Trying to find out how to determine the differences/identifying features of the MV-75/a/a1. I have owned all three, sent an "a" back to be updated a million years ago and used to work for the local dealer where I coordinated a bunch of updates. Never found out what the differences were- probably wasn't concerned at the time. Tried CJ- they don't answer the phone or reply to emails.
TIA!
MV-75 Versions
Re: MV-75 Versions
We have all three schematics in our database I believe. If you pull the schematics, you should be able to see the difference (unless perhaps the components were simply upgraded with better quality but same spec replacements).
-admin
Home Theater in Member Gallery
Main stereo: ART Amplifier and ET7s2. 2nd stereo: PV-14L and MV-55. Previously Owned: PF2 preamp, Evolution 2000 Amp, PV-12AL preamp, D/A-2b Vacuum-Tube Digital Processor.
Home Theater in Member Gallery
Main stereo: ART Amplifier and ET7s2. 2nd stereo: PV-14L and MV-55. Previously Owned: PF2 preamp, Evolution 2000 Amp, PV-12AL preamp, D/A-2b Vacuum-Tube Digital Processor.
-
AnotherJohnson
- Ultimate
- Posts: 5219
- Joined: Sun Apr 26, 2020 12:29 pm
- Location: Tennessee
Re: MV-75 Versions
I happened on the answer while listening to Kenny Burrell & John Coltrane tonight.
I was browsing the December 2020 issue of TAS … I’d run across it in a closet while looking for a map.
In any event, Bill & Lew were written up for their induction into the TAS High End Audio Hall of Fame, and in the write up some of their accomplishments were cited, including discussion of the MV75.
Here’s what they said.
MV75A upgrade provided high voltage fuses for protection against power tube shorts and replaced Mylar caps with polypropylene.
MV75A-1 upgrade reduced the impedance of the regulated power supplies for the voltage-gain and phase-inverter stages.
Incidentally, Kenny and John recorded this album in 1958 as John was easing out of Miles Davis’s band. Rudy Van Gelder was the engineer. This is another true Jazz Gem.
- image.jpg (2.11 MiB) Viewed 681 times
In any event, Bill & Lew were written up for their induction into the TAS High End Audio Hall of Fame, and in the write up some of their accomplishments were cited, including discussion of the MV75.
Here’s what they said.
MV75A upgrade provided high voltage fuses for protection against power tube shorts and replaced Mylar caps with polypropylene.
MV75A-1 upgrade reduced the impedance of the regulated power supplies for the voltage-gain and phase-inverter stages.
Incidentally, Kenny and John recorded this album in 1958 as John was easing out of Miles Davis’s band. Rudy Van Gelder was the engineer. This is another true Jazz Gem.
It’s just stuff. I like mine. I hope you like yours. I probably like yours too.
-
Big Dog RJ
- Ultimate
- Posts: 2361
- Joined: Sun Sep 07, 2014 6:30 am
- Location: Melbourne, Australia
Re: MV-75 Versions
I think the MV75 was definitely one of those special amplifiers that endured all the hallmarks of CJ's golden glow. It had this special sort of musicality that was very hard to match. Partnered with the right gear, it was an absolute pleasure to own. Later on the MV60 replaced it, also replaced the mv55 and Premier 11A. The MV60SE was another special unit offering great sonic and that wonderful tonality. After that last MV and PV series gear, everything that came after offered more neutrality and more of the recording was transparent.
It's pretty amazing to have experienced these changes as the business morphed but now I'm not sure whether CJ will ever consider an affordable line, such as the mv or pv series. Having said that even their new classic series is rather pricey and the ART series is way up there... these are for the big boys with big toys!
Anyway, always nice to see some CJ vintage gear getting some love... enjoy those fine tunes!
Btw, AJ mate, I've got that album on vinyl, it's outstanding I must say.
Very very nice. A big woof on that one!
Woof!!! RJ
It's pretty amazing to have experienced these changes as the business morphed but now I'm not sure whether CJ will ever consider an affordable line, such as the mv or pv series. Having said that even their new classic series is rather pricey and the ART series is way up there... these are for the big boys with big toys!
Anyway, always nice to see some CJ vintage gear getting some love... enjoy those fine tunes!
Btw, AJ mate, I've got that album on vinyl, it's outstanding I must say.
Very very nice. A big woof on that one!
Woof!!! RJ
Re: MV-75 Versions
My plan is to go through this one and update the wiring, caps, etc. I have been searching the various forums for suggestions/mods/etc. Some of it is the "If it was me..." sort of stuff. Very little "I did this, this and this and it sounded..."
Trying to determine the difference between the a and the a1, I did manage to find some schematics and all I noticed with a first-pass look was the addition of one capacitor. I'll have so sit down and really dissect the circuits. I did get a sense in reading some postings discussing schematics that there were some authenticity questions- one poster pointed out a couple of errors. The schematic shown had a CJD legend box on it.
If anyone has info or experience on parts updates, etc., I'd definitely like to hear. Likewise, if you've seen something from another source, a link would be greatly appreciated.
Trying to determine the difference between the a and the a1, I did manage to find some schematics and all I noticed with a first-pass look was the addition of one capacitor. I'll have so sit down and really dissect the circuits. I did get a sense in reading some postings discussing schematics that there were some authenticity questions- one poster pointed out a couple of errors. The schematic shown had a CJD legend box on it.
If anyone has info or experience on parts updates, etc., I'd definitely like to hear. Likewise, if you've seen something from another source, a link would be greatly appreciated.
-
Big Dog RJ
- Ultimate
- Posts: 2361
- Joined: Sun Sep 07, 2014 6:30 am
- Location: Melbourne, Australia
Re: MV-75 Versions
My trusted techie would know this stuff inside out... however he's inundated with many many repairs, of which people have taken their gear to others and buggered it up big time! So now he's fixing & servicing away... to the point of no return!
A few months ago, he'd love to chat for a while but now, simply no time, must keep those tubes a glowing! Recent visits to his service centre, I saw a huge pair of Apogee full range ribbons and Quads. Again, owners have taken to the wrong place for a quick fix and ended up with a few ribbons & stat panels getting fried! Ouch!
For what it's worth, I'll just ask him though if he's willing to assist, nothing lost.
On a similar note, aren't there other knowledgeable techies on this forum? I remember one chap helping out Vivian who restored her late husband's pv1 and a Linn TT... I forget his name, whatever happened to him? He was well versed with CJ gear and tech in general, I'm sure he's out there and not in the Ukraine? Oh dear!
Best, RJ
A few months ago, he'd love to chat for a while but now, simply no time, must keep those tubes a glowing! Recent visits to his service centre, I saw a huge pair of Apogee full range ribbons and Quads. Again, owners have taken to the wrong place for a quick fix and ended up with a few ribbons & stat panels getting fried! Ouch!
For what it's worth, I'll just ask him though if he's willing to assist, nothing lost.
On a similar note, aren't there other knowledgeable techies on this forum? I remember one chap helping out Vivian who restored her late husband's pv1 and a Linn TT... I forget his name, whatever happened to him? He was well versed with CJ gear and tech in general, I'm sure he's out there and not in the Ukraine? Oh dear!
Best, RJ