** Hi all,
speaking of UK Vintage Hi-Fi, a Rogers Cadet II system turned up for repair this week. Three units in a cardboard box - main amp, control unit and phono pre-amp. See pic of similar system:
http://lab.sekaimon.com/img/fetch/i/321656407324
There was a little rust on the tops of the units suggesting storage in a garage for some time, the white plastic buttons on the push switches had disintegrated and the front of the control unit was discoloured. OTOH, the large can electros had been replaced and all the valves were Mullard made in UK.. I doubt if they were the originals.
Both power amps were dead or good as. A check with a multimeter showed that many composition resistors had gone high value or were open. Once they were replaced, good operation was restored. The control unit needed similar attention while the RIAA pre-amp was OK.
I guess the ECL86s are a bit worn as the most power I could get was 6.5 watts into 15 ohms. At 4 watts, THD was around 0.2%.
Internal wiring is very neat with no PCB or tag board used, components are strung between pillars fitted to the chassis and travelling through in case of the two pre-amps. Not the fastest way to build something, but it sure makes repair easy.
Is the Cadet II "a poor man's Leak" or is that too harsh ?? Making the phono pre-amp an option surprises me, limiting use to Ceramic PUs and radio tuners for most buyers.
The ECL86 valves are no longer made and only NOS and used examples are on offer - at rather high prices. Might be smart to rewire the main amp to use EL84s and add a pair of ECC83s on the chassis. Replace the selenium rectifier with a silicon bridge and you could get 10 watts per channel.
..... Phil