View Full Version : Quad II with a 33 preamp
I have recently taken possession of a pair of Quad II valve power amplifiers and is seeking advice on a suitable preamp to partner these Quad II power amplifiers.
How good is the vintage Quad 22 preamp without spending silly money in upgrading the components for little gain in sound quality?
Not sure if it is worth the costs as I have read that the 22 needs a lot of work and a better option would be to go for a modern preamp from other manufacturers. My budget is a modest £500.
I am also exploring the options of possibly using older preamps from the Quad stable such as the 34/44. Again these would need upgrading too for better sonic performance.
I do have an aging 33 that I can be using until a better preamp is bought for the permanent set up. However I am confused with how to connect the 33 to the valve power amps.
The 33 has 2 switched AC mains outlet sockets supplying power using a 2 flat pin (very similar to the American style 2 pin power plug). I assume that these will be fed to the Bulgin plug that is fitted to the Quad II valve amps.
The Quad II are also fitted with a single phono socket replacing the 6 pin Jones connector Where do I connect this to the 33
..which Din input socket?
Another point of clarification regarding the power supply would the Quad II be normally connected to the power socket and not directly to the 33 preamp if another brand of preamp was used.
I look forward to hearing your advice on the above. Thank you in advance.
Peter
Rare Bird
13-09-2012, 22:26
Concordant 'Excelsior' or the loverly Rose Industries 'RV-23S' id have thought would be nice..
I have recently taken possession of a pair of Quad II valve power amplifiers and is seeking advice on a suitable preamp to partner these Quad II power amplifiers.
How good is the vintage Quad 22 preamp without spending silly money in upgrading the components for little gain in sound quality?
Not sure if it is worth the costs as I have read that the 22 needs a lot of work and a better option would be to go for a modern preamp from other manufacturers. My budget is a modest £500.
I am also exploring the options of possibly using older preamps from the Quad stable such as the 34/44. Again these would need upgrading too for better sonic performance.
I do have an aging 33 that I can be using until a better preamp is bought for the permanent set up. However I am confused with how to connect the 33 to the valve power amps.
The 33 has 2 switched AC mains outlet sockets supplying power using a 2 flat pin (very similar to the American style 2 pin power plug). I assume that these will be fed to the Bulgin plug that is fitted to the Quad II valve amps.
The Quad II are also fitted with a single phono socket replacing the 6 pin Jones connector Where do I connect this to the 33
..which Din input socket?
Another point of clarification regarding the power supply would the Quad II be normally connected to the power socket and not directly to the 33 preamp if another brand of preamp was used.
I look forward to hearing your advice on the above. Thank you in advance.
Peter
Hi Peter,
Currently, I am using a 2nd hand QUAD QC-24 in driving a pair of Ls3/5a with very good results. Actually, I have just found one on ebay UK asking for £550. The results would be better if you upgrade some of the component inside. What do you think ?:scratch:
Cheers
Kenneth
Concordant 'Excelsior' or the loverly Rose Industries 'RV-23S' id have thought would be nice..
That Excelsior preamp is a great vintage amp shame that these are rarely available here in the UK.
Thank you for you suggestions.
Peter
Hi Peter,
Currently, I am using a 2nd hand QUAD QC-24 in driving a pair of Ls3/5a with very good results. Actually, I have just found one on ebay UK asking for £550. The results would be better if you upgrade some of the component inside. What do you think ?:scratch:
Cheers
Kenneth
The QC-24 on sale is collection only. Does it come with a remote control?
The Quad IIs have been upgraded by the previous owner so hopefully should not require any further work in the foreseeable future. Just want to fire them up with the correct connection to the 33:).
StanleyB
14-09-2012, 21:45
The 33 uses some nastly CMOS 4066 ( or 4016) ICs to do the audio routing. Just to get and idea of how much that IC robs from the signal you should try bridging the signal across it. The ON resistance of the chip used in the original production was several tens of Ohms.
Hooking a 22 onto it won't produce the sort of sound that the 22 is capable of when matched to a better preamp. The Q33 gets my vote for one of the worst audio switching method for such a nice looking unit.
Rare Bird
14-09-2012, 22:58
Since when has 'Q33' used CMOS IC's?
Stan, you may mean the 34 and/or the 44, both of which can be upgraded/refurbished by the likes of the Dada kits into something very nice indeed and perfect for the II's. The 33 in stock form, in my opinion as a bodger of same and end user, is that it's just too old and now does affect the sound passing through it quite noticeably. The net-Audio boards turn it into something quite different however, but by then you've spent silly money...
From personal CURRENT experience, may I suggest any of the preamps made by Glenn Croft? The Micro Basic is a tad "raw" in presentation, ALWAYS putting the music first and being hopefully as reliable and long lived as the II's themselves. Perfect for balancing the over-romantic sounds of the II's, the end being more than the sum of the parts in my experience.
Glen Croft products are very well regarded with great reviews. I would love to try one with the Quad IIs. Anyone here have any experience with this combo?
phoenixpete
15-09-2012, 12:59
I used to use a Quad 44 when I had my IIs, the 44 has the 3 different connections for various power amps and I think mine had the outputs for the quad II's, 303 and the 405 power amps.
I had mine connected up to 2 303's and my pair of II's as in the picture.
Why did I sell all of that stuff :mental:
http://i131.photobucket.com/albums/p294/phoenixpete_2006/Kef105-4.jpg
Glen Croft products are very well regarded with great reviews. I would love to try one with the Quad IIs. Anyone here have any experience with this combo?
I think Joe Blackadder used a Croft micro basic with Croft-modified Quad IIs not so long back.
Glen Croft products are very well regarded with great reviews. I would love to try one with the Quad IIs. Anyone here have any experience with this combo?
YES!!!!!!!!!!!!!!!!!!!!!
:lol: :eyebrows: :lol: :eyebrows: :eek: :ner: :ner: :ner: :cool: :cool: :cool:
http://i132.photobucket.com/albums/q8/DSJR_photos/432688db.jpg
hifi_dave
16-09-2012, 08:51
Glen Croft products are very well regarded with great reviews. I would love to try one with the Quad IIs. Anyone here have any experience with this combo?
Yes, over the years have often used and sold Croft pre's for use with Quad II and they sound great.
Thanks for all the comments so far.
Can anyone point me in the right direction regarding cable connection from the Quad IIs to the 33 preamp please:)
Would like to hear the IIs in working condition first before buying a new preamp.
Thanks
Peter
Rare Bird
16-09-2012, 09:29
http://i132.photobucket.com/albums/q8/DSJR_photos/432688db.jpg
Hi Dave
How much do those 'Super Micro' fetch these days?
Over £200 I think. Mines the Holco equipped 4SA-PP model, with a similar-to-R-level performance, all bar the single transformer in mine - the power supplies are very similar in general layout IMO.
ANY old Croft preamp is worth getting and if there's any doubt, get it back to Glenn for a thorough going over. Mine's been half done by myself under Glenn's instruction, but the phono stage updates and possibly power supply ones, will have to be done by the man himself. Should turn it into summat really special then I reckon, but since it's in such regular use, I haven't the heart to disconnect it and send it away for a few weeks.....
thebeathunters
20-09-2012, 10:29
hi quad fans
:D i don't mean to pollute the thread but as we're on quad II's and preamps ... i just have an opportunity to grab a nice pair of thoroughly serviced quads II with good-measured GECs, which is quite tempting... as i always had a soft spot for these
plan is to plug my variable linn genki cdp (output 2,2v) directly to them - as i do with other - tube or not - power amps.
but i know these quads are somehow tricky. there's that "negative feedback" between them and preamp i don't really understand (i'm a technically-challenged person) and the ground is probably a problem too and i read that passive pre can't play with them either...
so wha'ts your take and suggestions on this? what mods should be done to keep it real and simple? thanks :)
Hi Quad fans
:D i don't mean to pollute the thread but as we're on quad II's and preamps ... I just have an opportunity to grab a nice pair of thoroughly serviced Quads II with good-measured GECs, which is quite tempting... as I always had a soft spot for these
plan is to plug my variable linn genki cdp (output 2,2v) directly to them - as I do with other - tube or not - power amps.
but I know these Quads are somehow tricky. There's that "negative feedback" between them and preamp I don't really understand (I'm a technically-challenged person) and the ground is probably a problem too and I read that passive pre can't play with them either...
so wha'ts your take and suggestions on this? what mods should be done to keep it real and simple? thanks :)
Despite using Quad solid-state gear for much of my 'career', I have owned and used Quad 22/II valve gear on two occasions. There is no problem with using a solid state pre with the Quad IIs: I have run them with Quad 33 and 44 preamps, as well as a Hafler DH101 pre. To achieve full output from the Quad IIs the input sensitivity is, I believe, 1.4V. You won't get this from the Quad 33, but your Linn Genki, with it's output of 2.2V ought to be fine.
I don't know of the "negative feedback" between the Quad IIs and the preamp to which you refer. As far as I can tell (looking at the schematics for both) there is no negative feedback.
The chassis of the Quad II amps are grounded via the screening of the coaxial cable joining them to the preamp (pin 1 of the 6-way Jones socket). This arrangement is frowned upon these days. Personally I am quite happy with this arrangement - it is perfectly safe, provided your Linn Genki is itself earthed (that is, has a three core mains lead). If not, then you will have to provide a separate ground wire connected between the metal chassis of the Quad IIs and the mains earth.
Using a passive pre with the Quad IIs ought to work (as well as any passive pre does), as the input impedance of the Quad IIs is very high (1.5MOhm), but I have no experience of using such an arrangement. Success in using a passive pre will depend on the output impedance of your Linn Genki.
Trust this is of some help.
thebeathunters
20-09-2012, 13:59
Despite using Quad solid-state gear for much of my 'career', I have owned and used Quad 22/II valve gear on two occasions. There is no problem with using a solid state pre with the Quad IIs: I have run them with Quad 33 and 44 preamps, as well as a Hafler DH101 pre. To achieve full output from the Quad IIs the input sensitivity is, I believe, 1.4V. You won't get this from the Quad 33, but your Linn Genki, with it's output of 2.2V ought to be fine.
I don't know of the "negative feedback" between the Quad IIs and the preamp to which you refer. As far as I can tell (looking at the schematics for both) there is no negative feedback.
The chassis of the Quad II amps are grounded via the screening of the coaxial cable joining them to the preamp. This arrangement is frowned upon these days. Personally I am quite happy with this arrangement - it is perfectly safe, provided your Linn Genki is itself earthed (that is, has a three core mains lead). If not, then you will have to provide a separate ground wire connected between the metal chassis of the Quad IIs and the mains earth.
Using a passive pre with the Quad IIs is probably not a good idea, as the input impedance of the Quad IIs is not high enough.
Trust this is of some help.
hi barry
:) thanks for your feedback and good news! as long as the genki can play on it with my tannoys, i'll be happy
i'm sometimes using a small QED passive with my 8b instead of direct plug. i'm not sure i hear much difference between the variable volume of the genki and the QED anyway...
i guess if it fits the 8b it should please the quads
about ground
what i find odd is that the pre/amps are grounded in the first place. my early sixties vintage gear isn't (fisher, marantz, heathkits...)
what i discovered lately is that all main lines in my living room - house built in the 70's - aren't grounded. only some plugs in the kitchen and bathroom are, as were the norms back then (in france i mean).
so the linn has a 3-core IEC mains leads indeed, connected to a solid schuko ramp plugged to the wall mains - ungrounded - line...:D
hi barry
:) thanks for your feedback and good news! as long as the genki can play on it with my tannoys, i'll be happy
i'm sometimes using a small QED passive with my 8b instead of direct plug. i'm not sure i hear much difference between the variable volume of the genki and the QED anyway...
i guess if it fits the 8b it should please the quads
about ground
what i find odd is that the pre/amps are grounded in the first place. my early sixties vintage gear isn't (fisher, marantz, heathkits...)
what i discovered lately is that all main lines in my living room - house built in the 70's - aren't grounded. only some plugs in the kitchen and bathroom are, as were the norms back then (in france i mean).
so the linn has a 3-core IEC mains leads indeed, connected to a solid schuko ramp plugged to the wall mains - ungrounded - line...:D
Maybe your '60s gear was double insulated, in which case you would not need an earth (ground connection). However the Quads are not double insulated, so the metalwork must be grounded. If a fault developed the metalwork could become live and dangerous. Not to earth it puts you and your family at risk. I would implore you to have a qualified electrician install grounded Schuko mains connectors for you audio gear.
You really are running a risk not to do so.
thebeathunters
20-09-2012, 18:12
thanks barry for your concern
i'll take care of it asap. i wasn't much aware of it until i became involved with vintage and tube amps.
thanks barry for your concern
i'll take care of it asap. i wasn't much aware of it until i became involved with vintage and tube amps.
You're welcome Phil. :)
I think that, back in the day, the II's were hidden away, usually in a huge cabinet which housed the turntable and preamp/tuners and sometimes a tape machine as well.
My AVI preamp has a bandwidth tested as out to 300kHz or so (HFN review). It drives the II's perfectly, but I was worried about the excessive bandwidth of the pre, and any possible high level ultra-sonic mush that may find its way down the interconnects.. Having said that, the Croft preamp I have goes up to around 100kHz before severe rolloff and it sounds great..
The Black Adder
21-09-2012, 09:30
Glen Croft products are very well regarded with great reviews. I would love to try one with the Quad IIs. Anyone here have any experience with this combo?
I did indeed Martin.. I used a Croft basic pre (current model) with my Crofted Quad II's with superb results... You simply can't go wrong.
The 25 is much more refined if you fancy that. I now use the 25 with a 7R+
I also had a Quad QC-24 and that was very nice, lovely and warm sounding... but beware of hum on some units, mine and someone else at the time on another forum were not very happy with them. It can be fixed but at the time I wasn't impressed with the money I spent on it. I think I paid £600.
Adrian at Audioflair was superb with me regarding the Croft gear.
Another vote for the Croft preamp. Will consider this when it's time for the permanent set up.
In the mean time - Still no joy in figuring out how to connect the IIs to the 33.:scratch:
Anyone ??
Another vote for the Croft preamp. Will consider this when it's time for the permanent set up.
In the mean time - Still no joy in figuring out how to connect the IIs to the 33.:scratch:
Anyone ??
The 4-pin Din socket on the Quad 33 is wired as follows:
pin 1: left-hand channel
pin 3: right-hand channel
pin 2: common earth (ground connection)
(pin 4 has +15v on it, do not connect anything to this)
The 6-way 'Jones' connector on each Quad II power amp is wired as follows:
pin 1: earth (and chassis ground)
pin 2: input.
(do not connect to any of the other pins).
Use good quality screened cable, preferably coaxial with a substantial screen (as this doubles up as the safety grounding for the Quad II chassis/metalwork).
Trust this is of help
Ask Flashback Cables, as I think they make good quality interconnects with 4 pin "Quad wired" DIN to Jones plugs. If you have any doubt regarding making your own cable up, get a professional to do it for you!
Audioflyer
21-09-2012, 19:27
I'm in the process of updating a quad 22 preamp, so far I replace the back panel and started to rewire the switch bank.
The EF86 stage has been removed and will be replace with the Salsa phonostage (Diyaudio), the ECC83 stage will remain as will the tone controls
When I have a bit more time I'll start a new thread under the DIY section.
If you want to try this with the Quad 22 preamp try inputting a source into the tape out socket as this bypasses the EF86, make sure that all the maroon button are in the out position.
I've also tried a Quad 33 preamp with the Quad 11 but found the sound was a bit fat in the bass and not very detailed also there was not enough gain.
Sharif.
The 22 was so veiled sounding on all inputs though :(
Audioflyer
21-09-2012, 19:35
That's because they all went through the EF86 if you use the tape out as an input this goes straight into the volume control and then feed the ECC83 buffer stage.
The 4-pin Din socket on the Quad 33 is wired as follows:
pin 1: left-hand channel
pin 3: right-hand channel
pin 2: common earth (ground connection)
(pin 4 has +15v on it, do not connect anything to this)
The 6-way 'Jones' connector on each Quad II power amp is wired as follows:
pin 1: earth (and chassis ground)
pin 2: input.
(do not connect to any of the other pins).
Use good quality screened cable, preferably coaxial with a substantial screen (as this doubles up as the safety grounding for the Quad II chassis/metalwork).
Trust this is of help
Would appreciate more clarification please:
a) My Quad IIs have had the 6-way 'Jones' connector replaced with a single phono socket (see photo below) how is this connected to the 33?
http://i46.tinypic.com/35i6qkz.jpg
b) Power supply is this from the Bulgin plug to a power point via a 2 core power flex cable connected to a 3 pin plug and not directly to the 33?
Thanks.
Peter
Peter, you will have to wire up a 4-pin DIN plug with two lengths of coaxial cable as follows:
(a) inner core of one coaxial cable used for the left-hand channel to Pin 1
(b) inner core of second coaxial cable to feed right-hand channel to Pin 3
(c) the screens of both coaxial cables connected together at Pin 2.
The other end of the coaxial cable will have to be fitted with a phono plug to connect with each input socket of your modified Quad II amps.
As Dave (DSJR) has mentioned, Flashback Sales make such a lead, and I would recommend you contact them. They are very helpful and can make the lead as long as you like. 4-pin DIN plugs are difficult to find and all DIN plugs are fiddly to solder up. http://www.flashbacksales.co.uk/acatalog/din-phono-rca-audio-cables.html
The 2-pin Bulgin connectors supply the mains transformers of the Quad IIs. In order to be able to switch the power amps on with the Quad 33, you would need to wire up each Bulgin connector with 2-core cable and fit an American 2-prong plug at the preamp end. The American-style plugs will be plugged into the switched mains outlets at the rear of the Quad 33 (there are two of them).
There are two important points to be made:
(1) The American-style plugs are now outlawed in the EU and are now difficult to find, though I believe Maplin sell them.
(2) The chassis of each Quad is earthed via the screening of the signal cable. It is therefore important this is of high integrity, that is, use a coaxial cable with a substantial braided screen and good quality phono plugs (I would recommend Neutrix Profi.) This arrangement is now frowned upon, and it certainly does not conform to modern standards, where all mains powered items have now to be fitted with a three-way connector (unless the item is double insulated). If you run a separate wire between the metal work of each Quad II chassis back to either the earth terminal on the back of the Quad 33, or to the earth pin of a 13A mains plug, you run the risk of creating a hum loop. If you want to do this I would recommend you physically run the earth wires along the signal cables using either 'tie wraps' or better still 'spiwrap'. That way, you will minimise any hum pick up.
Finally, I ought to mention again the full output from the Quad 33 preamp is 0.5V. The Quad II needs 1.4V for full output, so the Quads will be under run and the combination may not be sufficient for your speakers. I have tried this combination in the past (with Quad ESL speakers) and found there was insufficient power available.
Barry,
Thanks again for the very detailed information provided. I was hoping it would be an 'easy' job to connect the IIs to the 33 - The joy of vintage equipment:lol:
As it was a temporary arrangement to partner the IIs with 33 so that I can check the condition/performance of the power amplifiers. They were last used by the previous owner over 10 years ago.
I think the sensible option would be to go down the modern route. Croft has been mentioned as a very good pre-amp for use with the IIs. It will be on my shortlist of pre-amps to demo.
I am also quite fond of the design of the 66 pre-amp - Is this any good and worth considering and a simpler connection to the IIs:).
Thanks.
Peter
I would endorse the use of Croft preamp. They are very well regarded by many of the members here, and whilst I do not use one myself, I have heard one (not sure which model, Marco will be able to let you know), and if I wanted a valve preamp would most likely choose a Croft.
As for the Quad 66, I heard a Series 6 system with ESL 63 speakers many years ago. It would suit your Quad II amps better than the 33, as the output of the 66 can be increased from the nominal 0.5V to 1.35V. The mains connectors are the modern EU miniature 3-pin style, though only one socket fitted. If you can find a Quad 66 (complete with remote) in good condition, then it would seem to be a viable option, though I have not heard a 66/II combination myself.
Regards
The 66 preamp is delightful, with a lightness of touch rarely found in ss gear. I'm sure there's a power supply in the box somewhere, but it's well hidden as I remember :lol:
Some 66 pre's have a few too many internal dry joints by now, so choose carefully.
Just had a look at images of the 66 and noticed that there is no control buttons on the unit so the use of that 'large' remote would be the only way to operate the pre-amp. At least it won't be lost behind the sofa:lol:
The 44 is another model that I would consider and again should have a simpler connection with the IIs. How does this compare with the 66?
Ah! - now that is one combination I have tried. If you want to use a Quad 44, try to find one of the later models (with the grey coloured case and buttons and missing the 'cancel' LED ). This is for two reasons:
(a) it sounds better than the early models (due to a redesign of the mother board),
(b) it has three outputs: 0.5V, 1.5V and 5V. The 1.5V output is via phono connectors, so you won't have any problems with the signal leads.
The Quad 44 has three IEC mains sockets to power your Quad IIs.
Barry, my memory is bad on this :eek: but did the later 44's have the three output levels? I seem to feel that the better sounding later model simplified these things quite a lot. As it is, i always felt the 44 sounded "best" from the high output sockets, even into a 405.....
Barry, my memory is bad on this :eek: but did the later 44's have the three output levels? I seem to feel that the better sounding later model simplified these things quite a lot. As it is, I always felt the 44 sounded "best" from the high output sockets, even into a 405.....
Hi Dave,
Yes, the later Quad 44 had three outputs, each at a different voltage. The 4-pin DIN socket provided 0.5V output and two sets of phono connectors provided an output of 1.6V and 5V.
Towards the end of the production run, Quad dispensed with the DIN connectors both on the input boards as well as for the output. I believe the choice of the three output voltage levels was retained; that at 0.5V being via a third set of phono connectors.
Apropos your comment about the 44 sounding better when feeding a 405 power amp from its hight output sockets, didn't you run into volume control problem: finding the lowest steps too coarse?
Regards
Who cares when you're young and want volume :lol:
Yeah, it (the volume control) was a bit cramped, but these days, one would reduce the gain on the 405 board, thereby reducing noise and distortion and putting more level through the interconnects, which must be a good thing?
Hi guys,
So tempting to go for the Croft pre-amp but only the basic model is within my budget.
Would this still be a better buy than an older Quad 34/44 ?
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