"Quad 510 spez." - pictures of modified 510 amps

  • No one logged in.

26-Apr-2012 03:28 PM

Glitterbug

Glitterbug

Posts: 73

Hello dear forum people,

for those interested in strangely modified quad equipment, I today purchased a set of heavily modified Quad 510's. 

Pictures of the outside and inside of the amps (they are absolutely the same inside and out) can be found here: https://files.me.com/c.sides/6fpap6 (7mb zip file)

I already sent the pictures to Joost and Stefaan, but thought that maybe there are some more enthusiasts here that are curious enough to look at them.

I got them for a rather low price, they work perfectly fine, but I couldn't audition them in my system because I just picked them up in Berlin and will only go back home in a couple of days. Very curious to hear what you have to say about them.

From the mail to Joost and Stefaan:

They do look absolutely different from all the pictures I have seen of the internals of 510s so far, and it seems like they received a full makeover. The guy I bought them from said they were from a recording studio in London, and that they have barely been used. They drove a pair of large Magnepan's with total ease, so he said. But they haven't been connected to anything in years, supposedly. He claims they were from one of the last batches of 510's that Quad made.

Very curious to hear what you think- I hope I didn't make a hasty (and wrong) decision. They do work, but since I am in Berlin, I can't tell you how good they sound, the friend I am staying with only has some shabby Tannoy speakers that I don't know. They seem to be incredibly powerful though, and they are dead quiet and don't deliver the slightest background noise or hiss. The two main caps are NEC and look fancy with golden letters (just so you can know if they were replaced before or not). I don't know what the two coils and the strange contraption with the caps on (what looks like) two large golden caps are, on the opposite side from the amp board, next to the main transformers.



  Reply

27-Apr-2012 04:23 PM

Glitterbug

Glitterbug

Posts: 73

Thank you so much for your insight Joost! I would have never gone into this adventure without you guys!!!

Just a few questins to make sure I understand:

- so the additional coils and caps work as some kind of isolating transformer? I have a huge one in my studio because the electricity in the house is bad and I gather a lot of noise through the electricity lines, so that doesn't harm I'd say. Also in the apartment building I live in, electricity isn't very stable nor clean. I would assume that it would help to have less noise in the signal?

- You wrote that the transformer works, or might work, on a fixed 4 Ohm load. The LS3/5a w/ AB1's they are supposed to drive have a load of 11 Ohm. Would that be a problem in its current configuration? Or in what kind of situation would I run into issues in its current configuration?

- I don't run long leads in the studio, so not having the input transformer is totally fine. My leads are 2m max, so I don't necessarily have to have balanced inputs. So I guess the current configuration is fine.

- is there anything special I need to know to change the XLR outs to regular speaker terminals, or just add those? I would assume not?

I will tell you next week what they sound like... I was kind of surprised to see that somebody put that much work in it, but left the amp boards untouched, or am I wrong here?

Again, thank you so much, Till

  Reply

29-Apr-2012 11:57 AM

Joost Plugge

Joost Plugge

Posts: 888

Hello Till,

The extra filter in the PSU could stay there, no problem. Because there is one PSU feeding one channel, instead of two in the case of a normal 520, the peak delivery will be ok.

If the amp is wired for 4 ohm, rather complicated to check from the pictures, than voltage clipping could occur when connecting a 11ohm speaker. But if you are careful with the volume, no harm can be done. If you wish we can sort out the hardwired schema for 8ohm. 

I should leave the XLR's in place, and make a short conversion cable. It is also possible to add a set of 4mm binding posts, see our webshop. But you have to drill extra holes. And connect them in parallel to the XLR's

Regards

Joost Plugge

www.dadaelectronics.eu

 

 

 

 

 


Joost Plugge

  Reply

30-Apr-2012 09:52 AM

Glitterbug

Glitterbug

Posts: 73

Hello again,

I am a bit afraid of re-cabling the transformers... thats too much stuff that could go wrong and quite a bit of current to do harm. Or do you think it wouldn't be too complicated?

Shipping them is not really an option, each weighs almost 20kg! That would be crazy shipping costs.

I assume you are right about the 4 Ohm setting; they were powering Magnepan 20.6 speakers, and I just checked: all of the Magnepans are 4 Ohm systems. That's what they were re-built and optimized for. I should have checked that before. Is there a way to check if that really is the case? Where and how should I measure with the multimeter? Or do you need better pictures of the transformers?

So, if you could help me to re-wire the transformers for 8 Ohm speakers, that would be great. Changing them to the originally intended versatility is something I definitely wanna do, but later, and I think I would schedule an appointment in Antwerp for that, and come by car.

Thank you so much, and speak soon, Till

  Reply

30-Apr-2012 10:29 PM

Glitterbug

Glitterbug

Posts: 73

All right, I am back home, and the amps are up and running in my chain. And the difference to the 405 is incredible and by far more dramatic than I would have imagined.

My chain at home: Camtech C101 pre, Beresford Caiman Gatorized DAC which goes through a Rock Grotto converted Musical Fidelity X10-D with Russian 6N23P-EB tubes, Technics 1210 MkII with Linn Akito / Goldring 2300 and Herbies Way Excellent Mat. If I don't listen to records, I stream lossless files from my computer using Fidelia or use a Pioneer DV717 as a transport and the Beresford as DAC. They drive Rogers 11 Ohm LS3/5a's with Rogers AB1's.

The 405 sounds amazing, warm, enjoyable. I can listen to music for hours, and there was nothing I was missing so far.

I was listening to Stevan Kovacs Tickmayer - In Memoriam Andrei Tarkovsky (ECM).

Using the two 510's throws me into a whole new league. I can hear tiny background noises and the room where the piece was recorded is just- there. The precision of these amps is almost scary. You can hear the bows on the violin strings before they start playing. One hears one of the musicians breathing. There is information in the recording that simply was not audible before, and I had no idea that it was there! Both my wife and I were sitting on the couch with our jars to our knees. I wouldn't necessarily say they are more enjoyable, they are merciless. You can hear everything. The stage is huge. The stereo separation is nothing like I have heard before, at least not with passive speakers. And that was just the first piece of music we listened to.

I guess I made a good catch!! There was not the slightest clipping or distortion, so I suppose they work fine as they are. I will add some normal speaker cable terminals though.


  Reply

01-May-2012 09:39 PM

Joost Plugge

Joost Plugge

Posts: 888

Hello Till,

The signal to noise ratio of a 510 is better than the S/N ratio of a revised 405. Also the dual mono design of the 510 helps. No frequency or load depended crosstalk anymore. These are small improvements, but with the modern high resolution digital material, they become more important. I look at the pictures, your 510's are wired for 8 ohm (33V max output), so they where not optimised for the Magnepan, why? So they are fine for the LS3's. The input sensitivity is 0.5V so becarefull with the trottle.

Regards

Joost Plugge

www.dadaelectronics.eu

 

  Reply

01-May-2012 10:12 PM

Glitterbug

Glitterbug

Posts: 73

Hello Joost,

thank you so much! 

It was really like listening to a new system; If somebody would have told me that the power amps could have such an impact, I would have called them crazy. I really just stumbled upon them by chance! I still love the 405 though; it doesn't even come close to the resolution of the 510's, but it has a more round, slurred, tube-ish sound, if I compare it to some old tube outboard gear I have in the studio vs. their solid state brethren in the rack. 

But the 510's are still Quads; they are super precise, but still not metallic like my old Yamaha PC2002 or some Accuphase stuff I had a chance to listen to some time back. They very easily are the best amplifiers I have ever listened to. 

Other than adding regular speaker terminals, I won't put any work into them for now. I love them as they are.

I would be so curious to know their full story and also who did the conversion. The "spez." does not sound all that English to me... ;-) And some parts of their history don't really add up. I was told they were build for Magnepans, but I suppose that can't be because they all are 4 Ohm systems. 

I guess I'll never know.

Are there any improvements I can do to the 405 to increase it's resolution? Since I need to sets of amps for two sets of LS3/5a's (and my wife wants a pair of LS3/5a's too, she is a photographer and video artist and she hates the monitors in her editing room, so that's another Quad amp that will eventually join the family), I guess there will be more Ebay hunting and a lot more parts to order from you guys! :-D

Thank you so much for your insight and help with all of this!

Best from Cologne, Till

  Reply

23-May-2012 09:50 PM

Not Available

Posts: 2

Hi Joost

Thanks for the valuable input.
Can I please ask your recommendation and help.

I can source two Quad 510 Amplifiers from work at a very good price....well I still need to make my boss an offer. They are in mint and original conditional. I might have to hard wire the outputs on the transformer as the supplied voltage boards are missing.

They currently have 18 Ohm 40Volt boards. Would this be ok test test with? I would like to upgrade my current system. I currently have an Adcom GFA-535 60 Watts stereo Amp.

 I would also need to source 4 x 3 pin round input/output connectors before I can test, so I would just like to know if it is going to worth my while to invest in them? I am sure they work. I powered them on and they look fine from the outside. They look realy good inside as well.

Kind Regards
Jason

  Reply

26-May-2012 04:43 PM

Not Available

Posts: 2

I tried the Quad 510 and it sounds brilliant. I could only test on one of the two amps, and even with just one channel it sounds great. So natural and accurate.

  Reply

27-Aug-2012 11:41 PM

branko

branko

Posts: 6

Hello Quad admirers,

I am a little late to this discusion maybe, but I would like to post some coments on Quad 510 power amps.

Over the years I used to have different Quad amps, in permanent use, and to my great pleasure. These were models such as 405, 405-2, 303, 306, 606, 606MkII and Quad II.  Among them I had my favorites (such as 303) and some maybe not so highly regarded (such as 606). But in my view, all these amps are equaly good and very often better than competitive models of the same price or power from other brands.

And two years ago I was lucky enough to pick up a pair of 510 monoblocks. Well, I thought , here are probably another good Quad amps. I was totaly unprepared for the sound quality delivered by these monoblocks. Not only that these amps greately outperformed all other Quad amps I ever had, they are quite simply THE best power amps I ever had (and I had a good few including brands like Krell and Mark Levinson)  

So, my advice is to grab these monoblocks at any cost and discover what was Peter Walker thought when he said that ideally reproduced recording should carry musical message to the listener, as he is in audience during live performance.

Regards

Branko



branko
  Reply

29-Aug-2012 07:28 PM

Glitterbug

Glitterbug

Posts: 73

Hello Branko,

despite the fact that I have never before owned mono amps (other than the ones in my active monitors in the studio), I totally agree. These will be my final amps, and I see no reason to ever use anything else in their place. They are jaw dropingly detailed and still so beautiful sounding, that I am still not finding the right words to describe their sonic attributes. I feel very fortunate to have found them- actually totally by chance. Yet, they are very different from other 510's as far as their builds (did you look at the pictures?) since they were so heavily modified, but it didn't do them any harm I guess. I enjoy them immensely.

Happy to read about other happy owners!

Best from Berlin, Till

  Reply

05-Sep-2012 01:26 PM

branko

branko

Posts: 6

Hello Till,

I have not seen the photos of yours 510 but I am interested.

My 510s are not modified, they are in original factory condition. Serial numbers are 002163 and 002164. I remember that technician who checked my 510s was thrilled by the amps and said that these are amplifiers of rarely excellence.

I consider these amps something like a Holly Grail in audio – you can look long and hard but it is unlikely that you will find beter amps.

These amps managed to unite detail and transparency of tubed single end amps, power and slam of best solid state designs and great musicality and naturalness which you can often find in Quad amps. Also you can add absolute reliability and you have something as close to a perfect amps as you will ever come.

To those people who havent been lucky to hear these amps at home, with familiar music, these words of mine means nothing, they will probably think – here is a happy guy who will have some other amplifier to praise next year. But, you and me my friend, knows that our search for final power amp is finished. These amps will play any kind of music as it was intended by composer and will drive any speaker with confidence. What more could we ask ?

 

Regards



branko
  Reply

05-Sep-2012 01:56 PM

Glitterbug

Glitterbug

Posts: 73

Hello Branko,

for me it's the same as the quest for finding the right speakers, which has ended too. I am happy with my Rogers LS3/5a's plus AB1 subs, and the active speaker in my studio is a Klein&Hummel O96. And it will stay like this for as long as I can still repair these.

Here is a new link to pictures of my 510's: https://www.hidrive.strato.com/lnk/4UCY2xdV

I bought them this way, the story remains unclear. Supposedly they were deployed in a recording studio in London; but the "spez." on the fronts suggests a German modification... but what matters in the end is: what they sound like. Maybe they are slightly different from other 510's as far as their sonic attributes, but I am so happy with them that I wont change even a wee bit, other than caps that wear out over time. 

I actually just purchased a 520 in addition- to drive my second pair of LS3/5a's that were previously driven by a heavily Dada modified 405. Fantastic amp, but outperformed in every aspect by the 510/520 range. The 520 needs some serious care taking though; thus I wasn't able to A/B them. Also my 510's are built around the last board revision before Quad closed shop.

The 405 is now happy to drive an old rescued pair of Celestion Ditton 15XR's that underwent some serious tweaking with new caps on the crossovers, fresh internal cabling, new Morel tweeters, and a second bass driver instead of the passive driver. A very nice combo that is! But nowhere near the Quad 510's plus LS3/5a's.

Where are you located? And what does the rest of your chain look like?

Best, Till

  Reply

05-Sep-2012 07:51 PM

branko

branko

Posts: 6

Hello Till,

Yes, yours 510s seems to be seriously modified, but it seems to me that it was done by qualified technicians. I guess that you would like to know how your modified 510s compares with unmodified 510s. You will probably have to buy unmodified pair to discover that. But I think it is very difficult to find a pair of 510s in any condition. My 510s came from a recording studio in Vienna.

Regarding speakers, I like BBC derivates produced by Rogers, Spendors, Harbeths and alike. It is very good that you have subs with your Rogers because 510s really shine with full range speakers.

I am using old american speakers AR3a but also ATC SCM20 are at hand. Preamplifier is fully restored vintage Sony 2000f, and source is hard disc via Quad cdp 99 DAC, and there is also my beloved Revox A76 tuner.

I am located in Belgrade, Serbia and you?

And please tell me how 520 sound? It could be quite good but I doubt it can come close to 510 (just my guessing)

Regards



Branko

  Reply

07-Sep-2012 07:29 PM

branko

branko

Posts: 6

Hello Till

I have been thinking about your 510s. I would not touch them, I would not try to restore them to the factory condition. I would not do that because , it seems to me, that somebody put serious effort and knowledge to make something special out of them, and he did it with success.

The proof of this success is in listening. As you have described, they work excellent and I believe you. I also believe that heavily modified 405 must be a very good amp which is not easy to beat by any amplifier, and yet yours 510s can do that easily.

Just keep these 510s and enjoy them. Maybe you could try to buy an unmodified pair of 510 and than to compare. Since you also have a studio, one pair of 510s can always been accomodate there.



Branko

  Reply

07-Sep-2012 09:58 PM

Glitterbug

Glitterbug

Posts: 73

I totally agree. They really came to me just by chance, and I guess it was fate! ;-D

I will not do anything with them. I might change the input voltage though; the volume knob on the preamp (Camtech C101) cant be turned further than 9 o'clock, anything more would harm the speakers. They are pretty powerful beasts. They also got an adequate set of speaker terminals to accommodate normal speaker cables (a humble pair of Kimber 8PR).  

I am writing with Dada for repair and restore parts for the 520, and I will keep you posted about my successes, and it's sound quality. But it might take me a few weeks to find time for that. The main element, the amp boards, are very similar in the 510s and 520s (it's the same line anyways), and they might not be as precise with things like stereo field and separation (monos are monos... ), but I believe the 520 will be as close to the 510's as anything can get. And that is exciting!

I love the 405, and I would not let go of it ever, but it's not in the same league, not even with all the reconditioning and revision it underwent. It's a fantastic amp, but nowhere near the 510s. I was happy with it and thought it's gonna be the last amp for the purpose I need, until the 510'd came and dethroned the 405 in seconds.

I am in Berlin by the way, and my last time in Belgrade is way too long ago. I had a show / performance with the B92 people, and a wonderful time there. But that must be at least 12-13 years ago. The city must have changed drastically.

Have a great evening!

  Reply

08-Sep-2012 08:26 PM

branko

branko

Posts: 6

O yeah, B92, a candle in the darkness at that time...

Maybe you remember Gordan Paunovic from B92, two of us share the same love for music and hifi.

Reading articles about quad 510 I found that there were total of 8 amplifier board issues. My boards are No. 6 issue, and are very slightly different from other issues. For example, on my amp board there is only one small capacitor, not two as usually seen. Anyway, it does mean nothing to me.

One small thing about my 510s could be anoying. It is about speaker terminals which are XLR type.

So, it is not so easy to connect different types of cables, and I will certainly not going to drill back side of amp to accomodate some fancy binding posts.

I am using an old Quad speaker cable, which fits perfectly in XLR chinch, and which is also a strong performer.

One more interesting thing : each and every friend of mine, also hifi enthusiasts, who came to my place and hear 510s, well each of them said that these amps sound fantastic. And why is that fact so interesting? Because, hifi lovers will rarely agree about sound merits of components. But in the case of 510 just everybody agree that they sound great. The reason for that is, in my opinion, because the sound of 510s are so much more superior to anything we listen before that just everybody can hear that easily.

Hear you



branko
  Reply

16-Oct-2012 09:55 AM

branko

branko

Posts: 6

Hello Till

Have you received quad 520 from service ? If so, please tell me how does it compare with 510 monos?


branko
  Reply

18-Nov-2012 09:19 PM

Ac

Ac

Posts: 1

Hi all.. I have a pair of 510 that are original inside but the exterior is a bit modified . I bought them 5 years ago and they work great. 

I live in Israel and will be ready to ship to anywhere .. 

My mail is mcamit@gmail.com so if anybody wants them ...

It looks like the previous owner tried to glue them together on on top of the other.. I can't understand why , but thay are not new and as you know each owner likes to put in a bit of his touch to their setup. 

  Reply

25-Aug-2013 05:53 AM

wesang

wesang

Posts: 1


I am a bit late to read this forum.

Have you sold your 510 ?

If not please email me : howkiwong@hotmail.com


Thanks.

  Reply