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Running a Poweramp without fan?

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Re: Running a Poweramp without fan?

PostPosted: Thu Jul 09, 2020 11:46 pm
by DGL.
In regards to getting the Quad fixed maybe ask over at the Vintage radio forums (vintage-radio.net), I', sure someone will either be able to fix it or give advice on what might be wrong and how to fix.

Re: Running a Poweramp without fan?

PostPosted: Fri Jul 10, 2020 12:10 am
by cyrano.mac
Hugh Robjohns wrote:Lots of good info and recommended updates here:

https://quadrevisionspot.blogspot.com/2010/04/revision-of-quad-520f.html

Yep. Stefaan knows more about Quads than anyone else. He's been repairing/restoring Quads for nearly 20 years, professionally:

https://www.dadaelectronics.eu/

He's even developed upgraded, new boards for some amps. Antwerp seems to be Quad country. One collector spouts four Quad II sets, a dozen 303s and seven 405s, all of them driving Quad or IMF speakers. Most of them lovingly restored by Stefaan.

Re: Running a Poweramp without fan?

PostPosted: Fri Jul 10, 2020 7:56 pm
by Sam Spoons
Quad said they were not able to repair the 522 so it will be winging it's way over to Folderol in the next few days. :thumbup:

Re: Running a Poweramp without fan?

PostPosted: Fri Jul 10, 2020 8:07 pm
by Hugh Robjohns
I'm surprised Quad don't want to know. I wonder why.

Re: Running a Poweramp without fan?

PostPosted: Fri Jul 10, 2020 10:19 pm
by Sam Spoons
I was too... I spoke to somebody on customer service and left it with her after she promised to get an answer and call me. She phoned back later having asked the service department if they could help but no was the answer.

There's londonsound.com and DADA in Antwerp (probably a bit trickier to get it shipped) but I gave Will a get-out clause and he said he'd like a stab at it so I'd rather put some money his 'new gear fund'. I will converse further when he has had a look.

Re: Running a Poweramp without fan?

PostPosted: Fri Jul 10, 2020 11:47 pm
by ef37a
Sam, did you tell Quad that you had had another tech look at the amp? Even send those photos?
Some companies you see have a policy of not taking on products when someone else has 'had a go'. Harsh perhaps but I have seen some right butchery in the past and a tech can never be confident in guaranteeing the work. Yes, a block replacement of both PCBs would do it but likely to be uneconomic?

Even so, I would have expected a company of Quad's standing to take such a problem on the chin?

Dave.

Re: Running a Poweramp without fan?

PostPosted: Sat Jul 11, 2020 11:14 am
by Sam Spoons
Hi Dave, No just asked a simple question "Can you repair my ex-BBC Quad 522?". They were unhelpful when the last tech phoned for advice (which seems odd if they are not prepared to attempt to repair it themselves) maybe they remembered his call? They just said "sorry, we can't service 522/BBC any more".

I didn't send the pics either but, it's probably inevitable that a 34 year old professional power amp will have been repaired at some point (even if it's just re-capping).

I had a quick look for replacement PCBs with a view to rebuilding it myself (I can solder but have negligible experience of faultfinding electronics) but it's probably too obscure.

There are a couple of 520s on ebay but buying another doesn't keep mine out of landfill, and it won't be my Quad 522 so I may as well stick with the Studiospares amp if mine can't be fixed :cry:

Re: Running a Poweramp without fan?

PostPosted: Sat Jul 11, 2020 11:30 am
by ef37a
Ok Sam, well there is always the chance that the Studiospares bruiser will blow your Kefs?

Have you considered gutting the Quad and using the power supply with a pair of modules? I have an amp I built years ago with a pair of ILP HY60s. Served me well as a hi fi amp for many years. The mains traff is one I salvaged from a Philips VCR2000! The amp is not used at the moment but I have plans!

But then we must give Will a fair go.

Dave.

Re: Running a Poweramp without fan?

PostPosted: Sat Jul 11, 2020 11:31 am
by Hugh Robjohns
I'm sure Will will be able to sort it. As I said, it's really not that complicated an amp, and component parts are readily available. So as long as the PCBs aren't completely wrecked it should be fixable.

The 52x series was an unusual excursion for Quad and I don't think they made that many in comparison to their other lines... I'm disappointed that Quad won't service them...

I don't think you can get replacement complete amp cards for them like you can for 405s and so forth -- at least, I've never seen any online! -- so repairs would have to be component level rather than board swaps. But at least the schematics are available, and the technology is very similar to the 606/306 and derives from the 405.

Re: Running a Poweramp without fan?

PostPosted: Sat Jul 11, 2020 11:39 am
by Hugh Robjohns
ef37a wrote:Have you considered gutting the Quad and using the power supply with a pair of modules?

Yes, in the unlikely event that it does turn out to be irreparable, I'd do what James did with his broken 405 and rebuild using Hypex class-D power amp modules and associated power supply.

I have an amp I built years ago with a pair of ILP HY60s. Served me well as a hi fi amp for many years.

Me too! My university years music reproduction was with a home-built amp using ILP HY60s driven from a modified Sinclair discrete transistor preamp module, and working with a pair of Videotone GB3 bookshelf speakers! Front end was a Hitachie 3-head cassette machine and a modified alarm clock-radio, and in my last year I added a salvaged Garrard 301 with an SME 12-inch arm and Decca London cartridge! (These were quite literally thrown out of the university Students' Union's Hi-Fi society because they was deemed old fashioned! They threw out a pair of Tannoy Lockwoods too, but I didn't have space for them and a friend took them and kept using them for decades).

Re: Running a Poweramp without fan?

PostPosted: Sat Jul 11, 2020 12:05 pm
by Folderol
Had a look at a copy of the schematic - interesting, and some surprising decisions.
Unfortunately with the usual Internet search I've only found a fairly low resolution image. It's usable... just! Does anyone know where I can get a good copy?

Re: Running a Poweramp without fan?

PostPosted: Sat Jul 11, 2020 1:40 pm
by Hugh Robjohns
I think have a decent version, but I'm not near my network at the moment so I'll dig it out and send it later. If you're in a hurry, I think there's a version in the resources section of the dada site I listed earlier. You might have to register to access it.

H

Re: Running a Poweramp without fan?

PostPosted: Sat Jul 11, 2020 4:02 pm
by Folderol
Hugh Robjohns wrote:I think have a decent version, but I'm not near my network at the moment so I'll dig it out and send it later. If you're in a hurry, I think there's a version in the resources section of the dada site I listed earlier. You might have to register to access it.

H
Thanks Hugh - I'll wait. Haven't got the amp yet :thumbup:

Re: Running a Poweramp without fan?

PostPosted: Sat Jul 11, 2020 4:59 pm
by Sam Spoons
Will, have a close look at the pics before I send it, there seem to be a fair number of repaired traces on the PCBs which might be what is making the repair troublesome.

Re: Running a Poweramp without fan?

PostPosted: Sat Jul 11, 2020 5:30 pm
by Hugh Robjohns
Folderol wrote:Thanks Hugh - I'll wait. Haven't got the amp yet :thumbup:

Email with attachments sent to your registered SOS email account.

H