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Allen Wright inspired world class DIY balanced tube HiFi preamp kit

Allen Wright RTP3C inspired world class DIY balanced tube HiFi preamp kit.

I think this preamp is seen as one of the best balanced tube preamps in the world. The set consists of 2 fully balanced line stages without RIAA, with integrated SuperReg type PSU´s, which are supplies with a Constant Current Source, followed by an advanced shunt regulator.

The pair is delivered as 2 assembled PCBs, without tubes, including full documentation on CD and including Allen Wrights book ”Building tube preamps”. On the pictures you will see that a few parts are missing on one of the PCBs, that is because they were used for a mains filter, that didn´t have a positive influence on the sound, and therefore is bypassed.

They original amp has an L-C PSU configuration that is quite hard to work with, so this design has several integrated regulators in a more conventional design. The amp can be build as one double decker or with a separate box for transformers. A full set of Toroidy transformers for a dual mono build is included, consisting of the following special made and over dimensioned Toroidy audiograde pottet toroid transformers: 2x15v - 100VA, 2x12v - 50VA, 2x20v - 10VA, 2x24v - 10VA og 2x250v - 100VA.

I will only sell the complete package, and it is only recommended for an experienced DIY´er.

I have bought the PCB´s as prebuilt and tested, but have never myself had power on them. You will need 5 pairs of ECC88/E88CC, PCC88/PCC189, 6922, or equivalent, because tubes are not part of the delivery.

On the transformer picture I only show 4 of the 5 transformers, because at the time I didn´t have the 5th, but I have now.

They reason for selling it is that realistically I will never have a fully balanced system, so I will never be able to get everything out of this fine design. The price is Euro 525, and Euro 35 extra for sending inside EU.
 
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