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| On-line-Übersetzung zum Deutschen |
In 1988 ReVox came out with the B250 amplifier and the B260 FM tuner (= Studer A764). I think these are two of the best looking pieces of audio equipment ever built. A year or so later came the "s" version (S derived from Signature* ) with tacky gold feet and gold lettering on a black face - which I don't like nearly as much as the first generation silver. And then the lower spec B150 and B160, which don't have real glass tilting doors.
"The Signature" was a limited edition B226 Compact Disc player, to celebrate Studer's 40th anniversary. It is distinguished by a black anodized facia, but has champagne metal pushbuttons. The subsequent 'ordinary' B226 was designated the B226-S and retained the black facia, but got black metal pushbuttons as well, with a slightly golden sheen to them. "The Signature" was the only ReVox CD player to ever come standard with its own dedicated remote control handset.
The anniversary was also celebrated in South Africa by the opening of "The Gallery of Sound" in The Firs in Rosebank (in front of which now stands the hideous Rosebank Hilton). "The Gallery of Sound" was a dedicated outlet and audition space for ReVox and AKG equipment exclusively. The very small niche market meant that The Gallery was short lived, and amalgamated with Lincoln Bros Music, a once-fabulous purveyor of orchestral musical instruments and sheet music. Both companies then facing an ever dwindling client-base, now no longer exist. ReVox moved off to Strijdom Park industrial estate, under the auspices of 8th-Avenue Sound, and then entirely ceased to be represented at all, when the Motor-Columbus/Harman catastrophe happened.
Long ago, I built the ETI-5000 (aka ETI 477) mosfet power amplifier (2x150W) from the March 1983 Electronics Today International Magazine, but it never got a nice case or front panel or 'user interface' - it was just a plain box with no controls. So I'm re-boxing it to match my ReVox amp, tuner and CD player (B226).
There have also been some small & simple circuit mods to the 5000 since its publication, which I will apply to mine.
The 'painting' at the top of this page is the intended end result.
It might have made even stern-faced Dr Willi Studer smile - a bit.
If they had made an amplifier like this, it would have had a model number something like B241, since the control amplifier that looks like this was the ReVox B240, and the very austere 'black box' power amplifier was the ReVox B242.
| If I chose to clone the B250 S-variant, my amplifier might look something like this: | 
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The 'ordinary' B200 series had side panels in matte battleship grey, The S-variants had trapezium-mitred, gloss black side panels. I'll use wood-veneered sides, as I like that look very much - see what I did to my Studer D740 after I took off the rack ears.
The front panel is the key to getting 'the look'. This is easy to make using aluminium 'L" extrusion, bought from almost any hardware store. It comes in 2m lengths, is fairly inexpensive and very useful to have around for all kinds of projects.
The two moving coil meters I already had in my box of collected NOS components. Type "PKD3", made in 1977 by Neuberger Messinsrumente KG, Munich, they were likely very costly instruments - which is appropriate for a Studer clone. Unfortunately they have no means of scale illumination, but either front-LED or EL-panel lighting will be added. The real ReVox components dim or brighten their displays in response to ambient room light levels, and this feature needs to be copied.
My 'glass' windows are made from darkened Perspex, although ReVox used real glass. I have been unable to find any company that can edge-polish small pieces of glass for me. Perspex is far easier to work than glass, and looks almost as good -if it it treated carefully to avoid scratches.
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| Aluminium extrusion cut to size. | Moving coil meters. |
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| Windows & door cut from black perspex. | 5mm Aluminium sheet; prospective buttons. | Face with meters. | A resemblance starting to appear? |
The meters, when installed upside-down with the pointers hanging (as on the G36 / A736 tape recorder), zero on the right. The drive electronics will account for this. Right-zeroed meters that swing over to the left when the electroncs power up were once quite common on vintage pro equipment, because it gives desirable meter ballistics that would now be created electronically. It gives it a nice arcane look to have meters that park on the right.
The pushbutton mechanisms are made from a double printed circuit board, made as a widely spaced sandwhich, with the upper edge of the top PCB free. The springiness of the PCB phenolic provides a soft push feel, but also a laterally rigid mounting on which to glue the aluminium 'button'. Mounted on the bottom PCB is a miniature momentary action push switch, and the two LEDs (left side two reds for standby and overload, right side two greens for speaker A and speaker B)
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Fortunately the operational simplicity of a power amplifier only requires 3 buttons. Hand fabricating a panel of 15 or more buttons for a different device would be quite arduous - filing out all those rectangular holes to look perfect.
| The headphone socket is a spare part for a TV set, the square aspect is unusual. The pushbutton is a Rafi 'Lumotast' - with a black paper insert, the blue lens appears almost black. On the B250 and B260, this button opens the glass doors. I am not using doors that open, so the pushbutton allows extra electronic operations (mode selection / status programming) | 
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| The VU meter illumination is by 24 LEDs, 12 per side. | Unfortunately my photography does not show the amazingly deep electric green of these 520nm LEDs. They are not the usual insipid yellow-greens. It has to be seen to be believed! |
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| The four retaining studs for the glass windows/doors are made from 4mm machine screws with their heads filed flat, and painted black. |
| Artwork for the moving coil meter scale. Printing on white card gives maximum reflectivity from the green LEDs. The GIFs shown here are of reduced resolution - my originals for printing are high res. |
| The amplifying components. The circuit is the ETI5000 (same as TA-477 when originally published in Australia), but the PCB layout is changed radically to remove distortion and parasitic capacitance problems found with the originals. The PC boards were bought from A.P Electronics when they were still in Pritchard Street - I did not do the improved layout. I have further modified them recently to balance the voltage drop across the two halves of the "outer-most" LTP.
Only one transformer and two capacitors pictured here - i.e., power supply for one channel only. |
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