COLIN WONFOR: SEAC kits – the current state of play

Alan Elsdon (Colin's business partner) writes .....

There are two versions of Colin's SECA amps available for DIY.

The 10-15 watt version which has been detailed on AudioChews, there are three boards available for this version, an Amplifier board which has its own power-supply built in, this gives the cheapest and quickest build. A Tracking Power Supply board does as its name suggests it tracks the Amplifier boards requirements and adjusts its output to compensate. A third board allows for a Soft Start avoiding any nasty turn on thumps.

I personally use the Amplifier + Tracking PSU and with my Infinity RS3B speakers there is no problem with switch-on nor any problem driving the speakers to quite loud volumes in my 5 x 3 metre room.

The second version is a 40-45 watt version, only one of these currently exists and was built by Sovereign(James). The single board for this combines the Amplifier and Tracking PSU boards but with more output devices - so it is the 10-15 watt ON STEROIDS. The board has thicker copper tracks to cope with the extra load. James so likes his amplifiers (and having had them on my system I can see why) that he wanted another amplifier to allow him to bi-amp his speakers.

When James asked for more boards Colin and I decided to do a limited run of these boards and so 12 were made, I was going to keep 4 but due to the interest shown by a few people I will keep 2 which Colin is building to ensure that the Bill of Materials we have is correct.

Pricing of the boards has been mentioned and I have also said I would see about getting the SMDs soldered to boards. I have also been ensuring that the parts are available from Farnell and looking at supplying all the parts needed to complete the boards.

I am making a spreadsheet of everything required to build one of the 40-watt amplifiers assuming 2 SMD-populated boards, a pair of transformers, a suitable case from Modushop and sundry bits. James used 4 big heatsinks available from RSComponents and built his own case - obviously we cannot price that but we can give links to the heatsinks.

I will give some ROUGH figures now for a build - but I reserve the right to change them!

  • 2 x 40-watt boards unpopulated £120 including delivery.
  • Kit of parts to populate two boards £280 including delivery.
  • 2 x Airlink Transformers 225va 22-0-22 £58 plus vat + delivery from Airlink, 300va 22-0-22 £62 plus vat + delivery from Airlink.
  • 1 x Modushop Case Pesante Dissipante 4U or 5U - website currently down but £200 plus for this, more if you want the holes drilling.
  • Cables / Phono Sockets / Speaker Posts / Mains Inlets / Switch - allow a minimum of £25 - lots more for boutique parts.

So ROUGHLY about £800 for an amplifier plus your time. We would supply the parts and boards only and you would need to get the transformers / cases and sundries at your leisure.

If any interest is shown in the 10-watt Kit then we will look into offering the same sort of deal for the boards and parts.

I will make the finished BOM and spreadsheet available when completed and checked.

END