Quad34/306
- Thread starter Jono_13
- Start date
Tony L
Administrator
Yes.
I use the above 34/306 in my main system driving Tannoy Monitor Golds and like it a lot. It's been fully serviced by Rob and the phono stage lightly tweaked (HPF reduced) and setup for my cart (an Ortofon 2M Black) and it sounds excellent. With the HPF reduced / removed the Quad 34 phono stage is very good IMO, I actually ended up preferring it to an EAR 834P, which more than surprised me to put it mildly. The 306 is a great amp too, punchy, clean, quiet, very well put together and easy to service (doesn't even need biasing etc IIRC).
PS I actually have two 33s, three 34s, a 303 and a 306! In fact I've just bought the last 34 very recently, it's a tatty late grey one which went rather cheaply on eBay. I plan to get Rob to service it and then I'll transplant it's chassis into my mint early bronze colour case so I've got one that aesthetically matches my 303 but has RCA sockets and more sensible gain! It means I've now got a donor one for parts too! I've almost got a working 33 too, there's just something not quite right with the balance control on the good one, I suspect a cap is out somewhere.
I use the above 34/306 in my main system driving Tannoy Monitor Golds and like it a lot. It's been fully serviced by Rob and the phono stage lightly tweaked (HPF reduced) and setup for my cart (an Ortofon 2M Black) and it sounds excellent. With the HPF reduced / removed the Quad 34 phono stage is very good IMO, I actually ended up preferring it to an EAR 834P, which more than surprised me to put it mildly. The 306 is a great amp too, punchy, clean, quiet, very well put together and easy to service (doesn't even need biasing etc IIRC).
PS I actually have two 33s, three 34s, a 303 and a 306! In fact I've just bought the last 34 very recently, it's a tatty late grey one which went rather cheaply on eBay. I plan to get Rob to service it and then I'll transplant it's chassis into my mint early bronze colour case so I've got one that aesthetically matches my 303 but has RCA sockets and more sensible gain! It means I've now got a donor one for parts too! I've almost got a working 33 too, there's just something not quite right with the balance control on the good one, I suspect a cap is out somewhere.
Tony L
Administrator
Just grab it. Assuming it's in good tidy condition the worst thing that can happen is you'll double your money!
Indeed,
I wish I could have found a pair at that price, when I started to look for some Quad gear for a second system a year ago. I think the 34 / 306 is a much underrated combination.
Although I now have an "Amplabs" refurbished 44 / 405-2 / FM4, I still regret my decision to sell the 34 / 306 / FM4 system which I had purchased new in '92, when I thought I was going to leave the U.K. in 2010.
Regards
Mike Kelshaw
I wish I could have found a pair at that price, when I started to look for some Quad gear for a second system a year ago. I think the 34 / 306 is a much underrated combination.
Although I now have an "Amplabs" refurbished 44 / 405-2 / FM4, I still regret my decision to sell the 34 / 306 / FM4 system which I had purchased new in '92, when I thought I was going to leave the U.K. in 2010.
Regards
Mike Kelshaw
hughjampton
pfm Member
I've recently bought a 33/303 to set up a vintage system. I contacted Quad to check on servicing the 303 but they won't uprate the output caps and will just put it back as standard. I know Robert who posts here does that as a matter of course as I think Amplabs do too. But it is nice to get something serviced by the maker...
Nearly twenty years ago I used a 33/303 for a few years and Quad repaired and serviced the 303 for just £50 which was a stonking bargain when you consider what Naim were starting to charge by then. They quote about a hundred now depending of what they find wrong with it.
The speakers I'm going to use are 8 ohm and never go below 6.5 ohm so I wonder if anyone thinks the original rated output caps might be good enough? I can't really see why Quad insist on using exactly the same caps as when it was new, it's not really a modification just using more modern components.
I am toying with letting Amplabs do it and put one of their nice facias on it though which would make it easier to use with another preamp.
mjkelshaw.
What do you think of Amplabs work?
Nearly twenty years ago I used a 33/303 for a few years and Quad repaired and serviced the 303 for just £50 which was a stonking bargain when you consider what Naim were starting to charge by then. They quote about a hundred now depending of what they find wrong with it.
The speakers I'm going to use are 8 ohm and never go below 6.5 ohm so I wonder if anyone thinks the original rated output caps might be good enough? I can't really see why Quad insist on using exactly the same caps as when it was new, it's not really a modification just using more modern components.
I am toying with letting Amplabs do it and put one of their nice facias on it though which would make it easier to use with another preamp.
mjkelshaw.
What do you think of Amplabs work?
Tony L
Administrator
If it sounds ok it probably is ok! Signs of a less than happy 303 are a rather tubby and ponderous bass and a lack of dynamics IME. Mine is entirely stock, Quad serviced and sounds how it should to my ears, but by saying that if I wanted to use a speaker it wasn't happy with I'd just swap-in the 306 instead. For me the magic of the 303 occurs when it's used in it's correct historical context with ESL57s, big Tannoys, old Celestions, LS3/5As, Spendors etc. It's just not the right tool for say a little inefficient modern stand-mount IMO, e.g. I can't imagine it would match something like a pair of Kef LS50s despite their being a superb speaker, whereas I bet a 306 or 606 would. This is the reason I have no preference between my 303 and 306, they are both great amps but are sufficiently different that they fit into a different context.
John_73
pfm Member
Is it the paint that's just scuffed, or the metal as well? I have a spare one here, but it's been stripped and needs priming & painting. You're welcome to it if it's of any use?
John.
John_73
pfm Member
I can only speak for the Q34, but if recapped with good quality items (Panasonic FC/FM for all PSU duties, and Nichicon KZ for signal works really well), and a few caps bypassed altogether, it's surprisingly good, even compared to a passive pre.
Many go OTT with op-amp replacements, but other than the phono stage (possibly!) I really don't think it's necessary. As with a lot of audio, there's better 'on paper', and then there's real-world performance. Those original opamps are perfectly fine.
I run a 34/606 combo and it sounds superb no matter what music I play through it. The 306 is just a lower powered version of the same circuit IIRC, so it should sound equally good into appropriate speaker loads.
John.
hughjampton
pfm Member
Thing is most speakers of the era were around 8 ohm too. I used a pair of KEF104 abs with the 33/303 I had in the nineties and they were 8 ohm and were about the same age as the amps. They worked really well with it BTW. I picked up a nice looking pair of Celef Domestics to use with this system that were being sold nearby and they are a year or two older than the 303.
The Spendors, LS3/5s, Tannoys, et al go for a bit more than I want to pay for what is a third system. Nice that they are.
Robert
Tapehead
On the 303 the regulated power supply imposes a current limit which is why output falls into 4 ohm loads. The 2200uf output cap means that output will be 3dB down at 20Hz. No great shakes but it's first order electrical, so LF is still perceptibly lightened up to around 40Hz.
Subjectively that sound like the amp is a bit weak and lacking punch into such loads. Damping factor is also reduced at these frequencies. By contrast an 8 Ohm loading moves the -3dB point down to 10Hz, and 16 Ohm gives us -3dB at 4.5Hz. So you see why the amp prefers higher impedance loads.
Bump the coupling caps to 6800uf and with 4 Ohms our -3dB point is now at 5Hz and there is no downside. The 303 will still only deliver around 30w into such a load due to the regulated supply but it's now a solid, great sounding 30w.
Subjectively that sound like the amp is a bit weak and lacking punch into such loads. Damping factor is also reduced at these frequencies. By contrast an 8 Ohm loading moves the -3dB point down to 10Hz, and 16 Ohm gives us -3dB at 4.5Hz. So you see why the amp prefers higher impedance loads.
Bump the coupling caps to 6800uf and with 4 Ohms our -3dB point is now at 5Hz and there is no downside. The 303 will still only deliver around 30w into such a load due to the regulated supply but it's now a solid, great sounding 30w.
What do you think of Amplabs work?[/QUOTE]
I am really pleased with the work that Amplabs did on my 44 / 405-2 / FM4. In addition to a complete service I wanted RCA input sockets and 'binding post' outlets fitted to replace the standard arrangement on the 405-2. Rob also replaced the battery on the FM4 with the CPU /Flash memory modification and also removed a 'smudge' on the display.
I had purchased all the units S/H, and they were sent to Amplabs for checking / servicing before being 'switched on'.
After they were returned I connected them to a pair of S/H Celestion SL6S, sat down to listen, and then wondered why I had spent so much on my 'main' system.
Regards
Mike Kelshaw
I am really pleased with the work that Amplabs did on my 44 / 405-2 / FM4. In addition to a complete service I wanted RCA input sockets and 'binding post' outlets fitted to replace the standard arrangement on the 405-2. Rob also replaced the battery on the FM4 with the CPU /Flash memory modification and also removed a 'smudge' on the display.
I had purchased all the units S/H, and they were sent to Amplabs for checking / servicing before being 'switched on'.
After they were returned I connected them to a pair of S/H Celestion SL6S, sat down to listen, and then wondered why I had spent so much on my 'main' system.
Regards
Mike Kelshaw
Changing the output capacitors really is one of the easiest jobs to do on a 303. The change of capacitors doesn't need any other changes to the bias, power supply setup. It's a safe change in that it's easy to put the standard ones back with no obvious stress. The whole job takes less than 1/2 an hour.
Even Quad changed the cap value along the way.
Even Quad changed the cap value along the way.
Shuggie
Trade: Ammonite Audio
I never realised that the 34's volume knob was metal! As far as I can tell, it's the paint that's scuffed - since that is the case, maybe careful touching up with a car paint repair kit would be the most practicable solution.
Tony L
Administrator
Here's the guts of a fairly late 34 if anyone's interested:
A fair bit going on in there! Really nice quality Alps stepped attenuators for the volume and tone controls (let down somewhat by a crappy balance slider!) and all nicely stuck together IMO. This one appears to my eyes to be untouched and is the one I'm planning to get Rob to service, tweak the phono LF roll-off etc and I'll then swap the front casework and transplant the chassis into my early bronze case as a matching partner for the 303. I need to think about gain, output etc a bit as ideally I'd like the combo to be usable with both the La Scalas and the JR149s, and that's a 21db difference in efficiency! It may actually be easier to use attenuator RCA plugs (I've got some Rothwell ones) with the La Scalas as I'm not sure there's enough range on the Quad's stepped attenuator to find a useful compromise.
A fair bit going on in there! Really nice quality Alps stepped attenuators for the volume and tone controls (let down somewhat by a crappy balance slider!) and all nicely stuck together IMO. This one appears to my eyes to be untouched and is the one I'm planning to get Rob to service, tweak the phono LF roll-off etc and I'll then swap the front casework and transplant the chassis into my early bronze case as a matching partner for the 303. I need to think about gain, output etc a bit as ideally I'd like the combo to be usable with both the La Scalas and the JR149s, and that's a 21db difference in efficiency! It may actually be easier to use attenuator RCA plugs (I've got some Rothwell ones) with the La Scalas as I'm not sure there's enough range on the Quad's stepped attenuator to find a useful compromise.
Robert
Tapehead
Here's the guts of a fairly late 34 if anyone's interested:
A fair bit going on in there! Really nice quality Alps stepped attenuators for the volume and tone controls (let down somewhat by a crappy balance slider!) and all nicely stuck together IMO. This one appears to my eyes to be untouched and is the one I'm planning to get Rob to service, tweak the phono LF roll-off etc and I'll then swap the front casework and transplant the chassis into my early bronze case as a matching partner for the 303. I need to think about gain, output etc a bit as ideally I'd like the combo to be usable with both the La Scalas and the JR149s, and that's a 21db difference in efficiency! It may actually be easier to use attenuator RCA plugs (I've got some Rothwell ones) with the La Scalas as I'm not sure there's enough range on the Quad's stepped attenuator to find a useful compromise.
That's the No1 failure in these units and the most frequent cry for help.
The little sprung contacts which contact the track break free of their internal plastic mount, causing loss of one channel. Fortunately the plastic can be heated and reformed to re-seat the contact for a 100% fix.
If you visualise the way the power connections on a train press up against the overhead power line you get some idea of how it works
