What are you referring to as a "gen"?
How could it be possible to substitute two 100uF electrolytics caps with films?
Congratulations for the blind test. I have already assembled my DCB1 board, onl y rests to hook up my new trafo, which I've just received from Farnell. I can't wait hear to it! 😀
Again
That's DC B-1 BLIND TEST (shown) is NOT MINE 😀
I Don't have a money to buy expensive parts 🙁
You've Got Mail, Salas!
Regards
La Ode
That's DC B-1 BLIND TEST (shown) is NOT MINE 😀
I Don't have a money to buy expensive parts 🙁
You've Got Mail, Salas!
Regards
La Ode
I measured my DCB1 Mezmerize build a while ago using Pete Millett's Sound Card Interface and audioTester V2.2 software.
The red line in the graph is the DCB1 output [the blue line is the soundcard for reference]. The graph shows THD for a 1V signal [input and output - no attenuation]. There is just a little bit of third harmonic visible at 3kHz. The second harmonic and all higher harmonics are pretty much concealed by the very low noise floor.
You can also see that the power supply is very quiet: 60Hz is again pretty much buried in the noise floor. 120Hz is the only power supply harmonic that sticks out a bit, but again at a very low [extremely low] level.
audioTester also computes a signal to noise ratio [S/N]. You can safely ignore that in this case because it gets the value totally wrong.
Overall pretty nice.
The red line in the graph is the DCB1 output [the blue line is the soundcard for reference]. The graph shows THD for a 1V signal [input and output - no attenuation]. There is just a little bit of third harmonic visible at 3kHz. The second harmonic and all higher harmonics are pretty much concealed by the very low noise floor.
You can also see that the power supply is very quiet: 60Hz is again pretty much buried in the noise floor. 120Hz is the only power supply harmonic that sticks out a bit, but again at a very low [extremely low] level.
audioTester also computes a signal to noise ratio [S/N]. You can safely ignore that in this case because it gets the value totally wrong.
Overall pretty nice.
Grufti,
Thanks for doing that research! We havent seen anything like that on DCB1 yet so am glad to see what we probably all suspected but didnt know.
Uriah
Thanks for doing that research! We havent seen anything like that on DCB1 yet so am glad to see what we probably all suspected but didnt know.
Uriah
😎
I was there and confirmed that it did performs beautifully terrific!
Clean sound without loosing any dynamics!
Congrats for your design, Salas!! 😎
No. Maybe with adjustable V1.2 shunts that I beta test currently, they have only film caps on the vrefs and outputs. Remote sensing to star earthed load nodes, some investigation on what happens in higher amplitudes and with what voltages and mismatches or degeneration the B1 core could be linearized on peak swings.
Since early October this has been a permanent addition to my modest sound system, possibly the best piece of audio gear I have ever built. It gets used most nights. From the ashes of a nearly-failed group PCB design/buy arose this current PCB design, and it got put into production, thanks to a few dedicated people. Just wish to express my thanks again. DIY is so strong these days...thanks to the willingness of more experienced people to share their ideas. Sharing is giving from the heart, it is so good to see this happen, in a world that seems to be becoming more dog-eat-dog every year, or maybe I'm just getting old. Anyway, back to the gen mods, not all designs stand still... 🙂
Ian.
Hi Salas, I start to build my DCB1, but after test all my 50 pcs jfet, all Idss are from 6.70mA to 7.01mA. May I know is it ok to match them with Idss=7mA ? I using 9v battery to test them, battery "+" -> DMM -> drain -> source and gate -> battery "-" . May I know is it correct method?
I newbie in DIY audio, your advices are very much appreciated.
I newbie in DIY audio, your advices are very much appreciated.
sugden, you are right in using those 7mA matched fets. Though, they don't need to be matched, just to have close values of idss.
Something like pairing a 6.9mA and a 7.1mA would be enough. But the more closed, maybe the better. I suppose.
Something like pairing a 6.9mA and a 7.1mA would be enough. But the more closed, maybe the better. I suppose.
If I use an external lightspeed attenuator on the input of the dcb1 buffer, should I change any of the input/output resistors?
I might be integrating the lightspeed eventually.
Any suggestions?
I might be integrating the lightspeed eventually.
Any suggestions?
Hi Salas
are there benefit to add more value than 4700uF for smoothing cap
can you advice your values for electrolytic caps