a little background - I own a CJ MV60 and it is my humble opinion that it deserves a better line stage preamp than the Emotiva PT-100 that is currently feeding it. I found the Oddwatt Audio Forewatt line stage kit online and they are in stock. It seems like it is good quality - Alps Blu...
by 4thtimeaudiophile
Sat Dec 04, 2021 2:38 pm
Forum: General Discussion - CJ related topics
Topic: Recap is a must?
Replies: 19
Views: 1738

Re: Recap is a must?

A friend of mine has an old Fisher tube amp that he has had in storage for quite some time. I offered to buy it from him, but it is a keeper for him. So, I have made an offer to recap it for him. I would do it at no cost just to keep the venerable old Fisher alive. In this case, all of the electroly...
by 4thtimeaudiophile
Thu Dec 02, 2021 8:49 pm
Forum: Off-topic
Topic: Biggest disappointment in equipment sound quality?
Replies: 14
Views: 4764

Re: Biggest disappointment in equipment sound quality?

My most recent recollection of a disappointment would be an Adcom GFP-555II preamp. I bought this from a friend for $100 when I was getting back into audio for the 4th time in my life. I was using it on the bench to switch source material for my DIY 6L6 SE amp. It ruined the class A sound of the tub...
by 4thtimeaudiophile
Thu Dec 02, 2021 8:04 am
Forum: Amplifiers
Topic: Premier 140 and MV60- Respect?
Replies: 37
Views: 3492

Re: Premier 140 and MV60- Respect?

In my limited exposure to CJ, I am unable to disrespect anything that CJ makes. My first CJ amp is an MV45. I bought it from my friend Bill for $200. I had to replace the power switch, a power supply electrolytic cap and the RCA input jacks. Bill had lived close to the CJ factory in Virginia. He had...
by 4thtimeaudiophile
Sun Jan 15, 2017 8:58 pm
Forum: Troubleshooting/problems/manuals/schematics
Topic: Help with an MV45(a?)
Replies: 4
Views: 1371

Re: Help with an MV45(a?)

RJ, Thanks for the compliment. As a young lad, I cut my teeth on vacuum tubes. Now, almost 50 years later, I am trying rekindle this old friendship. In 11th grade in high school, my entire term of electronics class was on vacuum tube and their circuits. I have not worked with them too extensively ev...
by 4thtimeaudiophile
Wed Jan 11, 2017 11:03 pm
Forum: Troubleshooting/problems/manuals/schematics
Topic: Help with an MV45(a?)
Replies: 4
Views: 1371

Re: Help with an MV45(a?)

I have resolved the problem. There were quite a few runs on the circuit board that were cut, as part of the factory update, I assume. There was one which had flashed over, so I had assumed that run was burnt instead of cut. I mistakenly bridged it with a jumper wire. When I cut the jumper out, the p...
by 4thtimeaudiophile
Sun Jan 08, 2017 7:48 pm
Forum: Troubleshooting/problems/manuals/schematics
Topic: Help with an MV45(a?)
Replies: 4
Views: 1371

Help with an MV45(a?)

I recently acquired an MV45 from a friend. It had been in storage for quite some time. I removed the top cover and cleaned the dust from the chassis and tubes. I assumed that the amp just needed to be powered up for awhile before being used. I connected a pair of Polk bookshelf speakers and nothing ...
by 4thtimeaudiophile
Sun Jan 08, 2017 5:57 pm
Forum: Member Presentation Thread
Topic: Greetings and help with an MV45
Replies: 1
Views: 670

Greetings and help with an MV45

Best regards to the C-J owners on this forum. It was about 45 years ago when I was first introduced to vacuum tubes. I have re-kindled my interest in hi-fi and vacuum tube audio as well. Recently, I purchased an MV45(a?) from a friend who was the original owner and had some factory updates done in J...