GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Melquiades Amplifier
In the Thread: Single-stage Melquiades vs. DHT amps

Post Subject: Hum vs voltagePosted by DHT4ME on: 5/13/2009

…they say: “The 4Volt technique gives best ratio between diameter and length of the filaments”. It does not sound very credible to me, in fact is sound more like marketing BS.

This is true. It comes down to thermal cycling. I love the #26 tube but it is real hard to get quiet. It has a 1.5v 1a filiament. The heavy draw causes thermal cycling which is very hard to null out. There is also more ratiated garbage from the current. A tube with 2.5v is far easier to get noise down. Go the opposite direction and it starts to get bad again. The #10 is a Thoriated Tungsten filament 7.5v and it is a bitch. It has a thin wire filament. The #50 has a 7.5v filament but is oxide coated and much thicker. The #50 is less hum prone than the thin wired #10. I have never bought any euro DHT's but have heard nothing but high praise for them. I one day would like to try the RS241. It is supposedly stunning.

Rerurn to Romy the Cat's Site