“Retro-EAR834p” - an EAR834p tube MM phono stage

This is the third of these MM phono stages I have built and all for commission jobs. As an addition here a MC step-up stage was also built. The MC stage is the La Pacific single FET, battery driven stage and is seperate from the MM stage. The PS is external and uses a Hammond tranni. The EAR kits come with a PS board with HT and filament DC rectification and filtering. The HT is smoothed by a high voltage power FET. Works well. 

Looks smart on the stippled Hammond wood cheek chassis. With Tung-Sol and LinLai tubes sounds detailed and transparent and the new owner reports excellent bass. We are both happy with the result.

“ZeroOne-A” - 100 year old globe DHT tubes preamp.

 

Inspired by my 71a tube amp I thought I would try another DHT preamp but with a 01a tube. Again Cunningham tubes used as with the 71a but with the 71a I also have RCA tubes. These globes are from the mid 1920s. Where the 71a preamp - “MWH” - has mainly carbon film resistors in the signal path and a Russian PIO output cap this build has all metal film resistors and a Mundorf EVO oil output cap. 

To enhance the performance of both preamps I built a new much beefier external PS on a repurposed cast AL chassis which already had a RFI/EMI power filter added. The 5V DC on the heaters is regulated and balanced. The 01a preamp has a remote Alps volume control and two inputs. Hookup wiring is via fine silver plated copper wire and high quality heavy duty RCAs ate  used. Not a lot of gain but a very revealing, detailed sound with extended reverb. Love the colour - Iron Stone.