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.

Specifications

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
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.
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.
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.
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…!
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.

Thanks for reading, leave a comment and let me know what you think!