Quad 44 Preamplifier Service

Quad 44 Preamplifier Service

I’ve just serviced a Quad 44 preamplifier. In this article, I’ll show you what the 44 looks like inside and explain some of its features.

Along with a Quad 405 power amplifier, I recently serviced this Quad 44 preamplifier, both owned by the same customer. I’m told he purchased them after a chat we had about resurrecting his KEF speakers, and purchasing some Quad gear to power them!

The Quad 44 is a compact, CMOS switched preamplifier, with minimal wiring, and high-quality parts. It has a few too many controls for my liking, though there are some useful tone controls and filters. The bad news is that all the mechanical switches and pots in the signal path, along with quite a few op-amps and CMOS switches, impact on the sound.

To my ears, this a slightly opaque sounding pre and not quite up to the same high sonic standards of 405-2 power amp. It is very nicely made though and there are still hard-core Quad 44 fans out there who would no doubt disagree with my assessment.

For more details, check out this excellent review of the Quad 44. The Quad 44 preamplifier matches the later Quad range, including the 405/405-2 power amplifier, Quad 34 preamp, and Quad FM4 tuner.


As always from the Hi-Fi Engine:

  • Frequency response: 30Hz to 20kHz
  • Total harmonic distortion: 0.05%
  • Input sensitivity: 3mV (MM), 100mV (line)
  • Signal to noise ratio: 72dB (MM), 86dB (line)
  • Output: 100mV (line), 0.5V (Pre out)
  • Dimensions: 321 x 103 x 207mm
  • Weight: 4kg
Quad 44
Typically funky looking Quad facia, with some kooky tone controls and filter options. These are OK, the worst part is the horrible balance slider that has no centre-detent.
Quad 44
With the cover removed, you can clearly see the modular construction. The modules are well-made, but fairly simple in the way Quad tends to be. The red, modular power supply was designed to be easily replaced, when needed.
Quad 44
Here, for example, is the phono board, featuring a simple TL071-based phono gain stage, with good quality passive components and adjustable gain. Gain selection via top-mounted switches is a nice touch.
Quad 44
Here you can see those switches, plus the general layout of the preamp. Note the very high-quality ALPS potentiometers and switch for the filters. Also note the liberal use of polyester film capacitors, which are great for audio. Keen-eyed readers may spot the lonely ERO capacitor. It wasn’t there for long…!
Quad 44
Close-up of those potentiometers and switch. There wasn’t much to do in this service. I replaced the ERO capacitor, cleaned and lubricated all the switches and controls and reconnected a chassis ground wire that someone had previously lifted.

Quad 44

Liquid Mike

At 10 I was pulling apart electronics and by 13 I'd have Dad's hi-fi in pieces when my parents went out! Later, I started Liquid Audio, a specialist electronics repairer known for detail-focused service, repair and restoration of hi-fi electronics & turntables. Keeping classic hi-fi gear alive and well is what we do. Our mission: to deliver TLC for classic Japanese, American and European hi-fi stereo equipment. In my spare time, I ride motorcycles, travel, listen to music and research interesting topics.

This Post Has 6 Comments

  1. Olivier R

    I am the very happy but very inexperienced owner of a Quad 405 amp and Quad 44 pre-amp.
    My question is, is there a point in changing the power supply cables from both of them, as they seem to be the original ones?
    And if so, are there restrictions or specific cables I would have to use (Amperage, voltage,…) ?
    Sorry for this beginner’s query, I am just getting into these old beauties and I’m in love with them.

    Thank you for your articles !

    1. Liquid Mike

      Hi Oliver, thanks for your question. In terms of power cables, they certainly can be improved, but as long as they are good quality standard 10A mains cables they will be fine for now and there are other things I suggest you look at first. With equipment this old, it’s very important to have them inspected/serviced/overhauled and known issues addressed. Having this work done properly will make a much bigger improvement and save your 44 pre-amp for example which will fail without it. It will also allow the person assessing them (assuming they know what they are doing) to determine whether previous work has been done and if that work and parts are appropriate. Take a good look at interconnects too, improving these is well worth doing.

  2. Roberto Yu

    hi..i bought this QUAD44 ,,my problem is the selector switch suddenly stop …i have to switch again what i am playing …and left channel also a weak sounds ,,,,405-2 amp has no problem

    1. Liquid Mike

      Hi Roberto, thanks for your question. Like all older electronics, these preamps need attention at this age. I’ve seen these symptoms before and they can be hard to track down and resolve, but it can be done. I’d strongly suggest an overhaul with careful attention paid to areas relating to the symptoms you’ve described. Are you able to get the preamp to me for a better look?

  3. Lev

    Hi, i’m a proud owner of Quad 44 preamp and 405-2 amp and are planning to use them with Kef LS50 speakers.

    Maybe you or your customer can share how good those systems work together?

    thanks a lot for the article

    1. Hi Lev, thanks for your comment. I think the best way to answer that is to actually listen to them together. The 405-2 will drive any sensible pair of speakers, the LS50 should work well with the 405, but you need to to hear them together, in your listening space to really get a feel for how they will work for you. The 44 preamp is the weak link technically and sonically, so it’s worth listening with other preamps as well, to get a feel for how they impact the sound.

Feel free to leave a comment, technical questions should be asked via our Contact page