Listened to the preamp today through two other amps. AJ and TSSA. Sounds great. bumping head on ceiling, IMO. will be more about tweaking of cirucit from here on. Listening to Patricia Barber, Companion, SACD, and it just excellent. Speaker limited at this point. Gotta try UGS to compare. Got the transistors, so will be working on that, populating shunty, and BA output. Will probably go 4 pairs@.5A on output. Gotta figure SE resistor value. Been looking at BA1 output as possible SE CCS.
Botte and me discussed about a year ago that our BA-3 unbalanced builds had around 8-9x gain, though theory says about 30x!
There were many tries to calculate the exact gain in the thread, but a bit contradictory.....
so it seems calculation and part dependent......
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A BA3 Balanced schematic
The simplified schematic is attached. It is a different topology from that done by Mr. Pass. It shows two conjoined BA3 Front Ends. The P-MOSFETs are configured like a differential amplifier. Ditto for the N-MOSFETs. I'll gladly elaborate if needed.
The simplified schematic is attached. It is a different topology from that done by Mr. Pass. It shows two conjoined BA3 Front Ends. The P-MOSFETs are configured like a differential amplifier. Ditto for the N-MOSFETs. I'll gladly elaborate if needed.
Attachments
The following is the expected performance of proposed circuit; pending experimental confirmation:
- DIDO; diff in to diff out
- SIDO; single ended input to diff out
- Potential for vanishing distortion across a load which is connected between the output ports.
Please clarify your question. A bit obscure which prevented an answer. In your opinion, what is the impact on performance by the absence or presence of an error current.
buzz, that FPC is awesome stuff, you can buy by roll, should even make nice low cap speaker cable, like copper foil thingy without all the work. the board connectors for it are nice for making your own with flex PCBs, which is what i'm doing for some line level stuff i'm working on.
as for your gain mate, good chance your output on the DAC will be going up some with the NTD1 too.
BTW keratherm landed at Mikes in the US yesterday morning, should be with you shortly.
as for your gain mate, good chance your output on the DAC will be going up some with the NTD1 too.
BTW keratherm landed at Mikes in the US yesterday morning, should be with you shortly.
I am going to redesign he preamp for about 10dB of gain with balanced ouput. Still gonna be too much for my horn setup. If NTD1 has little gain then perhaps all is moot and passive pre is in store. Not big deal, as lessons carry over to other things like power amps.
Antoinel, Nelson speaks of distortion reduction due to error current in his Zen V6 article. From what I understand it is the result of special feedback for which he is known, and is different from standard balanced/bridged operation.
Antoinel, Nelson speaks of distortion reduction due to error current in his Zen V6 article. From what I understand it is the result of special feedback for which he is known, and is different from standard balanced/bridged operation.