advertisement


QUAD II Classic monos input sensitivity

Nagraboy said:
Well, if these gain figures are correct then yes the Quad II Classic should be fine, as the Sugden is acceptably quiet through the Nagra + Falcon LS3/5a combo, whereas the 303 is not (unless I use a 34 pre). However, I’ve been quoted 1.4 Volts today from the head of Quad service dept, so I’m none the wiser really...although it is perhaps encouraging that JA has actually measured the amp and come up with a figure that would be about right.
Click to expand...

Well, if it's 1.4 V input for 15 watt, the gain is down about 18 dB. Even better from the noise point of view.
 
irb said:
Well, if it's 1.4 V input for 15 watt, the gain is down about 18 dB. Even better from the noise point of view.
Click to expand...

Do you mean the gain will be 18dB so I’ll just need to turn my volume control up by about 11dB on the scale compared with the Sugden I use now?
 
Nagraboy said:
Do you mean the gain will be 18dB so I’ll just need to turn my volume control up by about 11dB on the scale compared with the Sugden I use now?
Click to expand...

Yes, essentially. The power amp has less gain, so you need to turn up the gain in the preamp - i.e. turn up the volume control - to get the same output. That should maximise the signal to noise ratio in the preamp.

(Of course, you need to have enough gain in the preamp if you're not to find yourself short of gain overall. But I'd think the Nagra should be OK in that respect.)
 
If you have too much gain in the power amp, you have to turn down the volume a lot in the preamp. Unless the volume control comes after the line stage (which it generally doesn't, and certainly not in the Nagra), then the noise from the line stage will stay at the same level even when the volume is turned down, reducing the preamp's effective signal to noise ratio.
 
Got an email back from Quad service dept this morning. He’s sent a PDF of part of the owners’ manual which shows a figure of 1.4V, and said this is correct and the website currently showing 775mV is wrong. Thing is, the PDF manual I found online (with the same issue number!) says 775mV.

Either way, it’s pretty irrelevant as there is still no new stock in the UK for months now. I’ve been offered a pair of Quad II-forty monos at a good price but I’m not sure about those and would prefer the reissued Classics.
 
Nagraboy said:
I’ve been offered a pair of Quad II-forty monos at a good price but I’m not sure about those and would prefer the reissued Classics.
Click to expand...

Would steer clear of the Quad II Forty's. What about tacking down a really nice pair of original Quads IIs. There must be some of these left?
 
G T Audio said:
Would steer clear of the Quad II Forty's. What about tacking down a really nice pair of original Quads IIs. There must be some of these left?
Click to expand...

Yeah I’m not keen on the II-forty after seeing an article written about how badly designed they were. I do try keep a look out for nice originals on eBay.
 
When I represented Avantgarde Acoustic years ago, I always kept a nice pair of restored Quad IIs to hand just to let customers hear how quiet the noise floor could be with Horn speakers. That is if they couldn't stretch to a Tron amp.
 
Hi,

I use my Quad II Classics wiith the Quad QC24 pre amp, sounds very good indeed.

I did find out when I bought them that they were thin on the ground, something to do with making them in small batches and it was just luck the dealer I asked had a pair on the shelf in their stock room.

Have to say they go loud enough for me, I have Linn and Naim systems as well and I never found the 15 watts an issue in volume.

I was tempted a while back to sell them however I would have wanted to sell the whole combination pre and amps so I decided to keep them, one day I might find the perfect speakers to go with these, am currently using the Shahinian Super Elf's but did think of trying the Quad Z3's as the Elf's now I have them on Sara stands sound best with Linn, shock horror.......

Just get yourself in the queue for a pair, they are really good, I had a pair of the original Quad II serviced by Quad and these new Classics are every bit as good.

Cheers

John
 
You must log in or register to reply here.


advertisement


Back
Top