The Altec 436 and 438 series are vari-μ tube compressor-amplifiers that were famously used at Abbey Road in the 1960s, when the Beatles were there. The 438C is the best of these models, in that it has a built in mic preamp, and also control of the threshold and release, which make the compressor a lot more usable.

I have been looking for one of these for some years now, to the extent that I even built one from scratch – but of course without the gorgeous meter. I finally took the plunge and bought this one on US ebay, for (what I considered to be) a fair price.

Altec 438C compressor

Having paid the ransom to release it from customs, I picked it up from Parcel Force today. Happily, it looks to be in good original condition, and it should not be too much of a challenge to get it up and running again.
There is plenty of vintage dust inside…

Inside the Altec 438C compressor

A few things will need to be done. These were built for the US market, and the transformer will need to be swapped to a 240V model. It would also be prudent to swap out the electrolytic capacitors. All the original transformers are present, which is a relief as these are difficult / expensive to find.

The ‘clone’ has been in regular use for years, and it will be interesting to see how the original compares!

Home made 438B compressor