The use of CCS in HT power supplies is well known, however generally misunderstood why it can be a good addition to some circuits. There is an excellent article from Gary Pimm which has been lost and luckily I found it on my archive. Here it is in case you haven’t read it. Worth it as a refresher or for anyone who is new to the subject:
Continue reading “CCS in power supplies”Tag: Filament Regulator
DHTs and cathode bias degeneration
A few years back I went down the path of exploring different DHT in pre-amp stages for sonic improvements on detail and dynamics. I explored all sorts of different DHTs as have posted in the blog and many more I never got around to write up about.
Ba DHT Preamp Build
Just in the last days before the arrival of our second child, I had a spot of luck and managed to get some free time to work on my DHT preamp experiments.
Originally I was put off by the hum pickup susceptibility of the Ba German DHT. However, I decided it was time to listen to the design I worked and experimented in my workshop time ago. I remember listening to this valve and was very pleased with its sound.
Continue reading “Ba DHT Preamp Build”DHT Audio Shootout @ London
Here’s the summary of the shootout day we had yesterday at my place with Tony Rees and Andy Evans
Test Music
For testing the pre-amps Andy suggested the following 2 tracks:
- Ravel Feria (Cleveland/Boulez)
- Janacek The Cunning Little Vixen Act 3 Scene 7 “A vixen’s running through the woods” Prague Theatre/Gregor
Andy Evans
The Ravel is orchestrated for a large orchestra and percussion, and listening was particularly for the timbre of strings, brass and woodwind and the clarity of the percussion. The Janacek is for several different voices and chorus, and listening was for the tone and character of the voices and how well they were differentiated from each other. In both cases the overall clarity, life and crispness was considered.
Although I wasn’t familiarised enough with these 2 tracks myself, I found them to be an excellent choice and a reflection of Andy’s musical experience and knowledge as musician.
Continue reading “DHT Audio Shootout @ London”DHT Push-Pull filament regulators
A new article is available regarding filament regulators in push-pull designs
4-65a SE Amplifier: testing filament regulators
The Rod Coleman Filament Regulators were already tested in the New Year. It seems a long time indeed. Here is a selection of pictures after fitting the regulators in their heat-sinks and doing a final test before assembly:
4-65a
Testing the 4-65a filament regulators
4-65a filaments are lovely
46 filament bias and the regulator
46 Driver regulator