• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

WE417A Valve Preamplifier

Dear Members,
Just like to share my latest construction.
It’s a preamplifier (line level), based on the small WE417A valve (one each channel), using output transformers. The final result is shown on the attached picture (hope you enjoy it).
List of inside goodies:
- One input resistor from Shinkoh.
- Volume Pot from TKD.
- Balance Pot from Alps on its Black Beauty version (my new old stock).
- Input control from front panel through C&K switches, to relay input board.
- Input relays from Nais (TDS).
- All aluminum chassis (based on Hifi2000 parts), 20mm sides, 10mm CNC machined front.
- Stainless steel shafts for front panel knobs connection to the pots.
- 4 special polymer bearings to guide the shafts (feel is incredible).
- 2 machined connectors from shafts to pots.
- Lundahl mains transformer.
- 1 double Lundahl choque.
- 2 more choques from Hashimoto.
- 3 double Elna Cerafine 100uF/500V power supply caps.
- All power cabling Nordost single strand copper.
- 5AR4 valve rectifier.
- 2 TDO 25W resistors to lower plate voltage from 200V to 180V.
- New old stock Western Electric Valves.
- 2 Tentlabs Heater supplies.
- Hashimoto output transformers.
- Direct connection from input to 1 resistor, next to volume and balance pot, into the valve grid, and direct to Output transformers. Nothing more, just a direct connection to output connectors through the 600 ohm transformer connection.
- All signal wiring is cryo treated pure silver from Audio Consulting.
- Neutrik RCA panel connectors.
- Furutech IEC connector.
It sounds simply astonishing with these impressive Hashimotos.
Best wishes for 2011.
 

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