Hi
just buy the jc-2 kit from eBay:
the recommends are:
• Input stage : 2.5-3MA
• Voltage amplifier stage : 20-25 MA
i suppose that VR2 change the currents input stage? and 3mA*R17=0.18v ??
how i change the amplifier stage currents ?
the gain according to eBay is 3.7, can i change it? how?
thanks
just buy the jc-2 kit from eBay:
the recommends are:
• Input stage : 2.5-3MA
• Voltage amplifier stage : 20-25 MA
i suppose that VR2 change the currents input stage? and 3mA*R17=0.18v ??
how i change the amplifier stage currents ?
the gain according to eBay is 3.7, can i change it? how?
thanks
Attachments
you talk about the feedback? i think the big cap its the feedback.If I remember well, there's another part of the circuit that is not included in the schematic, involving an output capacitor.
the input, its balance or un balance?
thanks
If I remember well, there's another part of the circuit that is not included in the schematic, involving an output capacitor.
The output capacitor is on the mainboard, I´ve posted the schematic already here:
http://www.diyaudio.com/forums/solid-state/10160-need-build-jc-2-preamp-8.html#post3407627
I have played with LT Spice today and did a simulation of the
line stage.
Thanks to Bob Cordell (for the models) and dado (models and
spice parameters).
Now this is just a simulation, but at least from this theoretical
point of view it is perfect:
gain of 10, ca. 1V out, Total Harmonic Distortion: 0.000022%
line stage.
Thanks to Bob Cordell (for the models) and dado (models and
spice parameters).
Now this is just a simulation, but at least from this theoretical
point of view it is perfect:
gain of 10, ca. 1V out, Total Harmonic Distortion: 0.000022%
Attachments
No.
The input is unbalanced.
Sorry if I am a little dense, but I had same question - what is -IN for if not balanced input (missing the R15 // C6 to ground)?
Attachments
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- Need to build JC 2 preamp