In the 1970s and 1980s Sound Technology test equipment was the best you could get but somewhere along the line the company faded from the headlines. The first dedicated audio test equipment I used professionally was the Radford low distortion oscillator and matching Distortion Measuring System in the 1960s. When I moved to Cambridge Audio at the start of the 1970s I was introduced to the Hewlett Packard 334A which was a dramatic step forward because it had automatic tuning so having set the level the distortion figure could be read directly.  When used with the Radford LDO it could be usefully used to read down to about 0.01% distortion.

However there was a dramatic change around 1970 when Sound Technology appeared on the scene.  A group of ex-HP engineers had got together to design some excellent equipment which was both accurate and quick and easy to use.  The first product was the model 1000A FM Stereo Alignment Generator. We bought a load of these instruments to use in the factory and also became the UK distributors of the product line.

The 1000A was quickly followed by the model 1700A which was a state of the art audio measuring system which could read distortion (THD) down to 0.001% and whose auto-tuning was super-fast.  Indeed we ran an advertisement for the 1700A which read “Testing, testing, tested”.  Once again Cambridge Audio used this system throughout the factory; after which it was sold to Lecson, Quad and others and rapidly became the industry standard instrument. The oscillator section was available as a separate instrument the 1400A. The 1700B appeared next which offered several upgrades.

I personally used the 1700B until I changed to the Hewlett Packard 8903 in the 1980s and then to Audio Precision gear in the 1990s.  I found Sound Technology equipment very easy to use and very reliable.  Indeed I only sold my last 1700B about a year ago and actually found I still had three of the model 1000A generators at the back of the garage.

Sometime in the 1990s the company moved into computer based testing and whilst they still service old equipment they don't appear to provide support or manuals

www.soundtechnology.com/service.html

“Googling” the company brings up very few hits and servicing information seems to be hard to find so I have scanned copies of the User/Service Manuals for the models 1000A; 1100A and 1700B together with the original literature; some reviews and some advertisements.  If you need them go ahead and download them in PDF format.

And if anybody can add anything to my short story of Sound Technology please contact me and I’ll add what you know to this page.

A lot of this equipment is still in use but there is virtually no information on the web. Here you'll find manuals and literature and in time I'll add more information. The pictures below show the 1700B Distortion Analyser and the 1000A Stereo FM Measuring System. Below the pictures you'll find PDFs of the manuals and some literature.

If you would like to upgrade the ST 1000A there is a great article here by Brian Beezley. I've tried the mods and they are really worth doing.

The famous 1700B Distortion Measurement System followed the 1700A and was the ultimate measurement system in the early 1970s

Inside the 1700B

The ST-1000A FM Alignment Generator was Sound Tech's first instrument and was an immediate sucess.

The picture shows the grey box which was an optional module which offered much higher specifications for the stereo separation between channels

I wonder what ever happened to Willene who assembled this 1000A ? She'll definitely be retired by now.

The RF Generator box showing the external adjustments

An inside shot showing the piston type attenuator

The inside view of the one transistor RF oscillator

The model 1510A Tape Recorder Test System was a sophisticated test system for tape recorders and record players and ST supplied matching Test Tapes and an LP Test Record.

It can measure:

• AC Volts
• Phasing
• 2nd harmonic distortion vs level
• 3rd harmonic distortion vs level
• Frequency response
• Channel separation
• Noise, composite and spectral
• Change in speed and drift
• Wow and flutter, average and spectral
• Dropout vs time

The 1510A is a microprocessor-controlled analyser which runs automated tests and displays both alphanumeric and graphically displayed test results on the built-in CRT monitor. Photocopies of the model 1500A and 1510A operating and service manuals can be bought from http://slbender.exactpages.com/manuals.html

It has previously been very difficult to get the manuals and circuits of these products so I've added some of them to this site together with a few other downloads that might interest particular visitors. If anyone has any documents they'd like to add I'll be happy to host them here.