The original X1 is the only Wilson I would consider truly SET friendly. 95db and a moderate impedance and phase. Rocks like hell with 30 good SET watts.
Stereophile | January 2017 Issue
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The original X1 is the only Wilson I would consider truly SET friendly. 95db and a moderate impedance and phase. Rocks like hell with 30 good SET watts.
Yes thats a very easy load plus it has 95 db eff , it drops to 2 ohm but not in the audible band :
n the event, the Wilson presents a relatively easy load to an amplifier (fig.6). It's not quite classifiable as an "8 ohm" loudspeaker, which is defined as having a minimum magnitude of 6.4 ohms, though it comes close. For example, in music's main power band (120Hz-10kHz), the loading does not fall below 6 ohms, and averages 7.3 ohms. The magnitude does drop from 5 ohms at 15kHz to 3.2 ohms at 20kHz, which will give rise to some "dulling" of the treble balance both with SE-type amplifiers and with others featuring a higher-than-usual output impedance (1-3 ohms, say). Conversely, the X-1's commendably uniform mid-band impedance means that it will remain neutrally balanced with many tube power amplifiers.
image: http://www.stereophile.com/images/archivesart/Wx1fig06.jpg
Fig.6 Wilson X-1/Grand SLAMM, electrical impedance (top) and phase (bottom) (2 ohms/90 degrees/vertical div.). For reference, the value at 1kHz is 7 ohms.
A fall to just over 2 ohms can be seen above the audioband, but this isn't likely to be of much significance. At low frequencies, the lowest impedance value is a pretty harmless 4.6 ohms at 80Hz. It doesn't fall again until the minimum of 5 ohms at 24Hz—the well-damped port-tuning frequency.
Read more at http://www.stereophile.com/content/...eaker-system-measurements#oKiu5sioZeSIKKxi.99
Yes, i have the original 1994 review by Martin Colloms with all of the measurements, and while i cannot say i totally understand all the measurements, i have read them more than few times over and asked questions (including of DDK, Steve, JackD201 and yourself...thanks!). I have always found the X1s quite a special speaker.
30 watt set ??
No you wanna try a 18 watt set on them , probably the most famous /used one ,the LAMM 18 watter .
If it plays with lamm it opens up possibilities for buyers.
Haven't tried mine with lamm , but ive tried with 20 watt transistor
No you wanna try a 18 watt set on them , probably the most famous /used one ,the LAMM 18 watter .
If it plays with lamm it opens up possibilities for buyers.
Haven't tried mine with lamm , but ive tried with 20 watt transistor
30 watt set ??
No you wanna try a 18 watt set on them , probably the most famous /used one ,the LAMM 18 watter .
If it plays with lamm it opens. up possibilities for buyers
I was using a KR VA350
That is a truism and can be shown very easily by just looking at the masking thresholds. If that is all it said it would be fine. But instead it embarks on a journey to work backward from author's predisposition for SET amps to say that they are somehow fundamentally superior. And that feed-back based solid state amplifiers are not. This simply is not supported using psychoacoustic analysis no matter how much the author dabbles in that.
Simply put, the preference for SET amps cannot be explained using psychoacoustic analysis that he uses. Such analysis when done correctly shows that the distortion products for feedback based solid state amplifiers until clipping is well below audibility. It would also be trivial to set up controlled blind testing to show the same.
The most credible and obvious reason SET amps can sound different is what I highlighted in blue from his text: that their output impedance is high and hence interacts with that of the speaker far more than solid state does. In that regard the SET amp comes with an equalizer built-in that differs with the speaker used. That variation is readily audible, and provable with both psychoacoustics and subjective listening tests.
Simply put what you claim is clearly not the whole story. You can use high impedance speakers...or hell headphones and easily hear differences where now the FR difference is negligible. So easy to disprove this "all amps below clipping sound the same "
If what you say is true about audibility then nearly all SS amps would sound indistinguishable and yet this simply isn't true.
30 watt set ??
No you wanna try a 18 watt set on them , probably the most famous /used one ,the LAMM 18 watter .
If it plays with lamm it opens up possibilities for buyers.
Haven't tried mine with lamm , but ive tried with 20 watt transistor
Yes...i was seriously tempted by the Lamm ML2 which some people even preferred to the then current 2.1...today, i would also look at current ML2.2. That said, using the system to watch movies (action), i am happy to have plenty of amplifier firepower for special effects.
Yeah but still. iirc you have a mk3. .
If you have a similar impedance curve and efficiency , 18 lamm watts might be more then enough /plenty of control .
Sometimes you just have to try to find out , I'm sure the lamm can do things your gryphons can't and vice versa
If you have a similar impedance curve and efficiency , 18 lamm watts might be more then enough /plenty of control .
Sometimes you just have to try to find out , I'm sure the lamm can do things your gryphons can't and vice versa
That is not what makes the audibly different. Impedance can be high or low. What makes a SET amp an equalizer is the *variations* in impedance, not its nominal marketing number. Here is the author himself again:
"The output impedance of these amplifiers is in the ohms range, hundreds of times worse
than solid-state push-pull amplifiers. This requires careful mating with loudspeakers that
do not have great impedance variation with frequency. "
So what I am saying is 100% the same as what he is saying. I welcome you to find speakers with flat line impedance curve.
Just like THD we do NOT want to use single number impedance values.
How would you prove it?
Got a link to anywhere where this analysis is indeed 'done correctly' ? I'd be very interested indeed to read it. Wiithout the analysis being available to critique your words are merely unsupported claims.
The headphone impedance forms a potential voltage divider with the amp's source impedance. Once the load impedance gets into hundreds of ohms (as it would if you tried the experiment with a 600R pair of DT880s for instance) then the variations in headphone impedance become pretty much immaterial because the division ratio of the divider barely changes. Which I'm fairly sure morricab realizes but seems you do not Amir.
You are stating what I and the paper said. That is, you need to do the math and see if the variations in the speaker/headphone couple in a meaningful way with the high impedance of tube amp. If they do not, then that is not a factor. But if they do, then you are inserting a tone control with that SET amp. This is by far the "high order bit" as to difference in sound of SET amps vs negative feedback SS amp. And no, morricab doesn't accept this or we would be done.
BTW, speaking of DT880 this is its output impedance: http://www.innerfidelity.com/conten...dt-880-600-ohm-headphones#7W79dh3USJOoOGoT.97
It has a near ruler flat impedance at around at around 32 ohms. Now compare that to the other headphone on the same graph with low of 50 ohm and peak of 220 ohm. If you get a low impedance, then you don't need to worry about such large swings. But with a SET, you need to be careful and do the math and see what the impact will be. The wider the area of impedance variation, the larger its chances of audibility.
If you have 600 ohm load, then sure, it will not be material. Hopefully you are not saying this is the typical case for speakers and headphones.
People (Martin Colloms was one of them) have taken a high damping solid state amplifier and connected a power resistor in series with the loudspeaker having the same value of the output impedance of the SET amplifier with it. It was reported that it does not sound like a SET at all. I also tried it and can confirm it (although not in DBT), so you should take it just as my opinion.
The Krell D'Agostino stereo and the DartZeel 108 have the same relatively high output impedance for a solid state amplifier (.3 ohm). I had them side by side in my system with speakers having a wide variation of impedance and they sounded quite different (also in sighted conditions).
Why would you disagree with morricab then? I'm picking up on his point that amplitude variations (which are certainly an issue no doubt about it) aren't the whole story. He said you can use headphones to eliminate this issue because there are some headphones with high enough impedances. Or I'd add you can use a transformer in conjunction with headphones to get even higher impedances.
Looks to me that he does accept its an issue, he's saying its not the only issue. Looks to me that you're saying its the only significant issue, would that be fair? In which case the discussion is about what's significant and what's not.
BTW, speaking of DT880 this is its output impedance: http://www.innerfidelity.com/conten...dt-880-600-ohm-headphones#7W79dh3USJOoOGoT.97
It has a near ruler flat impedance at around at around 32 ohms.
Here is a perfect example of you not listening to what's being said Amir. Let me highlight what I wrote to which the above is a response :
Once the load impedance gets into hundreds of ohms (as it would if you tried the experiment with a 600R pair of DT880s for instance)
I have bolded what you seemed to skip over. DT880s are available in 3 impedance versions, you choose specifically the 32ohm ones but I referred specifically to the 600ohm ones. What gives?
Indeed I am not suggesting its typical, merely that 600R is the highest I'm aware of and the higher the better for this particular experiment.
Sure. When more than the ear is used to evaluate audio gear, anything goes. And rarely do those opinions agree with each other as evidenced by this thread.
Also, there can be secondary reasons SET amps sound different than SS+resistor, one of which could be it soft clipping. Or having higher distortion to being with.
No, I know what you said and hence my reference to 600 ohms.
Have you read that paper and agree with it? That is the discussion point.
You have to read the paper to realize the point of disagreement. In a nutshell the paper says psychoacoustics supports a natural order and levels of distortion which tube amps have and SS doesn't. And hence the SET Tube amp is transparent. Clearly SET amp with high output impedance is not transparent into many loads as we are discussing. And there is no basis for the psychoacoustics conclusions he is drawing. The goal here should be to get the distortions below audibility, period. Then it doesn't matter what their order is.
Then please do explain the relevance of the introduction of the plot of the impedance of the 32ohm DT880s.
No I haven't read the paper.
To show that you were attempting to say that it is typical for headphones to have impedances of hundreds of ohms which is not correct.
That, you have to do.