PDA

View Full Version : P3ESR and Quad Amplification



Labarum
18-02-2010, 05:38 PM
My first post. I am just dipping my toe in the water!

My big box system is on its way to Cyprus to use in a large detached bungalow in Nicosia

Squeezebox Classic, Beresford Caiman DAC, Quad 405-2 refurbished by 405man - Quart 980s German Tower Loudspeakers.

These Quarts were in the same price bracket as Quad Electrostatics when I bought them 20 odd years ago.
http://www.hifi-wiki.de/index.php/MB_Quart_980_S

The Quad 405 I added after I stopped spinning CDs and took to streaming via the Squeezebox - the "Preamp" function of the Caiman DAC was sufficient, so my Quad 77 Integrated amp was moved to the study after finally retiring a 30 year old Sudden A48 where it had powered the study system for many a year.

Now I have retired we have a flat in UK and will spend a lot of time in Cyprus, so I need a system for a UK flat with a fairly large lounge.

I am considering:

Squeezebox Classic, Beresford Caiman DAC, Quad 77 Integrated Amp, P3ESR and Sony MDR-F1 Headphones

My question: Will the pre-amp section and remote volume control of the Quad 77 compromise the system?

I could sell the Quad 77 Stack and invest in another refurbished 405 or buy a modern power amp.

I never thought the 77 strained to drive the big Quarts, but when I got the Quad 405 I thought it more weighty and more detailed than the 77.

Any Harbeth, however, will be far easier to drive than the Quarts - and, I guess, more revealing.

Any ideas? Any suggestions.

garmtz
18-02-2010, 07:10 PM
I think you will be fine with the Quad 77!

s.a.b.
18-02-2010, 08:08 PM
I own both the Quad 99 and 909 power amps. I actually prefer the smaller 99 with my Harbeth C7s as it's a bit leaner/crisper sounding (though I'm sure many audiophiles would prefer the 909).

My guess is that you'll be fine with the 77.

John Geisen
19-02-2010, 02:24 AM
I agree with both of the forum members above. While the P3ESR will let you hear the differences in amps, they are not fussy nor difficult to drive. Start with the 77 and if for some reason you feel you want to change later you can always explore alternatives.

John

Ferdinand777
20-02-2010, 12:17 AM
the P3esr are easier to drive than the predecessor.
I drove them successfully with a 60watt LFD amp and it was great.
Much to my surprise they sounded fabulous with the 14watter leben CS300x int amp.
Great little speakers !!

DSRANCE
22-02-2010, 05:16 PM
Brian, you know my views already..... :)

DO IT!!!!!

Miles MG
29-11-2013, 10:04 PM
I own both the Quad 99 and 909 power amps. I actually prefer the smaller 99 with my Harbeth C7s as it's a bit leaner/crisper sounding (though I'm sure many audiophiles would prefer the 909).

My guess is that you'll be fine with the 77.

I have only just received my P3ESRs and use a Quad 303 to power them.
I have no idea what ' leaner/crisper ' is. I just know the speakers sound fabulous...

broadsword
06-12-2013, 12:04 PM
Does anyone have any experience of the Quad 77 Integrated? Considering one to partner my C7s, eg. I'd like to know how easy the tilt control is to use via the remote.

Labarum
06-12-2013, 12:47 PM
Does anyone have any experience of the Quad 77 Integrated? Considering one to partner my C7s, eg. I'd like to know how easy the tilt control is to use via the remote.

The Quad 77 Integrated Amp has no tone controls - tilt or conventional.

You have to go to the Quad 77 Pre-amp for tone controls.

broadsword
06-12-2013, 03:17 PM
The Quad 77 Integrated Amp has no tone controls - tilt or conventional.

You have to go to the Quad 77 Pre-amp for tone controls.

I could see there were no tone/tilt controls on the amp itself but hoped this might be an option via the remote commander.

Labarum
06-12-2013, 04:33 PM
I could see there were no tone/tilt controls on the amp itself but hoped this might be an option via the remote commander.

Sorry. A vain hope I have had a Quad 77 Integrated for many years and from new. It is a fine Amp. I no longer use the remote - it never was that reliable and is now most unreliable. But no, the 77 Integrated has no tone controls.

Have you a manual? I have been meaning you scan my set and upload them to a forum that makes the generally available.

77 Integrated Amp Reviewed here

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDIQFjAA&url=http%3A%2F%2Fwww.avx.hu%2Fforum%2Findex.php%3F app%3Dcore%26module%3Dattach%26section%3Dattach%26 attach_id%3D209228&ei=tfuhUqD5C8OBhAekhoCoAQ&usg=AFQjCNEa6CbuO2Ggc8mcVnY2QaDmYJH2hA&bvm=bv.57752919,d.ZG4

77 Pre reviewed here

http://www.meridian-audio.info/public/77sys%5B1592%5D.pdf

Miles MG
24-12-2013, 12:48 AM
The Quad 77 Integrated Amp has no tone controls - tilt or conventional.

You have to go to the Quad 77 Pre-amp for tone controls.

I drive my new P3ESRs with a Quad 34/303. The tilt controls are very useful. I use a little bass cut on occasion with some CDs. I was using a passive preamp. previously the 34 is very useful with its controls.

The combination of Quad amplification and the P3ESRs work together superbly, and I purchased both the amplifier and control unit at a very reasonable cost.

Martyn Miles .

Andy264
31-12-2013, 12:22 PM
Given the difference in cost between a standard, unmodified Quad 303 (say, for argument's sake, £150), a modified one (£400) and a pair of Quad 303 monoblocks (£400 for the donor pair and a further £500 - £600 to modify them professionally), is the monoblock route an expensive and unnecessary case of overkill? These costs also put you into Quad 909 or Elite QSP territory, more modern power amps with supposedly better components than the 30-year old 303. The theory, as I understand it, is that monoblocks improve stereo separation, but the stereo 303 with P3ESRs seems to be a great amplification match, so I wondered if any HUGgers have any experiences here.

This is my first post, so best wishes for a music-filled 2014.

Andy264

DSRANCE
31-12-2013, 05:31 PM
I know amps aren't supposed to sound very different from each other, if at all, but damping factor extremes, along with clipping performance (as discussed elsewhere here) may well count for a lot of the difference, even if conventional distortion measurements don't these days.

The 77 integrated is a lovely sounding thing I remember, but currently despised because it's so limited outside of the complete system. I think I can now say that, in my experience and under non stressful conditions, good properly working examples of the 303, 606 series, 306 (possibly, but for pop/rock it's my least favourite Quad, along with the 34 preamp) should sound broadly the same, the main difference between them all into something like P3ESR's I suspect, being in terms of percussion 'slam,' for want of a proper word.

Apologies for being confused, but the 77 amp always sounded lovely with the original P3's, which are still great little boxes by the way. I'd better leave off before I go even more subjective, but to conclude, may I say that my admiration for most of Quad's power amps especially, has increased hugely in the last twenty years and it's lovely that these can easily be serviced and updated where necessary, by Quad and others.

A 303 in serviced stock form is fine for most speakers except the most current-hungry and although I never pushed mine, which I hope to have back in the coming months, I remember it (the 303 as a model) clipping very gently indeed. The cost of 'bodging' a mono pair is a bit silly in my view, as 606's are so good, so much more load tolerant (220W per channel into 4 ohms) and can be got in good order for under £500 still I believe.

Labarum will also be aware that I'm a closet fan of the 500 'pro' models, which look far 'meaner' in the flesh than they do in pictures, but best not say too much about these as prices are already getting silly :)

willem
31-12-2013, 07:20 PM
I still treasure the memory of a private (blind and level equalized) demonstration by Peter Walker that his amplifiers all sounded the same. The only reason to choose a particular model would be the power output that one needed, he said.

As for powering P3ESR's, I think a 303 should be just fine. These are not speakers for playing loudly in a large room. Getting my 1970 303 refurbished was a good investment for me, and did not cost a fortune. Parts like capacitors etc do age, and with modern components and slightly changed values for some parts to better suit modern sources like cd players, the sound seemed to have become more dynamic. It looked good on the scope as well.
Willem

A.S.
31-12-2013, 08:24 PM
There is just one thing I'd like to mention. It would influence my choice of (QUAD) amp. I don't want to question your use of choice of any amp (I have a couple of Q303s myself, and all Harbeth tweeters are measured and graded on a Q303) but to intelligently decide upon amplifiers, we need to look inside.

If you take a look here (http://reocities.com/ResearchTriangle/lab/6722/quad303cir.html) at the circuit digram of the left channel of the Quad 303 (QUAD's first domestic transistor amp) fed from a common PSU arrangement (not shown below). The identical right channel is not shown. There are really, honestly, no mysteries about amplifier design, but they can/do/will/may/might indeed sound different. If we can get to the root of what, technically, could lead to those differences, we are equipped to understand what's really going on.

I reproduce that single channel schematic here, and have removed the power supply. What we are looking at is one audio channel, from input to output. The input (1) is a DIN socket over on the left, and the output is the two sockets on the right, SK2 and SK3, around which I have drawn a red box.

Now there are some very interesting things to not about this first generation solid state amp.

1 & 2) Trace with your eye the connection from the input socket 'ground' line right the way across the circuit to the black output socket SK3. Apart from one very small resistor (R115) the cold output is, for all practical purposes, connected to the input cable shield.

3) Note carefully that on pin one of the amplifier PCB we see that there is (+) 67V delivered from the PSU. The ground line from the PSU circuit is connected to the amp card's pin 8.

4) Very important note! Can you see that next to the amp cards pin 5 there is a tiny number? It says 33V.

5) Can you see that between the amp card pin 5 and the output (red) socket SK2 there is the symbol for an electrolytic capacitor (white and black bars) marked C1L and this has a value of 2000u.

Do you appreciate what this circuit arrangement means? It means that all and every note that you hear will have to pass through C1L (and C1R on the other channel) before it arrives at the red speaker terminals. We can say, with confidence, that the entire performance of this amplifier is critically connected with the inherent real-world electro-chemical characteristics of C1L and C1R.

2913
Is it also clear that the voltage indicated at my (4), 33V or thereabouts, is half that of the PSU voltage at my point (3). That means that, even when there is no music playing, there is a standing voltage of 33V (33.5 ideally) which if output (blocking) capacitor C1L was not present (or was leaky) would fry the speakers in a few seconds.

Can you also see that the critical nature of the output capacitor in both protecting the speakers and feeding them with music cannot be guaranteed over many years (electrolytic capacitors degrade rather quickly, then leak) and that it is also likely that the subjective and measurable sound such a circuit will deliver must inevitably depend upon the condition of the output capacitors, their age, and to a greater or lesser extent upon the precise electrical load that the speakers present? More difficult loads would draw more power, and that would stress the capacitor and shorten its life.

These are very well known issues in the amp business. Can you guess then that amp designers were itching to get rid of output capacitors, and that by the 70s, had done so. Can you imagine how?

That's my final contribution for 2013. I'll continue to do my very best to illuminate the not-at-all mysterious world of audio at home for the benefit of making better decisions and leaving more time and money for the music.

Happy New Year and thanks to all of you for the generous support. We really appreciate it.

THIS THREAD HAS BEEN FORKED AND CONTINUES HERE (http://www.harbeth.co.uk/usergroup/showthread.php?1872-The-modern-amplifier-and-its-sonic-performance&p=26512#post26512)

chirhonix
31-12-2013, 11:22 PM
Thanks, Alan,

that is very interesting. All the best for 2014 to you and your family.

Peter

hendrik
01-01-2014, 12:07 PM
but to intelligently decide upon amplifiers, we need to look inside.

First of all; happy new year for all !

For me (and most people I suppose), I simply don't understand the scheme and explanation what is going on inside the amp. It's not my business, I want to enjoy music end leave the technical aspect's to the expert's.

As an architect I sometimes feel the need to educate people in the field of architecture but in the end, the aim is to translate the wishes of users in the best possible way in a good and responsible building.

For users like me a list of recommended amps by Harbeth in different price ranges would be great, or maybe a cooperation with another brand who builds amp's ! (in terms of marketing probably not possible)

A.S.
01-01-2014, 12:27 PM
It's not my business either, but to turn your back on knowledge is to live in the dark. Surely my selective and carefully considered explanation of the function of one, all critical component, through which all signal passes on its way to the speaker makes some sense doesn't? We're not deconstructing the entire circuit, we're focusing on one, crucial, $1 component.

Absolutely not: we are not getting into recommended lists of amps. That would be commercial dynamite. You have to make that choice yourself, based on some knowledge. Or not. Its up to you.

hendrik
01-01-2014, 12:43 PM
Of course it makes -some sense-, and it always good to have some understanding how things work.

That's why this forum and your involved participation is great !

A.S.
01-01-2014, 12:58 PM
Of course it makes -some sense-, and it always good to have some understanding how things work.

That's why this forum and your involved participation is great !Well, would you do me a favour please? This new year I start with a list of current projects as long as my arm. I have never been so busy with so many parallel tasks. I could work 24/7. Evenings spent on HUG have to be justified against the other tasks I simply have to give time to. If an explanation here doesn't make sense (or does) I need some feedback, and pronto, so I can better the explanation, or just drop the subject, or take it in a more useful direction. This is your forum, not mine.

The milestones I have set myself to achieve this year are almost overwhelming. I need feedback to confirm that what I'm investing time in here actually makes sense. Otherwise, I've failed you.

Join me for a New Year's pint at the local?

hendrik
01-01-2014, 01:54 PM
I would love to.. never been in the UK.

DSRANCE
01-01-2014, 08:09 PM
It's not my business either, but to turn your back on knowledge is to live in the dark. Surely my selective and carefully considered explanation of the function of one, all critical component, through which all signal passes on its way to the speaker makes some sense doesn't? We're not deconstructing the entire circuit, we're focusing on one, crucial, $1 component.

Absolutely not: we are not getting into recommended lists of amps. That would be commercial dynamite. You have to make that choice yourself, based on some knowledge. Or not. Its up to you.

Actually, I don't think this output capacitor is a $1 component. The size and rating wouldn't go amiss in a power supply circuit so around £10 ($14) I reckon. Thank heavens for those that sensitively restore these dear old amps (I used Dada since they try to stay true to the original concept, rather than re-invent the design). The components inclined to wear out are known, with respect, and purchasers of such an old amplifier are 'usually' aware of what to do to maintain good performance.

Certainly, I believe HUG members are rather savvy when it comes to the restoration and conservation of vintage kit of this nature.

Anyway, I'm getting tedious and still think a Quad 606/707/909 series' model would be best :)

A.S.
01-01-2014, 09:56 PM
Actually, I don't think this output capacitor is a $1 component. The size and rating wouldn't go amiss in a power supply circuit so around £10 ($14) I reckon. Thank heavens for those that sensitively restore these dear old amps (I used Dada since they try to stay true to the original concept, rather than re-invent the design). The components inclined to wear out are known, with respect, and purchasers of such an old amplifier are 'usually' aware of what to do to maintain good performance.

Certainly, I believe HUG members are rather savvy when it comes to the restoration and conservation of vintage kit of this nature.

Anyway, I'm getting tedious and still think a Quad 606/707/909 series' model would be best :)I'm really not quite sure what point you are trying to make, David.

A suitable capacitor (in fact, rather better than any likely to be fitted in a vintage amp) is here (http://uk.rs-online.com/web/p/aluminium-capacitors/0575406/) and it has a trade one-off cost of about $7. That equates, I guess, to a manufacturing cost of around $1. But so what if it's $1, $10 or $50. It's part of a $$$ amplifier. The point is that the entire amplifier performance depends upon that cheap component through which every single musical note is played. You can also see that the very typically wide +/- 20% tolerance even for first grade capacitors like this which, if the left channels cap was -20% and the right channels was +20% at first switch on (this must be assumed to be a realistic scenario) would result in a channel difference.

You might also want to consider from here (http://docs-europe.electrocomponents.com/webdocs/0bee/0900766b80bee6e6.pdf) that after a mere 2000 hours of powered-use, the performance is permitted to have degraded by a further +/-20%. For an all critical component to have such dramatic change in characteristics is not at all a good thing. Hence, it was designed out.

As far as tube amps are concerned, they have their own but slightly different issue. Almost all tube amps have not an output capacitor, but an output transformer. Every note played must pass through this transformer which feeds the speakers directly, and yes, just like the output capacitor, the output transformer will influence the performance to one degree or another, probably rather more so than the solid state amp's output capacitor.

By the way: you've mentioned what you say is the importance of "power amplifier damping" from time to time. I think you'll find if you research that, that it is a non-issue and completely irrelevant in the case of normal half-decent power amps driving normal half-decent speaker loads.

anonymous
01-01-2014, 11:05 PM
By the way: you've mentioned what you say is the importance of "power amplifier damping" from time to time. I think you'll find if you research that, that it is a non-issue and completely irrelevant in the case of normal half-decent power amps driving normal half-decent speaker loads.


Just to expand on Alan's point regarding damping factor, see Doug Self:

http://books.google.com/books?id=ia1PAYE3QKQC&lpg=PT37&ots=3oV3lLgtfU&dq=damping%20factor%20douglas%20self&pg=PT37#v=onepage&q=damping%20factor%20douglas%20self&f=false

willem
02-01-2014, 09:40 AM
Of course it is great that new designs make amplifiers less dependent on parts quality. That was always Peter Walker's design philosophy as well. In the case of these large capacitors it is my understanding that they were the biggest that fitted in the existing case.

These days they can be physically much smaller (and are of far better quality). So higher values can now easily be incorporated. That was one of the things that were done to my 303, and according to the engineer who refurbished it largely responsible for the improved sound quality. I will not hesitate to have them replaced again in a decade or so.
Willem

DSRANCE
02-01-2014, 10:59 AM
Then I stand corrected, obviously influenced in recent times by so called 'experts' who may have an agenda in promoting the negative aspects of passive crossovers on the amplifier's ability to control a loudspeaker drive unit. Apologies all! I still like the old 303 though, but obviously, it's an old design and more recent Quads on the used market (in this case), will provide a safer? proposition for not much more outlay.

I'm trying here not to dig my hole ever deeper ;) A wonderful learning process though, so best for me to continue to quietly read the unfolding scenario as I really don't wish to put unintended spanners in the works :)

A.S.
02-01-2014, 11:52 AM
Then I stand corrected, obviously influenced in recent times by so called 'experts' who may have an agenda in promoting the negative aspects of passive crossovers on the amplifier's ability to control a loudspeaker drive unit. Apologies all! I still like the old 303 though, but obviously, it's an old design and more recent Quads on the used market (in this case), will provide a safer? proposition for not much more outlay.

I'm trying here not to dig my hole ever deeper ;) A wonderful learning process though, so best for me to continue to quietly read the unfolding scenario as I really don't wish to put unintended spanners in the works :)Hats off to you David!

Regarding those "experts", by which I assume you mean those consumers who write/rant about audio but are not on the manufacturing side of the desk, is there any excuse for the downright ignorance shown about how audio equipment (or the ear) actually works in this internet era? We all have at our fingertips a vast treasury of knowledge which, if we are so motivated, we can pull down to our computers and ruminate over.

Real "experts", like Peter Walker for example, or James Moir, or Dudley Harwood or D.E.L. Shorter, are/were too busy making a living out of their insight to sit night after day prattling on with assumed authority to those sadly absorbing without inspection, what they read.

The really great thing about audio is that it's possible to demonstrate just about everything but the most advanced maths (which I certainly don't understand or need to understand) on the kitchen table or living room with a tiny investment in audio equipment. The door to knowledge in this field of life is wide open to all. No chemicals. No dangerous tools. No protective gear. Just a pair of ears and an open mind! No excuses?

P.S. I'm taken back to about 1975 when at the tender age of 18 or so I purchased a Q33/303. The pride of ownership was fantastic. Properly made, properly designed, British made equipment. I can still recall the shock of changing the 303 to the 405 shortly after it came out. It was so much better. So much more open. So much more powerful ... or so I thought at the time as I congratulated myself on the upgrade. What I discovered many years later was - and the key to this was in the self-evident extra hiss that the idling 405 had that the idling 303 didn't, but which I adapted to - was that the gain (aka amplification multiplier) of the 405 was so much greater than the 303 that for the same volume control setting on the preamp, the signal loudness at my ear was many decibels greater, all other factors being the same. Consequently, as we know now, it was ridiculous to compare the subjective quality of these two amps when we had not made the slightest effort to remove the huge elephant-in-the-room confounding variable of the difference in gain. As Peter Walker later showed, when gain was carefully adjusted to be equal, the sonic difference between the valve Quad II, and the transistor Q303 and Q405 vanished. We've covered that here. (link to follow)

willem
02-01-2014, 12:58 PM
Peter did actually tell me at the time that unless I needed the extra power (I did not, with a pair of the ESL57's) it would be waste of my money to śpgrade' to the 405, since the 303 had a somewhat better S/N ratio. Fascinating analogy, Alan: I bought mine in 1971, at the tender age of 18. And boy was I proud. I had worked hard for it during the holidays. It gives me great pleasure that I still use it, refurbished and all. I am sure there are better amplifiers now, but not so sure that they will sound better.
Willem

DSRANCE
02-01-2014, 01:17 PM
I remember that and 'at the time' couldn't understand it. These days, and with speaker loads so much more benign than I was dealing with back then, I can easily hear the similarities (I have some rebuilt II's as well as the 303 I directly compared them with). As for gain, both the 303 AND the 405 models (series 2 for me, but this is for another day as distortions - slight crossover artifacts - were dealt with as well as current output) can have their gain reduced at the input and this does seem to benefit performance noise-wise as well as making them more suitable for modern sources and preamps 'I'm informed.....'

Interesting 'stuff' here - hope I'm not causing too much drift in suggesting this - http://www.keith-snook.info/quad-stuff.html

alvin1118
16-01-2014, 05:13 PM
Just acquired a Quad 909 to replace Marantz PM15S2.

I'm an electronic engineer, was wondering why Quad designer did not put in any speaker protection / on-delay protection to prevent DC inject into speaker in event of amplifier fault / surge. Contrary, Marantz has lot of protection relays to reduce the risks.

Weigh between sound quality and protection, which one should come first ?

Puzzled :-)

Andy264
11-02-2014, 01:58 PM
The relationship between Harbeth, the Quad 303 power amp and many satisfied HUGgers is well documented on this forum, but I wondered if the mods to the amp proposed by the likes of Net Audio and others are worth considering and, if so, is there an appreciable difference in sound quality between original and modified versions?