No. The output voltage is not 7.75V. I refered to the voltage at the collector/drain. Output voltage is 12.75V.
So the power should be 20.32W 8Ohms
Or I made a giant f***up during design.
What is it about the Wilson designs that the speakers are so hard to drive? (excepting Alexandrias)
- Thread starter caesar
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No. The output voltage is not 7.75V. I refered to the voltage at the collector/drain. Output voltage is 12.75V.
So the power should be 20.32W 8Ohms
Or I made a giant f***up during design.
Steve, that makes perfects sense. However, you are fortunate that your speakers work well with low output amps...plus they do not have a nasty impedance drop for the amp to deal with.
One of my a'phile friends just sold his lower powered amp because his new speakers have a vicious load characteristic that requires a brute of an amp...even though this speaker is using small drivers ( 7-8") in the bass dept.
Most Wilsons that I know of, require a very hefty amp upstream, one that can push an unfriendly load. Also, since most of these models are deigned for a larger room, the partnering amp had better have some serious muscle.
BMCG, I do believe that what i posted above is a major factor. Sure there are some very expensive SET's on the market, but to the --shall we say- "less experienced" hobbyist, they will have less appeal at the dealer than the mega powered amp with the mega price tag. That dealer can now state that the mega powered amp is a perfect match for the Wilson under consideration.
No. The output voltage is not 7.75V. I refered to the voltage at the collector/drain. Output voltage is 12.75V.
So the power should be 20.32W 8Ohms
Or I made a giant f***up during design.
How do you get 12.75V from 7.75V at the collector/drain? And the expression you quote refers to RMS , supply voltages give you peak values . If you then correct for 1.404 you will get half the power value.
FIY I have experience with several current Wilson models (Sasha and Alexia) being driven with ease by the Audio Research REF150 ($15k).
The Sabrina can be driven easily by the REF75 or Audio Research integrateds.
A good friend has a great sound with Sasha and the Jadis DA88 integrated.
My still resident conrad johnson MV125 did a wonderful job driving Wilson 5, 7 and Maxx3.
And the conrad johnson SS premier 350 drives all of them with great pleasure.
I do not consider any of them them "mega powered amp with the mega price tag"
The Sabrina can be driven easily by the REF75 or Audio Research integrateds.
A good friend has a great sound with Sasha and the Jadis DA88 integrated.
My still resident conrad johnson MV125 did a wonderful job driving Wilson 5, 7 and Maxx3.
And the conrad johnson SS premier 350 drives all of them with great pleasure.
I do not consider any of them them "mega powered amp with the mega price tag"
Hi Microstrip,
Let's leave rock music out of the equation for the moment. Surely the drum snaps playing jazz music sounds crisper and more realistic with high powered SS than with any tube amp? No?
And also, since you have the CJ 350, how does it compare to the newer, more state of the art SS you have hosted?
No one is addressing particular types of music or realistic levels at 10 feet - and what is more realistic in sound reproduction would keep us busy for long.
Paired with a cj preamplfier the permier 350 is still a a great amplifier, powerful, very dynamic and nice sounding. Compared with modern designs such as the Dartzeel NH108 or the Centaur II with their respective preamplifiers it is not as transparent, does not have the fine layering capabilities of them and voices have more grain. The premier 350 performance improves considerably when used with a Trasparent Audio XL Gen V or MM2 power cable.
I would also state so looking at the impedance data, but in practice it sounds great! And, supreme blasphemy, some people prefer it on the 8 ohm tap!!!
This is in fact true.
The 8 ohm tap is the usual choice on ARC amps with Wilson speakers.
It's been a while but the 8 Ohm tap was my preference with ARC Ref 250s driving Sasha 1s. Maybe a wee bit less lower frequency articulation but more tonal depth.
Steve Williams
Site Founder, Site Owner, Administrator
Mark Seaton
WBF Technical Expert (Speaker & Acoustics)
That all depends on what your definition of "properly driving" is. Transformer outputs may not ideally match the impedance and will therefore change the frequency response of the speaker, but they tend to not go into heavy distortion with low impedance. They just don't deliver as much signal/power there. In the case of a more conventional amplifier with very low output impedance, it could easily run out of current driving this speaker load. When the current demands are too much, this will cause less ideal sound from amplifiers increasing distortion and/or causing clipping prematurely as the power supply sags.
On the plus side it lets audiophiles more easily use their amplifiers as tone controls.
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(...) On the plus side it lets audiophiles more easily use their amplifiers as tone controls.
People have though about it - measuring the frequency response of the tube amplifier loaded with the speaker and reproducing the situation using a SS amplifier with low impedance and an equalizer, more recently even with DSP. Unfortunately it measured alike, but did not sound great, like the tube amplifier did!
Mark Seaton
WBF Technical Expert (Speaker & Acoustics)
People have though about it - measuring the frequency response of the tube amplifier loaded with the speaker and reproducing the situation using a SS amplifier with low impedance and an equalizer, more recently even with DSP. Unfortunately it measured alike, but did not sound great, like the tube amplifier did!
I don't think many are actually measuring the output from the speaker with the amplifier connected, or they don't have a repeatable enough measurement setup with enough fine resolution. I see many saying that "both amps measure flat" but in fact that "flat" measurement is driving a test resistor. I've measured frequency response differences between different solid state amplifiers driving a real speaker. My TEF 25 measurement system using its time and frequency gating is extremely consistent from one measurement to the next, making it very easy to see such changes. In some cases they are very subtle, but some times the electronics can make small, but broad and wide changes that are readily audible. That's not to say there aren't other aspects beyond the frequency response that can be heard, but these are simple technical matters where some degree of frequency response differences should be expected.
That all depends on what your definition of "properly driving" is. Transformer outputs may not ideally match the impedance and will therefore change the frequency response of the speaker, but they tend to not go into heavy distortion with low impedance. They just don't deliver as much signal/power there. In the case of a more conventional amplifier with very low output impedance, it could easily run out of current driving this speaker load. When the current demands are too much, this will cause less ideal sound from amplifiers increasing distortion and/or causing clipping prematurely as the power supply sags.
On the plus side it lets audiophiles more easily use their amplifiers as tone controls.
Thanks. That's exactly what I was driving at but said much more eloquently of course.
I have a similar issue with my Focal Maestro speakers (which have an even nastier impedance curve) and it was abundantly clear that my 300W monoblocs weren't driving them properly.
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