On Fri, 06 Jan 2006 21:47:24 GMT, " Dave xxxx"
wrote:

Stewart Pinkerton wrote:
Absolute garbage! That combination is nowhere near capable of
extracting everything that the 989 is capable of delivering -
especially as it's valved.......................

That From the guy with **** for brains

The guy who built the Quad amps the design team of the speakers the
service department all say they work ok, and I think there point of
view is going to hold more sway. than your rantings

Working 'OK' is not the same as driving to their full potential, you
twit. You think Quad people are going to say that their most expensive
amplfier does *not* work 'OK' with their most expensive speaker?

now I have used 57 63 988 speakers
with Quad 405 405-2 606 606 mark2 909 Quad II-forties
Various low powered Croft valve amplifiers pre and power
now you can sit there and do all the sums you want but when it gets
down to the proper testing

which for the stupid is using mark one ears

the 988 with Quad II-forties sound very nice

I'm sure they do - which has nothing to do with getting the *best* out
of the 989. For that, you need a good SS amp, such as the 909.

989 - 909, hmm, you think they might be designed to work together?

Anyone in possession of a functioning brain is well aware that the
II-40 is simply a cynical cashing in on the famous Quad II name, which
would never have been sanctioned by Peter Walker. He was a *real*
engineer, and always moved forward with his designs, never backward.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

In article , Dave
xxxx wrote:
Stewart Pinkerton wrote:
Absolute garbage! That combination is nowhere near capable of
extracting everything that the 989 is capable of delivering -
especially as it's valved.......................

That From the guy with **** for brains

The guy who built the Quad amps the design team of the speakers the
service department all say they work ok, and I think there point of
view is going to hold more sway. than your rantings

However there is a distinction to be made between "they all work OK" and
the OP's asking about what might be the "best setup"...

I have no doubt that many amplifiers "work OK" with the 63/988/989
speakers. However if "best" includes getting the desgned frequency response
and the full dynamic range up to the limits of the speakers, then some amps
might not allow the speakers to perform as well as others.

now I have used 57 63 988 speakers

with Quad 405 405-2 606 606 mark2 909 Quad II-forties

Various low powered Croft valve amplifiers pre and power

now you can sit there and do all the sums you want but when it gets
down to the proper testing

which for the stupid is using mark one ears

the 988 with Quad II-forties sound very nice

I am sure you are correct. I've also heard the ESL63's producing very nice
results when powered by an old Armstrong 626. However I doubt this is a
combination many people would say is a candidate for the "best setup"...
:-)

I think it may be for the OP/others to decide what their definition of
"best" might require. And they may not all share the same requirements.

If they only play the speakers at modest/low levels, and have no need to
drive them anywhere near the peak levels, then a 40wpc amp like the II-40
may well be OK on that score. (Although the same might then be true of a
303 in good condition.)

If they are also quite happy with the moderate alteration in response
caused by the output impedance of the II-40, then it may also be OK on that
score. (But, again, they might find the 303 did something similar.)

BTW Bear in mind that PJW/Quad wanted the 303 to serve as a replacement for
the Quad II. (And then the 405 for the 303.) Indeed, PJW insisted they
produced indistingushable results provided they were used as he advocated.
[1] I suspect that a secondhand 303 or 405-2 would be cheaper than a II-40.
However I don't know if this would meet the OP's requirement of "best
setup" or not... :-)

OTOH if the OP wants a power amp that can provide up to the peak levels the
989 can use, including at frequencies where the speaker impedance drops
well below 8 Ohms, then he might decide to avoid the 303 and the II-40.

Up to him, I assume. :-)

FWIW Personally I'd be quite happy with a II-40 driving 988s or 989s. But
then I tend to only use low power levels, and the change in response would
not concern me much. However I have no idea if the OP would be like myself
in these respects. And I'd personally be inclined to use something cheaper
than the II-40 as I suspect it would do just as well to my ears. But again,
I have no idea if the OP would agree. Given that he has chosen 989s as
distinct from the 988s I chose, he may want higher power levels to be
available than myself - e.g. he may have a larger room.

Slainte

Jim

[1] And a listening test run by HFN indicated he was correct. None of those
involved could tell the Quad II from SS amps. This surprised/shocked some
audio journalists. However I don't really know why. Did it not occur to
them that PJW *did* actually listen to what he designed and Quad produced,
so might have some idea what he was talking about? :-)

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Jim Lesurf wrote:
1) The II-40 has a nominal power of 40wpc. This nominally
translates
into
17.8 Vrms and 25 Vpk for an assumed 8 Ohm tap. This is well below
the
maximum which the 989 can accept. This means the combination will be
'safe', but not be able to reach the same peak sound levels as a
more
powerful amp.

2) The II-40 has an output impedance of 0.4 Ohms. Given that the 989
has an impedance that drops to just below 4 Ohms at some frequencies
this may cause a change in the response of the order of 1dB in the
region around 10kHz and below 30Hz.

3) I don't have a value for the peak currents the II-40 can provide.
However unless it is significantly higher than implied by (1) the
actual levels may be further restricted when the signals have
components in the regions where the impedance of the 989 dips down
well below 8 Ohms.

Hence although the combination may sound fine, the above factors can
be expected to have some impact on the results. If you only ever
play
music at low levels, the above may not matter.

Slainte,

Jim


Well everyone at Quad I have spoke with and I know them in service and
sales

say they are a good match and are shown as such in much of the sales
blurb

now why should the people at quad (oh and andy who designed them) not
know what they are talking about

sure on paper a few problems but I go for what they sound like and
have used 57 63 and 988 with Quad II-forties

and they sound great

In article , Derrick Fawsitt
wrote:
I have just acquired Quad 989's Electrostatic Speakers and I find them
the ultimate and definitive solution, at least for me. I currently use
entirely Quad units to drive them, i.e. Quad 909 with its pre-amp
together with a Quad 99 CD Player.

I would tend to regard the current/recent Quad amps like the 909 as a
perfectly reasonable choice. Quad will probably have had this in mind...
:-)


However, I noticed one US reviewer of the speakers stated that while
the 909 Amp must have been designed with the Speakers in mind he found
that he got the best results with other amps, is this true and what
therefore do you consider the "best" setup to drive and to use with the
989s.

Well, FWIW I use an Armstrong 732 to drive my 988's and ESL63's.. :-)

However I doubt you will find one of the above, and I have reasons to be
biassed in favour of that amp. But I'd say it was 'the best' so far as I
was concerned - although I suspect that many other amps would do just as
well.

In general, I'd be inclined to take comments by magazine reviewers with a
pinch of salt.

As Serge has said, the peak voltage which are acceptable with the
988/989/63 is around 40/55 volts, so an amp that can give much more than
this should only be used with caution.

The speakers are less demanding as loads than something like the ESL57's.
They dip below 4 Ohms in the 10kHz region, and below 20Hz, though. Hence if
you were to be cautious and assume a 3 Ohm min and 55V peaks, it implies
you will want an amp that is happy to provide peak currents of over 18 Amps
to ensure no current limiting when playing music.

In practice, though, I'd expect/hope you don't normally get near these
limits.

My reaction in your position would be to use the 909's and enjoy the music.
Ignore reviewers. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html