AOS Exclusive Review of Eco-Fan Sound Pre-Amp and Power Amp

[Jack Williams]

"Giant Haystacks" asked: How do i build amps? Well i never build one amp. Even two doesn't take twice as long as building one, but six or so is a good number.

Old system: Lay out sockets etc on a piece of wood to see what size the chassis has to be and make a drawing on that size piece of paper.

Mark out position of sockets etc as underneath and get actual capacitors and other things and lay out where they have to go, moving sockets a bit for best fit. Draw a representative of them on the drawing, with all the wires shown. This can then be used as a paper "prototype" while actually later assembling.

Make a full scale drawing and take to metalworkers and get them to bend and weld a bunch (the more, the cheaper per each). Then i drill, punch and file all the holes using a template to mark the centres. That was the old system, where the local blokes didn't have the hole punching etc. However, now we have a local firm (Design Steel) who, if i make the drawing with all the holes also on it, can punch, bend and powdercoat, so all i have to do is assemble.

So then i put in all the sockets, tag strips etc and then put first the wires in, then the components. While the metal guys are generating the chassis, i have been winding all the transformers and chokes for them.

Once the amps are wired up, i then mount the transformers, and connect in the wires from same. In the case of the 6A3 amps, there is a board with tag strips, diodes and capacitors for the D.C. filaments of the 6A3s which i have completed, and this is mounted over the power transformer winding after the transformers are installed, and connected in.

Next is to install the valves, connect to instruments and fire up. Usually, if all the valves are good, there you are, a bunch of amps! At present i have a collection of 6A3, SV811-10, and single-ended big monoblocks on the go. Unfortunately these chassis are the old system. The "Bufferzone" and "Boost-its" are the new one though.

[Jack Williams]

How in fact do "Ecofan" products stack up in the "Ecological' stakes?? Here is a bit of a breakdown: Materials: Built mostly of steel and made to last. The longer a product lasts, the more ecological it gets as it staves off the use of materials to provide a replacement. Some recycled materials where possible. Copper wire, and some plastics in the usual components and panels. Components are chosen for quality and sound, generously rated and it is rare to have to replace much. Power consumption: Per watt RMS valve amps are less efficient on the surface than solid state. But when it comes to listening, given the same RMS, valve amps, especially triode output ones produce a lot more perceptive sound . The current 6A3 triode amps, using techniques for a big sound, appear more powerful than the cold bench instruments would suggest. But the real crux is the efficiency of the speakers.Obviously a set of efficient speakers will require not such a big amp, and thus a smaller power bill. The 6A3 amp would compare favourably with the consumption of the average TV set, and you don't necessarily need a huge set of speakers. The 6A3 amp sounds huge on classical music on a pair of John Blue Fours, which have single 4" cone and stand about 18" high.

[Jack Williams]

Could't resist posting this picture. How to clean your vinyl records!

[Jack Williams]

Friends brought these classic Ecofan amps in for a look over.

[aquapiranha]

Some lovely pics there Jack, many thanks for sharing! I am only sad I never got to listen to the Ecofan's Neil had when I visited.

[Jack Williams]

A photo of "Ten Tube Preamp" of same era, with power supply, but can also be run from the power amps.

[Jack Williams]

Not a lot happening. Here is the photo that got me banished forever from the local audio site!

[Jack Williams]

That is a lot better than the blue denim dress one. (I would delete it!) but here is a good one soaking up live music over three days at the WOMAD yearly music festival.
Jack

[twelvebears]

That is a lot better than the blue denim dress one. (I would delete it!) but here is a good one soaking up live music over three days at the WOMAD yearly music festival.
Jack

That kind of behaviour will NEVER cause problems here at AOS.

I fact a read through may of the threads on here will soon reveal that it is something of a pastime for certain key members!

[Jack Williams]

Look at this device. Made in the 1920s. More expensive than a transformer at the time. Without it the world as we know it could not exist. No radio. No internet. This is one of the first commercially available Capacitors.
And still measures 100% O.K. today!