Quad 44

[vento]

Is there adjustment pots for the volume control on the 44? Still hear sound on zero setting.

Thanks for any advice

[Mooly]

I think the 44 and 34 are similar and use an active volume control. This put's the pot in the feed back loop of an OpAmp rather than the normal arrangement but either way I suspect what is happening is this. The Quad was designed before CD and so on came on the scene together with much higher output voltage from source components. Old stuff used to be around 100 mv, CD players nearer 2 volt maximum. If the volume pot does not give a true zero ohms at minimum some gain will still exist in the active control stage. The fact that you may be feeding a high signal into it makes the effect worse. You could attenuate the inputs -- in the Quad itself if you want, you can try cleaning the volume control as well. Are both channels the same ?

[vento]

Yes, it on both channels. I should add that it has a CD module installed.

[Mooly]

In real terms how loud is it ? With both channels doing it it will not be a fault as such. Here is the circuit for the 34 volume control.
Minimum volume is when the pot shorts out pin 2 and pin 6. Even a few ohms residual resistance will cause some audio to be heard.

[vento]

Hi,
Thanks for that.
The situation is as follows, I have owned the 44 for about 12 months, and was not aware of the problem, (assuming that it is one). I sold it last week, but the new owner is having problems, mainly to do with the volume control, hence my post. In addition to this, the volume level is too loud on setting 3! Rather than 12-17, and too low on setting 2. As you know the Quad 44 has three output options to the power amp; 0.5v, 1.6v and 5v, and I personally suspect that the problem he is experiencing is to do with this. When I used the 44 it was connected to the 405-2 and worked perfectly in all the time I owned it, he is trying to use it with the Quad 606, but I cannot assist him as I have never owned one. Firstly, which of the three Power Amp output should he be connected to that match the 606, or secondly, what else could be causing this problem?

Thanks
Dave

[Mooly]

Hello Brian,
Done some digging. It's going to be normal ! The 44 is similar BUT different to the 34. See the volume control, that 6k8 (R500) resistor prevents the output from being attenuated to zero. I don't know the input sensitivity of the 606 but it's worth trying it on the 1.6 volt output-- the 0.5 volt looks to be on a Din socket.
It will only minimise the effect though, the bottom line is it's normal. You could always reduce the value of R500. I suspect it's been done this way to reduce the problem of poor matching of the left and right tracks on the volume pot. Cheap pots ( Does the Quad use cheap pots ? lets say commercial grade ) suffer badly here and to a music lover there is nothing worse than the image shifting suddenly to the left or right as the volume is altered.

[Mooly]

And heres the output sockets,

[Mooly]

Why did I call you Brian !!

[vento]

Managed to get some info on the 606, and the signal input level is 0.5v for 140watts into 8ohms, and he has now tried connecting it to the .5v output of the 44 but the result is the same; volume too high on 3. As I don’t think that the 44 is faulty, I’m beginning to consider the CD sensitivity. He is using the Meridian 602 CD player, and California Audio Labs "Alpha" DAC.

Any thoughts?
Regards
Brian....sorry I mean Dave

[RogerGustavsson]

I run a Quad 44 with 405-2 for some years. Always the 0.5V output. My CD-player had the normal output of 2V.

Roger