16 ohm speakers: any amp sounds better with more resolution. speaker cables less critical.

Ralph, What I recommended to Elliot is that he first experiment with the settings of the L-pads in his speakers until he arrives at a solution that he wants to live with long term. Doing this would automatically involve accounting for the driving ampifier and the length of speaker cable. Once that steady state is arrived at, do you see anything wrong with swapping the L-pads for high quality high wattage discrete resistors that represent the resistance across each L-pad after their final adjustment? Anyway, that is what I would do. My approach is based only on listening to my Sound Labs speakers (first the M1s, then the 845PXs) with vs without the Brilliance control in circuit. Big improvement in transparency and air without that L-pad.

I don't doubt it. But as I said, if you make changes in the amp or speaker cables you might find that you want to change the setting as well. Once you know what it is, of course a fixed resistor of good quality will be better.

JC-1’s are great monoblock amplifiers and is unfortunated that today are out of production because can compets or could be a true challenge to even names as FM Acoustics, Boulder, Gryphon, CH, Dartzeel and the like.

The JC-1 was a good solid state amp for its time, but like many other amps from that time didn't have enough feedback to really sound neutral- and that is why it can be a bit bright and harsh- all due to distortion. Combine that with an ESL and its going to be very bright... fortunately the Sound Lab has adjustments to allow you to adjust the speaker to the voltage response of the amplifier, so you can tone it down a bit.


The reason the distortion is there is due to insufficient feedback. This prevents the distortion caused when feedback is applied to be suppressed. Put another way, feedback suppresses distortion, but then makes some of its own. To allow the amp to get rid of that, you need more feedback, and most of the solid state amps of this era (and before) lacked the Gain Bandwidth Product and phase margins that were needed to run the required feedback. So they simply didn't.


So ya picks yer poison; harshness and brightness, or a little extra warmth but the highs are detailed and relaxed. This is why tubes are still around BTW; solid state is supposed to be 'neutral' but its hard to call it that when its bright and harsh.

Dear @atmasphere : Totallñy wrong about the quality level performance of the JC-1’s or today top SS amplifiers where almost all of them are non-feedback and many pure class A, the JC-1’s works in class A with its first 30 watts.ear .

Did you heard the Evidence’s mated with the JC-1’s or the top Soundlabs with those monobloks or with other top speakers?

" all due to distortion .." what are you talking about, where are your facts? as always only bla, bla, bla and low knowledge level audiophiles here and elsewhere think that because you are a tube manufacturer you are the bible on amps but about SS you have nothing and always you trying to diminish the SS alternative with no facts and the only reason you do it is that you are taking money as other tube manufacturers from low knowledge level audiophiles that unfortunatelly just have no idea how live MUSIC sounds at near field position. As all of us you are a member of the corrupted AHEE and unfortunatelly you are the darkness part of that AHEE.

Here it’s the measured " distortion " of the JC-1’s even at 1 ohm where puts nothing less than " 4.2kW into 1 ohm (27.2dBW, magenta). The latter is equivalent to an output current of 64.7A! "

https://www.stereophile.com/content/parasound-halo-jc-1-monoblock-power-amplifier-measurements

This is the J.Atkinson conclusion after he finished the measurements and along that it’s the review down there:

" This is excellent measured performance. The Halo JC 1 is not only the best amplifier to come from Parasound, it ranks up there with the best high-end heavyweights. "

If you don’0t have true facts/measures on what you said stop to spread your poison/false information and please learn that live MUSIC at near field position is everything but warm and it’s brigth, agressive, high dynamic power, with ryhtm, extraordinary at both frequency extremes, sometimes harsh ( listen to a trumpet/horn player at real SPL seated at 3 meters . ).

Recording microphones are " seated " at near field positions not at 20m-30m.

Warm, sweet, relaxed, and other ridiculous adjectives to explain the MUSIC sound in a room/systems is exactly what the corrupted AHEE teachs/teached for the last 50 years to audiophiles but that AHEE in this specific subject were and are only spreading lies deceiving/misleading audiophile gentlemans only to take their money and people like you even try to explain that kind of deceive with no facts.

I don’t care what the audiophiles like ( it’s a personal privilege. ) but with out any doubt all the tube owners are listening ( no matters what ) something really away from what the recording microphones pick-up during recording sessions and in the other side good SS electronics designs ( like the " old " JC-1’s. ) puts any one of use nearer and truer to the recording where tube is only a " caricature ".

Go a head making money, nothing wrong with that but stop to spread false information against SS that you can’t prove or proved and learn from other tube manufacturers that never post in any internet audiophile forums that totally false information in favor of tubes and against SS electronics . Learn from all those honest gentlemans.

R.

" all due to distortion .." what are you talking about, where are your facts?

Your inability to understand the facts isn’t my fault. I’m writing this so you understand that I presented the facts *already*.


If you actually have a genuine interest in learning more of what I posted previously (instead of simply acting on a desire to make me wrong), google ’Gain Bandwidth Product’ and ’phase margin’ and read up. Then you will see why what I posted is correct. FWIW these are engineering topics and may be a little dry. For more information you might also read this article by Bruno Putzeys on feedback. In this one you don’t have to work out the math, if you allow yourself to trust that he did his math homework (in case you don’t know who he is, Bruno is one of the top designers of class D product in the world, responsible for the Purify and Hypex modules):
https://linearaudio.net/sites/linearaudio.net/files/volume1bp.pdf

After reading this article, you should understand why the Parasound is running insufficient feedback, and so has a brightness.

Ignorance is curable- stupid is forever. I’m pretty sure you’re not the latter, so now you have an opportunity.

Dear Raul you posted above {all the tube owners are listening ( no matters what ) something really away from what the recording microphones pick-up during recording sessions} and { Learn from all those honest gentlemans}  = Non-Sequitur ie Sweeping generalizations followed by special pleading The generalization is the fallacy here. The pleading follows it in order to avoid offense or some such measure.

Dear @johnk : Please re-read my post and why I posted that way:

"" or a little extra warmth but the highs are detailed and relaxed. "

again where is that warm or relaxed kind of sounds coming from live MUSIC at nearfield listen to, a horn, cymballs, drums or even a violin or a piano. It does not exist and this is not a generalization and a fallacy: just does not exist.
Things are that the recording microphones are at nearfield position.

I posted :

"" and it’s brigth, agressive, high dynamic power, with ryhtm, extraordinary at both frequency extremes, sometimes harsh ( listen to a trumpet/horn player at real SPL seated at 3 meters . ). ""

That’s how at real SPL sounds/performs a good SS electronics designs. Music have all those adjectives and many more: natural brigthness or natural agressivenes or even sometimes harsh sound is how the JC-1's will performs when the recording asked for. It's not because it needs higher feedback levels.

Issue is understaND HOW LIVE music SOUNDS AND WHAT RECORDING MICRO’S PICK-UP AT REAL spl: THAT’S ss THAT’S THE ONLY WAY TO STAY NEARER TO THE RECORDING TRUER TO THE RECORDINGS. tUBES CAN’T DO IT FOR SEVERAL WELL DOCUMENTED REASONS/FACTS. ( capital letter a finger error. ).

That manufacturer is totally wrong and as usual he never gives/gaves a first hand measured facts that can prove his false information. Exacvtly like today always takes/took another reference that proves nothing here, so useless to give him an answer.

You know, in the world exist honest and dishonest people. Make your own judgement because this " episode " is repeated again for the 1,000 time.

Btw, I respect your opinion and I don’t try to make any offense to any one but only post facts and that’s all.

R.