They look very nice in the dark. A pair per channel to provide 150V well regulated thanks to a cascoded DN2540 CCS. Each CCS set to around 37mA…
Tag: 26 preamp
26 pre-amp build near complete!
Today made significant progress on the new version of the 26 pre-amp. Only bits outstanding are the CCS modules part of the HT supply on board. Tested glow valves, output transformers and filament circuits…
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Preamp work in progress
New modular preamp 26/01a and 4P1L
Today made some progress in building the modular pre-amp using my latest design on the 26. I’m planning to make this preamp a modular one to enable quick changes and replace pair of valves and OT. This will enable to use 01a and 4P1L as well…
I used a floor plank I found around as the base. The front is a simple aluminium piece that holds the stepped attenuator. Both 4-pin sockets are standing with the rubber suspensors that DHTRob kindly sent me. The two resistor arrays for filament bias are placed between the valves and the OPTs.
There is plenty still to be done: connectors, filament regulators and HT bits. Once all drilling is done, I will then move onto wiring…