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In Reply to: Peak Listening Levels - Some analysis and some thoughts... posted by DevillEars on February 28, 2007 at 09:22:27:
I understand the Wife part but you're using somewhere between 250 & 500w to drive those Tannoys?
Isn't that a wee bit of overkill? Somehow I had you figured for 30-40w of tube amplification for those speakers.
Maybe it's just my predilection for high eff. speakers and low wattage amps.
jac - desperaudio
Follow Ups:
To understand the situation, some of the background is necessary.When I first got the D700's, I had an Audiolab 8000A MkII - a competent 60wpc integrated - plus am Audiolab 8000P MkII - another competent device, albeit a 100wpc power amp. After buggering about with a passive bi-amp set-up, I fell back on using the 8000A just as a pre-amp as this sounded more musical.
Burglars removed the Audiolabs and - using the insurance payout + a few bob extra - were replaced by Classe' CP-50 and CA-100 (still 100 wpc) as Audiolab distributorship had folded. This offered some discernible overall improvement - as I'd hoped.
There was still some nagging doubt in my mind about the overall system - I felt that the D700's were not performing up to the level I really expected. Low bass seemed slightly "loose-ish" and the soundstage lacked depth.
When the next burglary happened and the Classe' pre/pwr became third world currency items, I was initially attracted to the Classe' CP-500 and CA-2100 (still 100 wpc) as they were virtually direct replacements and my insurance policy was geared for this.
Then I did some research and noted that the CP-500 and CA-2100 were quite a lot more expensive than the CP-50 and CA-100 had been - even allowing for inflation and currency fluctuations.
To cut short a long story, I got the assessor to agree to the CP-500 & CA-2100 (as replacements), and then to agree to a switch from CA-2100 to the Rowland 201's.
I'd been eyeing the 201's for about a year and had also done a fair amount of internet study on speakers, LF response and spatial cue reproduction, and had reached a tentative conclusion that Damping Factor (DF) was the culprit as far as my perceived problems with the D700s' LF/staging.
Classe' avoid any and all mention of their power amps' DF values, while Rowland were quite candid and quoted a number > 1,000.
So, I got the 201's and have not once regretted the decision. The combination of Classe' CP-500 & Rowland 201 is a match made in Heaven, while the D700's now have an upstream partner that really makes them sing!
The 201's must take credit for tightening up the low bass (that damping factor provides great control) and, indirectly for really opening up the soundstage (probably due to the improved control across the spectrum).
As far as the CP-500 is concerned, this is one seriously good pre-amp and is an order of magnitude better than the CP-50 it replaced.
So too for the in-built phono stage - the new phono stage on the CP-500 is a dual-mono design consisting of four daughter boards and not just a single daughter-board. Each channel has separate boards for gain and equalisation. The overall effect is to produce a very quiet, inky black backdrop to vinyl playback that - to me, at least - is a first.
The 250-500 watt issue? I initially felt this may just have been overkill but one day a colleague who has a yen to get into audio came 'round to listen and made a comment that rung a bell...
He said (amongst other things) that he felt that the system's sound was like a "mailed fist in a velvet glove" - nice and delicate, but with huge reserves of clout.
This triggered a train of thought around dynamic headroom - a process which culminated in that dBW arithmetic result of ~108dB (which is way, way above my preferred normal listening level of probably between 90dB and 96dB - I have the CP-500 configured to limit the maximum volume setting to 70 out of a 100).
The bottom line is that it works very well for me and does what I want it to - play music very well!
"mailed fist in a velvet glove" - that part I can understand. I like that concept. Most of that is likely why I've never really been able to get my Epos es22s to sing to me and why they're (a) in storage and (b) for sale.They need some headroom I've never been able to find or afford. Closest has been driving them with a QUAD 405 on the woofers and a tubed Dynaco on the mid/tweeters - close but no ceegar as it's been said.
I've not heard any of the "Classe'" gear but I know I'd really like to. Everything I've heard has tweaked my interest.
I'd also like to try to find the tubed Copland CT-305 pre-amp. Not nearly as well known but highly regarded. And has a lower output gain than most pre-amps I've had through the system. Most of the SS pre-amps I find tend to have a gain factor measured in the mid-hi 20s and with the efficiency of both the Cornwalls and the Corals I can turn the volume up to a touch over completely off before it's to loud. The only unit I've been able to find with low gain (14dB) is the QUAD 34 and while it is quite good it isn't tha last word either.
I'll wait. The right one parts will show up sometime.It is an interesting path you've taken to get where you are. Albeit a wee bit painful given how an invasion of your living space made the upgrades necessary.
My library of Tannoy knowledge has now increased by several measures thanks to both you and Tim.
Now that I think about it - I do remember hearing a pair of Tannoy Churchills in my (late and lamented) favourite audio store. They were being driven, on separate occasions,by a 200wpc Sim Audio Moon and a home brew 3wpc tube amp. Different sounds as night and day but both with merits. The Moon had the bass thundering - as would be expected - but something went missing in the mid-upper end and the little tube dealy had almost no low bass but had a very sweet fluidity in the middle.
Remind me to, if I haven't already, to tell the tale of the other listener, a youngish 30something lad, who left the presentation complaining of a lack of bass with the Moon amp doing the honours [Sim Audio pre-amp and a Wilson-Benesch TT). That's a great story on its own.Thanks for taking the time to explain it all.
jac - desperaudio
MC reviewed them in July 1993 for HFN&RR and rated tham as nearer a 4 ohm load than a 6ohm load. And they can handle 250 watts of power pretty easily and they can drive lage rooms and DE does have a large room IIRC.Collioms noted how easily the load killed amps at high levels.
I would think that you'd need a 'big PSU' type BIGG valve amp, SS diodes, chokes and lotsa capacitance say a pr of ARC 100 watters tapped for 4 or less ohms, to make them kick arse.
From 100 hz to 300 or so the measured impedance under 1 watt drive is 3.1 ohms, and the phase angle is a bit fierce down there in the bass, too. So CURRENT demands are high! How low the Z might go and under heavy drive, as per Matti Ottala's findings*, we don't know.
* EG. the supposedly easy load (> 8 ohms effective under test conditions) of the Yamaha NS1000M, (a pr of which I didn't buy and bought the spheres) can fall to 2.5 ohms in the bass and midbass under hard drive. Linn's Sara's and Isobariks were a good deal worse!!!
Note that IME and others the 1000's LOVE Quad II and Leak St20's.
;-)!!!
WarmestTimbo in Oz
The Skyptical Mensurer and Audio ScroungerAnd gladly would he learn and gladly teach - Chaucer. ;-)!
'Still not saluting.'
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