Kingston
Well-known member
It's been a long time coming, as this was my first bigger project. I had my share of beginners errors, and a few good mistakes here and there. It works like a charm now and is fully utilised in the studio already. I had to move the (now bulky) PSU out of the unit as it was causing far too much hum. There's phantom, -20dB pad, gain, DI input and 5-step output attenuator on both channels:
Hi-res version: http://www.michaelkingston.fi/files/NYD-two-bottle.jpg
Hi-res version: http://www.michaelkingston.fi/files/NYD-two-bottle-inside-highr.jpg
Noise at mingain, 200-ohm load. Balanced output to RME HDSP soundcard.
Noise at maxgain (+50-60dB or so, didn't measure it yet), 200-ohm load. Balanced output to RME HDSP soundcard.
Frequency response is damn near flat throughout the gain range, with 0.5dB deviations here and there from 30hz to 20khz. (tested with sine sweeps, pictures to come)
I'll post sound examples later, recorded with ribbons and such that this preamp seems to like quite a bit. Needless to say with jensen JT-110K-HPC (I scored them used for cheap) and OEP output trafos the sound is absolutely top notch. The +48V is from Gyraf G9 schematics (thanks Jacob).
This has been a tremendous learning experience. Thanks to everyone who helped me here in misc threads. If there's something to improve, it would be the layout. Right now the sound and noise performance are good enough for me - much better than I ever expected, but next time I know to start the whole layout design from "ground up".
What a great feeling that the best preamp I've heard was built by me. All the credit goes to the designer, of course, and this is where I tip my hat to Newyorkdave. What a great sound. :green:
Hi-res version: http://www.michaelkingston.fi/files/NYD-two-bottle.jpg
Hi-res version: http://www.michaelkingston.fi/files/NYD-two-bottle-inside-highr.jpg
Noise at mingain, 200-ohm load. Balanced output to RME HDSP soundcard.
Noise at maxgain (+50-60dB or so, didn't measure it yet), 200-ohm load. Balanced output to RME HDSP soundcard.
Frequency response is damn near flat throughout the gain range, with 0.5dB deviations here and there from 30hz to 20khz. (tested with sine sweeps, pictures to come)
I'll post sound examples later, recorded with ribbons and such that this preamp seems to like quite a bit. Needless to say with jensen JT-110K-HPC (I scored them used for cheap) and OEP output trafos the sound is absolutely top notch. The +48V is from Gyraf G9 schematics (thanks Jacob).
This has been a tremendous learning experience. Thanks to everyone who helped me here in misc threads. If there's something to improve, it would be the layout. Right now the sound and noise performance are good enough for me - much better than I ever expected, but next time I know to start the whole layout design from "ground up".
What a great feeling that the best preamp I've heard was built by me. All the credit goes to the designer, of course, and this is where I tip my hat to Newyorkdave. What a great sound. :green: