Yes Al and that why I say a Quad 57 is voiced around a low power low current tube amp, but with Martin Logan's statement:
"Quote:
However, it is important that the amplifier be stable operating into varying impedance loads: an ideally stable amplifier will typically be able to deliver nearly twice its rated 8 Ohm wattage into 4 Ohms, and should again increase into 2 Ohms." Quote:
This is why my ML Monoliths have very subdued/rolled off character in the uppermid/highs and dynamics when driven from my tube Rogue 120 monoblocks.
Yet they sound perfect and well extended when driven by my big current pushing solid state monoblock amps.
Cheers George
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Yet they sound perfect and well extended when driven by my big current pushing solid state monoblock amps. 'Current pushing'? This sounds like a misconception to me. Again, Martin Logan is specific about the amplifier to use with their speaker because they have made the speaker so hard to drive. 0.5 ohms is hard on all amps, not just tubes! What you want to consider is how the amplifier distorts when presented with a low impedance- and in this case, **all** amplifiers, tube or solid state, will have higher distortion which will result in brightness. I suspect this is why Paul Speltz got a letter from Steve McCormick, wherein Steve described how even though his amps can drive 4 ohms effortlessly and with double the power of the 8 ohm load, the fact was that they sounded better (smoother, greater detail) when using the ZEROs to drive the same load. The simple fact is that you don't want an amplifier to work hard- it will have greater distortion which is to say it will sound harsher and with less detail. George, you should give a set of ZEROs a try with your Rogue amplifiers. I think you will find that by using them, they keep up with your solid state amps in the highs. That is the experience of many people using the ZEROs. The ZERO website ( http://www.zeroimpedance.com) has many comments in that regard. |
I've had a pair of Zero's given to me, to me they are a band aid fix for an amp that not right for the speaker it's being use on, and the disadvantages far outweigh the advantages.
Your far better off getting the right amp for that speaker.
PS: I gave the Zero's away as well.
Cheers George
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I have to say that my own expearience of the Zero's into ML CLX's would seem to parallel with MrLoFi's, given the many favourable endorsements on line I was most surprised to find that IMHO the Zero's rather than opening up the presentation produced the opposite effect within my system
( Configuration and polarity checked and double checked for user error) |
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^^ Did you speak to Paul about it? Your experience is unusual (although much depends on the amp too). |
Atmosphere, I did not, as there was nothing radically unusual in any of the three valve amplifier models ( two pentode PP and one Ultra Linear ) that I experimented with, the latter being right on the recommended minimum for CLX's and therefore in theory should have produced the most perceivable improvement, if any, of the three.
As I say, entirely unexpected considering the due diligence before purchase! |
Ralph, take a look at the impedance curve for the CLX, shown at the bottom of this page. Could it be that Tsushima1's negative experience with the Zero was the result of the speaker's extremely high impedance at low frequencies being multiplied 2 or 3 or 4 times, resulting in the tube amplifiers he used running essentially unloaded at low frequencies? Or, at best, running into impedances at low frequencies that were non-optimal for the output taps provided on the amplifiers? Best regards, -- Al |
Hard to say Al, he's not said what phenomena he ran into with any specificity.
Paul Speltz is very supportive though and often has suggestions for how to sort things out should one run into problems. |
A simple way to hear what negative effects they have, is to put them on an amp that has no problem driving a speaker.
Then you will hear what negative effects they have when they are in.
In my view they are interim fix, to allow an amp that has problems driving the speaker, to make it usable with that speaker. And I use the word "usable" lightly.
A owner is far better off getting the right amp for the speaker, or the right speaker for that amp to start with.
Cheers George
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An informative review from HiFi World there Al, however from my own in-room measurements 92 to 96 db peaks were demanding 120 to 140 Watts of the amplifier, therefore I must say that I am somewhat sceptical of the reviews 'more than adequate' power recommendation of 50 Watts! |
Do what the maker recommends.
It'll all work. It's just a matter of how well. The maker should know best what works best. Once you've done that, then you are in a position to try something different and see how that works in comparison. You never quite know what will sound best to someone, however its much easier to determine what will perform best from a technical perspective. Optimal performance is usually the best place to start. Where one ends up after that might still be different, but at least you know you started out on the right road.
If you need an adaptor, impedance or otherwise in order to make things work well, you probably did not start out on the right road. |
hi everyone,
I had actually pose my opinion in another article, but I think this subject here is more suited and I wish senior members would share their valuable knowledge & experiences.
We had seen many varieties of impedance coupled with varying phase angles charts, especially from ESL speakers when they behave like a giant cap into high freq.
When some audiophiles describe tubes amp suit well for ESL, we are assuming the tubes would handle the voltage & current needed by the speakers optimally, at a certain range of frequencies. because, generally tubes cannot provide enough high current into magnetic coils when required for high excursion of speaker drivers into low bass and high frequencies due to same reasons too.
Now, I do not know how tubes behave given the ever changing phase angle in relation to impedance,(voltage leads or lags before/after the current), but I suspect that tube can offer more "fluctuation" or "more tolerant" to out of phase signals when required by the speaker to produce music. I believe tubes are naturally more "forgiving"(tubes can give more voltage without rising current) as compared to output transistors when facing these out of phase requirements posed by speakers, especially ESLs. I guess transistors usually have a tighter range to work with electrical signal. transistors are generally linear devices am I right? my bet is that transistors work best when voltage and current are output simultaneously(meaning linear), to provide the power needed by speakers, so if transistors need to work beyond its specification(non-linear, as required by out of phase angle signal), it would clip even before it reaches its full rated power(watt) regardless it is a single or multiple transistors trying to provide power into a given load.
base on above assumption, I perceive that tubes would better suited for ESLs but there are caveats, that's the songs the listener is playing should not contain low bass & high notes i.e. no punching bass, no high pitch like triangles or in harps, electric guitars etc.. (please also bear in mind tubes are slower in response, transistors are faster)
just my two cents |
Transistors and tubes are the same speed (speed works out to bandwidth, so imagine how it was that color television was possible with tubes; color television requires some bandwidth!).
It is the output transformer of a tube amp that usually limits its speed. However, delivering the 'current' to play bass on an ESL is no problem at all for a tube amp, in fact generally speaking transistors are less able to deliver the power needed, simply on account of the fact that the bass region of most ESLs is also the region of the highest impedance, which is often ten times higher than it is at 15-20KHz. |
