Quad 606 - An unbiased review

Deczor

NZ HiFi Guy
How many 20 year old amps have you done a DC test on and found it to be absolute zero? I don't mean 1.4mv, or even 0.1, but bang on 0.0? I thought it would be a fluke with the 606, but since both of these ones test absolute zero on both channels, it seems to say something about a quality IMO.

Anyhoo, I hooked one up to the 4311's using the SX1080 as a preamp. There was a little high pitched buzzing, but pretty low volume, a problem which turns out to be the 1080 itself. I played a boutple of FLAC's and thought "good, but whatever". Hooked the 1080 back up and played the same tracks. Sounded the same as the 606 pretty much, but the 1080 has more control over the JBL's whereas the 606 seemed to be running away with itself.

Now the shoe box is running my t-lines, which is the hardest load speaker I've got by a long shot. 5 drivers, massive crossovers and incredibly inefficient... essentially the best speakers made in this arm of the galaxy. I'm using my Perreaux SM4 as a pre and a Pioneer DVS969 as a CD player and it sounds...

Sorry, just had a Gomez moment and weed myself a little. Yeah, it's that amazing. Trust the bloody English to know what kind of amp English speakers need. My Perreaux 3000b is good, damn good, with any load. It's lively, controlled, delicate when needed and just lush on your ears.

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The Quad is another league altogether. I didn't think the T-lines had recessed mids or anything before, now I realise what was missing. The bass is still there and still has the ability to make a turtle head peep out of the unsuspecting listers ring, but it's not drowning out everything else. Much tighter and refined. It's like the difference between a Corvette and a Bently. the Bently has more power, but is much less flashy about it. You don't have to put your foot down all the time to show how fast you are, but when you do your arse ends up in the boot and everything ahead has a blueish tinge to it.

Treble comes out of the speakers and waves Jazz hands in front of your face then dances around a little, in a sort of jolly, skipping fasion before settling down and being a precice player doing just the right thing at the right time to make ramdom notes turn into sweet jazz.

Mid range has turned from a mere hired cleaner that turns up once a week, but because she's really short your house is only ever cleaned to a hight of about 5 feet, into a Victorian era butler. Completely invisible, but always there dependably pouring the best cup of tea money can buy and polishing the silverware on his day off. Finally I own an amp that really, really knows what to do when you give it pair of B110's, which is beat them into doing EXACTLY the right thing at the right time using nothing but a sock and a bar of soap.

So, to summarise: the Quad 606 is alright.
 
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Nice review. Another member of the transmission line contingent on AK :D The driver compliment looks suspiciously IMF TLS80-like, did you DIY those?

Is the 606 a permanent part of this system now? Also what's that rackmount...thing(amp maybe?) on the floor underneath the cabinet, below where the turntable is?
 
The quads are nice amps. Lots of folks like the early ones, but they get better to my ears with successive generations. I haven't heard a 606 in a long time (never owned one, but I have a 520f), but my memories of it were really good. What are the specs on it?
 
Nice review. Another member of the transmission line contingent on AK :D The driver compliment looks suspiciously IMF TLS80-like, did you DIY those?

Is the 606 a permanent part of this system now? Also what's that rackmount...thing(amp maybe?) on the floor underneath the cabinet, below where the turntable is?

They were build by an engineer and were stored for many years after he died before I rescued them. There is still much to do in terms of finishing, but sound-wise they are pretty much there.

The amp you can see is a Perreaux PMF1150b, next to it is the 3000b.

The quads are nice amps. Lots of folks like the early ones, but they get better to my ears with successive generations. I haven't heard a 606 in a long time (never owned one, but I have a 520f), but my memories of it were really good. What are the specs on it?

The manual has this awesome graph for working out the power. If I'm reading it right it will do about 140wpc into 8ohms "steady state sinusoidal power" or up to 180wpc "instantaneous output power'. Not bad for a shoe box, eh?

THD is about 0..01% up to 130w
Frequency response is 13Hz to 40kHz
Get this, the draw current can go up to 850w! I've not seen many amps with this much output power that use even half that! No wonder the lights dim when I turn it on.

This could also explain why it handles the B139's so well. A chunk of the power could be stopping the driver. I don't know what the term is, but imagine it to be something like a 'stop on a dime test' thus:

Imagine two Aston Martin DB9's lined up to drag. They both have to accelerate to 180kph as fast as they can, and stop on a line 500 meters away. Both cars have the same power, same weight, same aerodynamics, same tyres. The only difference is that one is fitted with the brakes off an Austin Princess. The cars take off, get up to speed, brake at the last possible minute, but one has to brake much harder than the other and isn't as sure of it's stoping power and always overshoots the mark.

This is what my ears were telling me was happening with the t-lines before. The 3000B would exitedly jump into low notes and have a great time for a few seconds, but when the note finishes the amp seems unable to stop on the mark. It kind of sovershoots and scrapes to a halt. The Quad just puts it's foot down and the ABS and big discs stop it right on the money without any stress at all.

Sorry, that's really abstract, but it's what my ears are telling me the B139's are doing.

I think at least one of these will be in the collection permanantly. Best amp I've owned so far.
 
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