Regenerator and my CJ monoblocks

[AnotherJohnson]

I've seen a lot of positive comments on the P20 over at the PS Audio forum. Your description succinctly highlights its advantages and I'm gonna keep my fingers crossed that it plays nicely with your LP275M amps.

Thanks.

The PS Audio Forum denizens are nice people.

I cruised it a few days, got sucked into the fuse discussion, and realized that it could cost a fortune to get interested.

I’ve come a lot farther down Tweak Rd than I ever thought I would, but I’m still re-fusing to re-fuse my gear.

[admin]

I commented the P20 in another topic but this should be interesting. Considering how impressed you were with the results of the P12 on the audio quality of the system, this should definitely be a nice upgrade. As mentioned above, the P20 is more than just increased power capacity compared to the P12. It's simply a better unit in all respects (except for potential back injury!).

Looking forward to seeing if it plays nice the the LP275Ms.

[AnotherJohnson]

I commented the P20 in another topic but this should be interesting. Considering how impressed you were with the results of the P12 on the audio quality of the system, this should definitely be a nice upgrade. As mentioned above, the P20 is more than just increased power capacity compared to the P12. It's simply a better unit in all respects (except for potential back injury!).

Looking forward to seeing if it plays nice the the LP275Ms.

I’ve lived with the P12 for a few months now. I bought it to address TVA power stability issues that were heretofore unforeseen at my house. I bought a couple of Niagara 1200s and the P12 to solve the variable input issue. I was suspicious of both, and bought them as much to see them as to use them.

Anticipating nothing of note, I was taken aback by the impact of the P12 on what, to my ears, seemed to be a nearly perfect system. Taking the P12 out, and reinserting it confirms the audible effect. The Niagara 1200 brings improvements too, though not as dramatically as the P12.

Why bother with the P20?

I think it is my curiosity again. The P12 chokes on the LP275Ms. I’d like to hear these incredible amps with clean power. With the 30 day free trial, there’s nothing to lose but the return shipping.

[AnotherJohnson]

In another thread (surprised by power) the unsuccessful attempt to run the LP275Ms is discussed.

Suffice it to say that the LP275Ms run beautifully if sources, preamp and amps are plugged into the same $25 power strip. Or into the Niagara 1200.

But they do not play nicely with the P20. So … if you want to try a power regenerator with the CJ monoblocks, be sure the seller is willing to give you a free no risk trial period

I’m keeping the P20 because it is even better than the P12 on my ARC REF 75SE. But if I were just considering it as a power source for the LP275Ms, it would get sent back.

[Big Dog RJ]

Yes, those LP275M's are outstanding amplifiers. CJ's former top of the line SOTA monoblocks!

However, as you rightly pointed out, they do have their quirks and until these quirky jerky's are sorted out, they'll just continue to hiccup. Sometimes they play nice in the right setups and all is well for years, no issues. In other setups, things really go funny. I just don't know what the heck it is ... but you just gotta love the sound!

Cheers, RJ

[Big Dog RJ]

When you get your S-Daw's, if you still have the LP275M's, would be a fantastic combination I'm thinking... as long as the quirks are under control. I suppose you'll prefer the ARC gear though, since you've also got a very good ARC preamp, with the REF75SE is a fine combination!

If by any chance you manage to set up the S-Daws with the LP275M's and they perform well, do let us know your thoughts.

Cheers, RJ

[admin]

When you get your S-Daw's, if you still have the LP275M's, would be a fantastic combination I'm thinking... as long as the quirks are under control. I suppose you'll prefer the ARC gear though, since you've also got a very good ARC preamp, with the REF75SE is a fine combination!

If by any chance you manage to set up the S-Daws with the LP275M's and they perform well, do let us know your thoughts.

Cheers, RJ

I too would definitely be interested in how the LP275M's sound with such a great Wilson speaker. Although I don't think AJ will be going that way. He has built up a top of the line ARC system with multiple components and the P20 which elevates everything to the next level. To give up that synergy just to get the LP275M's into the system is a hard sell.

[AnotherJohnson]

I would dearly love to use the LP275Ms … but they are thwarting me at every turn with their single ended inability to deal with disturbances.

Side by side compared to McIntosh, the sound of the LP275Ms made them worth putting up with whatever quirks they had (specifically this need to run the whole system through one duplex outlet).

Side by side compared to Levinson, the trade off was more difficult to rationalize because the Levinson sounded incredible too. And then the Levinson failed and spent nearly four months in warranty repair. So the LP275Ms won again.

But side by side compared to the REF75SE, the kabuki dance of the power strip is aggravating. The REF75SE runs quietly on any power source it sees. It is safe on 95V all the way to 140V. And it sounds gorgeous.

So … maybe if I had big stat panels, I’d want the extra power. But I don’t have or want big stat panels.

No XLR based system I’ve had, including Cambridge Audio, Krell, Levinson, McIntosh, or ARC, have ever given me these kinds of ground headaches. I can’t help but think that’s a factor. The only other gear that has been even more aggravating is modern VPI. Their forum is replete with inquiries about ground loops, and I had trouble with two high end tables from the 2017-2019 era myself.

In higher Marantz single ended only designs, specifically the Ken Ishiwata signature line, everything is encased in copper for shielding. Those didn’t give ground issues either. I had a couple of PM-KI + SA-KI combos and installed them in three different buildings without issues.

So … if I had a second serious room to install a second system here, I would try very hard to use the LP275Ms and work through their ground quirk. I would run the whole thing on one 15 amp duplex outlet. The preamp would be my LS28SE. Speakers would be the Sabrinas or the Revel F228Bes based on audition. The sources would be the SA-KI Ruby and the lesser of my LP12s. I’d probably buy another ARC phono preamp. I’ve sold both of my TEA units.

Instead, what I really need to do is find a good home for the LP275Ms with someone who is committed to vintage CJ and wants to get out in front of the curve. These were the $25k flagship from 2007 up until the ARTs. And I probably need to commit to helping the new owner work out the inevitable ground issue that will be encountered.

JF says he has to deal with this EVERY DAY. I’m not surprised.

[roberto]

AJ,

I was wondering from where you have hum. If you disconnect the input RCAS, do you have the hum? If you do, something is wrong with them. If not, then you have to chase from where the hum is coming. I do know that you have done all possibilities, but still, you do have the problem. If you do have the hum, disconnect from the mains AC only one and turn on the other, also being having disconnected the input RCA cable. If you do, something is wrong with them...both? That's the strange and odd possibility.

[roberto]

Do you have their chassis connected to ground?

[AnotherJohnson]

I have gone through all of this twice with JF.

It is not the interconnects. It is not another element up the chain.

The solution is to run everything via a multi outlet power strip which runs into one duplex outlet.

Works every time. JF and I went through it in 2018 and again last week.

There is no other low hanging fruit solution.

Unless every ground plane is perfectly merged, the very sensitive amps will find the difference and audibly share it.

Merge the ground planes- problem solved.

CJ has stated in print that ground loop questions come up literally every day. I have been told this twice to boot.

I have been assured that there is nothing wrong. The amps are perfect and behaving normally.

[AnotherJohnson]

Meanwhile, I am listening to Bach’s St. Matthew Passion in German right now. On my ARC system with the P20 and the AQ “loom,” it is as though they are in the room singing in clear concise totally understandable German. This is the best I’ve heard so far. Last night I listened to several performances with difficult to parse English lyrics. Also presented more clearly than ever before. Many subtleties are revealed.

You can never know how close you were until you’ve heard the next level.

What this system is doing is presenting more detail with less distortion than any of my prior seemingly perfect systems.

Would the ART series or ART 300 or ART 108A be as good? Maybe. Maybe they would be even better. I don’t know. The expense to find out is just not worth it to me.

[AnotherJohnson]

FWIW, I have used 1.5 meter, 2 meter, and 3 meter rca AQ McKenzies with the same effect. If these interconnects are defective, all 6 of them are defective… highly unlikely. Further, as JF has pointed out twice, it would be unlikely that both amps would fail in the same way at the same time (concurrent every time in a new installation).

These amps are just incredibly sensitive … far more so than others I’ve used.

I’ve never seen/heard this with any of my XLR based systems.

We’ve discussed cheater plugs too … they may be an alternate solution, but they are illegal according to code and CJ advises against them.

This is just a quirk that may be endearing … but it is also exasperating. Especially when it is not manifested in the alternative options.

They sound GREAT. Very musical. Very powerful. Probably the best available in 2007. Better than Premier series for shear finesse and grunt. But time marches on.

[admin]

In all honesty, I think the experimentation with the LP275M's is pretty much complete. I don't really think there is anything else at this point. As you mentioned, the solution is to have them connected to a common power strip. There is only so much you can do with ground loops. I've had them in my system before as well, and you do the best you can, often finding a solution, but deviating from the solution will bring back the problem.

This doesn't detract from the LP275M's in my opinion, it's just a inherent property to that particular amp. Different components have their requirements, limitations, positive qualities, etc...

[AnotherJohnson]

I was wondering from where you have hum. If you disconnect the input RCAS, do you have the hum? If you do, something is wrong with them.

JF said that this is an unreliable test. He said that the open RCA inputs will pick up noise too, and the amps will present it.

Regarding grounding the chassis, that is what the third wire in the power cord does, as I know you know. No, it is not disconnected. No, I have not set up a separate chassis ground. That’s just asking for another ground loop if you’re not using a cheater plug.

[roberto]

You can short the rca cable at the other end.

[roberto]

On the contrary, I want to isolate the ground. Could be that power cord. Do you have the original power cords by a chance?

[roberto]

All I want is to tryouts all the possibilities again. Sorry to be myself so stubborn.

[roberto]

Measure the chassis to any OV point of the amp. Sometimes ground is not the same as the neutral 0 V reference. Some amps are even up to 50 ohms between the chassis and the OV reference. Flouting ground. Just thinking why you have that.

[AnotherJohnson]

Roberto, you are a hopeless romantic. I only run these with the OEM power cords.

I’m sticking with JF’s analysis. If it is his expected behavior, you can spend hours in the rat hole trying to prove him wrong. Entropy generation …