View Full Version : FS - Quad 405/2 - Full Net Audio Upgrades
As part of my ongoing clear out of kit surplus to requirements, I have up for grabs my superb late model Quad 405/2 (RCA socket version) with FULL Net Audio Upgrades worth over £350 all undertaken just a few years back. These include:
- New replacement upgraded PCBs with uprated power transistors and upgraded Burr Brown Opamps (604AP);
- Dual mono power supply Caps
- Full Capacitor upgrade
- Rewire
Lovely quiet background (no hiss or hum), oodles of power (100w into 8Ohms) and a very very refined muscular sound. Better than a 909 or 606? I think so.
Rare to get one with such extensive upgrades in such fabulous A1 electrical condition. Casework generally good all bar the odd scrape commensurate with age.
Comes packaged in original box and can be couriered nation wide for £17
Asking a very modest £385ono...absolute bargain for a fully NetAudio'd example!
Oldpinkman
07-06-2013, 13:42
So why are you selling? Interested to know what you are upgrading to. Mine is at the doctors for the minute, but ignoring some silly money options I haven't found better. Certainly the Arcam 10P I am using as a temporary sub is a poor substitute. Did your pimping include internal hard-wiring?
So why are you selling? Interested to know what you are upgrading to. Mine is at the doctors for the minute, but ignoring some silly money options I haven't found better. Certainly the Arcam 10P I am using as a temporary sub is a poor substitute. Did your pimping include internal hard-wiring?
Only reason for selling is that I have 3 amps too many! My better half has strongly suggested that a few pairs of speakers, a few amps and a few tuners are cleared out and she's probably right! Its a cracking amp. Surprising grunt for its size and more refined than the standard 405. In a different league sonically to the standard 405/1. Internal wiring is as Net Audio left it, using their foo wires but terminated using spade connectors. I am happy to hardwire with silver solder for the lucky new owner. The Arcam 10p couldn't really hold a candle to it so not surprised at your findings. There's a few amps I'd like to try (I may be selling some kit but the cash is always reinvested to try something new! Its a hifi merry-go-round).
and up....
Slight reduction to £375 folks but can't afford to sell for any less. That's the cost of the mods and the amp essentially thrown in for free! This thing is a superb sounding amp with real power. It'll drive some fairly difficult loads too. You could buy an origianl and tired 405/1 or 405/2 for £225 then spend another £375 on it to get it to this level, or you could buy this one! Will post anywhere in the UK/Eire
southall-1998
14-06-2013, 13:36
Come on people, this is a nice tweaked Quad 405!!!!
Don't miss out!
Oldpinkman
14-06-2013, 17:01
Can only join the endorsers of this amp. Gagging for mine to come home. Punches way above its weight. But just the one will do for me
Some photos to do this wonderful amp some justice:
Casework is very good for the age with just a few usual signs of light wear commensurate with age but no dings or major scratches:
http://i1140.photobucket.com/albums/n577/24pacman/Hifi/_MG_6941_zps22cc517b.jpg
http://i1140.photobucket.com/albums/n577/24pacman/Hifi/_MG_6942_zps0baffda4.jpg
Rear: shows that this is the latest of the Mk2 405 units using RCAs:
http://i1140.photobucket.com/albums/n577/24pacman/Hifi/_MG_6943_zpsd8916a3f.jpg
Internals: Immaculate as you'd expect for an amp which has had the full NetAudio upgrades: NetAudio Dual Mono power supply upgrades clearly visible (the large blue caps for the dual mono power supply upgrade):
http://i1140.photobucket.com/albums/n577/24pacman/Hifi/_MG_6947_zps0f62f5ad.jpg
http://i1140.photobucket.com/albums/n577/24pacman/Hifi/_MG_6950_zps6cd79f08.jpg
NetAudio Upgraded PCBs: Full cap upgrades, OpAmp upgrades and other major component upgrades including power transistors/resistors
http://i1140.photobucket.com/albums/n577/24pacman/Hifi/_MG_6952_zps72166aab.jpg
Close up of Opamp:
http://i1140.photobucket.com/albums/n577/24pacman/Hifi/_MG_6952R1_zpsd4d25198.jpg
Binding posts/wiring:
http://i1140.photobucket.com/albums/n577/24pacman/Hifi/_MG_6954_zpsb71aab03.jpg
A rare beast. All in all in excellent condition. Electrically 100% perfect and good for another 40 years! A steal at the price. No further reductions considered so £385 firm please.
It's a LATE mk2 case too with proper binding posts and phono sockets :)
Original ones go for ONLY a hundred quid less (the Net-Audio bits ain't cheap) and sorted 606's for rather more. A bloody good amp this one and fantastic with a Croft preamp :lol:
Will somebody pleeeease buy this, as it's burning a hole in my pocket at the moment . . .
http://i173.photobucket.com/albums/w63/greatgig/hide.gif (http://s173.photobucket.com/user/greatgig/media/hide.gif.html)
Rare Bird
23-06-2013, 14:27
Im suprised it aint gone cos those black ones are quite thin on the ground
It's a LATE mk2 case too with proper binding posts and phono sockets
Original ones go for ONLY a hundred quid less (the Net-Audio bits ain't cheap) and sorted 606's for rather more. A bloody good amp this one and fantastic with a Croft preamp
I agree David. It's as good as a 405 gets imho and I prefer it to some of the later (Chinese made) 909s. I also prefer it over a stock 606 which can sound a little dull by comparison. Superb with the Croft and superb driving ESLs for which I understand it was originally intended.
Will somebody pleeeease buy this, as it's burning a hole in my pocket at the moment . . .
it's futile Tim....listen to the Force....buy it, you know you want it :yesbruv:
Im suprised it aint gone cost those black ones are quite thin on the ground
They're even rarer in this condition and to this high spec. I'm not to concerned if it doesn't go as it's one of those classic pieces of kit that deserves the great reputation it's earned, so if it stays with me for the foreseeable, I'll not be losing any sleep.
606mk1's are funny things, often needing a couple of hours before the grain disappears. The mk2's had a larger reservior supply and maybe this helped as the rest was similar IIRC. Oh, the transformer changed too, but this wasn't a sonic thing I believe.
TIM, I bullied you on the little Celestions. I PROMISE that this 405-2 will be in its element with the SHL5's. Just remember the absolute phase may be inverted (it is on the stock article) and that the gain may need to be usefully reduced a little for some preamps (Net-Audio may well have done this already as it measures better for noise and distortion at the input and was only the way it was because of the 33 preamp the early ones were used with not having enough output as modern preamps do).
julesd68
23-06-2013, 16:22
Im suprised it aint gone cos those black ones are quite thin on the ground
I didn't even know they made them in black ...
My 405-2 was very lightly modded and a superb perfomer. I'd love to hear one with all these upgrades, so please someone buy it near London and bring it round!! :lol:
Rare Bird
23-06-2013, 16:31
Aye. They made the '405-2' all way up to the early 90's.
It's also worth mentioning that these 405/2's were PROPERLY designed and engineered and included important engineering considerations such as DC offset protection which the newer Quads lack (I had looked at a Quad Elite before buying the 405 but the lack of DC offset protection plus the "thump" through the speakers completely put me off). They were a pretty common site as back-up units in many broadcast studios too.
Someone have a crack at this before I change my mind! You wont get a better 405/2 anywhere.
might be interested in a few weeks if I could find a suitable pre at a low price....waiting on a sale completing...
was thinking about a integrated valve job by, but this one and a hybrid on wam are both interesting me.
It's a cracking little amp and runs silently...no hum or other issues with this one. Much cheaper than even the cheapest valve integrated too! Works well with a passive pre by the way, but most preamps should work well with it.
what's it like at low volumes Paul?.
Pretty good at low volumes which is one of the things I particularly like about it. Very valve-like in its low level resolution.
getting more interested...my sale should complete middle July when Redmotor arrives in the country from Sydney. if you still have it then, I shall see about what I'll need pre wise. if it goes before then your laughing anyways.
There's plenty of interest Grant but no sale as yet. Happy to hold onto it if you want it.
Final price reduction to £350. That's it folks. If it doesn't go at that, I'm keeping it.
Update:
There's been a lot of interest in this by people who seem confused as to exactly what upgrades were undertaken. If this makes it clearer, I'm happy to confirm that it was a full Net Audio Upgrade but NOT the later MK3 upgrade. The earlier full upgrade entailed upgrading the 405/2 boards with Seaget Capacitors, upgraded transistors and resistors, upgraded wiring and a dual mono power supply which utilises the fact that the 405/2 transformer has dual secondary windings connected to one rectifier and the upgrade simply takes each set of windings through its own dedicated high performance power supply caps essentially creating a true dual mono power supply. It also has the upgraded op-amps (not the top spec latest ones but the very well respected OPA604 op amps); new gold plated speaker binding posts, hard-wired transformer connections. I believe that the cost of the work was circa £270. That makes this a very cheap upgraded 405/2 at £350. Some people have been haggling and trying to get it for nothing, but please don't as it will not be given away.
Canetoad
30-06-2013, 11:15
Hi Paul, If Barry isn't interested I may be. :)
Oh FFS, isn't this thing sold yet?
Re op-amps.. I'm advised to beware of too fast a modern op-amp as the rest of the circuit may not like it. I think the low noise offered by an OPA604 or OPA134 is more than enough bandwidth (which goes out to MHz I believe as it is), so don't think the latest is always the best - good idea to upgrade what's fitted as stock though to a sensible FET type though, since lower distortion and noise is a definite bonus in this application I'm told.
Oh FFS, isn't this thing sold yet?
Re op-amps.. I'm advised to beware of too fast a modern op-amp as the rest of the circuit may not like it. I think the low noise offered by an OPA604 or OPA134 is more than enough bandwidth (which goes out to MHz I believe as it is), so don't think the latest is always the best - good idea to upgrade what's fitted as stock though to a sensible FET type though, since lower distortion and noise is a definite bonus in this application I'm told.
This has the OPA604 which is more than good enough. Loads of interest and it may be provisionally sold...just waiting to hear back from Bernie.
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