Quad 909 Monoblocks

I use Quad 909 in both by systems, stereo in the smaller system, monoblocks in the larger one.

Have acquired a passive pre-amp and now have a fully balanced system - except the 909 monoblocks are unbalanced inputs only. I have put in a balanced amplifier and it is beneficial. I am therefore probably looking to move to balanced QMPs.

Quad 909 monoblocks are extremely rare. They were not sold in Europe due to some bizarre regulation related to their high power output, but were sold elsewhere. They are 300w Class A power dumpers. These came from a German Quad main dealer.

One has a small scuff on the top, possibly from stacking, could perhaps be polished out. Otherwise excellent. One was recently serviced by Quad. They don't run very hot and don't need warming up.

I have never seen them advertised before. I understand they are a bit of a collector's item.

Enquiries invited

Hi sls.. You need to state a price and show pictures of your amps ...this is a requirement, as is havingvyour name on your profile or in signature.
Asap please ..thanks

SLS
What about trying a pair of Quad '510' mono's?

Price - looking for £1,300 - pictures will follow, but look the same as 909 stereo.

510's are 135wpc rack-mounted amps. 909's are 300w and QMP's 260w.

I learned at some expense that nothing can make up for power - and lots of it. Harbeth speakers work very well with 60wpc, but push them hard with lots of power and they become very special indeed.

You can link multiple '510's for more power

Quote:

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Originally Posted by Virtual-Symmetry

You can link multiple '510's for more power

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I am not an audio hobbyist and do not want a complicated life. I tried valves for a few years after 30 years of integrated amps (3 in total) and realised valves' serious limitations. I then bought a Quad 909 stereo, wanted more power, so put the 909 stereo in my office (was using a UnitiQute2 - attached it to the pre-outs) and bought a s/h Plinius, which I recall was a little fatiguing after long sessions. Anyway, the 909 mono's came up and the Plinius went in the loft. The Plinius is now in use as it is balanced and there are real benefits to the balanced inputs in terms of sound, particularly high definition downloads. It must be left on, which is an issue. The 909's sound great when stone cold, coming home late and wanting an hour or 2 of music. The 909's are easier on the ear for long sessions, although those are rare as I am out at concerts or shows most evenings. So if I find the Plinius tiring I will probably get QMPs, their price is sensible, and I am not interested in hunting down vintage kit.

For what it's worth, I posted this thread to sell, not to buy. If I find the Plinius fatiguing, I will go to hifi Dave and listen to the QMPs. They are probably indistinguishable from the 909's, but the 909 sound seems to have suffered since putting in a passive pre-amp.

Finally, the monoblock thing does not seem to be an issue unless driving at or close to full output. The 909 mono's work well because of their power and current dumping circuitry. Using a balanced signal path seems to improve clarity and imaging. If Quad made a 250w to 300w balanced dual mono amp I'd be interested, but the QSP is only about 160w, so QMPs it will probably be. The Plinius actually has separate circuits sharing a single transformer, but images superbly well.

Images - incidentally, I have Quad boxes for these.

https://farm8.staticflickr.com/7319/...cc508b7ce3.jpgUntitled

https://farm8.staticflickr.com/7465/...83a83d248a.jpgUntitled

This is the scuff mark referred to, otherwise fine

https://farm8.staticflickr.com/7677/...577d831bb0.jpgUntitled

SOLD