Salas DCG3 preamp (line & headphone)

diyAudio Chief Moderator
Joined 2002
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It can be done capacitor coupled output too but I don't recommend it. Everything is audible, very simple signal path, very fast circuit. Couplers spoil it.

(build example by V George)
 

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diyAudio Chief Moderator
Joined 2002
Paid Member
I had question about using 2SK389-V Toshiba. Answer is yes it will work. J3 (with R3 as degeneration) fixes the JFET LTP total current at about 5mA so the IDSS of the monolithic chip won't matter as long as it is >3mA tested per element. What will happen is THD will go 0.00025% but the flat trend will go rising trend. I know because I have tested K170BL and V matched pairs. LSK389 does not go such so much because it has less pF. I have tested that too. Its elements curve matching is visibly worse than uPA though. The NEC behaves closer to 2SK117. Pins order is compatible to Toshiba 2SK389. Don't connect the sub pin to anything or it will hum.
 

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My DCG3 Experience

Hi All, I am really grateful to Salas for including me as a beta tester for DCG3 project.

I started sometime early June when I received the schematic. With a lot of help (and patience) from Salas, I have managed to put together my working DCG3 prototype and has been tweaking/listening to it the last month.

Let me state upfront that this is my most eagerly anticipated DIY project. I set out to build it double mono, power it with V1.2 main rail and with LDR volumn control, the result is a great sounding and most satisfying preamp in my system.

Let me attempt to describe how it sounds (subjectively in the context of my all DIY system); compared to my last preamp which is based on a famous buffer stage/LDR attenuation/V1.2 psu, it sounded faster, equal to if not more transparent, has better resolution, more detailed, better tone and image density, and exhibit tight control when the music gets complicated.

I strongly recommend everyone here to try this out in your system.