Radfordman
pfm Member
Perhaps go for a 303 instead. Good old workhorse.
Quad current dumping amplifiers
- Thread starter johnfromnorwich
- Start date
johnfromnorwich
even my wife noticed the dif..
I've considered it but does it have enough grunt to drive ESLs?
Radfordman
pfm Member
If it's ESL57's or ESL63's then the answer for me in a fairly large room is yes. I have two pairs ESL57, one set ESL63, Quad 303 Quad 405-2 and Quad II's (and a lot more)
Robert
Tapehead
If you want a current dumper for ESLs the 306 is excellent and has plenty of power.
Remember that the ESL is essentially a 16 ohm load - yes it dips to 1.5 but right up a the top end where you only a handful of watts.
So into ESLs the 306 will behave like a good 25-30w amplifier (because it is driving 16 ohms) - and that is plenty.
Remember that the ESL is essentially a 16 ohm load - yes it dips to 1.5 but right up a the top end where you only a handful of watts.
So into ESLs the 306 will behave like a good 25-30w amplifier (because it is driving 16 ohms) - and that is plenty.
Analog addict
pfm Member
On the Quad front, I've only got a measly three 405s, a 30-odd year old 405 clone (designed & built by a siemens apprentice and modified myself to eliminate the trafo hum) and a 33.
You should let me unburden you, I'm in need of a pair of ESLs to hook my Stereo 20 up to (Quad IIs seem to cost the earth at the moment)!
303s are lovely but 405s better. Both are pretty well bulletproof IME. F actory repair has cost me £80-100 a time in the past but they don't go in for wholesale cap replacement unless asked.
As for "do 303s drive ESLs?", well, the 303 was launched in 1967 to replace the 2. At that time Quad's speaker was the ESL57. So, let's take a wild guess - (a) their best new amp can drive their best speaker a treat, or (b) No, Quad never thought anyone would use them together and it won't work. What do you think?
As for "do 303s drive ESLs?", well, the 303 was launched in 1967 to replace the 2. At that time Quad's speaker was the ESL57. So, let's take a wild guess - (a) their best new amp can drive their best speaker a treat, or (b) No, Quad never thought anyone would use them together and it won't work. What do you think?
Radfordman
pfm Member
Agreed, and the Quad 405 instructions say that the power limiter must be in when using 405 with ESL57
Compare and contrast the Quad approach of designing an amplifier which will drive the same company's speakers flat out all day with Naim's 250, which won't drive the Ovator speakers (albeit at ear warping levels) without shutting down.
Well done boys, brilliant design there. An amplifier from near the top of your range won't drive a pair of speakers from near the top of your range. I'd never have thought f anyone putting those together after all. Superb thinking.
Well done boys, brilliant design there. An amplifier from near the top of your range won't drive a pair of speakers from near the top of your range. I'd never have thought f anyone putting those together after all. Superb thinking.
Radfordman
pfm Member
Well, I'm not absolutely sure but I think I remember Quad not recommending the 306 for ESL63.
I bought my immaculate 63's in about 1988 from a guy that was using a Quad 306 with them. Seemed to work fine.
johnfromnorwich
even my wife noticed the dif..
Well I've shipped the 405-2 back to the seller, so I may think again. Either a 306 / 606 or another 405-2. Many variables to consider. Meanwhile I have a PhD thesis to defend and a wedding to organise so this may have to take a bit of a back seat for a while (unless I spot a bargain of course).
Radfordman
pfm Member
Ah, the Hi Fi bug rarely goes away, many have it, even though they may deny it!
All the above amps should be good (don't think Quad ever made a bad model) however 39 years of experience of 303's and 34 years of experience of 405's (quite a number of each) I would say that the 303 is the more reliable. The most likely failure in a 303 are the two big smoothing caps and the two big speaker coupling caps. Easy to check (see if leaking/ bulging) and replace.
A badly set-up 303 sound just about acceptable (depending on ones standards) and a well set up one, to me is better than a 405-2.
Tony L
Administrator
I've never done the comparison, but the 303 does seem to be the one that gets the most respect on t'internet. How would you describe the difference in sound (assuming both amps are comfortable within their power limits)?
I'm rather enjoying my 303 in my second system. It's perhaps a little gutless (though this may be my use of a passive pre), but remarkably clean and non-grainy into the tube-loving Heresys, certainly the best non-tube amp I've tried in this particular context. It just seems to get out of the way and not draw attention to itself, certainly plenty good enough for the TV and Spotify. I'll give it another try into the Tannoys at some point now the new caps will have burnt in.
Tony.
Radfordman
pfm Member
Well, to me all 405's and 405-2 do bass OK, however the original 405 sounds confused! 405-2 better in that respect, but still not a good as a good 303. 303 bass can be a bit loose into some speakers, but not too bad into most speakers (of course absolutely fine for ESL57's).
Early 405's can be improved drastically, just by plugging a new (later type) op amp in each amp board. This costs only pence.
303 should work really well into Tannoy DC's. If your DC's are 15 Ohm, even better. The 303 has lower distortion into 15 Ohms (see the 303 spec.) and the slight bass roll off caused by the series output capacitors is reduced.
Sorry, for some reason in my mind I thought that you had Tannoy DC's, still the above is true.
Early 405's can be improved drastically, just by plugging a new (later type) op amp in each amp board. This costs only pence.
303 should work really well into Tannoy DC's. If your DC's are 15 Ohm, even better. The 303 has lower distortion into 15 Ohms (see the 303 spec.) and the slight bass roll off caused by the series output capacitors is reduced.
Sorry, for some reason in my mind I thought that you had Tannoy DC's, still the above is true.
Pete The Cat
pfm Member
John,
For what it's worth I'm selling two 405-2s again (details in classifieds 5/7/10). My sale fell through, not because there's any problem with them, but the buyer wanted phono inputs and these are unmodified olive greens. They're both working fine in my second system.
On the wider debate, the only older Quad that I wouldn't recommend is the 707, which just doesn't have the "house sound" somehow.
Pete
Tony L
Administrator
I have, 15" Monitor Golds! I have two systems, the Klipsch Heresys are in the other room.
Tony.
Radfordman
pfm Member
So my brain was sort of working. I'm afraid that the one brain cell left is not that good.
hifienthusiast
Vintage by heart
Both the 707 and 909 have Quadlink, the music signal can be connected to a Quad 77 or 99 preamp via the Quadlink. If the Quadlink is not used, there is a set of phono sockets which can used with other preamps. The design of the power amp board of 606, 707 and 909 are the same.
Could it be the phono inputs of the 707 going through the Quadlink which explains the difference to the house sound? I read in a forum that when using the phono inputs, bypassing the Quadlink can improve the sound of a 909.
606 power amp board:
909 power amp board
606 inside with no Quadlink:
909 inside with Quadlink PCB
Tony L
Administrator
Back in the 80s when the 303 was partially rediscovered by Hi-Fi Answers it was considered a good match with a Meridian 101 or Crimson preamp, so I don't see why not. The only thing to consider is the input of the Quads is DIN level so a lot more gain than normal line level, which is one reason they are apparently a good match with passive preamps. I have plenty of available volume using the Audio Synthesis passive into my 303.
Tony.