[[email protected]]

I believe that it will need at least 35W per channel.

At the moment I'm using a Quad 520f and 44 (modified.) There's a Musatex DA=
C and all input is digital streamed over wifi via a Logitech squeezebox.=20

It sounds excellent, but I have the urge to see what the fuss about valves =
is all about. I would like to get a tighter bass for organ music, most of t=
he music I listen to is small scale classical.=20

Any recommendations need to be available and serviceable in the UK. And a r=
eliable product please! And preferably not much more than =C2=A32000 -- new=
or second hand.

[Peter Wieck[_2_]]

On Thursday, March 29, 2018 at 10:47:54 AM UTC-4, wrote:
I believe that it will need at least 35W per channel.

The 520F has 100 wpc/rms/8 ohms.
The Quad ESL63 gives 86dB @ 1 watt @ 1 meter. Not very efficient.
35WPC *will not* sound anything like 100 WPC. You will miss that headroom. Badly.

There are a goodly number of 60+ & 75+ WPC tube amps out there, and I would start there.

Here is one source for non-Chinese *NEW* units at reasonable prices.

http://www.tubes4hifi.com/bob.htm

Peter Wieck
Melrose Park, PA

[[email protected]]

Thanks for doing the number work. It makes me wonder whether valves are such a good idea. I mean, maybe the ESL 63 was designed with solid state amps in mind.

[Peter Wieck[_2_]]

On Thursday, March 29, 2018 at 2:03:52 PM UTC-4, wrote:
Thanks for doing the number work. It makes me wonder whether valves are such a good idea. I mean, maybe the ESL 63 was designed with solid state amps in mind.

Perhaps. But much depends on the overall size of your venue, shape and finishes in your room and preference of signal. Writing only for myself, I would want at least 100 WPC/RMS for an 86dB speaker. But I am 'feeding' a room that is 17 x 28 x 10 (feet). My speakers are Maggies, about 85dB, and I am feeding it with a 225 WPC amp. Works well. Less power, not so much. My best tube amp at 75 WPC simply could not do it. But that amp does very, very well in a smaller room also with 85 dB speakers.

Peter Wieck
Melrose Park, PA

[[email protected]]

On Thursday, March 29, 2018 at 1:28:43 PM UTC-4, Peter Wieck wrote:
On Thursday, March 29, 2018 at 10:47:54 AM UTC-4, wrote:
I believe that it will need at least 35W per channel.

The 520F has 100 wpc/rms/8 ohms.
The Quad ESL63 gives 86dB @ 1 watt @ 1 meter. Not very efficient.
35WPC *will not* sound anything like 100 WPC. You will miss that headroom.
Badly.

Badly? BADLY? Really?

Assuming the ratings are real, 35 W is hardly "badly" lower than
100W, only 4.5 dB.

There are a goodly number of 60+ & 75+ WPC tube amps out there,
and I would start there.

Okay, these are "barely" 3 dB more than 35W, and 3 dB barely makes it
to a JND without careful close omparisone, and more difficult audibly
assuming the gain of each is the same AND the only audible comparison
is in headroom.

Here is one source for non-Chinese *NEW* units at reasonable prices.

http://www.tubes4hifi.com/bob.htm

Peter Wieck
Melrose Park, PA

[[email protected]]

I used to use a quad 303 to drive the ESLs. When I moved to the 520f there was a noticeable improvement in the attack of notes, and I think in the firmness of the stereo image. I don't want to lose that in the transition to valves.



Has anyone tried the new quad valve amps with the ESL 63

[Peter Wieck[_2_]]

Here goes the math again - into the Quads:

1 watt = 86 dB
10 watts = 96 dB
100 watts = 106 dB

35 watts = 98 dB
75 Watts = 103 dB

The monoblocks linked were 125 WPC.

Depends on where you start your count. Point being that in the 'real world' even a very good 35-watt amp into highly inefficient speakers (such as the quads) will be greatly outmatched in a large venue. Not hardly in a smaller room, but in a smaller room what is the point of that speaker. And a 100-watt amp of decent design will do fine. Headroom is necessary, in general, only a small amount of the time. But, clipping is no fun at all. Yes. Badly..

Courses for horses.

Peter Wieck
Melrose Park, PA

[[email protected]]

On Friday, March 30, 2018 at 7:55:54 AM UTC-4, Peter Wieck wrote:
Here goes the math again - into the Quads:

1 watt = 86 dB
10 watts = 96 dB
100 watts = 106 dB

35 watts = 98 dB
75 Watts = 103 dB


Maybe you want to run your math ONE more time. You claim:

75 Watts = 103 dB
...
100 Watts = 106 dB

Well, double the power results in a 3 dB increase in level,
assuming everything is reasonably linear. So how do you get
from 75 watts = 103 dB to 100 watts = 106 dB?

Assume, however, that 1 watt = 86 dB, the system is linear,
and that we're still assuming that dB = 10*log10(Px/Pref),
thus

1 Watt = 86 dB (Pref)
2 Watts = 89 dB
5 Watts = 93 dB
7.5 Watts = 95 dB (really 94.8)
10 Watts = 96 dB
20 Watts = 99 dB
50 Watts = 103 dB
75 Watts = 105 dB (really 104.8)
100 Watts = 106 dB

So the difference between 75 watts in and 100 watts in is NOW 3 dB, but
about 1 dB.

[[email protected]]

On Friday, March 30, 2018 at 10:56:35 AM UTC-4, wrote:
So the difference between 75 watts in and 100 watts in is NOW 3 dB, but
about 1 dB.

Sorry, that's "NOT 3dB, but 1 dB".

[Peter Wieck[_2_]]

On Friday, March 30, 2018 at 1:20:30 PM UTC-4, wrote:
On Friday, March 30, 2018 at 10:56:35 AM UTC-4, wrote:
So the difference between 75 watts in and 100 watts in is NOW 3 dB, but
about 1 dB.

Sorry, that's "NOT 3dB, but 1 dB".

We are looking at the difference between 35 watts (proposed) and "about anything else that is more", on the basis that the 100 watt solid-state amp in place does the trick. 35 watts is, and remains, woefully inadequate to drive those speakers to adequate levels without clipping badly at difficult passages.

If the OP wants to try tubes - a laudable effort - he needs to develop enough headroom to make the effort worthwhile. He may do that at the linked site (amongst others) within his budget using well made equipment available in GB. He will not do that with a 35 watt amp at any price.

Peter Wieck
Melrose Park, PA