Tuesday 10 November 2020

SJS Arcadia Model 7 dark star

Busy during lockdown, and ready to bounce back with the new dark star version of the SJS Arcadia 7 linestage preamplifier.

Enhanced version in black with choke loaded triode gain stage, Duelund CAST capacitors and pure silver wiring throughout.

Standard version in natural with Duelund RS capacitors

Standard and Enhanced versions now on demonstration at Definitive Audio in Nottingham.

Friday 10 January 2020

Arcadia 18W PSE 300B Amplifier Repairs

An original Arcadia 18W PSE 300B amplifier has been in for servicing and repairs.

Originally supplied in 1997 it was enhanced with a large external dual-mono power supply in 2004.

Following a number of amendments, and a period of time in storage, it has been thoroughly repaired and serviced. A couple of damaged chokes have been replace, some of the psu capacitors replaced, a new pair of 6072A input and 5687WB driver valves, and a new set of EH Gold Grid 300Bs are now being used instead of the TJ mesh plate 300B/n valves shown.

The PSU contains a large mains transformer for each channel, plus valve rectifiers, choke input and first psu cap for the input/driver psu. The psu is remotely switched on/off from the main chassis.

Inside the main chassis there are two mains transformers for the 300B filament supplies, and six more chokes for the various power supplies.

In total there are three valve rectified, choke input filtered power supplies per channel, making six in total. One for the 300Bs, the second for the input/driver stage, and the third for the negative bias supply.

The components inside are typical of the period, including Elna Cerafine HT caps for the 300B ht, a lot of Black Gates, Hovland coupling caps, Mills and Rhopoint wirewound and even a couple of tantalum film resistors.

The servicing should see it good for many years to come.