Quad II & 22- advice needed (and service in Susssex area?) - UK Vintage Radio Repair and Restoration Discussion Forum

Simon Turner · 17th Jan 2010, 2:18 am

Hello,

I'm hoping that someone might be able to help me.

I've had a couple of Quad IIs, a 22 Control Unit and a Tuner in my loft for a few years (actually decades). I've just fixed the Quad IIs up to some old Linn speakers and fed a network music player directly into them. The lush, rich sound has bowled me over. I'd like to get them serviced and use them for my main hifi.

I don't want to put them in the post. Does anyone know someone experienced ith valve gear in (or near) Sussex that might be willing to have a look at them? I don't think there is too much wrong with the power amps. They look pretty mint, untouched and have the original valves. One of them does hum a bit though and now it's been running for three hours I can hear that the sound is beginning to distort a bit.

I've not tried the audio section of the 22 Control Unit and have only rigged it up to provide power to the Quad IIs. I am not certain why I need this as my network music player seems to work OK directly into the power amps (although probably doesn't go as loud as it might). I'd like to try it (in stereo) though but can't figure out which inputs to use, radio 1, radio 2, tape, those funny din ones marked PU. I assume that the output of the network music player is the same as a conventional CD player (except of course it has a volume control!).

If I do not have to use the Quad 22 Control Unit as a pre-amp I'm a bit stuck on what to do about a power supply. Does anyone know if there if a suitable off-the-shelf power supply exists?

Any help with this would be gratefully received and very much appreciated.

Simon Turner
Lewes, East Sussex

GrimJosef · 17th Jan 2010, 11:16 am

First let me say congratulations. These are beautiful amps and they would have cost you a pretty penny if you'd had to buy them on the open market.

Second, you're correct - if they've not been touched for years then they will almost certainly need some attention. They have a strong tendency to develop small faults (mostly capacitors, but also resistors and valves sometimes) which are easy and inexpensive to fix but which can cause major and very expensive failures if not dealt with. Frankly I'd recommend that you don't switch them on any more until they've been looked over, particularly if one of them is starting to distort.

They can be posted without too much risk provided you can extract the valves without damaging them (generally quite easy unless the glass envelope of any of the KT66s or the GZ32/34s has come loose on its base). But they're heavy, so it's not cheap of course.

Third , again you're right in suspecting that you don't need the 22 pre-amp. You can simply detach the two-pin Bulgin connectors from the leads which comes from the 22 and wire them direct to mains leads of their own. You don't need a special power supply. However for safety's sake you ABSOLUTELY DO NEED TO MAKE SURE THAT YOU GET THE AMPS' EARTHING ARRANGEMENTS SORTED OUT. Even if you use the 22 these can be a bit suspect. The earth is normally connected via the 6-pin Jones connector which can quite easily pull out. While you're trying to work out why the music's stopped you might well touch the un-earthed amp. Not recommended. And of course the Bulgin mains connectors don't meet modern safety standards. If this worries you, and if you don't mind changing the amps' cosmetics, you can get a modern IEC connector fitted instead which will give you much more peace of mind. (Keep all the original bits though, in case a purist should ever want to restore them.)

You can get the 22 restored if you want. You'll then have a complete set of bits which can look very good. However the 22 is more complex than the power amps, the moving parts (switches and pots) are more prone to wear and failure and the insides are more cramped and fiddly to work on. So professional work on the pre-amp is likely to be pricey. If you want to get the full volume out of the power amps you will need some kind of active pre (the IIs are unusually insensitive, so they need plenty of drive signal - 1.4V rms is the spec). And you'll also need a lead made up with a 6-pin Jones connector on one end, or you can buy phono-to-Jones adaptors. Many people think that the 22 isn't very well-matched to modern sources and prefer to use a modern pre-amp instead. But in the end the choice is yours of course.

I don't know of a restorer in Sussex (that's not to say there aren't any, I just don't know of them). If you get stuck and fancy a drive to South Oxon I could sort the amps out for you. I'm afraid the pre would take more time than I have spare though.

Cheers,

GJ

oldticktock · 17th Jan 2010, 11:29 am

Hi Simon,

I used to live in Saltdean, not far from you before relocating up north. I know of a chap who is in Worthing, I will PM you his details.

P.S.
I miss all the great flea markets and antique shops in Lewes, I was there most days hunting the bargains.

Regards
OTT

yestertech · 17th Jan 2010, 5:39 pm

Simon, have sent you a PM - ANDY

Simon Turner · 18th Jan 2010, 4:45 pm

Thanks for all of these replies.

I have done a fair bit of research since posting this and come across Dc ~ Daylight (http://www.dc-daylight.ltd.uk/Valve-...-and-Info.html). I've yet to absorb the info properly but I am beginning wonder if I might get a few simple things sorted out myself before deciding if it is worth going any further and/or using a professional. One of the things I have to understand first if the only source I want to use with it, Logitech's not-yet-in-the-shops Touch:

http://www.logitechsqueezebox.com/pr...box-touch.html

is powerful enough to drive the input of the power amps. The device has a pre-amp of sorts (it has a volume control) but somehow I doubt if it's enough to optimally drive the input of the Quad IIs. I am attempting to get specs for the analogue out but imagine it is pretty much the same as it's predecessor the SB3 which is quoted as full 6.0Vpp line-level signal output.

BTW, thank's very much GrimJosef for your input. Due to your post I realised that I am using the amps entirely unearthed (gulp)! I need to get the mains supply and a power switch sorted as a priority as I do not want to involve the 22 Control Unit in my proposed set up. I'm going to look at replacing the voltage switcher with a modern mains IEC socket and switch (without altering the chassis hopefully) a la DC ~ Daylight mod, as a priority!

I have swapped the valves over from one amp to the other and this has stopped the hum and distortion (how does that work

). It now sounds very sweet again. I've also tried them with a friends Shahinian Arcs (which they are not really powerful enough to drive correctly) and the sound was quite sublime.

BTW. If I am to rekindle my early aborted career in electronic engineering (after a thirty year gap) where is the best place to buy bits nowadays? Is it still Radio Spares?

I've posted a photo below of my temporary (and unearthed) set up. The Quad IIs are plugged into the black Linn speaker(s). The USB drive on top of the Sony tape deck holds about 2,000 (losslessly ripped) albums..

Simon

ppppenguin · 18th Jan 2010, 8:21 pm

If nothing else please replace the pair of 100n caps that feed the grids of the KT66s. If either of these is leaky you can easily damage the KT66s, the output transformer, smoothing choke or mains transformer. All of these are expensive.

Schematic can easily be seen as a link from this page:
http://www.drtube.com/audioamp.htm#Quad

RS (was Radiospares) and Farnell are still major suppliers of components. Now joined by Rapid and Maplin.

leungch · 2nd Feb 2010, 6:03 am

The attached photos is the current modification, please help to comment also.

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Herald1360 · 3rd Feb 2010, 12:23 am

Not sure exactly what is asked here..... maybe start a new thread with a more specific request?

Just looking at the pictures- someone has done a neat job of replacing the old capacitors and resistors. Silver lead out paper in oil is a bit audiophool OTT for my tastes, but probably sound enough electrically. The electrolytic across the cathode resistor might usefully bit a bit further away from the heat, (as it was in the original layout), but if it's a 105C rated part it'll probably be OK for now.

Over to the experts......

Chris

17th Jan 2010, 2:18 am	#1
Simon Turner Retired Dormant Member Join Date: Jan 2010 Location: Lewes, East Sussex, UK Posts: 2	Quad II & 22- advice needed (and service in Susssex area?) Hello, I'm hoping that someone might be able to help me. I've had a couple of Quad IIs, a 22 Control Unit and a Tuner in my loft for a few years (actually decades). I've just fixed the Quad IIs up to some old Linn speakers and fed a network music player directly into them. The lush, rich sound has bowled me over. I'd like to get them serviced and use them for my main hifi. I don't want to put them in the post. Does anyone know someone experienced ith valve gear in (or near) Sussex that might be willing to have a look at them? I don't think there is too much wrong with the power amps. They look pretty mint, untouched and have the original valves. One of them does hum a bit though and now it's been running for three hours I can hear that the sound is beginning to distort a bit. I've not tried the audio section of the 22 Control Unit and have only rigged it up to provide power to the Quad IIs. I am not certain why I need this as my network music player seems to work OK directly into the power amps (although probably doesn't go as loud as it might). I'd like to try it (in stereo) though but can't figure out which inputs to use, radio 1, radio 2, tape, those funny din ones marked PU. I assume that the output of the network music player is the same as a conventional CD player (except of course it has a volume control!). If I do not have to use the Quad 22 Control Unit as a pre-amp I'm a bit stuck on what to do about a power supply. Does anyone know if there if a suitable off-the-shelf power supply exists? Any help with this would be gratefully received and very much appreciated. Simon Turner Lewes, East Sussex

17th Jan 2010, 11:16 am	#2
GrimJosef Dekatron Join Date: Sep 2007 Location: Oxfordshire, UK. Posts: 4,311	Re: Quad II & 22- advice needed (and service in Susssex area?) First let me say congratulations. These are beautiful amps and they would have cost you a pretty penny if you'd had to buy them on the open market. Second, you're correct - if they've not been touched for years then they will almost certainly need some attention. They have a strong tendency to develop small faults (mostly capacitors, but also resistors and valves sometimes) which are easy and inexpensive to fix but which can cause major and very expensive failures if not dealt with. Frankly I'd recommend that you don't switch them on any more until they've been looked over, particularly if one of them is starting to distort. They can be posted without too much risk provided you can extract the valves without damaging them (generally quite easy unless the glass envelope of any of the KT66s or the GZ32/34s has come loose on its base). But they're heavy, so it's not cheap of course. Third , again you're right in suspecting that you don't need the 22 pre-amp. You can simply detach the two-pin Bulgin connectors from the leads which comes from the 22 and wire them direct to mains leads of their own. You don't need a special power supply. However for safety's sake you ABSOLUTELY DO NEED TO MAKE SURE THAT YOU GET THE AMPS' EARTHING ARRANGEMENTS SORTED OUT. Even if you use the 22 these can be a bit suspect. The earth is normally connected via the 6-pin Jones connector which can quite easily pull out. While you're trying to work out why the music's stopped you might well touch the un-earthed amp. Not recommended. And of course the Bulgin mains connectors don't meet modern safety standards. If this worries you, and if you don't mind changing the amps' cosmetics, you can get a modern IEC connector fitted instead which will give you much more peace of mind. (Keep all the original bits though, in case a purist should ever want to restore them.) You can get the 22 restored if you want. You'll then have a complete set of bits which can look very good. However the 22 is more complex than the power amps, the moving parts (switches and pots) are more prone to wear and failure and the insides are more cramped and fiddly to work on. So professional work on the pre-amp is likely to be pricey. If you want to get the full volume out of the power amps you will need some kind of active pre (the IIs are unusually insensitive, so they need plenty of drive signal - 1.4V rms is the spec). And you'll also need a lead made up with a 6-pin Jones connector on one end, or you can buy phono-to-Jones adaptors. Many people think that the 22 isn't very well-matched to modern sources and prefer to use a modern pre-amp instead. But in the end the choice is yours of course. I don't know of a restorer in Sussex (that's not to say there aren't any, I just don't know of them). If you get stuck and fancy a drive to South Oxon I could sort the amps out for you. I'm afraid the pre would take more time than I have spare though. Cheers, GJ

17th Jan 2010, 11:29 am	#3
oldticktock Retired Dormant Member Join Date: Nov 2009 Location: Weardale, UK. Posts: 1,981	Re: Quad II & 22- advice needed (and service in Susssex area?) Hi Simon, I used to live in Saltdean, not far from you before relocating up north. I know of a chap who is in Worthing, I will PM you his details. P.S. I miss all the great flea markets and antique shops in Lewes, I was there most days hunting the bargains. Regards OTT

17th Jan 2010, 5:39 pm	#4
yestertech Nonode Join Date: Dec 2002 Location: Coulsdon, Surrey, UK. Posts: 2,130	Re: Quad II & 22- advice needed (and service in Susssex area?) Simon, have sent you a PM - ANDY

18th Jan 2010, 4:45 pm	#5
Simon Turner Retired Dormant Member Join Date: Jan 2010 Location: Lewes, East Sussex, UK Posts: 2	Re: Quad II & 22- advice needed (and service in Susssex area?) Thanks for all of these replies. I have done a fair bit of research since posting this and come across Dc ~ Daylight (http://www.dc-daylight.ltd.uk/Valve-...-and-Info.html). I've yet to absorb the info properly but I am beginning wonder if I might get a few simple things sorted out myself before deciding if it is worth going any further and/or using a professional. One of the things I have to understand first if the only source I want to use with it, Logitech's not-yet-in-the-shops Touch: http://www.logitechsqueezebox.com/pr...box-touch.html is powerful enough to drive the input of the power amps. The device has a pre-amp of sorts (it has a volume control) but somehow I doubt if it's enough to optimally drive the input of the Quad IIs. I am attempting to get specs for the analogue out but imagine it is pretty much the same as it's predecessor the SB3 which is quoted as full 6.0Vpp line-level signal output. BTW, thank's very much GrimJosef for your input. Due to your post I realised that I am using the amps entirely unearthed (gulp)! I need to get the mains supply and a power switch sorted as a priority as I do not want to involve the 22 Control Unit in my proposed set up. I'm going to look at replacing the voltage switcher with a modern mains IEC socket and switch (without altering the chassis hopefully) a la DC ~ Daylight mod, as a priority! I have swapped the valves over from one amp to the other and this has stopped the hum and distortion (how does that work). It now sounds very sweet again. I've also tried them with a friends Shahinian Arcs (which they are not really powerful enough to drive correctly) and the sound was quite sublime. BTW. If I am to rekindle my early aborted career in electronic engineering (after a thirty year gap) where is the best place to buy bits nowadays? Is it still Radio Spares? I've posted a photo below of my temporary (and unearthed) set up. The Quad IIs are plugged into the black Linn speaker(s). The USB drive on top of the Sony tape deck holds about 2,000 (losslessly ripped) albums.. Simon Attached Thumbnails Last edited by Brian R Pateman; 18th Jan 2010 at 7:18 pm. Reason: Embedded image converted to thumbnail.

18th Jan 2010, 8:21 pm	#6
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: Quad II & 22- advice needed (and service in Susssex area?) If nothing else please replace the pair of 100n caps that feed the grids of the KT66s. If either of these is leaky you can easily damage the KT66s, the output transformer, smoothing choke or mains transformer. All of these are expensive. Schematic can easily be seen as a link from this page: http://www.drtube.com/audioamp.htm#Quad RS (was Radiospares) and Farnell are still major suppliers of components. Now joined by Rapid and Maplin.

2nd Feb 2010, 6:03 am	#7
leungch Retired Dormant Member Join Date: Feb 2010 Location: Oscar By the Sea, TKO, Hong Kong Posts: 1	Re: Quad II & 22- advice needed (and service in Susssex area?) The attached photos is the current modification, please help to comment also.

3rd Feb 2010, 12:23 am	#8
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Quad II & 22- advice needed (and service in Susssex area?) Not sure exactly what is asked here..... maybe start a new thread with a more specific request? Just looking at the pictures- someone has done a neat job of replacing the old capacitors and resistors. Silver lead out paper in oil is a bit audiophool OTT for my tastes, but probably sound enough electrically. The electrolytic across the cathode resistor might usefully bit a bit further away from the heat, (as it was in the original layout), but if it's a 105C rated part it'll probably be OK for now. Over to the experts...... Chris