Quad update

[Bonky]

Hi,

So impressed was I with a modified Quad306 that I looked for a 405-2 model or 606; then I came across this UK maker and distributor of 405 clones at an unbelievable price:

www.ebay.co.uk/itm/332079392104?ul_noapp=true

OK, the cases look 'industrial' to say the least and I'm not sure that the VU meters are really needed but the build quality and customer reviews look appealing.

The silver edition looks much better than the black I think.

He also does preamps and other power amps.

Does anyone have any knowledge/experience of these?

Usual disclaimers.

Thanks,

(Also messaged to the Audio Standard forum)

[Arkless Electronics]

Chinese modules put together in UK by the look of things.... Just saying...

[Bonky]

Chinese modules put together in UK by the look of things.... Just saying...

Yes I agree; the PCB is Chinese but it's all up-front and honest as far as I can see. I hope the boards are populated by UK-sourced components (in the main). At least it comes with a UK-based 12 months warranty. Is it THAT much different to a new 'genuine' Quad made in China?

Thanks.

R

[agk]

All looks a bit gash to me. Quite an untidy layout inside.

[Arkless Electronics]

Yes I agree; the PCB is Chinese but it's all up-front and honest as far as I can see. I hope the boards are populated by UK-sourced components (in the main). At least it comes with a UK-based 12 months warranty. Is it THAT much different to a new 'genuine' Quad made in China?

Thanks.

R

I would guess the boards are bought in populated from China. It's still ridiculously cheap if they are being put together over here even and especially as the guy says he spends hours hand drilling and filing the casework! I know what that's like...

[Barry]

Chinese modules put together in UK by the look of things.... Just saying...

Without a doubt, and because of that I would be wary of Chinese cloned Quad 405 PCBs. There are some boards out there that have minor mistakes in the track layout. Caveat emptor!

[Bonky]

Ok, perhaps, I get the point, but better than a Chinese assembled modern Quad...without easy access to a UK warranty? Better than a UK Quad (say 306,495.606 etc) with old caps. transistors etc?
BW

R

[Barry]

You can pick up a Quad 405-2 on eBay for about £200. New caps would only cost, say, £50.

[Bonky]

Well, £250 -£265 perhaps, but + DADA and/or RedHill upgrades (say £250), not all components being tested, perhaps an inferior PS, and if, in the case of DADA, one needs to do the upgrades oneself, little in the way of warranty...


..an interesting view of value I think we would all agree....and then ...'"well, it all depends on what it sounds like"...


Has anyone on this forum got one?

BW

R

[Arkless Electronics]

The problem of fake semiconductors from China is real and present... and far more widespread than you may imagine. I would be pleasantly surprised if there were no fakes in the cheapest Chinese kit. Very definitely caveat emptor!

[Bonky]

The problem of fake semiconductors from China is real and present... and far more widespread than you may imagine. I would be pleasantly surprised if there were no fakes in the cheapest Chinese kit. Very definitely caveat emptor!

OK, but surely fake transistors and diodes would soon fail or show-up in poor performance. The manufacturer says the pcb is Chinese, but, and perhaps I'm wrong here, he doesn't state that the populace of the board is.

Has anyone any evidence that there are errors in these pcb boards...as someone has opined?

I find it somewhat amusing that, having just been interested in another forum on £90 audiophile fuses...where subjectivity seems to be key....that here SQ seems to be marginalised.

Thanks


Again, has anyone either hard evidence of poor Chinese workmanship on this kit, and/or actually listened to this amp?

[Light Dependant Resistor]

Hi
Like you I have tried 405.2 and 306, the 306 is a better device and better design.
The Chinese clones are either poor copies with design faults of a 405.2 which I alerted
to in another thread , or based on a 405 Mk1

There is nothing hugely wrong with an original Quad 405 or 405.2, but a 303 generally sounds better
but a 306 better again.

I would not waste my time with clones rather,put money available into another 306 and use one channel of each for
your amplification needs. This is what I do like a mono block, just using one channel of each amp.

Cheers / Chris

[Bonky]

Hi
Like you I have tried 405.2 and 306, the 306 is a better device and better design.
The Chinese clones are either poor copies with design faults of a 405.2 which I alerted
to in another thread , or based on a 405 Mk1

There is nothing hugely wrong with an original Quad 405 or 405.2, but a 303 generally sounds better
but a 306 better again.

I would not waste my time with clones rather,put money available into another 306 and use one channel of each for
your amplification needs. This is what I do like a mono block, just using one channel of each amp.

Cheers / Chris

Thanks Chris (and others). More food for thought ...and cheaper too!

BW
Richard.

[mikmas]

I did some searching around 405 clones a year or two back when I was looking - in the end I got an original 405-2 in good nick (eBay - £200) and it's done well.

This is a good thread about the topic, albeit relating to clone boards rather than complete amps. Note post #6 relating to the inherent fault in some (mentioned earlier).

http://www.diyaudio.com/forums/solid-state/180968-cheap-ebay-quad-405-clone-measurements.html
"The 405 clone boards faithfully reproduce the well-known error on the original 405-1 schematics and PCBs: the output Zobel network is grounded to the input signal ground (which is isolated from the power ground by a 10R resistor), not the power ground as it should be, explaining why I experienced catastrophic oscillation which destroyed a tweeter the first time I plugged one of these things in without anything connected to the signal input ground."

Likely that the bloke on eBay you are looking at has sorted this problem but worth bearing in mind.

Personally I've had no problems whatsoever with the original I bought but yes, it can be pot luck given the age of these beasts.

[Arkless Electronics]

OK, but surely fake transistors and diodes would soon fail or show-up in poor performance. The manufacturer says the pcb is Chinese, but, and perhaps I'm wrong here, he doesn't state that the populace of the board is.

Has anyone any evidence that there are errors in these pcb boards...as someone has opined?

I find it somewhat amusing that, having just been interested in another forum on £90 audiophile fuses...where subjectivity seems to be key....that here SQ seems to be marginalised.

Thanks


Again, has anyone either hard evidence of poor Chinese workmanship on this kit, and/or actually listened to this amp?

There are many variables here. Sometimes they use a die from older lower spec transistors, sometimes even ones rated for half the power of the ones you think you are buying. Failures can and do happen. You may not notice the difference in performance.
I NEVER buy semiconductors from ebay or similar sources as the chance of them being fake is just too high. I pay maybe 5 times as much for guaranteed quality from approved stockists.

I'd avoid the 303 if I were you. The worst of the Quad amps in many ways. They do have a following but personally I wouldn't give one house room... other than as an objet d' art with a 33 pre and FM3 tuner in a bedroom or workshop system. They don;t produce any "nasties" such as hard or "transistory" sound or anything like that, they just fail to deliver on grip, speed, transparency etc and although they can sound ok in isolation comparison with a modern amp soon puts them in perspective!

[RothwellAudio]

All looks a bit gash to me. Quite an untidy layout inside.

Yes, I agree, not the tidiest of layouts. In itself that may not be a problem but it would undermine my faith in the product.

[Idlewithnodrive]

I've owned at least a couple of each of the 303's, 306's and 405-2's and my order of preference goes 405-2 first (by a long margin), then the 306 and a fair way behind the 303. I would buy a good condition 405-2 and get it serviced by Quad (£70).

[agk]

The problem of fake semiconductors from China is real and present... and far more widespread than you may imagine. I would be pleasantly surprised if there were no fakes in the cheapest Chinese kit. Very definitely caveat emptor!

Yep. The amp I currently enjoy is known to employ some fake WIMA caps as it comes from the factory. Mine fortunately has been sorted but it's a definite issue to be aware of.
Not to say all fake caps are bad caps but you have no way of knowing.

[Gordon Steadman]

I've owned at least a couple of each of the 303's, 306's and 405-2's and my order of preference goes 405-2 first (by a long margin), then the 306 and a fair way behind the 303. I would buy a good condition 405-2 and get it serviced by Quad (£70).


Just goes to show...... the exact reverse of my taste! Can there be a definitive answer to these things?

My Leak Stereo 20 has suddenly making 'orrible distorted noises and without France's resident guru (how dare you move back the UK:doh:) it has been necessary to put it on the spares pile.

The only two amps I have here I will trust with the 57s are a 303 and a 306. I know that I preferred the 306 to the 405/2 I no longer have. It was very quickly established that the 303 is the one that makes music and offers more insight with the 57s. They were designed to compliment each other. I tried both 303s I have and they both did the same job.

So clearly, choosing a speaker relies on being able to drive it with your chosen amplifier before laying out the readies.

[DSJR]

Jez will diss or confirm I'm sure, but the current dumper circuit is very fussy around the 'bridge' and crap design here ruins the performance. Not an easy circuit to 'clone' successfully and Quad themselves went though several layout changes until the first mk2 boards came along (issue 7). Quad did have new replacement boards not that long ago (issue 10 I seem to remember)... Link to mk1 updates below.

http://www.keith-snook.info/quad-405-mods.html


Must be just me, but I always found the 306 gutless, even with other preamps. The 303 has it's place, but not necessarily in a modern system (my old speakers were voiced using a 303 with its particular and sonically way of doing things so it kinda makes sense as a base reference in my particular case).

606mk2's aren't hugely expensive these days and I still think they're bloody good - the mk1 may need some updates as they could take a while to 'warm up' and lose the grain heard on cold-switch-on I remember, something the mk2 avoided right from the off on the samples I demo'd.

[Idlewithnodrive]

To these ears, the306 just sounds too bouncy, too mid forward in presentation; almost like it's trying too hard to impress.

The 303 is very musical but in a 70's veiled sort of way.

The 405-2 almost as musical but more open and a bit more detail and control at the frequency extremes, although none of the three could be considered dynamic IMHO :)

[Barry]

Although Quad tried to make their first solid-state amplifier, the 303, 'universal', it was optimised for use with the Quad electrostatic speakers and the combination of the two is especially fine, as I reported a while back.

Of the current dumping designs, the 405, 510, 520, 306, 606, 909, my own experience is with the the 405, 510 and 520. One of my 405-2s has been upgraded to NET level 3, with dual-mono power supplies. Another pair have been 'monoblocked' by tubehunter with the circuit modified to Keith Snook level 3, precision high-tolerance components fitted in the bridge circuit, as well as higher rated power output transistors and the power supply diodes replaced by 35A bridge rectifiers. Some of the resistors around the input IC have been replaced with Z-films. All of these modified Quad 405s sound excellent when feeding Quad 57 speakers.

As do the Quad 510 monoblocks, both these and the monoblocked 405s were successfully demonstrated at the last MiBO with Firebottle's Quad 57 speakers. At the end of the evening we played the Who's "Don't get fooled again" at a loud level - no lack of dynamics there, the Quads can boogie with the best of them!

[DSJR]

Personal subjective comments these, but I remember back in 1992, when I first forayed into ATC territory with the hideously inefficient SCM20's, I used a freshly updated 405-2, in stock Quad form and using replacement standard spec supply caps. Poor thing ran very hot indeed at the volumes I played at (I used to be a 'HiFi hooligan'). I replaced it with the stereo AVI power amp rated at 80WPC and although maximum volume was barely different in all honesty, the AVI ran barely warm and sounded at least as good into the ATC's. The AVI mono's though, were comfortably louder and better all round I felt and they sometimes come up on eBay for under £500. Servicing shouldn't be difficult either as the circuits were simple as I recall.

[Idlewithnodrive]

Although Quad tried to make their first solid-state amplifier, the 303, 'universal', it was optimised for use with the Quad electrostatic speakers and the combination of the two is especially fine, as I reported a while back.

Of the current dumping designs, the 405, 510, 520, 306, 606, 909, my own experience is with the the 405, 510 and 520. One of my 405-2s has been upgraded to NET level 3, with dual-mono power supplies. Another pair have been 'monoblocked' by tubehunter with the circuit modified to Keith Snook level 3, precision high-tolerance components fitted in the bridge circuit, as well as higher rated power output transistors and the power supply diodes replaced by 35A bridge rectifiers. Some of the resistors around the input IC have been replaced with Z-films. All of these modified Quad 405s sound excellent when feeding Quad 57 speakers.

As do the Quad 510 monoblocks, both these and the monoblocked 405s were successfully demonstrated at the last MiBO with Firebottle's Quad 57 speakers. At the end of the evening we played the Who's "Don't get fooled again" at a loud level - no lack of dynamics there, the Quads can boogie with the best of them!

I too owned those monoblocks briefly and although they were, undoubtedly, very good, to me they just seemed to lose their connection to the music, erring more towards hi-fi. So, I went back to a single 405-2.

It seems we all hear things differently, or listen for different things.

[Barry]

Interesting. That either means you don't like the improvements suggested by Keith Snook (inter alia), or you like two-channel amplifiers which share a common power supply.

When I demonstrated the 405 monoblocks at MiBO, one of the comments made was they did not sound clinical or 'hi-fi', but natural and involving. (They were used with Quad 57 ESLs)

Anyway the later stock 405-2s are very good - I have one. And as you say, we all hear differently - it would be boring if we were all the same. :)

[Macca]

At MiBO we used a number of different power amps with the QUAD 57 speakers, the presentation was noticeably different in all cases, and people's likes varied. Personally I erred towards the sound made by Barry's QUAD monoblocks, I thought they most exploited the unique advantages of the ESL speakers; but I can understand why other's preferences differed.

[Gordon Steadman]

To these ears, the306 just sounds too bouncy, too mid forward in presentation; almost like it's trying too hard to impress.

The 303 is very musical but in a 70's veiled sort of way.

The 405-2 almost as musical but more open and a bit more detail and control at the frequency extremes, although none of the three could be considered dynamic IMHO :)

Does this mean that reality changes according to when something is manufactured?

Every time I hear what is described to me as a dynamic amplifier, I end up covering my ears in protest at the screaming, harsh and unmusical sound. The 303 and 57s just communicate the music in a no nonsense way without feeling you are listening for what is wrong with the hi-fi.

I do get fed up with this received wisdom about Quad gear being safe, cuddly whatever.

[Pieoftheday]

Does this mean that reality changes according to when something is manufactured?

Every time I hear what is described to me as a dynamic amplifier, I end up covering my ears in protest at the screaming, harsh and unmusical sound. The 303 and 57s just communicate the music in a no nonsense way without feeling you are listening for what is wrong with the hi-fi.

I do get fed up with this received wisdom about Quad gear being safe, cuddly whatever.

My 306 wasn't bouncy or forward, it just made the speakers make music .I found it character-less, brill amp

[Idlewithnodrive]

I do get fed up with this received wisdom about Quad gear being safe, cuddly whatever.

I didn't say it was safe or cuddly Nodrog, as you could probably summise by the fact that i have kept my 405-2 above all other amps I have owned. I really rate Quad gear and have just explained how the relevant models stack up to these ears.

[Arkless Electronics]

For what it's worth I once had (still have the boards somewhere) a 405 mk1 in which I replaced the op amp with a much better one, improved the supply to the op amp, replaced various capacitors etc and disabled the protection circuity... from what I remember it was a bloody good amp! No lack of dynamics, no "pipe and slippers" at all!

[Barry]

I have a Mk. I Quad 405 on which I have made the same modifications. Used it successfully with my Quad 57s for about twenty years, before replacing it with a late Mk. II version (inter alia). The modified Mk. I now needs its power supply capacitors replaced; something which I ought to do sometime, but I have six other Quad power amps to see me through! (2 off 303, two off 50E, two 510s and a 520, as well as two 'monoblocked' and fettled 405-2s.)

I think the term "pipe and slippers" refers to the 303, but as I posted recently, the combination of the 303 with Quad 57 speakers is somewhat synergistic, an effect no doubt intentional. What sounds smooth, untroubled and musical to some might sound boring, dull and lacking in involvement to others. What sounds dynamic, exciting and "you are there", might sound uncomfortable, bright and unsettling to others.

[Arkless Electronics]

I have a Mk. I Quad 405 on which I have made the same modifications. Used it successfully with my Quad 57s for about twenty years, before replacing it with a late Mk. II version (inter alia). The modified Mk. I now needs its power supply capacitors replaced; something which I ought to do sometime, but I have six other Quad power amps to see me through! (2 off 303, two off 50E, two 510s and a 520, as well as two 'monoblocked' and fettled 405-2s.)

I think the term "pipe and slippers" refers to the 303, but as I posted recently, the combination of the 303 with Quad 57 speakers is somewhat synergistic, an effect no doubt intentional. What sounds smooth, untroubled and musical to some might sound boring, dull and lacking in involvement to others. What sounds dynamic, exciting and "you are there", might sound uncomfortable, bright and unsettling to others.

You're not wrong on all that Barry. A Mk2 is of course basically the same as a mk1 but with relaxed double slope protection. A mk1 with the mods we both made is better than a standard mk2... slightly...

[Bonky]

I see the Moderator has moved this thread to 'Past Masters', presumably because he thought the the OP was wanting to debate old Quad gear. In fact it was about 2017 Quad clones ...not quite the same thing perhaps...?

Anyway, I'm not complaining. Interested people may wish to know that I have asked the maker of the UK-based Quad clone site to answer some of the 'issues' that people have been kind enough to raise.

Thanks.

[Barry]

I see the Moderator has moved this thread to 'Past Masters', presumably because he thought the the OP was wanting to debate old Quad gear. In fact it was about 2017 Quad clones ...not quite the same thing perhaps...?

Anyway, I'm not complaining. Interested people may wish to know that I have asked the maker of the UK-based Quad clone site to answer some of the 'issues' that people have been kind enough to raise.

Thanks.

Yes, the manufacturer of the Quad clones mentioned in your OP has just joined. I'm sure he will be able to answer all your questions in due course.

[DSJR]

My vibe is that the PREAMPS were the limiting thing, deliberately in the case of the 33 and early 44, both seeming to improve drastically with updated components and relaxed filtering (I avoid Net-Audio 33 updates like the plague as their take is a different preamp entirely but used in the 33 case). The 303 is fine with efficient highish impedance speakers like old Spendor Bc1's and Tannoys for example, but seems to flounder badly with more recent 6 ohm (and below) jobbies.

These Chinese 405 clones may copy the basic circuit, but it's the LAYOUT as well which is so important and it's this that Quad altered several times. The 606's don't seem as fussy from memory and today, I should add the Artera version is superb for 99% of uses.

[Arkless Electronics]

My vibe is that the PREAMPS were the limiting thing, deliberately in the case of the 33 and early 44, both seeming to improve drastically with updated components and relaxed filtering (I avoid Net-Audio 33 updates like the plague as their take is a different preamp entirely but used in the 33 case). The 303 is fine with efficient highish impedance speakers like old Spendor Bc1's and Tannoys for example, but seems to flounder badly with more recent 6 ohm (and below) jobbies.

These Chinese 405 clones may copy the basic circuit, but it's the LAYOUT as well which is so important and it's this that Quad altered several times. The 606's don't seem as fussy from memory and today, I should add the Artera version is superb for 99% of uses.

To my enduring shame (even though I was right), when I was about 17-18 I gave Peter Walker a good talking to about what he had got wrong with the 44 pre amp:eek: He smiled beatifically, nodded at my points and said it was nice to speak to a young enthusiast so keen on the technical side of things. He was unflappable and a very nice bloke:)

[DSJR]

PW had a team/help even in the days of the 33/303 I understand. Not sure he did a huge amount on the 44, which used then newish fangled technology such as solid state switching and multiple early op-amps in the signal path I believe.

[Arkless Electronics]

PW had a team/help even in the days of the 33/303 I understand. Not sure he did a huge amount on the 44, which used then newish fangled technology such as solid state switching and multiple early op-amps in the signal path I believe.

Yep. Exactly what I told him was wrong with it...

[Barry]

Yep. Exactly what I told him was wrong with it...

What's wrong with the switches developed for System-X telephone exchanges? :rolleyes:

[Arkless Electronics]

What's wrong with the switches developed for System-X telephone exchanges? :rolleyes:

I worked on some of the last production of Strowger electromechanical gear at GEC in Hartlepool about 1981 ish as "works experience". Believe me they had a low opinion of system x there! It was the towns biggest employer and system x shut it down...

[Barry]

I worked on some of the last production of Strowger electromechanical gear at GEC in Hartlepool about 1981 ish as "works experience". Believe me they had a low opinion of system x there! It was the towns biggest employer and system x shut it down...

There's something wonderful about electromechanical gear. I worked as student in the summer at Pye TMC, setting up Carpenter relays for use in telephone exchanges. Those relays were beautifully engineered and I learnt a lot about electrical contact technology.

[spendorman]

I worked on some of the last production of Strowger electromechanical gear at GEC in Hartlepool about 1981 ish as "works experience". Believe me they had a low opinion of system x there! It was the towns biggest employer and system x shut it down...

So, another ex GEC guy, there's a lot of them about, including Spendorman.

[Barry]

So, another ex GEC guy, there's a lot of them about, including Spendorman.

Me too!

[Arkless Electronics]

Many years later I worked for a while for what had been GPT at Newton Aycliffe... It had been bought out by then (can't remember the name of the company I actually worked for) and it mainly did repair work on customer returns of BT cordless phones and answering machines.... Most of the test gear still had "Property of GPT" stickers on it...

[Bonky]

Off topic I know, but I can recall wiring Strowger gear at Shepton Mallett Exchange in 1967 for the Post office. Ericksons were the suppliers (my Dad worked for them; later Plessey).

The spare springs were very useful to small boys and also the regenerator units (remember those?)
Richard