I bought this at the boot sale because it was Denon and cheap. It turned out to be ideal for my needs.
First it needed some attention.
I was actually attracted to this to use as a standby amplifier for the occasions when my elderly Mission Cyrus is on the bench. The Cyrus is small and lives on a narrow shelf. Regular HiFi amps don’t fit, so this looked to be just the job. £10 secured it.
Closer inspection revealed that it was old enough to have a phono stage. Another bonus.
Before I get ahead of myself, lets power it up and see if it works. Three problems are immediately evident. The display is quite dim, the volume control jumps all over the place and the input selector switch doesn’t work. Can’t do anything about the display, its a symptom of old age and the vacuum weakening in the sealed unit. The volume control is a common problem caused by lubricating grease getting where it shouldn’t on the rotary encoder. This was fixed the same way as I did on my Denon mini system. I describe it in detail here.
The input selector switch is a similar problem to the volume control, but with a twist in the tail. It uses a smaller, lower resolution rotary encoder than the volume control.
This encoder is mounted on it’s own circuit board which stands just proud of the main front panel circuit board to give the correct spacing from the front panel.
I tackled this with my usual vigour by dismantling the decoder, clearing out all the crap then putting it back together. Connecting the cable all was well, so I reassembled the unit. After a couple of minutes of successful testing it stopped working. The knob turned, but nothing changed.
I took it apart again. The knob shaft and the plastic disc which carried the moving contacts were two separate pieces. Turning the knob did not turn the contacts. This came as something of a surprise to me because I had thought the shaft and disk were one and the same plastic moulding with no way of separating. Clearly not! I was able to glue the parts together and get it working. However, for the sake of £5 I bought a replacement encoder in the interests of reliability; keeping the repaired one as a spare. It all works now.
This got me thinking about my Workshop system. It’s all a bit Heath-Robinson. A Denon mini system provides for radio and CD playback. I also have a Turntable and Cassette deck on the other side of the room. A cheap phono pre-amp and a selector switch box connect these into another amp via a long cable. In the first instance the Denon replaced these two units, with the MD outputs feeding the other amplifier. A much neater solution.
A week or so later I re arranged my speakers and fed them directly from the Denon. The other amplifier was retired. This has become the main amplifier in my workshop system, while retaining the option of using it as a spare for the main domestic system.