[dazzlevision]

Hello,

Just before Christmas, my brother donated an HMV model 2401 Stereomaster (in teak veneer) to my collection. Now, I already have a very nice Ferguson model 3322 “Transistagram” (their first all transistor stereogram and quite highly specified for a Ferguson), so I wasn’t sure that I would keep the Stereomaster.

However, it is much smaller and lower than my Ferguson gram and it does look rather nice (the cabinet is very good). So, with permission from “the management”, it is to be restored. It dates from 1968.

Several models under the “Stereomaster” banner were made by the British Radio Corporation (BRC) over the years. Some only had a record player, whilst others also had VHF radio.

The 2401 model features a side facing bass/mid range speaker and forward facing tweeter (all made by EMI). The speakers are in their own sealed enclosures, with foam sealing strip around the removable rear panels and foam plugs in the holes for the speaker wiring, from the amplifier.

The record deck is a BSR MA70 unit, which is one of their better offerings from that era (fitted with a BSR C1 ceramic cartridge). The all-metal turntable is driven by the motor via an intermediate drive pulley and is of a larger diameter than found in their cheaper units.

The amplifier part uses a mixture of plastic silicon transistors in the preamp stages and AD161/162 output pairs. The radio section uses silicon transistors in the RF stages and AF12x in the IF amplifier section. The 24V dc power supply is (AD143) series regulator stabilised (mainly, I suspect, for the benefit of the radio tuner’s varicap tuning circuitry).

The VHF radio has with five presets and an AFC defeat switch. There is also provision for external (mono) radio and (stereo) tape recorder connections. This unit has provision for retrofitting a multiplex stereo decoder and luckily, I have found the correct item (a BRC type SD1 unit) in my loft. The SD1 plugs into a B7G socket, which currently has a B7G plug in it, containing a capacitor, resistor and some links between pins, to enable correct mono operation. It has a stereo transmission indicator lamp, which fits onto a bracket behind the red “stereo” indicator bezel on the control panel. There was a factory fitted stereo decoder version under model number 2402.

The unusual thing is that access to the electronics is from underneath; the rear is all teak veneer. The electronics (three PCBs) is mounted on a sheet of hardboard and at the top, is a metal rail which carries the rotary controls and VHF preset tuning pushbuttons.

CURRENT FAULTS

1. The BSR deck is missing its knob for “off/play/reject” and will doubtless benefit from a thorough clean and re-lubrication.

2. One of the preset VHF tuning station selector buttons is broken (the unit is made by “Preh” of West Germany).

3. A wire to one of the five pins of the “tape recorder” DIN socket has never been soldered.

4. The left hand channel’s tweeter has been replaced in the past by a BRC supplied part, but it hasn’t been fitted very well and one of the four 4BA studs is missing its spring steel securing clip and nut/washer. I’d like to obtain and fit the correct EMI tweeter.

5. The two Hunts 2uF 25V reversible electrolytics that feed the tweeters are open circuit (surprise!). One has been bridged in the past by a 22uF polarised electrolytic.

6. There are a lot of “Callins”, TCC and Hunts electrolytics on the PCBs and most are likely to be out of spec by now.


Another Forum member has kindly donated a complete BSR MA70 deck for parts and I have found an identical but undamaged “Preh” preset VHF tuning unit in my loft.

I have a lot of electrolytics on order from Farnell.

To be continued……………..