Custom 301A DHT Preamp with Lundahl OPTs

This is a single stage custom made 301a directly heated(DHT) tube preamp using the excellent Lundahl LL2745 output transformers. The preamp was made by Radu Tarta, a very skilled builder using the best techniques and parts to extract the beauty from this legendary tube.
The input is direct coupled through dual Alps potentiometers. It uses Coleman filament regulators for a very quiet preamp. According to the designer using LL2745s the gain is about 3dB with an output impedance of around 470 ohms. This works perfectly for use with most current DACs which usually tend to have a high output and to drive most tube or Solid state amplifiers. I used it with my First Watt SIT2 amp with great success.

The audio tubes are select Cunningham CX-301A. These are readily available as NOS or used. These tubes are from 1920-1930s and have a special sound probably related to the fact that they use Thoriated Tungsten filaments. Their tube sockets are mounted using neoprene to isolate the tubes from vibration.

The power supply uses three transformers (one for power and two for the DHT filaments). The high voltage is provided by tube rectification (6BY5GA) and LCRC filtering with a 30H/40mA choke followed with two 10uF Obbligato caps parallel with 47uF Mundorf M-lytic and then followed by a solid state shunt regulator.

The attractive wooden enclosure is made of American cherry wood with a light oil urethane clear coat protection. The inside of the case is screened using a 5 mil 99.99 pure copper foil. Top plate is brushed aluminum. You can see the amp builders blog for the amp here:
https://simplepleasuretubeamps.wordpress.com/2015/03/
With my Omega Alnico single driver speakers the sound is very clear and rich with great dynamics and presence.

I will also include an extra rectifier and an extra matched pair of CX301A tubes. I have some other variations of the 01A tube available separately for some tube rolling fun or as another backup set.

$895 plus shipping (to US lower 48 states only).