Conrad Johnson Premier 140 Vs Conrad Johnson Premier twelve

[gregorioo]

Gregorioo,

If you really want to see what the full potential of the Premier 140 is going to be, I would use it alone to drive the speakers as roberto is suggesting. I'm not sure of what the advantage is of biamping your system unless you really feel you don't have enough power and your experiencing clipping. The 140 should have plenty of power by itself to take care of your needs. Also, mixing two such unequal amps may cause the sound to not be as cohesive as being driven by one amp. I feel that if going the biamp route, the best thing is to have a pair of the same amps driving the high and low end and not mixing amps that have very different outputs and audio signatures. But that's just my experience and others may disagree.

The KT120's are mighty fine tubes (which admittedly also cost a lot). I have 16 of them driving my ART amps. Whether that upgrade cost is worth your money, I can not say. Each system is unique so the ultimate performance results are hard to predict.

Whether different or the same amplifiers are connected - it does not necessarily mean that it will sound good or bad - each system must be assessed individually.
The construction of the IRS Gamma loudspeaker is completely different - 5 ribbon speakers and two bass ones with a coil - the differences in sound reproduction are much greater than between the SS amplifier and the tube amplifier, and the loudspeaker sounds quite nice.
I assure you that the bass matches the treble, the real problem is the acoustics of my room.
Take a look at the Mcintosh MC901 - it seems to me that the designers of this device know what they are doing.

[admin]

That's an incredibly complicated setup. If all those tweaks make it sound better, then at the end of the day, that is what is important.

But I will say that I think what sounds best is going to come down to experimentation. There are just to many variables to account for to make accurate predictions in this particular system to say for example "how KT120s would influence the overall sound when driving only the low end with a significant DSP alteration". Also, DSP is going to completely alter your sound (good or bad). There is almost infinite possibilities to change the overall sound when you start messing with DSP settings.

That's just my opinion however. At the end of the day, listen to your ears.

[gregorioo]

It seems complicated, but practically it is not, although I planned in my head how to connect it for a long time, and every time I changed something, I got a big improvement.

........................... DSP>servo>Primare A32> bass
Streamer > preamp >
............................ CJ> ribbon speakers

All devices powered by streamer with Trigger: https://www.audiophonics.fr/en/diy-kits ... ce-p-10661. html


DSP plays only for the sub-bass part.
I honestly wish it wasn't there but if I wanted to adapt the bass in this room I would have to get rid of the furniture and the table
It's not perfect with DSP, but it's even worse without it.
Perhaps with small bookshelf speakers and quiet listening there would be no problem with the bass, but I chose such a set and had to adapt it
In the new house, I will certainly be able to avoid DSP, and I put acoustic adaptation in the first place.

1670092949985.JPEG (206.71 KiB) Viewed 2562 times

In the meantime, I'm happy with what I have and I'm finally satisfied with the new purchase (until I get a new idea

Thank you all for your commitment, and I will definitely try the KT120 tubes

[AnotherJohnson]

Exciting times!

It is always nice to be rewarded with sonic improvements when you work to solve some shortcoming.

The room is certainly the biggest obstacle for most aficionados to overcome.

Enjoy the hunt!

[Big Dog RJ]

Ah! The good old IRS Gamma, by the legendary Arnie Nudell. I've met Arnie a few times, and whiles he was the chief at Infinity Systems, and then very briefly during his stint at Genesis Advanced Technologies. Always a learning curve talking to Arnie, his eyes would light up and there goes another 45mins talking all about the IRSV's.

My very good mate still has those old dinasours, they've been refurbed so many times, they're now parked in a corner behind his Genesis Dragons. I think he prefers to hold onto these IRSV's more for sentimental reasons, those Infinity's is what started all our dealerships in that region. The IRSV was our reference standard and from that point onwards we started the journey...

I had three Infinity systems from old Arine, started with the IRS 1B's, then Epsilon and finally Renaissance 90's. Looking at this line up, it's as if things are going backwards rather than forwards... so I'll explain the rationale;

The IRS systems were cumbersome, there was really nothing easy in setting these up. Far too many controls, servo units gave problems, Emit's Emim's along with the Watkins woofers were getting rare in parts supply... so we decided to downsize as the years went by. The Epsilon was slightly better but it still had that notorious servo control unit that gave N number of problems, not to mention it was highly coloured! Finally, onto the Ren 80's and my personal pair were the Ren 90's driven by VTL Wotans.

The Ren 90's were great! Plenty of oomph, dynamics and a powerhouse of amplifiers to drive it, no issues in blowing the roof off but it lacked musicality and finesse. These systems were great in its hey day but not anything close to high performance speakers of the more modern and advanced tech that you have now.

However, in saying that, once these systems were set up by the right tech, with the right skill, they were truly remarkable in reproducing a live event and what I mean by "live event " I'm referring to the live stage effect. As if the band is right there in front of you, in full flight and thunder, pretty much a huge blast! And it was great! We loved this gear to bits but there were days where it just wouldn't work. I lost count of how many times the Infinity tech had to fly in from Spore or HK to attend to our systems.

At the end of 2004, we sold off all our Infinity gear and the funny thing is, all the customers who bought them were actually musicians! Either band leaders or drummers or lead guitarists, so they really enjoyed this type of gear. It provided them with that raw power of deep bass and gutsy thunderous presentation, which they liked! They bought it all, including the VTL amplifiers, a great combination btw.

After that experience, we realised that the best approach to pure musicality, high definition and finesse is to keep the audio system simple! The more points of connections there are, the more the source signal degrades... and we realised how much clearer the Ren 90's were, driven by just a pair of monoblocks and no servo unit!

Bi-amping was an absolute nightmare, it never sounded natural, it wasn't color free, nor did it have any definition, all it had was far more dynamics. Then again, there are some systems, such as the IRS series that require bi-amp config, otherwise they won't work.

Fast fwd that era to now, and you'll hardly notice any speaker system that's in bi-amp mode. The majority are single amp mode or can be configured for monoblocks in horizontal mode, not vertical. To me, this is just so much clearer, clean smooth grain free bass lines, plenty of definition, finesse, dynamics, headroom and most of all, musicality. If it can't reproduce what's on the recording in its purest form, then what's the point?

I must say though, these IRS systems done by Arnie were an absolute American classic! Like those US made super cars, the Mustangs, the Fords and Camero's, real classic muscle power. A sheer delight to own and be proud of but whiles it was working properly... only then.

We all had our fair share of this Infinity classic era, I don't think any other brand had tried to reproduce the same thing, other than Genesis AT but that's quite different.

Cheers mate, and enjoy those Gamma's! That deserves a big WOOF!!!
RJ

[admin]

Nice system. Small rooms present more challenges than large ones, all things being equal. There is a bit of damping in that room (carpets, drapes, acoustic panels) so that should help. If you wanted to narrow the frequency response even further you could employ a calibration mike and runs some test tones and frequency sweeps. I've done that for my home theater setup and it can help with troublesome distortions introduced by the room.

But overall looks great.

[roberto]

Gregorio,

I have a little story to tell. In the 80s, I bought a real time analyser and played through my speakers at that time a pink noise. Using a top match microphone right at my golden seat, I played the pink noise at 75dB of SPL. Then with help of an equaliser, I adjust the sound as the the best flat frequency response possible. Then increased the level only +5dB and all the time I spent trying to get that curve flat, was now totally spoiled. Then I use that SPL (80dB) and readjust the equaliser for the flat frequency response again, then move up +5dB and again, all the curve changed dramatically again.

Then is though perhaps the curve for 75 dB is going to be the one, because I don't play the music too loud. You can't imagine how horrible was sound that I got. So, I start to learn more about sound an equalisation. The thing is that the sound is logarithmic. Peaks don't match the valleys. We are measuring wrong, the sound is not linear, so it is impossible to plot a frequency response in a room. The frequency response of the speaker is done in a special anechoic chamber, and our room is not that way.

Here is where I did understand which parameters I should use the measure my room, and the answer was to listen live unplugged music. Not too many musical instruments and voices. And then my seek started. Trying to have the naturalness of the musical instruments and voices was my goal, and even in these days.

What is the best instrument that we have to measure what is good or bad on hand and the instrument is totally free? This measuring instrument is your ears. They will tell if you like what are you hearing and if it is right or wrong. The harmonic texture of a guitar, or a piano, or any musical instrument is our pattern. The right size, the air between the musicians, and the way that the voices are projected in the air must be your pattern. If you have too much bass, you lose the mid range and highs. If you have too much highs then you have the cymbals next to you and the drummer way back of the stage playing the drums.

The midrange offers you a steady stage. Our ears are made for the language. But they are so good that we can hear a lot of detail and transparency in the recordings and enjoy the soul of the musicians playing for us in our own place. We can call which musicians are playing too. This naturalness is the clue. Tubes are the way, and forget that SS are better at low frequency. That was long time ago when the output transformers were not so good long time ago. On now days they are very good. Moving your speakers back and forward will adjust the naturalness of the bass at your seating position and toe-in or toe-out the speakers will adjust where you like to seat at the event, having the stage. Toe-in makes the stage forward. Tilting the speakers with focus the stage.

Also there are good recording and bad recordings. With the bad, nothing we can do to make them to sound as a good one. Your ears tell that easily,.

I don't want to enter in a debate about SS VS Tubes. Just let your ears decide. As I said before, my liking not necessary must be yours...but we know how a piano sounds, or a guitar, a cello, a violin, a double bass, drums, percussion instruments, wind instruments, voices, etc...

I can't impose to you my liking of course, and is you are seeking for this naturalness, this is the right place to talk about it. If you like big bass energy, that's ok too. It is your liking and I do respect that. Believe me what I say I have being there long time ago.

Another thing, I have a barrier language. My main language is Spanish, and if I am sounding rude, or a wise guy, it is not my intention to, and please I beg for your forgiveness.

Happy listening!

[admin]

Robert, wise words. There is no magic formula for optimal sound and all the things you mentioned play a crucial role in evaluating audio performance. No magic distance from speaker, toe in angle, distance from walls, etc. We start with a good guess and then use experimentation to optimize from there. All the components must function as a cohesive whole.

And then there is the entire field of psychoacoustics with a healthy smattering of personal preference.

I have used things like calibration mics and sound meters in my system to help with certain issues but at the end of the day, my ears are the final instruments that determine the outcome. Sound calibration although complex, is no more of an important tool in my setup arsenal as a simple tape measure (and I use the tape measure more frequently!).

I think calibration mics and direct signal adjustment is far more important in home theater setups than 2 channel listening. There is a lot more frequency interactions, room acoustic issues, etc... when audio is being produced by 6, 8,... or even more speakers. The model of the speakers in these setups are rarely uniform so they all have their output signature and are different distances/heights/orientations from the listener.

But even in these complex setups, once the "calibration and adjustments" are completed, one has to sit down and listen and make final adjustments appropriately to what your ear is telling you.

[roberto]

I forgot to mention that all rooms are inherent with room boundaries resonances. These resonances are the ones that we must treat in the room and they do not belong to the music. These resonances make to have usually a one musical note bass. Treat just the room corners. There is no need to treat all the walls. The best is for a dipole speakers like Martin Logan, Magneplanar, etc.. is behind the speakers, using a flash light, the beam will tell the exact point to be treated. Using a mirror too. There is a video for Martin Logan speakers that shows how to use the mirror.

https://www.youtube.com/watch?v=ckoqpBmS_mw&t=47s

Another point to adjust the room, is to make it not totally dull. The reverb is part of the naturalness of the musical instruments, and in most recordings, as a recording effect, the main musical instrument and also the voices uses reverberation.

[gregorioo]

Ah! The good old IRS Gamma, by the legendary Arnie Nudell. I've met Arnie a few times, and whiles he was the chief at Infinity Systems, and then very briefly during his stint at Genesis Advanced Technologies. Always a learning curve talking to Arnie, his eyes would light up and there goes another 45mins talking all about the IRSV's.
Cheers mate, and enjoy those Gamma's! That deserves a big WOOF!!!
RJ

You are very right in what you write. I am just completing my friend's first stereo equipment based on Ren 90 + krell KSA100S
Consider that IRS Gamma cost me as much as $6,000
And REN 90 equals $1,100
It is difficult to find a loudspeaker at this price, or even several times higher, that will sound as good as these Infinity.
I was at an audio show recently and all the speakers costing less than $30,000 I heard there - they didn't stand a chance with the IRS Gamma. I could easily sit down and listen to $100,000 speakers, and if I were to feel a significant improvement, I would have to aim for that price range (I'm talking about new equipment).
It is true that the lowest bass section has evolved quite a lot in the new constructions, but from the middle up IRS Gamma is already a very high level.
The music is played live, you get the impression of playing live music - especially on vocals, dental instruments, harmonica.
Bass without a servo is two worlds - I played without for a while when I serviced the servo. Bass servo is kicking more precise - the difference is audible from the first seconds.
As for the DSP in my system - DSP is not there to bring the sound to another level - it's like orthopedic crutches - sometimes you need it and then you walk better.
I agree that the simplest system should sound the best, provided that it is in perfect conditions.
The Infinity Gamma actually requires a bi-amp - now it's done differently
For me, in the 50 Hz range, due to the resonances of the room, the gain was within a dozen or so dB - some songs could not be heard louder. In this house, I do not want to invest in acoustic systems, because I hope to move into a place soon, with a room dedicated to the stereo. I don't know if each of you is aware of it, but the acoustics are no less important, if not more important than the equipment itself. For me, ordinary slats on the wall changed so much in the sound that you could do WOW.


As you can see in my previous posts - I pasted a photo from the REW program before applying DSP and after applying DSP for the bass section.
The IRS Gamma is just so good, because the bass is cut off from 120Hz, what is above is untouched and flows directly from the tip to the ribbons. The rule with such tuning is that if you raise, do it minimally, and lowering should also be done with reason. 3db more = 2x more power.
It is always the case that if we improve one thing, something else will deteriorate, but the point is that the final effect should be satisfactory.


Playing with the equalizer and looking for the perfect sound with a microphone for frequencies higher than 200-400HZ is pointless, because if you slightly turn your head or move 10cm - the measurement result will be completely different.
In my room, the type of amplifier used in the bass section is a minor problem, and the acoustics are the biggest. With small bookshelf speakers, the problem would not be so noticeable, but the Gammas are big, powerful speakers that need meters to sound good. I tested the Krell KSA100S yesterday and it confirmed my belief that it doesn't matter whether the tube or the SS plays, what matters is the specific amplifier in the system and I seriously wonder if I should leave it as well. This is the first amplifier in my SS speakers that actually plays music and I want to listen to it.
In my system, the quality of the bass is not the highest, because unfortunately I have a reference point for how bass can sound, but until I move to a new house, I will not look for improvement in the equipment, because it is a matter of proportions of the room, which has ugly mods.

I agree that the ears are the best measurement device - but if you feel the bass rumble at a certain frequency - then if you are an experienced acoustician you will immediately know which frequency is rumble, and if you are not, plug in a microphone and read it from the graph. You can take a few measurements and find the best listening position or find the optimal distance between the speakers and the wall in a few minutes without having to listen to the songs every time - I mean only bass, because at higher frequencies relying on a microphone and simple measurements is pointless

Anyway, the road to the perfect sound is long, and it's all about hobby and fun, and also about being surprised by something, experiencing and having something better than you had so far, and it doesn't necessarily have to be the best possible achievement, because that would probably mean the end of the hobby

[admin]

I forgot to mention that all rooms are inherent with room boundaries resonances. These resonances are the ones that we must treat in the room and they do not belong to the music. These resonances make to have usually a one musical note bass. Treat just the room corners. There is no need to treat all the walls. The best is for a dipole speakers like Martin Logan, Magneplanar, etc.. is behind the speakers, using a flash light, the beam will tell the exact point to be treated. Using a mirror too. There is a video for Martin Logan speakers that shows how to use the mirror.

https://www.youtube.com/watch?v=ckoqpBmS_mw&t=47s

Another point to adjust the room, is to make it not totally dull. The reverb is part of the naturalness of the musical instruments, and in most recordings, as a recording effect, the main musical instrument and also the voices uses reverberation.

ML makes great short but to the point videos. I recommend everybody watch their entire series.

I will also note that I found placing ML speakers easier than other completely flat planar speakers (such as my maggies). Their curvilinear design is truly unique and in my opinion makes ML speakers the only true "more than one listener at a time" planar speaker. I know every other planar manufacturer claims that the sweet spot is wider than 6 inches, but I have not found this to be the case (other than ML).

As for the DSP in my system - DSP is not there to bring the sound to another level - it's like orthopedic crutches - sometimes you need it and then you walk better.
I agree that the simplest system should sound the best, provided that it is in perfect conditions.

I think you room and speaker combo is definitely more challenging than most. At the end of the day, you have to listen to your ears. If the DSP improves the sound from a direct connection, then there is your answer.

[Big Dog RJ]

Ah! Yes the room, the room! 110% without a doubt!

I remember when I first came across the much older Infinity IRS 1B's in Spore. I was on the phone with my Infinity draler describing the whole thing. He was asking has it got that bass tower, has it got those big mids & highs panel on its own and the servo unit, and so on... he was more excited than I was, pushing me to get it, since at that second hand price it was an absolute bargain, so I paid and got the crates shipped out. Once it was set up, it didn't sound anything like at the dealer's demo room... I was getting disappointed. Then we moved this thing out into the lounge area, where my bro also had moved out much of his gear, so there was far more space for this multi-tower system to work. Oh! Look out! There she goes... it just took off! It was as if the whole system shifted gears to awd super charge v12! It was a massive enhancement in all levels. Only then did we realise the true potential of another marvel created by Arnie N.

Arnie's later series, the Gamma, Delta and Beta systems were further refined, and these were really top level speaker systems that only a handful could compete with. Once you're able to maintain the super Emit's & super Emim's, along with the necessary parts for the servo unit, this is one true SOTA system. Matching amplifiers have to be at the highest standards, otherwise the whole presentation is not quite there. Initially we drove these with VTL 300's then Manley Neo 250's then Melos 400 Triodes, and finally CJ's Prem8A's. That matched with the ART preamp was our reference standard for years... it drove everything and anything to full glory! No compromises at that level.

Of course things changed over time, down to Infinity's Ren90's, then Epsilon and then onto Apogee Diva's. All that wonderful gear and high performance speakers would have been far pointless if not for a proper room. Since our lounge area was the biggest we could accommodate such large systems with, it was an absolute delight to experience each of these during their hey day, marvellous!

Look after those Infinity's well, and do enjoy those fine tunes! Cheers, RJ

[gregorioo]

It seems that the problem that caused this lack of depth was the tubes. The seller from whom I bought the amplifier claimed that they were new - perhaps he was a bit far from the truth, or the problem with them was elsewhere.
Without believing in success, I bought the Electro harmonix KT88 tubes. The tubes warmed up for several dozen minutes and the depth I had in the LM508 amplifier returned - mainly the vocals, which were again in the space behind the speakers - sometimes it's called magic
My wife, who has an ear for music, also confirmed my enchantment. Perhaps the bias was wrongly set in the previous tubes, but I did not check it.

The conclusion is that when we buy a used tube amplifier, we also need to be prepared to replace the tubes with new ones, regardless of what the seller says. Lamps will have to be replaced sooner or later.

question:
Is my version the one with teflon capacitors?
Photo in the link:

1671612569292.JPEG (343.76 KiB) Viewed 2423 times

[gregorioo]

Ah! Yes the room, the room! 110% without a doubt!

I remember when I first came across the much older Infinity IRS 1B's in Spore. I was on the phone with my Infinity draler describing the whole thing. He ........................................
Of course things changed over time, down to Infinity's Ren90's, then Epsilon and then onto Apogee Diva's. All that wonderful gear and high performance speakers would have been far pointless if not for a proper room. Since our lounge area was the biggest we could accommodate such large systems with, it was an absolute delight to experience each of these during their hey day, marvellous!

Look after those Infinity's well, and do enjoy those fine tunes! Cheers, RJ

The Infinity IRS has evolved and continues to be produced under the guise of Genesis and still looks like Arnie's philosophy
In appearance, it looks like the equivalent of Gamma
https://www.genesisloudspeakers.com/forte
They cost about $140,000.
It's hard to say whether they sound much better than my Gammas, but I probably won't have the opportunity to check it anyway, but I don't feel the need ...
Paul from PS Audio on his channel describes the comparison of the IRS V with the latest Genesis - he states that they are better on the bass. The loudspeakers still use the Servo system to control the bass.
When it comes to the availability of parts in mine - the problem is only with the Lemi midrange ribbons. All other repair kits are available.
In Poland, I know a specialist who managed to repair the Servo, which is made of parts that are available.
The problem from what I've read is the Serva mechanisms in the older genesis speakers, which rely on microprocessors that are no longer readily available.

[Big Dog RJ]

The pic attached of the CJ amp has no Teflons, those are polystyrene & polypropylene caps. Teflons are large pure white caps and about 4- 5 times larger and 5 times heavier! When you see a Teflon, you'll know.

*I just noticed in the far mid corner a pure white cap or two... could be Teflons but only these two.*

Also, they require a lot more space to install and sometimes not all CJ amps have this added space. Hence, the C1 cap upgrades are done only on certain models. Now, these C1 cap upgrades are rare and Jeff doesn't send out the full SE upgrade kit anymore, which included Vishay resistors.

A full layout of Teflons, plus Vishays and upgraded tubes are now mostly reserved for the ART series amplifiers and even then Jeff sends these out only to authorised dealers or CJ HQ does the upgrades for the owner and charges a premium. That's the business model.

The Genesis speakers are outstanding! And so is the price tag. Friend of my good mate in Spore actually has the Genesis Dragons now replaced by the Primes. Upgraded servo unit and redone on the bass drivers, I think it's the only two pairs that are in Spore. There are quite a few Genesis Dragons in Malaysia and Indonesia and they love their Brazilian Rosewood finish. It's one of the most beautiful finishes I've ever seen on any speakers, and that type of cabinet work and drivers is what costs a fortune!

If you get a chance to pass through Spore, visit The Adelphi plaza, highend audio heaven at its highest level! No compromises! They also have the Gryphon Pendragon system and Rockport Arakis, 220grand USD, not too shabby.

However, at this level all this fancy gear is really not required, as long as your present system is reproducing your favourite music the way you intended. Once that's achieved, just sit back and enjoy those fine tunes!

Cheers, RJ

[MattHooper]

@gregorioo

A few things:

1. There was talk of a triode switch for the Prem 12s etc. They don't have a triode switch - nor has any other CJ amp that I'm aware of. Rather, there was an option for the Prem 12s and some other CJ amps to be put in to triode mode. But CJ would tell you that to access this mode and do it right/safely, that mod had to be done by your local CJ dealer or technician.

2. Soundstaging issues you mentioned earlier and tube changes:

My experience might be helpful.

I have owned the Premier 12s for over twenty years, and love the sound. I bought a pair of Prem 12s that had the Teflon upgrade so I could directly do A/B comparisons with my original 12s. When I first played the T-12s I was amazed: the sound was just bigger in every way. Bass seemed deeper, yet nicely controlled, the soundstage just seemed to expand as well as image sizes. It felt like my speakers had been upgraded to some new bigger model.

But the thing is, those T-12s came with KT120 tubes installed. I'd never tube rolled in my originals, only kept using 6550s which gave a consistant sound. So out of curiosity I swapped the KT120 tubes in to my old prem 12s. When I did so the sound changed very much like the T-12s: I got that enormous, wide, deep soundstage, larger images, deeper sounding taught bass, sparkly highs. So a bunch of what I was hearing from the T-12s was actually due to the KT120 tubes. That blew me away.

There were other aspects of the T-12s that were a bit better over my original 12s - they still did a bit better bass control, and also were more grain-free with a slightly higher sense of detail (the finer aspects of recorded acoustics or reverbs especially came through on the T-12s). But overall I got enough of a change with the KT120 tubes that I sold the T-12s and have stayed with KT120 tubes in my original Prem 12s. I also like 6550s (I have Winged C nos 6550s), which are a bit more dense and punchy. But if I had to choose between them I'd probably stick with KT120s.

Oh...also...if you ever go for KT120s be aware: Despite a lot of what you might read about the KT120s giving you more power, THE DO NOT. Not if you are merely swapping them in on an amplifier originally designed around 6550s. The KT120s are indeed capable of producing a bit more power than 6550s, but the amplifier circuit etc has to be designed to take advantage of the extra KT120 tube. Really in swapping in the KT120 you are just changing the sound somewhat, and if you like it you like it.

I like it

[AnotherJohnson]

Certainly an actual triode switch would have been contrary to typical CJ protocols. Nevertheless I seem to recall seeing one … but it could have been modded by an aftermarket technician. I dunno …

Before I wised up (about 40 years ago) I thought nothing of modifying my gear, adding pre out and amp in jacks with jumpers, changing transistors, resistors or caps, and similar tomfoolery. Mods that aren’t factory sanctioned are generally value reducers.

In agreement with Matt, JF told me that the KT120 mod for the LP275Ms did not increase the power, but did make it sound better … he implied that there were other mods done at the same time, but I don’t recall details. My LP275Ms ran with the KT120s during my entire ownership. I thought they sounded wonderful.

[AnotherJohnson]

Certainly an actual triode switch would have been contrary to typical CJ protocols. Nevertheless I seem to recall seeing one … but it could have been modded by an aftermarket technician. I dunno …

I think the idea that CJ would have put a switch on an amp to go from Pentode/Tetrode (ultra linear) to Triode has got to be a figment of my imagination.

It is completely contrary to the featureless simplicity that CJ has at its design core.

I must have dreamt this up, no doubt due to the guitar amps I’ve owned with a “modern - vintage” switch. Modern being Pentode/Tetrode and vintage being the lower power Triode mode.

[Big Dog RJ]

That's correct AJ mate!
CJ never had switches for UL or Triode, unlike Manley Labs or VTL did. So if you've come across any CJ gear with switches for Output mode... these are all mods!

Not factory certified either... CJ HQ wouldn't do this, only local techies in the area may re-engineer such circuits.

Cheeeers, RJ

[roberto]

Triode mode is a Class A type output. Once I asked why CJ did not have switches as other brands were offering this option. Lew Johnson said that all CJ power amps were designed taking in care the best quality sound possible in their design and having those switches might compromise the quality of the sound. They have options having linear output stage and class A.

Todays class A models are the Art27A and the Art108A. These are mono blocks. No stereo class A power amps.

Happy listening!