1-APRIL-2006
I've been busy designing some kind of magnetic amplifier recently, and didn't update my page for several months but still have some problem wait to be solved.
This is my recently built 1626 Darling amplifier for my customer, with over killed 5U4 rectification.
The schematic design is similar to the original 5965 driven type with minor adjustment on plate resistors to lowered the distortion. I search around for the 1626 tubes but only Sylvania and RCA can be found, and the conditions are not as clean and beautiful as my previous order, it looks dirty and not nicely kept but it sounds marvelous!
As usual I build real wood chassis with alluminium plate on top, paint it with epoxy undercoat and spray with flat black.
I build 2 wooden covers for choke and power transformer for more classic look.
I also found that JAN GE 5965 and Mullard CV455 sounds best on this design, with 27Kohm of plate resistor. The wood veneer output transformers are c core type that I had mentioned earlier in my DIY OPT page, but I wound it 4.7 k ohm as primary.
I also wind a c core 8H choke for this projects, and its sounds better than other type of EI type choke, with fast and solid bass. The 5U4 rectifier is svetlana, and it sounds better than my EH 5AR4.
Not much to tell about this amplifier, but the sound quality is far better when using tube rectifier with oil cap and also c core choke.
I include 4 ohm and 8 ohm for speaker terminal, for easier match with different kind of load.
Although 1626 amplifier looks simple, but this version looks quite big in size, same size as my 2A3 amplifier.
The schematic as shown HERE, I didn't share the cathode resistor for both channel for better sound staging, most of people believe that sharing cathode resistor won't effect any sound quality, but blind test proof that the imaging will be quite off focus.
