Anyone heard this speaker?

Got a very high review rating in The Absolute Sound:

"It is, as I said, the highest-fidelity, fullest-range, most transparent-to-sources two-way I’ve come across (and I’ve heard a few)"

" ... the Q1 come closer to sounding like a single-driver loudspeaker (on-axis) than any loudspeaker Magico has yet made. The effect is magical—like getting a Quad or a CLX (with better bass and large-scale dynamics than either) in a 9" by 14.2" by 14.2" package"

Rather pricey however!

Heard the speaker with full Nagra system (CDC, PLP, 845)and was rather dissapointed. Tight, mat and rather dry sounding.

Bass was quite impressive however, very controlled and with drive. Amazing for the size.

Then again, it could also be the Nagra that I didn't like, since I listened to that same Nagra with Sonus Faber Stradivari's, and it was defenitely not singing, not expressive on these speakers which otherwise were making beautiful music with quite a few electronics I tried this far.

I heard the Q3 recently at a show recently being driven by Audio Researc Ref5/Ref210. My expectations where high having read several very positive reviews, the technology seemed impressive and it is a sealed box which is my preference. They sounded terriblle. I kept coming back but the grating trebble, which made me think of early digital done poorly, and generally thin sound without body persisted.

Hans

Haven't managed to find a circuit for the 845 on line, but Nagra repeat the old lie in their advertising literature - "zero negative feedback". ALL triode amplifiers have considerable negative feedback, it's inherent in the design of the valve. Unoftunately it's direct from the anode to cathode, so although it reduces the distortion due to the triode's own non-linear grid-voltage to anode-current transfer function, the power supply and the output transformer lie outside this loop and their deficiencies are passed on unattenuated to the output. you can get a rough idea of the degree of nfb in any particular amplifier by looking at its measured output damping factor, though there's actually a bit more than this implies because the series resistance of the output transformer degrades the feedback-controlled damping factor.

So, for example, if the measured output impedance of an amplifier designed for 8ohm loads is 2 ohms, then it has around 12dB nfb.

So so-called zero negative feedback triode amplifiers are actually "Not quite enough feedback, and what there is in the wrong place".

I've often wondered. What they are really meaning - I think - is no more nfb than is already inherent in the configuration. But that's like saying you haven't spent anything this month because you haven't written any cheques, ignoring the fact that everything is paid by standing order.

You can't point to a particular resistor and say "this is negative feedback", but just because you haven't ADDED any more feedback doesn't mean that it doesn't exist.

The whole point of adding the screen grid on a tetrode or pentode was, as the name implies, to screen the cathode from the feedback effects of the anode voltage. So that's at least 86 years (pentode designed in 1926) that valve designers have been well aware of the feedback involved.

If you look at a single-ended triode output stage and follow the cathode current round the loop you will see that it flows through the valve to the anode, through the reflected load of the speaker across the transformer primary and then through the last capacitor of the power supply before returning to ground and then onto the cathode. This means that the AUDIO performance of the power supply capacitor is of prime importance to the resultant quality, much more so than the coupling capacitors that people get obsessed about, spending fortunes on bamboo paper, PTFE etc while still having rather ordinary PSU caps.

A lot of valve designers (e.g. Peter Qvortrup) don't really understand the circuits at all, they just know that if they use a pretty standard configuration they will probably work, and if you add enoguh buzz-word bits you can charge a fortune for the result. Designers who do know their onions (e.g. Tim de Paravicini) well understand the problems, and guess what? they don't use antique triode designs. One of the best audio power valves around is the PL509/EL509/PL519/EL519 series, for the very good reason that being designed for TV's with line circuits running over 15kHz the normal compromises of heater consumption/ cathode area/ anode current etc couldn't be used, they just have to work. Hence a valve that can deliver over 1A anode current and can be designed into stages with nice low anode impedances, and hence much less compromised transformer design.

Kengale,

I appreciate your comments, for they are to the point and plain honest.

I've heard so called specialist claim that Tv valves used among others by TdP are crap, no good for audio, taken only to save because of their availability an extended life.

So that's another myth that had to be nuanced.

To go back to the original question, I've not heard the Q1s, but I have had the Q3s at home, in my system (ARC Ref electronics), for a full weekend and they were fabulous, even though they were new out of the box. They did not sound hard or digital to me, at all.

The original Mini could be a bit 'hot' on the treble. This was much improved with the Mini 2, which sounded very sweet as long as the tweeter was not aimed at the listener directly. I've lived happily with the Mini 2 since late 2007. In the brief time I had the Q3s, I had them toed in a similar way to the Mini 2, i.e. with tweeters not aimed directly at the listening position (toed out), and they sounded very sweet indeed.

Jonathan Valin is a fan of the Magicos and has given most of the ones he has reviewed highly enthusiastic recommendations. It is a little unfair to pick on him however, as he is not the only one to have done so.

I'm looking forward to listening to the SP Acoustics SP1s, also sealed box but large...

Has anyone heard them ?

Edited by user 09 April 2012 09:56:27(UTC)  | Reason: Not specified

The designer is ex-AE. I have only heard "pro" users evangelise about them saying they are better than Wilsons, B&Ws etc. However they came down to earth a little when I pointed out the drive units are all 3 from Scanspeak- albeit top of the range and very good- and that the designer wasn't creator of all. And I have seen the "Dual Constrained Layer Damped" bits in my old AE-1s. Not saying it isn't a good package.....

Perhaps another one for Martin in his pro-monitor round up?

hmmm... a bit different from the old favourite Spendor SP1. How many speakers are there called SP1?