Category: Valves & Stuff

Nagra IV-S credit to DRs Kulturarvsprojekt Copenhagen, Danmark

Parts for Vintage Equipment

Where to get vintage gear spares? Over the last 6 months I have received quite a few mails from desperate individuals wishing to restore their old radios, tube and semiconductor, integrated amplifiers, turntables and tape decks. Belts and power supplies and many semiconductors have equivalents but we get stuck with Germanium, decals, knobs and switches…

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Transistor equivalents

Transistor Equivalents – old equipment restoration

Where to find transistor equivalents? Restoring old gear can be a nightmare when it comes to some of the more obscure transistor types, and a pretty expensive exercise as well. Transistor equivalents for substitution is often a necessity when repairing vintage gear. This applies equally well to silicon devices and not just Germanium. Years back…

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Hybrid Amps

Hybrid Amps: Some more circuits Using the first article to get our creative juices flowing I found some more well written well designed amplifiers using tubes and semiconductors. The design link below shows various permutations to feed a high voltage swing with little distortion to an emitter follower output stage.  This circuit, titled Hi-End Hybrid…

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Inside the The ART Digital MPA II

The ART Digital MPA II – Solid state and tube preamplifier This was my first microphone preamplifier and admittedly it was a grudge purchase. I was looking for the Behringer 2 channel 12AX7 preamplifier to do some mods, higher voltage plate and RIAA preamplifier.  At the price it’s a steal, then just over R1200.00 for…

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What’s a tube?

Radio Tubes or Valves Take your pick, tube or valve? All irrelevant – ones Americanism (tube) and the other English as in UK (valve). We have a plate (American) and anode (South African and English). Cathodes are directly or indirectly heated (indirect = heater to cathode) which emits electrons which is attracted to the positively…

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