Did I see the table of Edison's son?
The BA-3 without P3 correction seems to have much k2, so big bass is present......!
😀😀
The BA-3 without P3 correction seems to have much k2, so big bass is present......!
😀😀
Balanced killed some of it, but you can tell some remains. In truth the final version will probably be trimmed for lowest distortion, or st the least, similar 2k and 3k. Don't have time to fiddle for a while. Just wanted to get it playing. Right now have 100R between sides. I will bump that to 150-200. Little more degeneration of FE. The final version will probably have ZVP/ZVN4424 in the output. Look at the curves. What big transistor does it remind you of?
http://www.diodes.com/datasheets/ZVN4424A.pdf
http://docs-europe.electrocomponents.com/webdocs/002d/0900766b8002ded6.pdf
SJEP120R100A datasheet - * JFET, SIC, AUDIO, 1200V, 17A, TO247 * Transistor
SJDP120R085 datasheet - Specifications: Transistor Type: JFET ; Breakdown Voltage
Looked at the 2110, but the 4424 series is apparently a bett complimentary pair, from what I haev read.
http://docs-europe.electrocomponents.com/webdocs/002d/0900766b8002ded6.pdf
SJEP120R100A datasheet - * JFET, SIC, AUDIO, 1200V, 17A, TO247 * Transistor
SJDP120R085 datasheet - Specifications: Transistor Type: JFET ; Breakdown Voltage
Looked at the 2110, but the 4424 series is apparently a bett complimentary pair, from what I haev read.
So you are going UGS way.....
But the ZVN/P cannot be driven with the same current like the Toshibas
This project will branch into power amp FE and preamp. Preamp might be standard SUSY or other options, like no feedback folded cascode. Haven't decided really. My thinking is that I want the preamp as low noise and distortion free as possible without clamping the sound. Thinking I want the power amp to provide the color.
The Toshibas can take a lot more heat with these sinks. It will be interesting to watch THD spectra varying VAS bias up and down. BA3 seems to be pushing character of amp onto VAS. Intentional or even true, dunno yet.
The Toshibas can take a lot more heat with these sinks. It will be interesting to watch THD spectra varying VAS bias up and down. BA3 seems to be pushing character of amp onto VAS. Intentional or even true, dunno yet.
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ZM,
Should I design the preamp board to mount directly to the the Shunty clone to minimze trace link or is a flat cable connection OK. Digikey has flat ribbon cables made to length that can be used, but using a module on top is doable if beneficial in some way.
Should I design the preamp board to mount directly to the the Shunty clone to minimze trace link or is a flat cable connection OK. Digikey has flat ribbon cables made to length that can be used, but using a module on top is doable if beneficial in some way.
think heat
however - shunt reg is best put near load
you don't need flat cable for 3 wires/channel
however - shunt reg is best put near load
you don't need flat cable for 3 wires/channel
I would creata space for it, with all sinks flanking the oustkirts of the gain board. It will be small, so not too much real estate. I have a sense/shutn setup on the output, like Salas, reg to account for wire length. THe ribbon cable is cheap organized and clean, that is wht i thought about it.
Flat Flex Cables (FFC, FPC) | Cable Assemblies | DigiKey
Flat Flex Cables (FFC, FPC) | Cable Assemblies | DigiKey
The BA-3 frontend especially in balanced mode fulfills your wishes... I never had such a low distortion than with BA-3,even unbalanced, and with a source follower output. (F4 like)
The M2 xformer has higher distortion.
I am realizing after hearing this, how little gain I need, and that us with 87-88dB speakers. J River tells me original signal is 30-35dB down at pretty loud listening levels. Folded cascode FE gives low gain, from what I have read. I think someone said it is basically like a current transfer stage. FE Jfets largely determine the gain of the circuit. Supposedly very stable configuration, so feedback is not needed. I may not need any gain out of Preamp at all, with 5-6dB being plenty, but 10-15 will be my target. You know how things are, that may change ten times😀
@ZM, i did sense thing only becaus wit was simple. Abbraxalito has little blog about corcuit. I dropped the output stage of shunty and jut used TL431 and pass transistor. Main reason is ease of board drawing😀
@ZM, i did sense thing only becaus wit was simple. Abbraxalito has little blog about corcuit. I dropped the output stage of shunty and jut used TL431 and pass transistor. Main reason is ease of board drawing😀
at the moment I use also only unbalanced BA-3 and crippled F4, enough gain for the Lowthers/Tone Tubby.
With more gain I have problems to get the volume down with my pots....
With more gain I have problems to get the volume down with my pots....