Quad 44 Preamplifier volume

[Radio Wrangler]

OK, so it sounds like the best approach is to work apply a known good signal so a pair of inputs and to attempt to follow it through the structure. Slow, logical work, but it's certain to lead to the fault.

It's interesting that both channels are dead, because I assume you'd have commented if one was working. That would suggest something like a power supply down, or a dual opamp common to both sides.

What sort of test equipment do you have?

David

[teetoon]

Hi, just wondering, are we sure the right 2 sockets on the DIN to Phono lead are being used. Have you tried the yellow and black sockets?
It sounds as though the signal is being fed into the record outputs which would not be affected by the volume control.
Then very low signal through the other sockets but with volume control making a difference would be because the signal is on the wrong input pins.

David.

[SteveCG]

Can Zoe confirm that this system of the 44 and the 405 has ever worked properly. Or, as others have suspected, have these units just been obtained - without a manual showing how to connect them up?

[KeithsTV]

My 44 Pre amp, bought in 1987, has phonos and DIN connectors on all the input modules. These are effectively in parallel allowing you to use either type of connection.

The standard configuration 44 has one radio input module, one CD input module, one phono input module and two tape input/output modules. The positioning of the two tape modules and the phono module under the window in the top cover allows the input and output sensitivities of the tape modules and the senitivity and capacitive loading of the phono module to be adjusted.

The main difference between the Radio and CD modules is the sensitivity as a CD player has a higher output signal level than the tuner.

There are three output connections with different output levels for connection to the power amp. From memory the 405 uses the lowest output level.

Can you confirm what modules are fitted and how the CD player and power amplifier are connected, a photo would be good?

Keith

[threeseven]

When was the transition from DIN inputs, apart from the disc input to duplicated DIN & phono? Asking because mine is DIN only on all inputs except disc, and in my case CD because I modified it with a CD module.

[teetoon]

The 1.6v and 5v "ports" reffered to in post 12 are outputs. These will be feeding the CD signal to the power amp via minimal circuitry.
The picture shows the back of a 44 pre amp with phono and DIN sockets but the outputs can be clearly seen to have the 1.6v and 5v outputs.

I still suspect the DIN to phono cable is being used with the wrong 2 sockets.

David.

[KeithsTV]

Here's the rear panel of my 44 taken from the manual. It has both phono and DIN connectors on all modules. (Serial number 30068)

I've also marked the inputs and outputs.

Keith

[threeseven]

That would seem to make mine an early one, serial number 15209.