High Quality, Noise-Free sound output from the Sinclair Spectrum +2
If you have a grey-cased +2, you have probably noticed that its sound
output is very noisy, both from the rear-panel "Sound" socket, and via
the RF modulator TV output, and does not do justice to the AY-3-8912
However, there is a very simple modification that you can perform that
will give you crystal-clear, noise-free sound output via the “Sound”
I recently discovered, quite by chance, that nearly all of the noise on
the +2's outputs is caused by the Datacorder, whose very sensitive
amplifier is continuously switched on, even when the tape deck is not
in use, and picks up noise from the +2's other circuitry.
If the Datacorder is disconnected from the main PCB, or even just the
power is disconnected, the output from the "Sound" socket becomes
beautifully clear, with almost no background noise whatsoever. (Even
the TV sound output is dramatically improved, although there is still
some background noise present on this.)
However, with the Datacorder disconnected or powered down, it is
obviously not possible to load or save programs from tape, so I wired a
small toggle switch in the Datacorder's power lead, and mounted this on
the right-hand side of the +2's case, so that I could switch the tape
deck on to load or save programs, but switch it off again to obtain
noise-free sound output.
In the +2 I modified, the power wire was the red wire going to the
centre pin of the 5-pin plug connecting to the main PCB. Please check
which wire it is in your +2, as there may be differences between
models, and while it's unlikely that you'll do any damage by
disconnecting the wrong one, you might waste your time!
The only slight complication was that the power-on indicator LED is
also powered from the Datacorder PCB, so I had to make other
arrangements to ensure that this LED didn't go out when the tape deck
was switched off. This required only one additional wire to be added -
I chose to take this from one of the pins of my switch as this was the
easiest place to solder.
By carefully cutting the wires going to the switch at the right length,
I found it was possible to route them very neatly around the back of
the tape deck motor, where they sit in the groove between the motor and
the back panel of the case.
The simple modification is very effective, and I can highly recommend
it to anyone who wants to obtain noise-free sound output from their +2.
You only need basic soldering skills and the ability to handle a drill
to mount the switch - it really is a piece of cake, and well worth the
Another, slightly more involved, option is to solder some wires
directly onto the output pins of the AY chip, and run these to an
external amplifier. This has the advantage that the Load/Save tape
noise is not routed through your amplifier, but neither are the 48K
“beeper” sounds – this may or may not be desirable, depending on what
Please note that these modifications are applicable to the "grey-case"
+2 machines only, and may not be applicable to other models such as the
This page was last updated on 6th
Copyright Tim Fardell.