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In Reply to: RE: Conrad Johnson solid state amplifiers compared posted by AbeCollins on December 30, 2024 at 14:46:09
The Conrad-Johnson MF-2250A could have used more air, life, and treble extension.
It did not matter, how good the PF-R sounded; it was simply not usable. Like 90% of preamps, when the volume control was at or near min, the sound was TOO FRICKIN' LOUD!!!
And the polarity inversion was lame.
Because of these experiences, and with the prices increasing (which made the competition a better value, by comparison), my audiophile acquaintances stopped trying and using CJ products. It's certainly possible, that current-production is good.
Follow Ups:
I'm with Lummy on this one. Of the 3 earlier CJ pre-amps I've owned, (PV5, PV8 and Premiere 3) 9 o'clock was about as far as one could advance the volume pot setting. That said, the combination of either the PV5 or Premiere 3 with the MV50 was somewhat magical.....at least here . Both the PV8 and MV75A1 were non starters IMHO. My apologies as this has nothing to do with CJ solid state amps, but I had to chime in on the excessive gain issue. Also plagued my Audible Illusions 2B as well.
One of my mentors who was an audio reviewer lent me one to compare with my Threshold Stasis 3 in the early 80s. The C-J reminded me of the AR AU integrated (my first "serious amp" at age 15) in that it sounded great at high output but resolution fell apart at low levels - completely unlike the Threshold.
That was a great learning experience and why I didn't keep the AR amp very long. The Dynaco PAS-3X that followed a year later taught me another valuable lesson about impedance matching. With the preamp's highish 1k ohm output, you needed high input Z amplification. Like the Stereo 120 amp used with it having a 100k value. Forget using many other SS amps like the Crown D150 used the next year having one fourth that value driving double Advents - albeit with an H-K Citation 11 that had no problem.
Gain and impedance matching are both important considerations for ideal partners.
It eats 6550's like a moviegoer eats popcorn. Even GE's only lasted about a year.
The MV 75 had 590 vdc on the plates and if you used the LED bias, the idle current was 75 ma, which equals a dissapation of 44.25 watts of heat! The max rating for the 6550 is 35 watts for the plate. Is it any wonder tubes did not last or fail completely?
The solution was to change the cathode resistor from 20 ohms to 28 ohms and you can use the LED bias and not over dissapate the tube rating.
"Is it any wonder tubes did not last or fail completely?"
The company was formed by two economists and I suspect they didn't bring an actual engineer onboard til much later - but I'm just speculating.
Bill Thallman was employee number 3 and got the products going. Founded Music Technology after his stint with C-J. He was the go-to guy for updates on their early units.
While my VTLs run SED 6550Cs reasonably hard with 550V rails, I found a schematic for the MV75 and found it runs them at 590V!
My pair varied from 600V to 615V. Looked pretty cool when they red-plated!
In the 1990s, I would frequent San Francisco's Ultimate Sound. In time, you'd recognize other repeat customers. And sometimes, you'd exchange numbers, and invite one another over.
I *think* it was in 1996, when one such customer lived across the Bay in Oakland, somewhere off of Highway 13. I do not recall his name. But I do recall him and his partner having a Rega Planar 3 with Sumiko BPS; CAL Ikon Mk. II CD player; Conrad-Johnson PV-10A preamp; some Adcom power amp, possibly the GFA-545II; Kimber cabling; and a choice of NHT and PSB speakers. Most of these had been purchased from Ultimate Sound.
I don't recall the music, but the three of us were yapping. Because of that, the guy turned the knob of the PV-10A to around 8:30, and he remarked that they had never turned it that high. So it looks Iike we can add the PV-10A to the three CJ preamps you owned, as having not enough volume control range :-)
Ultimate Sound also carried Audible Illusions, which, at the time, was a "local" Bay Area company, at the intersection of 580 and 680. In the late-90s, BART would extend from Bayfair in San Leandro to Dublin/Pleasanton. But anyway, Ultimate Sound just could not sell any Audible Illusions products. The Modulus 3A preamp inconveniently had two volume controls, one for each channel. But, as was the #1 audio problem, the sound was quite loud, even when those pots were around the 7:00 position.
Interestingly, Conrad-Johnson's sister company, Sonographe, made a line-level preamp, called the SC26. This model had a volume control range of a 100db, in half-decibel steps. I'm not sure why this system wasn't incorporated in CJ's own preamps.
Yes, I even tried 10db in line attenuators. Gave me and tad more flexibility on the volume settings, but seemed to suck the life out of the sound. Ended up just dealing with the 9 o'clock ceiling on the volume setting. I can imagine if one were dealing with a 100 db horn loudspeaker, that 9 o'clock ceiling would be closer to an 8 o'clock ceiling or even less.
I was going through my old photos, and could not find one showing the Conrad-Johnson MF2250A in action. Here, it was used with a ProAc Response One SC - a good match.
I actually liked clicking on the remote, which came with the CJ Premier 18LS.
Here, we used the Premier 18LS with the hybrid ET250S power amp. While this was an excellent pairing, in terms of sound quality, note that the preamp was at "01," and the sound was already at a healthy volume.
When we moved the Premier 18LS above the ET250S, the aesthetics were beautiful.
Thank you very much, for bringing up inline attenuators. Coming out of the Premier 18LS, we used 12dB attenuators.
The attenuators allowed us to get a healthy volume at "12." But sonically, the attentuators were not transparent. They muffled the sound.
My problem with CJ tube gear is their 'house sound' which is very nice if you enjoy warm and polite but my pop, rock, and blues don't want to be THAT polite. The solid-state CJ MF2250A was more to my liking than their tube amps.
I liked its lively sound but I had to let the solid-state CJ PF-R linestage go because the Remote Control was just too twitchy. The entry tube linestages including the CJ PV-14L and my oldie PV-12L were both too polite and a bit rolled-off at both ends.
...an audio product actually performs the same, even when used in completely different rooms and systems. Looks like your CJ MF2250A and mine were consistent.
In the 2000s, I worked in property management. Eventually, when word got out that I was an audiophile, others who liked music and video games joined in. One of my colleagues tinkered in our music studio. From that experience, he did not feel the need, in his own home, for balanced XLRs. Moreover, he loved the champagne-gold faceplates of Conrad-Johnson gear.
Try not to lift the amp by its heatsink fins. They can scratch or cut your hands. When the room is quiet, place your ears near the amp. You might hear some low-level buzzing or hum. Also, give the amp a few inches of clearance, to allow for ventilation (though the MF2250A does not run hot).
My colleague said, "If you want to double down on what the MF2250A does," use Hi-Fi Tuning Gold fuses.
The Kimber Silver Streak interconnects and 4TC speaker cable were nice matches for the MF2250A. The placement of the binding posts does allow you to route the speaker cable away from the interconnect and powercord.
The MF2250A was not a good match for speakers which curtail the treble. Such was the case with the treble-challenged original Sonus Faber Concertino. Same with the Totem Model 1 Signature, which rolls off the top octave. OTOH, the MF2250A mated well with the otherwise boom-&-sizzle ProAc Response One SC.
I enjoy my MF2250A. I also own VTL & Manley tube preamps and amps.
Abe commented that the Pass Labs amp was superior to the CJ. Has anyone tried CJ preamps with Pass amplifiers?
"Abe commented that the Pass Labs amp was superior to the CJ."
Mostly very different and superior for my taste. The Pass Labs driven by a 'tubey' sounding Cary SLP-05 preamp was heavenly !
What were your speakers at the time with the Cary and Pass?
I had a pair of Tannoy Definition D500's and Thiel CS2.4. The Pass X150.5 was slightly under powered for the Thiels but the Tannoys were outstanding in this setup. Comments below from my Asylum profile:
Tannoy Definition D500: Mfg recommended 30 to 175w RMS. 6 Ohm nom, 4 Ohm min, 91db/m/w sensitivity, 8" dual concentric mid driver (brass tweeter in center), 8" bass driver. Crossover type: 1st order LF, 1st order HF. These speakers sound better with more than the recommended minimum of 30-Watts.
Thiel CS2.4: Three-way, floorstanding loudspeaker. Drive-units (all anodized aluminum): 1" (25mm) dome tweeter coincident with 3.5" (114mm) cone midrange; 8" (204mm) cone woofer; 8.5" by 11" (230mm) passive radiator. Crossover frequencies: 800Hz, 2.5kHz. Crossover slopes: acoustic first-order, 6dB/octave. Frequency response: 36Hz-25kHz, +/- 2dB. Phase response: minimum phase, +/-5 deg. Impedance: 4 ohms nominal, 3 ohms minimum. Sensitivity: 87dB/2.83V/m. Recommended power: 100-400W. In storage at the moment. The Thiels sound better with much more than the recommended minimum of 100-Watts. [Not in use at the moment]
I believe that most speaker manufacturers want their product to appeal to the widest possible audience so their minimum power recommendation is probably a stretch. Sure they'll play fine with power at the lower end of the recommended scale but in both cases my Tannoys and Thiels really "come alive" with more power.
In the late-2000s, my colleagues brought in a Conrad-Johnson Premier 18LS solid state line-level preamp.
Unfortunately, even at "00," some sound could be heard. And, at just "05," with normal sources, amps, and speakers, the sound was LOUD. The Premier 18LS was therefore unusable.
Which was too bad, because, in terms of sonics, the Premier 18LS seemed like it was in the same vein as CJ's own MF2250A. We tried a variety of amps with the 18LS, and unless those amps had a way to trim the gain, the sound was LOUD, even when the 18LS was at or near "00."
As far as Pass Labs goes, a different colleague brought in some power amp (sorry, I don't know the model number). But because this Pass Labs power amp ran hot, it was a non-starter, and my colleague did not retain it, not even long enough for us to see it and take pictures. For whatever reasons, my colleagues were not able to bring in other Pass Labs products, even though they seem to have good reputations for sound quality.
I didn't have a problem with the volume settings on my Premier 18LS. It was smooth and transparent sounding but again on the 'polite' side. It didn't have much 'punch' for a solid-state preamp. The more entry level and older CJ PF-R was better in that regard and I preferred its sound.I also had the fully Class-A Pass Labs Aleph 3 amp.
Yes it runs Hot !!
The photo was staged to get the point across ;-)
Edits: 01/04/25 01/04/25
As a college freshman, I entered "high-end audio," during spring break 1990. But this was all at home in San Francisco.
I spent the summers of 1990 and 1991 in Honolulu, my second home, and where all of my relatives were and still are. Whereas Bay Area audio stores would not give you the time of day, Audio Directions Ltd.'s late Stewart Ono (AA's UncleStu52) understood that a college kid (a) was not going to buy anything expensive right then and there, but (b), if treated well, years down the line could spent $$$$ on audio.
Stu slapped together a VPI turntable, CJ electronics, Kimber cables, and some Vandersteen loudspeakers. This was really what "won me over," and set the expectations. Stu mentioned that he also carried Quicksilver. He said that, dollar for dollar, the Quicksilver was more accurate than CJ. But, a majority of his customers preferred CJ.
Stu also mentioned that, although CJ were known for their $$$$ models, their entry-level products were juuuuuuust within reach of those who were leaving mid-fi, and getting into high-end audio. Sadly, because high-end audio actively shunned Gen X and Millennials, the industry never expanded, and has now relegated CJ to concentrate only on $$$$ products.
At that time, partially because of the recession, audiophiles were revisiting vacuum tubes. Stu acknowledged that audiophiles were feverishly lapping up old stock Mullard and Telefunken. But Stu cautioned that you just have listen, and it depends on your gear and tastes. He said that you'd be wise to keep a supply of GE and Sylvania 6CA7 and 6550 power tubes. He said that those may never be "sexy names," but in time, people would miss and crave these tubes.
I miss the latter half of the 1990s, when I could meet other customers at audio stores, exchange numbers, and then go over to their homes. Here in the Bay Area, the more affordable CJ products seemed relatively popular. One guy in the Oakland Hills said something like, "If you're coming from Adcom and NAD, they [CJ] make a lot of sense."
For the past 20 years, I really only get to meet an audiophile, if he's dropping off cables, to be placed on the Cable Cooker.
Eventually, a different colleague brought in a Conrad-Johnson MV-55 vacuum tube amp. To hell with "accuracy," the MV-55 was a chewy-sounding amp, a lot of fun, with certain speakers. In 1996, the $1995 MV-55 was CJ's entry-level tube amp. Sure, the Premier 11A was smoother and more refined, but it wasn't as fun as the MV-55. Moreover, the MV-55 did well with the affordable and plentiful Electro-Harmonix 6SN7 and EL-34.
As for Pass Labs, they do make Class AB power amps, so I'm wondering if those do not give off as much heat as their Class-A power amps.
I began exploring 'high-end' audio in the early 1990's when a co-worker at SGI invited me to his place in S.F. He had tall Martin-Logan speakers and hefty Krell amplification, a Krell CDP, along with a Nakamichi Dragon cassette deck. I had no idea what this stuff was all about but it surely sounded better than my Sony receiver and JBL speakers. He then introduced me to another co-worker who had an older CJ amp (I want to say MV-50 but I'm not sure). The amp was driving a pair of weird looking square-ish speakers that were old and a bit tattered. I think they were Quads but the setup was very warm sounding which I also enjoyed.The rest is history. My first audio show was a Stereophile sponsored event in S.F., also in the early to mid 1990's. Up and down the escalator looking at all the pretty high-end stuff. Wow, a whole different world compared to the department store stereo gear I was more familiar with.
My first 'high-end' setup consisted of a used Classe 10 amp (not DR-10), CP-40 preamp, Cal Icon MkII CDP, and Thiel CS1.5 speakers. I learned that even the smallish CS1.5 speakers were more 'effortless' sounding with more power so I upgraded to the Classe CA-200 which made a difference. The CJ Premier 11a came soon after. The thing that stood out the most with the CJ was the comparatively 3-dimensional soundstage vs the SS amps.
What was that thin publication with ads for used high-end Audio gear? It came in the mail. My co-worker subscribed to it and loaned them to me and that's how I discovered even more used gear before the internet exploded.
My CJ Premier 11a and Premier 18LS from a long long time ago:
I'm still using the short and stubby Salamander S20 audio rack today.
Edits: 01/04/25 01/04/25 01/04/25
In the summer of 1992, my family, as always, went to Hawaii, but I stayed home in San Francisco. Likewise, many of my old S.F. friends were back home from their respective colleges. So, although I didn't get to go to Honolulu's Audio Directions Ltd., I would go with a friend, to S.F. and East Bay audio stores. They did not have a whole lot of square footage, so they were limited, in the number of brands and demos they could carry.
Speaking of the summer of 1992, the July 1992 Stereophile had Jack English's review of the CAL Ikon Mk. 2.
Also in that edition was Corey Greenberg's review of the ProAc Response 2, which he said was not an audiophile speaker. That had an enormous impact on me, and influenced how I auditioned, shopped for, and judged audio products.
Given that I was used to tiny audio stores, you can see why the March 1993 Stereophile Show made such an impression on me. Although hotel rooms were small, how was that any different from most of San Francisco's tiny living rooms? But all in one place was a wide variety of brands, importers, stores, reps, and even musicians.
During Spring Break 1993, the April Stereophile arrived. As if on purpose, Larry Greenhill's review of the B&W Matrix 805 and Totem Model 1 appeared. I had previously heard the 805 at San Francisco Stereo Plus. And to me, the Totem Model 1, despite being one of the smallest speakers at the Show, did a credible job on pop/rock music.
In the mid-1990s, San Jose's Bay Area Audio carried CAL, Classe', and Thiel. When my girlfriend ACS had martial arts events in the South Bay, I'd visit Bay Area Audio. One time, they had a Classe' and Thiel system, lashed up with special-made MIT cabling. Were you still here, when Bay Area Audio existed?
I couldn't remember the name but I'm sure Bay Area Audio in San Jose is where I bought my Classe gear.
There was another audio store on El Camino Real I believe that seemed to be 'higher-end' with nicer showrooms. I visited them a couple times to window shop. They were more up toward Palo Alto, maybe Menlo Park. I don't remember.
...an audiophile will reach out to me, and adamantly insist that he had crossed paths with me. When you press him, he'll state that the photos, time frames, and music positively identify me and my friends.
And when it comes to crossing paths in audio stores, the guy will state that it was unequivocally Lummy, his music, and a girl or young woman depicted in my posts.
Alas, most of these audiophiles are no longer in the Bay Area, and can't just roll out of bed, and meet up with me.
When I was working at Stanford (above) and the mid-Peninsula, the only audiophiles I met in person were those who dropped off (and picked up) cables, which went on my Cable Cooker. Again, I don't know what a drug deal is like, but I got that vibe, when these South Bay audiophiles handed over the $$$$ and $$$$$ cables.
I had one stint, working for Stanford Student Housing. One morning, an electric cart had been dragged (undoubtedly by students) into Lake Lagunita, above. When we got closer, we saw that it belonged to us, and that we had no idea, where it normally was supposed to be parked/stored.
On the El Camino Real side of Stanford was an store called The Audible Difference. It was a flagship Mark Levinson dealer. I have never gone to that store, so whenever an audiophile claims that he saw me there, he is mistaken. Good heavens, we don't need more of me!
I did, however, go to another audio store, just up El Camino Real, in Menlo Park. It was called Sound Perfection, and carried, among others, Conrad-Johnson and ProAc. See, Sound Perfection and San Francisco's Ultimate Sound were friends. So when I went to Ultimate Sound (which was frequent), David always said that, if I needed any of the brands which SP carried, he could get them. And that's exactly how I, while living in S.F, was able to try CJ and ProAc. I did take advantage of this, and go through Ultimate Sound, to get a CJ EV-1 phonostage and ProAc Response One SC.
So perhaps you had visited The Audible Difference and/or Sound Perfection :-)
Up in Burlingame was an audio store, whose name escapes me, which carried Martin-Logan. San Francisco's Audio Excellence was tiny, and never had the room, to show off speakers, including Martin-Logan, in a good light. But the Burlingame store did have a little more square footage.
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