8 Track Cartridge Stereo recorder deck. The repairs

I’ve just acquired this magnificent beast. It’s old, so I don’t expect it to work properly.

Senn-Sound Inside
Senn-Sound Inside

It’s time to go inside and see what needs fixing and how it performs.

I like to have a look inside old gear before connecting up to the mains, just in case there is anything obviously dangerous that needs attention first.

Exposed mains voltage
Exposed mains voltage

There is exposed mains in several places. The fuse, the power switch on the tape mechanism and a tag strip. I insulated these points straight away with bright red tape for my own peace of mind.

Senn-Sound-Internal overview
Senn-Sound-Internal overview

It’s very clean and almost new looking inside. . The belt is intact and stretchy in a good way. The Matsushita motor has a date on it, 18th September ’73. These things date it to the early 1970’s. This machine was a contemporary of my Sony TC-377 Reel to Reel and TC-204SD cassette deck.

Senn-Sound lose pot
Senn-Sound lose pot

The right channel volume pot was wobbling about in the chassis. Easily fixed by removing the front cover and tightening the securing nut. I also gave all switches and pots a clean with a switch cleaning spray.

Senn-Sound Controls
Senn-Sound Controls

With a circuit breaker in place and a pair of cheap headphones plugged in  I turned on power and put a cart in. It works, playing at what sounds to be correct speed. Fast forward works. Eject works. Pause works.

The only bad news is that select doesn’t fully work. Only programs 1 and 2 can be selected.

Senn-Sound Track selector
Senn-Sound Track selector

The select problem was easily fixed by cleaning and re lubricating the selector mechanism. While I was at it I also cleaned all the push switches and the wafer on the select mechanism which operates the indicator lights.

Senn-Sound Head adjustment
Senn-Sound Head adjustment

A clean of the heads and capstan almost finished the job. The head alignment needed adjustment to eliminate cross talk between channels. Conveniently there is a fully labeled screw adjustment on the bottom of the unit for just that purpose. I just did what I was told and soon all was well.

senn-sound All done
senn-sound All done

Cosmetically the unit is in good condition and cleaned up well. Proper listening tests were extremely rewarding. The Beatles “Revolver” sounded fantastic.

The recording tests were a revelation. I recorded my Vinyl 2008 re issue of Steely Dan Aja. Hearing a modern recording come out of a 1970’s 8 track cartridge in Hi Fidelity was indeed a strange experience which demonstrated the capability of a format which was never developed to it’s full potential.

And I figured out what all the controls do.