Hiend Audio, DIY, Hi-Fi, Stereo, Electronics site, for lovers of high-fidelity music reproduction. High-End Vacuum Tubes. Silicon. Do-It-Yourself Audio Systems. Schematics: amplifiers, speakers, horns, CD, DAC. Circuits, Topologies, Acoustics, Cables, Speakers, Voltage Regulators, Equipment Upgrades, Modifications, Problems, Solutions, Tips, Tricks. ------ Dla pasjonatów Hiend Audio, najwyższej wierności odtwarzania muzyki na sprzęcie budowanym, modyfikowanym samemu. Wiedza: elektronika, układy lampowe i krzemowe, wzmacniacze, głośniki, kolumny, tuby, DAC, kable, DIY, porady, sztuczki, problemy, rozwiązania, tor audio.



Oct 11 2014

Print this Post

GU-81 by night …

P1120066 b

These are some preliminary shots of a GU 81 tube, after it is heated up – just a tiny little bit.

Actually, the heater requires 12,6V with a current of 11 A.

I used a 12,5 V AC toroid, rated at 150 W, but unfortunately, the toroid that I used, under the load, …  sort of … started sagging, so it gave no more than 11,7 V …

Therefore, it would be fair to say … that the tube is grossly underheated …

P1120072 b P1120075 b P1120077 b P1120054 b P1120056 b P1120057 b P1120059 b P1120060 b P1120062 b P1120063 b P1120076 b P1120078 b P1120055 b P1120058 b P1120064 b P1120065 b P1120068 b P1120069 b P1120070 b P1120073 b P1120074 b

Permanent link to this article: http://hiend-audio.com/2014/10/11/gu-81-by-night/