ReVox A77 Reveiw

The Mk 4 was introduced around 1975 and is built entirely in Germany with the exception of the capstan motor, which is made at a Studer plant in Switzerland. The most important improvement was the Mk 4 heads which have a life five times that of the earlier design and which can be fitted for around £500 to any machine. From a visual aspect, the Mk 4 has a dark grey lower shell and some new (and much better) knobs with solid skirts replacing the earlier perspex see-through type which tended to go yellow with age and be a bit wobbly. All the new buttons and the edges of the knobs and skirts having serrated aluminium edges. The new head cover of dark grey plastic replaced the previous brushed aluminium type fitted to some Iater Mk 3's.

Buying a second hand ReVox is a fairly safe bet, provided the price is right. But it's worth bearing in mind that it will probably be with you for a very long time, so the newer and cleaner, the better.

After checking the serial number, found under the hinged flap that covers the voltage selector at the back, examine the heads to find the approximate age and true Mk. Brian Reeves can give you a pretty good idea of the age of a machine from the serial number. Remove the reels, lay the machine on its back and in a good light and pull off the head cover. If there is a lot of oxide caked round the heads, it's pretty obvious the machine has not been looked after. You could ask if it has been regularly serviced. Next, measure the flat wear mark on the heads and make sure it is less than the 4mm which

could mean replacement may be imminent. If it is close, it's an excuse to knock the price down a bit, as the new heads will cost around £500, although if the price is right this can be an advantage. After all, you start off by having the machine serviced and fitted with new heads, it will then be performing like new. If the machine is said to be fitted with output amplifiers, and you will pay a bit more for this, check by plugging speakers into them. Or, if this is not possible, put the machine in a vertical position, remove the reels and, after taking out the four Phillips screws from the back and removing the remote multi-plug, gently walk the chassis out of the case. You will find the amplifier cards plugged horizontally to the bulkhead next to the transformer on the left. The fact that there is a button on the front of the machine marked "speakers off" means nothing as all decks are supplied ready-wired for the amplifier cards to be just slotted in. They are 8 watts per channel output and can be obtained from Brian Reeves, should you wish, for £128.08 each. Check for genuine high speed if this applies. Having kicked the tyres, so to speak, now for the road test, or a check on all the functions.

To test the playback, it is much easier if there is a good hi-fi to connect up to with preferably a CD or a Stereo Tuner as a source for record. If not, you will need a mike with a jack plug and a pair of low impedance headphones for source and replay.

There are two things to check, the mechanics, which includes the three motors, brakes, pinch wheel,

controlled by five push buttons, relays, solenoids, and the electronics which is the record, replay, monitor, and channel selection functions. By testing the electronics, the mechanics will also be checked.

Thread the machine with decent recording tape and select 71/2 ips and the appropriate reel size on the power switch. The red power-on light should come on together with the end of tape detection bulb which you can see with the lid flipped down. Press the "play" button, let the tape wind a few turns, press "stop" and reset the counter by the button beside it. From the left of the machine, set the output to 10, the skirt to "stereo", the next knob to "centre balance", the skirt to "input". Set the channel 1 volume to maximum (10) and the skirt to "mic lo", ditto for channel 2. Next to the VU meters are the press on/press off recording channel selections; press them both off. Press the start and record switches simultaneously and the machine should start. Press on channel 1, leave for ten digits on the counter, press off channel 1 and on channel 2 for ten digits, then press 1 again so both meters are lit for ten digits. Rewind, and connect the output which should have been unplugged, or the headphones. Play back quite loudly through the hi-fi while selecting the appropriate channels on the left-hand skirt, 1 for the digits, 2 for ten, stereo for ten. You should hear a smooth, rustling hiss without any crackles or pops apart from the noise of the selectors.