Results 51 to 100 of 116
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September 13, 2021, 12:35 PM #51
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Re: Power amplifiers that excel with very low impedance - and low efficiency loads
The Anthem P2 does not get hot beyond ambient air temperature, I have used a P2 amp for over 8 years and have never had it get hot or shut down and I have driven speakers down around 1-2 ohms for 10-12 hours at a time at 3/4+ power and this amp will just keep going. If you want look up the reviews for this amp they have been made for at least 10 years.
This amp is basically 2 mono amps in one chassis, no fuses, and I have never had the reset buttons pop to reset this amp, they run around 5k new but used can be had from 2-3k
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September 14, 2021, 12:44 AM #52
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Jim, my recommendation would be to give any of the Constellation amps a serious look. Caelin uses them in his audio showroom at Shunyata, and he says they will drive any impedance load into any speaker and never break a sweat. Also, he says they sound as good upon start-up as they do fully warmed up. They are also incredibly reliable, and having heard them first-hand at his showroom, I can say they sound...absolutely fabulous. Even that Argo integrated is really something else.
The other solid-state brand that comes to mind is DarTZeel...again, we're talkin' next level here, in my experience.
There are reasons why you never see Constellation or DarTZeel gear for sale at the used gear sites...'cause the folks that own them...NEVER sell them.
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September 14, 2021, 01:46 PM #53
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Re: Power amplifiers that excel with very low impedance - and low efficiency loads
To be honest i'm finding it very hard, to understand why we can not know what the speaker is, if it's a new company, so what, it will become common knowledge soon anyway, and if a new company is producing a speaker that you can hardly drive, unless you buy a pair of Dan D relentless amps at £250,000, then i really don't give them much of a chance anyway, so to be honest this thread is pointless,
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September 14, 2021, 02:06 PM #54
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
DPT4ME - Dynamics, Presence & Tone for Musical Engagement; MBP (3) - stripped down for music only; Shunyata Omega & Sigma USBs; ISO REGEN w/short Curious USB links; Berkeley Alpha USB; Aqua La Scala II Optologic DAC; Schiit Yggdrasil - fully updated; Ayre Codex dac - updated; Pass Labs INT-60 integrated amp; Wyred 4 Sound STP-SE-2 preamp, Quicksilver Mono 120 amps w/Tung-Sol KT150s; Quicksilver Mid Mono amps w/Gold Lion KT77s; Fyne Audio 703s; Symposium Svelte Plus & Ultra Platforms; REL S-812 subwoofers; Duelund DCA12GA speaker cables; AV Room Service EVPs, Stein Music Harmonizers, Duelund DCA16GA & 20GA ICs; Shunyata Denali 6000S/V2; Tripp Lite PCs; Wyred 4 Sound power cords; AudioDharma cable cooker; dedicated custom room; various GIK & ASC room treatments; etc.
www.getbettersound.com
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September 14, 2021, 05:30 PM #55
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September 15, 2021, 03:41 PM #56
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Such a driver is going to cause any and I mean any amplifier to make excess distortion, so keeping it corralled to one driver (or more likely, array) is a good idea.
If it is an array, it might be possible to wire the drivers in a series/parallel arrangement to get a higher impedance. Since the output of the amp has to be controlled by a level control to allow it to work with the rest of the speaker, doing this shouldn't be weird. But it would make the speaker easier for a wider range of amplifiers.
I know that you're not talking about what speaker. But you might be able to pass some information along to the manufacturer thru their customer, which is that there is no benefit using any amplifier made to running such a low impedance in the bass region. You're simply going to get into drive problems, the speaker cables will be a nightmare (since their DCR will become a thing) and it will make it hard to sell speakers. Look at how hard it is to get an amp that's suited for this kind of duty and you're not even the seller!
So he might consider a minor redesign.
Just FWIW Dept,: there's no good argument for low impedance speakers if audio excellence is your goal. You might have a weak argument if sound pressure is your goal. You'll simply force whatever amp can survive the application to make more distortion and if that amp is also driving the mids and highs make no mistake: that distortion will be audible as brightness and harshness. A simple way to make any speaker sound smoother and more detailed would be to somehow go to a higher impedance without changing anything else.
Now some people on this thread know I'm a manufacturer of tube amps (now for over 46 years). But I've worked on thousands of solid state amps in my career (I put myself through engineering school servicing audio equipment). Right now we're working on a class D amp of our own design. IOW I'm not being hyperbolic, I'm not making this stuff up; I'm simply being pragmatic.
As far as what amp to use, the first thing to know is how much power you need. Do you have any sensitivity specs and do you know the size of the room? Sorry if you posted that but I went through this thread and didn't see it.
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September 15, 2021, 04:04 PM #57
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Haha OK Ralph ..
Here we go, for an OTL toob amp you are 100% correct , for a transformer coupled toob amp you’re 50% correct , for an SS amplifier designed for low Z operation not so much.
A low Z operation SS amp will have both Bias and feedback scheme as well as output/driver stage designed for such a low impedance operation , only low to zero feedback amplifiers will have issues driving low Z loads, to be specific the loudspeaker should be of such a design to take advantage of being such a low load , case in point , direct drive ribbons, as the removal of meters of wiring thru inductive voice coils and resistors is easily overcome by being able to drive the diaphragm directly..
Regards
PS : For an high impedance 8 ohm easy to drive loudspeaker i would use a toob amplifier and not an SS amp , a well designed SS amp is at its best on low Z difficult loads , i do realize the current trend is low feedback SS amps for 8 ohm load type speakers and those type of amplifiers will suffer on difficult low Z loads with increased distortion and a lack of stability..* An Audiophile is only as old as his latest Class D incarnation *
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September 15, 2021, 05:50 PM #58
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Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Jim,
The Speltz Zero autoformers increase the impedance the amp sees. I run them on my AtmaSphere M60 OTL amps driving Kef Reference 207/2s which dip to 3 Ohms and they definitely do not add transformer euphonics. It could be an option that widens the choice of amps.
Evan
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September 16, 2021, 12:18 PM #59
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
I've yet to see a solid state amp (or class D) whose distortion did not go up when driving a 4 Ohm load as opposed to an 8 Ohm load.
If you know of one I'd be interested.
But you can see this in the specs if they are published. The thing is, that little difference you see is audible- since the ear converts all forms of distortion into tonality, and since it also uses the higher ordered harmonics to sense sound pressure, that slight amount of increased distortion (which is almost entirely higher ordered harmonics) is audible as increased harshness and brightness- and a loss of detail.
Harshness and brightness is the sort of thing that lowers WAF and if you have any hearing left, reduces your enjoyment of the actual music- it allows your brain to know that what you're listening to is a mechanical reproduction of some kind- electronics instead of music. This is just me of course- my goal in high end audio is to get the result to sound real and the more you spend at that effort, the more it had better pay off. So things like 4 Ohms (or less) loads play counter to that.
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September 16, 2021, 12:23 PM #60
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Harshness and Brightness is usually associated with clipping and or too low of compensated for class A bias at desired listening levels, these are known knowns with SS amps and how high is SS distortion vs Toobs distortion in General Ralph ..?
Distortion quantity either matters or it dont you cant have it both ways ...
Boulder 2150 :
Even at 4 ohms it register very little and JA using 40V is a very high irrelevant number as nobody domestically will be using 40V , a more realistic 1 watt at 8&4 ohm would be more relevant but distortion numbers were well into his test equipment noise floor ..
Now if you look at the still very low numbers of distortion at 4 ohm
(Magenta vs blue) its easily compensated by the lower distortion achieved from running multiple drivers Even with the lower ZMin from the Loudspeakers ..* An Audiophile is only as old as his latest Class D incarnation *
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September 16, 2021, 12:45 PM #61
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Now if totally optimized for low z operation those Boulder 8 ohm numbers could be matched at 4&2 ohms with modifications to the voltage , feedback and bias settings. Lamm attempts this route on their Hybrids to get their best low Z operation from those amplifiers, by applying both a high Z and low Z switchable operation ..
Regards* An Audiophile is only as old as his latest Class D incarnation *
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September 16, 2021, 01:14 PM #62
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
You're pointing out exactly what I'm talking about.
The thing is, the industry has spent a lot of time telling audiophiles that the slight difference you see in the charts is 'negligible' and 'inaudible'. Quite simply it isn't. What is being ignored here is that the ear has over a 120dB range and uses the higher orders to sense sound pressure- and so is keenly sensitive to them, far more so than anything else. As a result we can hear these 'tiny' (because that's how they look on paper) differences- that's why audiophiles hear differences in amps, not so much due to FR variation, but due to the distortion signature.
For the application the Boulder is probably one of the better choices! But saying that its going to sound its very best is an entirely different matter- the ability to drive low impedances isn't what makes an amp sound good or bad. Distortion is what does affect that and clipping has nothing to do with it. IOW the differences we hear between amps is due to the distortion they make when they are not clipping, because the ear pays a lot of attention to the tonality created by that distortion. Again, that's why you can have two amps on the bench that both measure perfectly flat, but one is bright and the other is not. The brightness is the result of non-clipping distortion.
That BTW is why the tube industry is still very much around; for the last 60 years we've been hearing solid state amps be bright (and of course the guitar world plays an enormous role). You might want to read what Bruno Putzeys has to say about distortion (if you've not already).
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September 16, 2021, 01:19 PM #63
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Toobs are still around because Audio has nothing to do with good sound it has and always will be about what one likes, one man’s Audio Euphoria is and will always be another's anathema, So there’s good sound available from Toobs , SS , digital and or analog and i have never owned or used a bright or Harsh SS amp in 40 plus yrs, its an old straw man argument very similar to what pro SS people do when they say Toobs are dark and slow ...
So while some toobs maybe dark and slow and some SS harsh and bright these are characteristics of poor design choices ..
That aside ,
you will have to prove That brightness between SS amplifiers were not from non clipping or running out of class A bias for the load , we have done that rodeo too many ( Bob Cordell even went as far as to do a show setup to prove this by showing how much power was necessary to prevent clipping from only 1-2 watt rms use ) times and a non clipping properly biased for the load SS amp will never sound harsh or bright unless from a very poorly designed amp, it’s academic we are not discussing poorly designed amplifiers and if you level match many properly designed amps will sound very similar, as to being without harshness and or brightness , its mostly there clipping /recovery characteristics is what really affects what most people hear and of course their choices ..!
Maybe you can explain away these high levels of distortion from toobs Or does distortion only matters with SS amps ....?
1 Audio Research REF 160S, Triode mode, 4 ohm tap, THD+N (%) vs frequency at 6.3V into: 16 ohms (left channel green), 8 ohms (left blue, right red), 4 ohms (left cyan, right magenta) 2 ohms (left gray).* An Audiophile is only as old as his latest Class D incarnation *
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September 16, 2021, 02:31 PM #64
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
I can,
This is an example of how the distortion signature affects the sound you hear. A large 2nd and 3rd harmonic helps mask the presence of the higher orders. This helps keep the amp sounding smooth even though it has more higher ordered harmonic content than most solid state amps.
Put another way, the distortion signature is pretty important to how smooth the amp sounds. The trick is getting it down overall- tube amps in general are not very good at that since its hard to build them with enough feedback to do the trick (IOW phase margin is an issue).
One other thing: the distortion really should be the same at 1KHz and 10KHz as it measures at 100Hz. Many amps have insufficient gain bandwidth product, which is another way of saying that as frequency is increased, the feedback decreases, so we see distortion rising with frequency.
The problem is that feedback introduces distortion in the form of higher ordered harmonics through the process of bifurcation (see Norman Crowhurst- he was writing about this 60 years ago). In addition you can get intermodulations at the feedback node if you're not careful. Since feedback suppresses the innate distortion of the amp, the remaining distortion is often that of the feedback itself and it is unmasked, so easy to hear.
If you have enough feedback you can get around this problem. Imagine a bell curve; feedback does its worst damage between 15-25 dB (which is an amount commonly used). If you get over 35dB the amp can clean this problem up and you can have a much smoother sounding amp. Class D seems to offer a nice way to do this in self-oscillating examples.
You can get tubes to sound just fine but not every manufacturer of tube amps is successful. Plus you do want to be careful to not use them with speakers that they are simply a bad match. But I've found that latter bit true of transistors as well: not every speaker works with every amp and vice versa.
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September 16, 2021, 02:53 PM #65
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
You have to match SS amps to the load in the same way you do for Toobs , any and all distortion is audible nothing is masked to those who can discern it , Class D or any SS has its sound same as high distortion toobs and or low distortion high feedback toobs, Only amps with bad open loop gain tend to have NFB issues ...
Again a lower THD high dynamic low Z operating loudspeaker is superior sounding to a high Z variant with less drive area , this will more than compensates for any small increase in amplifier THD ....!
A committed low Z designed SS can be of low distortion and flat bandwidth 20-20K same as 8 ohm if optimized in its design phase..
Lamm M1.2 Reference in low Z operation mode optimized , "1–6 ohms," THD+N (%) vs frequency at 8.95V into: 8 ohms (blue), 4 ohms (magenta), 2 ohms (red).
Is that flat enuff for you ...?
Regards* An Audiophile is only as old as his latest Class D incarnation *
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September 16, 2021, 04:21 PM #66
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
If I understand you correctly I partially agree. I'll make it a bit more clear: If they have the same distortion signature it won't matter what kind of amp it is, it'll sound the same. But what is meant by 'bad open loop gain'??
Again a lower THD high dynamic low Z operating loudspeaker is superior sounding to a high Z variant with less drive area , this will more than compensates for any small increase in amplifier THD ....!
A committed low Z designed SS can be of low distortion and flat bandwidth 20-20K same as 8 ohm if optimized in its design phase..
Lamm M1.2 Reference in low Z operation mode optimized , "1–6 ohms," THD+N (%) vs frequency at 8.95V into: 8 ohms (blue), 4 ohms (magenta), 2 ohms (red).
Is that flat enuff for you ...?
Regards
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September 16, 2021, 05:03 PM #67
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
I’m familiar with Crowhurst , Geddes , Putzeys, et al , its not relevant to the discussion about low Z SS amps as we are not debating distortion signature, we are debating your comment on why low z is bad in loudspeakers...
Regards* An Audiophile is only as old as his latest Class D incarnation *
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September 16, 2021, 06:10 PM #68
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Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Loved my Lamm M1.2 hybrid monos. Should have kept them.
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September 16, 2021, 06:16 PM #69
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Yea ,
unlike your Mac those can handle the Pre-conditioning test at 1/3 power ..* An Audiophile is only as old as his latest Class D incarnation *
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September 16, 2021, 06:21 PM #70
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September 17, 2021, 11:23 AM #71
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Hm. If you really think that then you missed the point of my comment. It was in fact entirely about how low Z loudspeakers cause all amps to have increased distortion. And yes, the writings of those authors are quite relevant. They can be quite helpful in guiding one towards something more musical as opposed to something less musical.
And with a lot of solid state amps that have a distortion signature that allows the higher ordered harmonics to be heard as brightness and harshness, this simply means that the system will sound less 'real'. But in the OP's situation, the distortion is corralled a bit by being limited to the woofer or woofer array, thus limiting the effect somewhat (unless the woofer also has a choke in series, some of that distortion will be reproduced).
By simply employing a higher impedance (which might be as simple as changing the series/parallel arrangement if its an array) this distortion will be reduced.
BTW you didn't answer my question about what is meant by 'bad open loop gain'. I'm very curious what you meant by that.
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September 17, 2021, 11:51 AM #72
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Well..
You missed my point entirely Ralph , mainly how SS amps designed for low Z operation( proven and shown as you requested look at lamm ) can have low distortion as well as how low Z loudspeakers if designed correctly has less distortion than high Z , making the whole combination superior granted far more technically difficult and not as easy as say an high Z , 2 way or 3 way system with usually higher Thd
As to your umpteen time Strawman argument about distortion signature , that’s all getting into subjective audio blah blah as to who likes what and is a total side step of the point being made.
Measured thd , not subjective likes and dislikes ...!
BTW , your suggestion of simple change of series / parallel to increase impedance load is nothing more than band aid for what is really an amp mis-match situation , you should investigate how series coils affects the sound vs parallel circuits, in regards to loudspeakers ..
Regards
PS: Maybe i should have used poorly designed open loop gain, instead of bad ..
My Bad ..* An Audiophile is only as old as his latest Class D incarnation *
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September 17, 2021, 12:40 PM #73
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
This is almost entirely false. All humans use the same hearing perceptual rules- for example all humans use the higher ordered harmonics to sense sound pressure. That's not a matter of taste. The masking principle is also common to all humans. There's no strawman going on; simply the nuance of what happens when you try to use any amp to drive an impedance that low.
The 'almost part' is the THD of the Lamm, which is unusual. But without knowing the distortion signature you can't just say that 'lower THD is better'. Lower THD and a proper distortion signature such that higher orders are masked is what will result in an amp that is musical and not bright. Low THD on its own can easily result in a bright sounding amp. You can try to make the argument that such is subjective, but its also well-known that humans find the higher orders unpleasant and that understanding was published way back in the 1930s. If you're going to subject an amplifier (including the Lamm in this case) to a situation where you know its going to make those higher orders you can count on the result being less musical and you don't have to hear it to know that. All you have to know is the science of how the amps work and how that interacts with human hearing perceptual rules.
If you design an amp without paying attention to the aspects of human hearing you stand a good chance of making something that will sound bad. Its not subjective so much as its engineering applied to physiology.
BTW , your suggestion of simple change of series / parallel to increase impedance load is nothing more than band aid for what is really an amp mis-match situation , you should investigate how series coils affects the sound vs parallel circuits, in regards to loudspeakers ..
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September 17, 2021, 01:30 PM #74
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Well i guess everyone hears the same and like the same sound, it’s settled then, err , if not for the unsettling Irony ...
Regards* An Audiophile is only as old as his latest Class D incarnation *
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September 17, 2021, 03:02 PM #75
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
That's not what I'm saying. I am saying that the rules that govern how we perceive sound are the same rules- this is how MP3s are possible. They rely on the masking principle to compress the file size. And its also true that humans don't like higher ordered distortion components - that's why most guitar amps are tube amps, although to be clear in the case of the OP I'm not talking about an overdriven amp.
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September 17, 2021, 03:07 PM #76
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
You’re obfuscating ,
It’s apples and oranges , the discussion has nothing to do with distortion harmonic (complete different discussion) structure its all academic really, these are all known knowns , yet you keep wanting to keep this circular Strawman argument, waffling between objective and the subjective ..
Whats your thoughts on Specialized vs Trek ..?
Regards* An Audiophile is only as old as his latest Class D incarnation *
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September 17, 2021, 03:15 PM #77
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September 17, 2021, 03:20 PM #78
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September 17, 2021, 04:15 PM #79
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
If you think I'm obfuscating or waffling, then you've missed my point.
Class D offers a way (through self-oscillating design) to allow for a large amount of feedback (+35dB) that is otherwise difficult to design into traditionally-designed solid state or tube amplifiers. This is done by intentionally exceeding the amp's phase margin, so it oscillates. The oscillation is then used as its switching frequency. This allows for an amp that lacks the typical brighter/harsher presentation than the prior art (otherwise to avoid this you have to avoid feedback altogether). A very nice benefit is they are also cooler running, more efficient and lower cost. Class D amps have a different artifact that is actually similar in some ways to tube amps. Dead time causes distortion; but it tends to be of the lower harmonic variety, as do non-linearities in the encoding scheme. This allows for an amp that not only has the right distortion signature, but also low THD, the best of both worlds. Of course if you overdrive it, it will clip like any other solid state amp. So don't clip it.
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September 17, 2021, 04:32 PM #80
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Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Could you hurry that up please? I would love a cool-running, high-power, great-sounding amplifier that I can lift.
All too frequently it is over 100 degrees here so no Class-A. Tubes are relegated to winter use but swapping amps is getting harder every year. Every Class-D amp I have tried did everything right--except make music. At least to my ears.
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September 17, 2021, 04:34 PM #81
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September 17, 2021, 05:47 PM #82
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
This week, partly for amusement, partly because I got a good price, I bought a pair of M700 PS Audio class D amps on the used market. We have a kitten in the house and the Parasound JC 1+ run hot as hell (all class-A for first 25 watts). No cat can resist sleeping on them. And the Parasounds don't sound good unless they've been on for a couple of hours. Being unable to ensure constant surveillance, I was in a bind. In fact, I am totally enjoying the M700s. They drive my Magic S3 Mk2 speakers very well. Paul McGowan and designer Darren Myers made quite an elaborate project of making the most of the ICE power module they used. It is very deliberately "voiced" to sound agreeably audiophile. Detail and imaging are abundant and they added a touch of musicality in addition to giving the midrange an obvious boost. The result is less a novelty than the audio equivalent of a perfect gourmet burger (wagyu beef and blue cheese included). I'm relieved to have something I can use with real pleasure during the week when I don't have time to heat up the Parsounds, and in summer when my air conditioning cannot keep up. They slide right into my system with the Aesthetic preamp and Lampizator DAC and give very clear voicing to the specific personalities of each. I am tempted to say that every audiophile should have a good class D amp kicking around for times when quick and cool are required qualities in an amp.
Magico M2
AMG V12 (Teatro cart)
Lampizator Atlantic Plus DSD512
Aesthetix Calypso Signature Preamp
Luxman C-900u Preamp
Auorasound VIDA (phono-stage)
Parasound JC 1+ monos
Aurender N100h
Nordost Frey 2
HRS, Rix Rax
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September 17, 2021, 06:05 PM #83
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September 17, 2021, 06:08 PM #84
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
* An Audiophile is only as old as his latest Class D incarnation *
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September 17, 2021, 08:46 PM #85
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September 20, 2021, 11:56 AM #86
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September 20, 2021, 02:36 PM #87
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
I take your point but I can find no meaningful fault with timbre from the PS Audio M700s. Listening to piano right now and all is very good. If you want anyone to "voice" the ICE module to sound maximum audiophile, Paul McGowan would the one the to choose. Justice is being done to my excellent sources and to my speakers. The M700 is just $3300. I admit I get a kick from the value. I also admit I wouldn't want to be confined to only class D. The Magico's come alive more fully when I use the JC 1+s. But given the feline problems and summertime heat problems I am happy to have these amps in rotation.
Magico M2
AMG V12 (Teatro cart)
Lampizator Atlantic Plus DSD512
Aesthetix Calypso Signature Preamp
Luxman C-900u Preamp
Auorasound VIDA (phono-stage)
Parasound JC 1+ monos
Aurender N100h
Nordost Frey 2
HRS, Rix Rax
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September 20, 2021, 03:34 PM #88
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Wow, this thread has taken such a digression from the subject of Jim's original post, maybe all the amp "techical side-bar dicussion" should be moved to it's own thread. Lots of good info here, but pretty far from JIm's original post.
Jim: I'd go with Constellation if it's in your customers budget. Just sayin'....
'
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September 20, 2021, 03:35 PM #89
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Not sure this qualifies, but here is the NAD C 298 specs:
Rated output power into 8 Ohms (Stereo) 185 W at 8 ohms (ref. 20 Hz-20 kHz at rated THD, both channels driven)
Rated output power into 4 ohms (Stereo) 340 W at 4 ohms (ref. 20 Hz-20 kHz at rated THD, both channels driven)
Rated output power into 8 Ohms (Bridge mode) 620 W at 8 ohms (ref. 20 Hz-20 kHz at rated THD, both channels driven)
THD (20 Hz – 20 kHz) <0.005 % (1 W to 185 W, 8 ohms and 4 ohms)
Sure looks like they claim same low distortion for both 8 and 4 ohm. Am I missing something or are they claiming that the distortion figures do not raise at 4 ohm?McIntosh C49, MC152, MR85, R778 | T+A DAC 8 DSD | KEF LS50 Meta w/S2, KC62 (x2) | Rega RP8, Ania Pro, NEO PSU | Technics SL-1500C | Audio Technica VM750ML | Hexmat Eclipse, Yellow Bird, Molekula, Molekula Mini | Pro-Ject VC-E | Falcon NW PC Server (Roon Core & HQPlayer) | Microsoft Surface Pro 6 (Roon Controller) | Wyred 4 Sound ISO Recovery, DC Recovery | Abyss Diana Phi | Schiit Jotunheim 2 | Astell&Kern SE200 | Oppo BDP105
“One of the great challenges in life is knowing enough to think you're right but not enough to know you're wrong”
"You can't use reason to convince anyone out of an argument that they didn't use reason to get into"
― Neil deGrasse Tyson
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September 20, 2021, 05:05 PM #90
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September 20, 2021, 05:08 PM #91
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
* An Audiophile is only as old as his latest Class D incarnation *
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September 20, 2021, 05:56 PM #92
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Dunno! But it would be interesting to see how it actually behaves. The amp doesn't double power- in sufficient heat sinks or power supply?? With a limitation like that imposed I would expect to see it affect distortion too.
Your memory fails you, we have had this and that discussion maybe 100 times already ....
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September 20, 2021, 06:23 PM #93
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
No Ralph your response is , not calling you out just saying your memory maybe failing you...
Regards
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September 20, 2021, 06:28 PM #94
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
* An Audiophile is only as old as his latest Class D incarnation *
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September 20, 2021, 06:51 PM #95
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Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Sorry Jim, I haven't heard this amp but I have heard its predecessor the JC1. Parasound claims that the new JC1+ mono blocks are stable with speakers that dip below 1 ohm.
My Gear- Mains System-Pass X250 amp, BAT VK-51se preamp, Luxman DA-06 DAC, Magnepan 1.6's, Thorens TD-145 TT, Dual Martin Logan Subs, Vintage Luxman T-110 Tuner, Cables-WW Platinum 7 USB, Cardas Parsec XLR, AQ Columbia DBS 72v XLR, Belden 8402 XLR.
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September 20, 2021, 07:06 PM #96
- Join Date
- Aug 2014
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- lachen / sz
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- 1,061
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
i think we are ok continuing the thread this way since jim (i think) is no more in search.
the client has a speaker with a nasty load. what can he do?
well, sell the speaker or buy an amp that can handle the load.
however, the client (if i understood correct) wanted to buy an amp on top to the existing one and drive the bass separately.
to make that sound good, you will need an extra crossover that will be capable of adjusting phase etc, you will need more cables and actually the SAME amp you already have.
so if your first amp cant handle the load why buy it again.
bottom line, if you do it right, it will be very expensive.
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September 20, 2021, 07:40 PM #97
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
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“One of the great challenges in life is knowing enough to think you're right but not enough to know you're wrong”
"You can't use reason to convince anyone out of an argument that they didn't use reason to get into"
― Neil deGrasse Tyson
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September 22, 2021, 11:11 AM #98
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
It isn't. Your use of hyperbole is failing you however. '100's of times?? Nope. Eight years ago we had no plans of a class D amp. None. That didn't happen until about 4 years ago. So how could I have talked to anyone about the project eight years ago?? The answer is simple: I didn't. In fact I kept silent about the class D project for about a year.
So please cease and desist about attacking me regarding the state of my memory. Reporting your post as the abuse that it is failed to get any response out of the moderation team (and being a moderator on another site I know the definition of abuse) so I'm simply stating here how to deal with this: if you disagree with someone on a topic, attack the post, not the poster. Get it??
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September 22, 2021, 04:58 PM #99
- Join Date
- Mar 2018
- Posts
- 435
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
If a person is going argue with Ralph about amplifiers I have just one suggestion for that person. Do not enter into a battle of wits unarmed.
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September 23, 2021, 03:57 AM #100
Re: Power amplifiers that excel with very low impedance - and low efficiency loads
Ralph,
I have been on the brakes very hard with you over this , you are the one doing the personal attacks , I’m only responding to your attacking rants ..
We have had many audio discussions over the years , most recently at the fla audio show in 2020, in your room, as well as numerous other times over the years in many different forums. In forums its your usual strawman arguments basically to support your limited power high impedance only driving amplfiers of choice, now I'm not going to use my time to search the WWW to prove any and everything about your class D amp rant , i don't care , But to say never Outside your company until recently is a joke Ralph, I’m guessing to protect your patent, well for the record no details were ever disclosed , you only mentioned in discussion you were looking into a class D design, it was some years ago ..
Here are a few mentions by others Of (going back a few years, first pic 2018 easily found) your no discussion until recently class D amps,
is 2018 recently Ralph ..?
We have had these and many discussions over the decades Ralph, so if not 7 or 8 on your class D ,maybe 5 ? it was some years back, again you mentioned you were looking into it and that it looked very promising, there were also discussions over your Vinyl cutting/ pressing issues , how backed up you were , how stereophile wouldn't give you a review, discussions on NFB, why OTL , why toob amps with transformers are bad , many this or that , blah , blah, blah ..!
So Please ...!!!
Strangely after bashing SS amps for decades here you are promoting Class D, is this because you now have commercial interest ? is anti NFB Ralph now pro feedback Ralph, bet yours is the greatest and sweetest kind of NFB...
No wait zero feedback class D ..!!
Is degeneration feedback? ...
Maybe ignore is best and give the mods some rest...!
Regards
PS : Congrats on the patent* An Audiophile is only as old as his latest Class D incarnation *
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AudioShark forum is a leading forum site for High End Audio Discussion, Stereo System Discussion, Home Theater System Discussion, Best Home Stereo System Discussion, Home Theater Installation Discussion etc.
The AudioShark forum was created for sharing the passion of high-end Audio. We have Audiophiles from all over the world participating and sharing their knowledge. From novice to experts, you will find a friendly environment for discussing about High End Audio, Stereo System, Home Theater System, Home Stereo System, Home Theater Installation, Amplifiers, Speakers, Subwoofers, Integrated System, Acoustic treatments & Digital Room Corrections and many more.
At AudioShark, we also have incorporated an exciting Marketplace where members can peruse terrific buys on used gear, as well as meet dealers and discuss the purchase of new gear.
We are as crazy about this hobby as you are! So come on in and join us! Audioshark.org the Friendliest Audio Forum!
Industry Participation Disclosure : The owner and administrator of Audioshark is the owner of Suncoast Audio LLC in Sarasota Florida. Suncoast Audio has a full brick and mortar presence in Sarasota with several great show rooms with many world class brands. More information can be found at http://www.suncoastaudio.com
Audioshark is a community of like minded individuals. Audioshark welcomes participation from all manufacturers and owners of all brands and products. It is our belief that online forums provide a community of like minded audiophiles and music lovers to encourage the growth of this wonderful hobby.
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I or anyone interested should see if FEDEX offers a domestic "LAST MINUTE RATE" for shipping heavy items within CONUS. Have no clue at this point - but when I have some time, I'll check. ...
Shipping Overseas 498 pounds w/3...