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


First,
  
Thanks to anyone who responds with whatever answers/opinions/advice comes from this. I'm retired, covid bound, Donna is taking care of everything holiday related, too much time, always curious.
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I happened across this in an old thread started by Ralph (atmasphere)

"Sixteen ohms, BTW is a very simple means for getting more resolution out of your system, as nearly every amplifier made sounds better on 16 ohms than it will on 4 or 8 ohms. Speaker cables become far less critical too."

My speakers are 16 ohms (Electrovoice horn tweeter, horn mid, 15" woofer, crossover, rheostats, from 1958).
Extremely efficient, I have more than enough power. Amp, now and in the past all had 16 ohm taps.
Of course I can hook them up to my Cayin's 8 ohm taps now and listen, but facts, opinions, advice, to learn is good.
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Lots of Questions? 

1. why/how do 16 ohm speakers make amps sound better, with more resolution? 

2. why speaker cables less critical? perhaps this is why I/we don't hear cable differences in my system?
I'm using my homemade twisted pair of cat 5 now (8 individually insulated small diameter solid core).

3.  to get exterior bias control: use 8 ohm tap for my 16 ohm speakers? (get alternate amp 4/8 no 16 tap,)

lose advantage(s)? 'sounds better'; 'more resolution'; 'speaker cables less critical'? 

this says slightly more mids:

http://blog.hughes-and-kettner.com/ohm-cooking-101-understanding-amps-speakers-and-impedance/

I can fine tune my speakers via their two rheostats: 'presence' and 'brilliance', so not really an issue for me.

4. Importance of Bias Control

how important is Bias? (I don't care about heat, power output, or tube life, just as bias affects sound). Frankly, using vintage tube receiver Fisher 500C, 800C and Fisher Mono Blocks 80Z, I have never checked or adjusted bias. I just put the control in the center position when cleaning insides/controls.

I have always used 16 ohm taps of various vintage tube and SS amps and newer current tube Cayin A88T. (original version, the only one with 16 ohm taps). It's bias control is internal, versions with safer external bias do not have 16 ohm taps.

5. replace their two rheostats? ('presence' and 'brilliance': copper wire-wound on ceramic body, mid/neutral position).
I have them in neutral position now, l/r frequency response equal.   

do I need to keep rheostats 16 ohms? use 8 ohm rheostat with 16 ohm drivers?

sales sheet says 16 ohm, but data sheet shows range 1.0 to 5k ohms. 

https://www.mouser.com/datasheet/2/303/controls_rheostats-1228697.pdf

does that mean, the drivers will draw whatever they draw (varies thru frequency range anyway), doesn't matter as long as rheostat range starts 1.0 ohm, extends past say 100.0 ohms?

https://www.mouser.com/datasheet/2/303/controls_rheostats-1228697.pdf

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thanks, Elliott











elliottbnewcombjr
Dear @mijostyn : 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.


Years ago I meeted by first time to the JC-1’s that were handled a pair of superlative Dynaudio Evidence speakers in the room/system of a friend of a friend of mine.

I readed in those times about the Evidence speakers but never imagined that were handled by so " humble " Parasound amplifiers and was a glorious listening time with both friends and we reapeated that kind of listening session several times. Here the Evidence:

https://www.stereophile.com/floorloudspeakers/286/index.html

Now and this you can be absolutely sure that no tube amplifier can beats the Soundlabs/JC-1’s experience and you can be sure too that the Sounlabs- self powered subwoofers ( 80hz-100hz. ) combination is a must to do it no matters what.

Enjoy it.

Btw, the 16 ohms issue really matters to tube amp owners, not many 16 ohms speakers in a market with 90% ( at least ) of 4 ohm-8 ohm nominal impedance specs.

In the other side SS amps as the JC-1’s can handle from low to high impedances where you can’t detect the small increment in distortion level.

When a tube amp normally ( manufacturer spec. ) has 1% a SS amp with low or high impedance could goes to 0.2-3% when the manufacturer spec overall gives 0.01%.
Normally tube owners " can’t " listen 1-2% of distortion in their amps or just do not care about.

With a little of patience any one can buy second hand the JC-1’s for very good price. John Curl made very good design job with.

This is what I'm talking about:

https://www.stereophile.com/solidpoweramps/774/index.html

R.
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.