I had a small transformer laying around and decided to try using it as part of an I/V stage.
I hooked it up between 4xPCM56k (4mA total) and an active buffer stage.
I put a 100R across the primary and let 'er rip.
I was literally amazed at the increase in clarity I was getting. Very good transparency as well. But there was one thing lacking that I couldnt get a grasp of. It felt like it was a little skinny.
Measuring the unit showed me what I was hearing. Using indivivual tones recorded at -20dBFS I noted that the voltage stays stable but the current rolls off starting at about 40Hz. 20Hz is only half the current output of 50Hz.
Can anyone explain to a layman why this is the case?
Thanks!
P.S. the transformer is model JT-DB-EPC from Jensen. Used as step-up. approx. 1:12
I hooked it up between 4xPCM56k (4mA total) and an active buffer stage.
I put a 100R across the primary and let 'er rip.
I was literally amazed at the increase in clarity I was getting. Very good transparency as well. But there was one thing lacking that I couldnt get a grasp of. It felt like it was a little skinny.
Measuring the unit showed me what I was hearing. Using indivivual tones recorded at -20dBFS I noted that the voltage stays stable but the current rolls off starting at about 40Hz. 20Hz is only half the current output of 50Hz.
Can anyone explain to a layman why this is the case?
Thanks!
P.S. the transformer is model JT-DB-EPC from Jensen. Used as step-up. approx. 1:12
I take it this is with the Wadia?
I found the same with transformers and passive I/V's good detail but no balls/rhythm. The Zap has loads of balls/rhythm and great clarity/detail.
Cheers George
I found the same with transformers and passive I/V's good detail but no balls/rhythm. The Zap has loads of balls/rhythm and great clarity/detail.
Cheers George
You are using the wrong transformer. 1:12 cannot work. What you need there is 1:1 or 1:2 max 1:4. With 1:12 what your DC sees is impedance that is 144 times lower than what it is on the buffer side. Roughly with lets say 150K of buffer input impedance your DC is loaded with only aprox 1K. Your buffer impedance is more likely less than 150 K, so you are most likely loading DAC with even lower impedance than 1K what is very bad.
This seems to be a step-down transformer which you use as a step-up. As there is no published data for this connection it is quite possible that the transformer runs out of inductance at low frequencies.
Yes, it is. BTW, George, I know you like the Zap, but I did manage to finally map out the Sledgehammer circuit. If you are at all interested or curious, let me know and I'll send you the schematic. Its actually far more simple than it looks.
I'm going to play around with the transformer a little more to see if maybe I can get it to work better.
I first tried this because I had it laying around anyway. But, short of the lack of bass, what I got in improved clarity was really quite amazing.
Thanks for the input everyone.
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