Quad II instead of Quad 303?

amplifiers, receivers and loudspeakers
Awg
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Quad II instead of Quad 303?

Post by Awg » 06 Dec 2010 19:40

Once, I got the idea to use Quad II instead of 303 S which I am now using.
Would it be possible to say, generally speaking, whether the sound in any way be different? I am listening to old analogue long playing recordings with classical music dating from 1949 to 1979.
Regards,
Awg.

moray james
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Quad ll Vs Quad 303...

Post by moray james » 06 Dec 2010 23:03

no reason not to try the Quad ll but it won't have the power of the 303 so this may be determined by your speakers efficiency and your preferred listening levels. It has been a lot of years since I listened to a Quad ll as I recall it was a nice and polite sounding amp. A rebuilt 303 is a good sounding amp (I have owned a couple) with perhaps not quite the magic of a really good tube amp. I have an Antique Sound Lab Tulip 2A3 stereo amp which has been upgraded and has some circuitry changes and though only 3.5 watts is a superb sounding little amp which does not sound little in any way.
Why don't you borrow the Quad ll and set it up and see what you think. Before you decide one way or the other see if you can afford to upgrade your 303 as by this time it is a time bomb waiting to go off. Fresh electrolytic caps and it will be good to go for another 40 years. Your 303 value should go up enough to cover the cost of recapping and you can keep it or sell with confidence knowing it will out last you.
Remember too that rolling tube can make a night and day difference in the sound of a tube amp in a given system and to suit your tastes. If you are into that the Quad ll will offer you a lot of enjoyment playing with tubes to reach your own sonic goal. If that is not what you want and you decide only on the basis of the tubes in the unit as you find it you are really in a hit and miss situation depending upon what tubes are in the unit you get. Fresh caps in your 303 will give you more control better bass impact and overall definition and the unit should sound more open and effortless. The overall sound character will be the same but everything should just sound better. Hope this gives you some food for thought. Best regards Moray James.

Awg
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Post by Awg » 07 Dec 2010 00:22

Moray James, thanks a lot for your answer.
My 303 S has recently been recapped by Quad, and it sounds very nice. So based on my listening impressions with Sonab OA 116 loudspeakers I am very satisfied.
As my Sonabs are not very efficient (87 dB), I think I need all the power coming from the 303. The sound is now effortless and very good with a fine 'timbre' of the musical instruments.
So I think I will still use the 303, but I am happy to listen to a pair of Quad II to compare them against the other.
Best regards, Awg.

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Post by Spinnr » 07 Dec 2010 11:18

Awg, agree with Moray here totally.

Also the 303 is all about delivering current, so very different in its ability to drive speakers than the Quad II.

To improve your system I suggest you buy another 303, have it also refurbished the same as your original, and use them as mono blocks. One driving the left, and one driving the right. With no channel cross talk, no stress in delivering to the lighter speaker load, and each amp humming just the one tune, the difference will be immediate to your ears.

Vinyl forever.

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Post by loonieboo » 07 Dec 2010 18:02

Hi, coming from the other side here , the Quad II
is in a different class to the 303 sound wise also you won't have a problem driving the sonabs just change the taps on the output transformers also the Quad II benifits from new caps as the 303 does. If you can audition a pair go for it as you may fall in love . :)

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some additional thoughts...

Post by moray james » 07 Dec 2010 20:59

You may well find that you can get away with a small tube amp as long as you don't do much loud or dynamic demanding listening. I have had 3/4 watt amps which would play at modest levels and sounded wonderful but if you played complex dynamic music they would soon get into the soup. So a small tube amp might get you to where you want to go and it would be worth your time to audition a few. The 2A3 and 6V6 come to mind and will cost less than the 300B's out there. Allnic have a very nice 300B integrated amp that sounds wonderful and would surprise you, while not cheap it is good value given the build quality fit finish and sound quality,.
http://www.allnicaudio.com/eng/products ... 010&page=1

The suggestion to purchase and re cap a second 303 is not a bad one either. I would however suggest that rather than running the stereo 303's as mono blocks I would suggest to to connect them (if your amp permits biamping) in a vertical biamp configuration. This means that the rt. channel of amp "A" would run the mid/tweeter and the lt. channel of amp "A" would run the bass driver. This provides as much total power as bridging and further yields more separation between drivers as well as much less work for each channel to to as a result of the limited bandwidth you are asking each amp to do. While bridging will result in more total watts you have the same amount of current and the horizontal configuration allows a base driver to clip on a transient while the mid/tweeter are left unaffected. With a good price on an old used 303 this would likely be your least expensive upgrade while retaining the sonic balance you now have, though things should become much more refined with a biamp set up. At the same time the right tube amp could also surprise you. So why don't you take some time with your system and experiment a little? I think that the time spent will be enjoyed and will bring you closer to where you would like to be regardless of your ultimate decision. All the best Moray James.
Just a note: if any of the amps you look at run 12AX front end tubes try some NOS (New Old Stock) RCA 7025's as they sound wonderful. A 7025 is an ultra low noise 12AX and is a direct drop in replacement.

Awg
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Post by Awg » 07 Dec 2010 22:12

Spinnr, thanks a lot for your answer.
The idea of make monoblocks out of 303s has come to my mind, and I could ask Quad to modify them. I do hope I will get the same nature of sound quality as I cherish the standard sound from the 303 very much.
Best regards, Awg.

Loonieboo, thanks a lot for your answer.
I am happy to try out a pair of II, and as they are valve amplifiers, I imagine the sound to be (somewhat) different from the 303.
Best regards, Awg.

Moray James, thanks a lot for your answer and for the link.
Unfortunetely, my Sonabs are not made for bi-amping. As to them, I have seen examples of use with both e.g. Quad II and Audio Research D 79.
I am listening to classical music, both chamber music and symphonic works, at moderate level in a 40 square meter room.
Once, I was listening half an hour to mono blocks of little single ended 12 watt amplifiers with the 211 valve. The instrumental timbre impressed me.
I have also listened to a 10 watt integrated 300B amplifier, and also this was a joy to listen to. I have never listened to a 2A3 amplifier but have read that such one sounds brilliant.
I am happy to experiment with several valve amps to see which ones would fit to the Sonabs.
Best regards, Awg.

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Post by cafe latte » 07 Dec 2010 23:14

I have had both in the past and the Quad II's were disapointing. I ended up restoring them and this improved things a lot,but ended changing the circuit quite a bit. Simply restored Quad II's are just not up to modern standards of valve amp. IMO you will be going backwards getting rid of your 303. A better sounding classic amp by far (also had one and stupidly sold it) is a Leak stereo 20. It does not look as dramatic as Quad II's, but sonically it wins hand down. The Quad II's are thin, over polite to a fault, but the Leak has inpact and bounce, even when compaired to modern valve amps (not surprising as the leak's circuit is still copied!!) If you can find one cheap stilla stereo 60 is just as good, but with a bit more power.
Quad II's can be made to sound good, (a company used to convert them), but aside from output transformers and valves the circuit is almost completely changed, so they are no longer Quad II's.
I sold my Leak to buy an Audio innovations and and had to convince myself the Audio innovations was better so good was the Leak. I was relieved of the Audio innovations by scumbags years ago..not insured either :cry:

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Post by loonieboo » 08 Dec 2010 14:23

Have to totally dissagree with cafe the quads are one of the finest most robust valve amps ever produced and in 40 odd years that's the the first time I have seen them described as thin if anything the leak is the thin sounding amp with it's little el84 tubes . The quads have a very solid if slightly laid back nature which can be overcome with new caps .

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Post by classicstylus » 08 Dec 2010 16:35

I'm interested in this thread because I have a complete Quad II (pre/power/radio) in my attic and am wondering what to do with it. The two power amps haven't been touched for 30 years! I was stopped one day in the street by a kind lady who knew how much I loved music and she gave me her late husband's equipment.

So... should I have the power amps checked over by Quad? Should I have them modified, and, if so, who by?

Michael.

Awg
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Post by Awg » 08 Dec 2010 21:42

Classicstylus, I would have sent them to Quad in Huntingdon for a general overhaul indicating that they be kept in fully original condition so that the circuit in no way be modified, that is, to change parts to new parts being alike, or almost alike, the original ones, and to leave the electrical circuit unaltered.

cafe latte
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Post by cafe latte » 08 Dec 2010 23:50

I do not understand people devotion to Quad II's Hifi world has a classic review from time to time, they describe the sound as hopelessy dated, low power and very hard to partner properly and I agree totally. the amps did not give a flat response, the bass was weak and wooley and the rest was thin, not fixed with caps. It is easy to poke fun at a Leak stereo 20 if you do not understand that it is one of the most successful circuit design (valve) ever and as I said is still valid and being copied tody. Putting a leak stereo 20 and a restored QuadII next to each other for a 'shoot out' the quads do not come close.. I know I tried, but it is not surprising either as the Quads came out in 1952 and the Leaks only came out in 1958 and the designer adressed many of the Quads problems.This aside thse were years were hifi moved on a lot, especially in amp design (stereo for a start), By 1958 the Quads were dated in many aspects of their design, now hopelessly so.
I too years ago was seduced by the big glass of the Quad and I admit they look amazing, but the sound has nothing on a restored Leak. I have been fixing valve amps for years (I also now build class A transistor as a bit of a hobby, my current valve amp is a Ming Da running 300B valves which sounds amazing.. Of course I would not swap for a Leak .. I would be mad, but it would not be a huge step down.

cafe latte
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Post by cafe latte » 09 Dec 2010 00:00

The amps in the attic, if it were me get them overhauled, sell them as they oddly fetch quite a bit and buy a Leak stereo 60 which will drive most things sound very nice and cheap to run in valves.The 10W of the Quad wont give much volume unless your speakers are very very sensitive

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Post by Spinnr » 09 Dec 2010 07:20

Awg.

Sorry to mislead, didn't mean for you to use as modified monoblocks. I know the Ohm Walshes are just one channei. What I meant was to not spend any more money other than get another 303, and have it serviced to the same level as your current, and then just use one for left and one for right.

Yes, that means one side of each will not have music going through it. What I have found is that the musicality and detail is dramatically increased for the following reasons.

          a. No cross talk as the amp circuitry is playing just one tune.
          b. The transformer isn't being pulled in different directions with two differnent requests for more instant power.
          c. The amp is running at half capacity, and is unstressed in all it has to do.
          d. The current going to each speaker is signal pure.

And as for Cafe dissing the Quad II's.

Well.

Must be all the foam dust he is high on at the moment. The original Morris MG was underpowered at just 15hp, was difficult to drive, and difficult to repair. But what a fantastic, gorgeous, classic piece of auto history, I would rather been seen in it on the weekends than some modern Honda built in China like everyone else showing off their lack of style, understanding, and badged as plain boring. I wouldn't rush home from work during the week with a bottle of wine to work under the bonnet on a Honda.

Yuck.

Shame on you Cafe (I really think he is teasing because he has had the Quad ESL's playing for the last twenty-five years at chex Latte). The ones I want to buy once he fixes them up. If he's still talking to me after this post.

Vinyl forever.

cafe latte
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Post by cafe latte » 09 Dec 2010 09:10

Foam dust.. That is what has been wrong with me in the last days!! :D
Look the Quad II's are a real piece of history (no denying that) and They can be made to sound great, but, this is a big but they need extensive surgery, not just a few cap changes.The transformers are VERY good, but 'under the hood' they are a bit dated. the other problem is they were made for esl57's which do not like a lot of power, not sensitive, but are a strange load for an amp and can go suprisingly loud with 10W. not so with many speakers.
Changing the caps will help things a lot, but to get anything out of them IMO you need to delve a bit deeper and for most speakers power will still be a limiting factor. Also Quad II's are FAR too expensive for what they are sonically (if you own them already then that is another thing). When I bought mine I think they cost me maybe 100 pounds or less, I do not remember, but what they are fetching today is daft as for the same money you can get so much more sound quality and a lot more power.
I hope I have not offended anyone, I am just giving my experience..
Spinnr no worries mate... Pesky foam.. If you do ever come up this way bring those amps and we will preform a little operation :D lthen listen over a beer or three or four....

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