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Old 14th Nov 2013, 8:39 pm   #1
zowieyuk
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Default Quad 44 Preamplifier volume

Hi
I have no volume control over my Quad 44 Preamp, the dial turns, I have good quality sound, just at a fixed level....any ideas??

Zoe
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Old 14th Nov 2013, 10:48 pm   #2
Herald1360
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Default Re: Quad 44 Preamplifier volume

Knob loose on the shaft?

Some kind of mechanical disconnect anyway between knob and pot wiper.
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Old 15th Nov 2013, 6:59 am   #3
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Default Re: Quad 44 Preamplifier volume

Does the knob rotate continuously, or does it meet end-stops normally?

David
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Old 15th Nov 2013, 7:16 am   #4
GrimJosef
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Default Re: Quad 44 Preamplifier volume

'Earthy' end of the pot track has become electrically disconnected from 'earth' ? (You can download the service manual from here http://www.hifiengine.com/library/quad/44.shtml.)

Cheers,

GJ
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Old 15th Nov 2013, 9:27 am   #5
SteveCG
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Default Re: Quad 44 Preamplifier volume

Does a Quad 44 use a pot for its volume control? I thought it was a stepped switch unit (ie there is a switchable resistor chain providing the attenuation).
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Old 15th Nov 2013, 10:03 am   #6
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Default Re: Quad 44 Preamplifier volume

Looks like it's a dual 500k pot.

Cheers,

GJ
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Old 15th Nov 2013, 10:52 am   #7
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Default Re: Quad 44 Preamplifier volume

It's a dual pot with stepped positions. It's built in 3 sections, pot for each channel and what I presume to be the mechanical detente section. Can only assume that the coupling from the detente to the pots has failed somehow.
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Old 15th Nov 2013, 12:12 pm   #8
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Default Re: Quad 44 Preamplifier volume

Thank you GJ and threeseven for clarifying the operation - 'yes' it is stepped, but 'yes' it is a pot.
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Old 15th Nov 2013, 5:02 pm   #9
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Default Re: Quad 44 Preamplifier volume

Many Thanks everyone, will try and let you know of progress
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Old 15th Nov 2013, 6:06 pm   #10
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Default Re: Quad 44 Preamplifier volume

Interesting as to how theyve designed the volume around the feedback loop of an op amp.

Many years ago I discovered that by accident that connecting a pot like this reduces the noise and crackles as the pot wears.
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Old 16th Nov 2013, 9:47 am   #11
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Default Re: Quad 44 Preamplifier volume

Just a thought - I assume the Quad 44 control unit has a line-level out as well as an output for connection to the power amp. You have connected these outputs correctly?
The line-level output will be unaffected by the setting of the volume control.
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Old 16th Nov 2013, 2:38 pm   #12
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Default Re: Quad 44 Preamplifier volume

The Volume is still fixed, when the phono leads from the cd are plugged into the 1.6v ports,the volume is loud but unajustable,when plugged into the 5v ports it is quieter but again, unadjustable.
I have tried plugging it into one of the din ports at the back, we got volume that was extremely quiet, but it was adjustable...

I looked inside to see if any wired had become disconnected,but everything seemed to be ok.
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Old 16th Nov 2013, 5:15 pm   #13
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Default Re: Quad 44 Preamplifier volume

If I'm interpreting this correctly so far I would guess you have just acquired the Quad so are not familiar with how to connect it up?
If so it seems you are confusing inputs with outputs. The inputs on the 44 are normally DIN, except for the phono, or disc input, unless, it has been modified with a CD input board which has din and phono connections. The 1.6 volt and 5 volt connections are outputs to a power amplifier, don't know how it has been giving any sound with the CD connected to an output.
So, if it has standard input connections you will need a phono to din cable to connect a CD player to it, this would be to the aux input.

What power amplifier are you using?
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Old 16th Nov 2013, 8:49 pm   #14
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Default Re: Quad 44 Preamplifier volume

Later 44's finished in darker grey with chocolate coloured buttons were pretty well all phono - just thought I'd mention it.

I ought to say this (apologies for teaching granny to suck eggs), but the output of one item goes to the INPUT of another. 44's of old had three variable outputs on them, set to different levels, although I can't remember if the later ones were similar.

It's got to be something simple I suspect and dry joints somewhere are probably the most likely. The controls were screwed in place with tiny Allen keys, so worth checking as they do work loose.
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Old 16th Nov 2013, 9:01 pm   #15
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Default Re: Quad 44 Preamplifier volume

Didn't know that the later versions were phono i/p's, thanks for that. Regarding the op's problem, variable level has been found, as per post #12 so I think it's a matter of connection error. I suspect there may be other configuration issues so we need to know what's connected to it and how.
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Old 16th Nov 2013, 9:35 pm   #16
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Default Re: Quad 44 Preamplifier volume

cheers guys.....i have the L+R output from the CD running into the Din plug connection on the tape port on the pre amp but still no luck, the cable is (i presume) phono to din, though it has an additional black and yellow connector....the power amp is a quad 405.....
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Old 16th Nov 2013, 9:52 pm   #17
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Default Re: Quad 44 Preamplifier volume

If an input were connected to either the 5 V or 1.6 V (phono) output sockets, as might be the case here, then it is likely that an attenuated version of that input would appear at the 500 mV (4-pin DIN) output. The attenuation would be greater via the 5 V input than via the 1.6 V input. Clearly connecting an input this way would bypass all internal circuitry.

Cheers,
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Old 16th Nov 2013, 11:14 pm   #18
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Default Re: Quad 44 Preamplifier volume

Quote:
Originally Posted by zowieyuk View Post
cheers guys.....i have the L+R output from the CD running into the Din plug connection on the tape port on the pre amp but still no luck, the cable is (i presume) phono to din, though it has an additional black and yellow connector....the power amp is a quad 405.....
Sounds like you are using a 4 phono to din cable? As long as you are using the correct pair of phono's it should work fine.
Can the click positions on the volume control be felt when it's turned?
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Old 16th Nov 2013, 11:21 pm   #19
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Default Re: Quad 44 Preamplifier volume

The tape inputs have adjustable input sensitivity, it might be that a low sensitivity is selected, hence low volume. Try the radio input, it's fixed 100mv so should give full output.
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Old 17th Nov 2013, 3:06 pm   #20
zowieyuk
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Default Re: Quad 44 Preamplifier volume

The click positions on the volume still work fine. I have tried it through the radio, but no sound at all.
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