我的CJ-PV3 - 摩機編

今次是摩CJ-PV3,方法一樣,量度各級电壓,靜態电流. 按照線路計算,第一級靜態电流1ma
第二級靜態电流2ma. 改動是第一級和第二級电壓放大,張第一級cathode电阻從110K改為92K. 再張第二級cathode电阻從56K改為47K.(只適合12AX7EH和12AT7EH)

再量度各級电壓如圖.在聽感上留保了引人入勝的音色和增加中低音的厚度.

Do you need ORCAD(PSPICE) for analysis ?

http://www.lynx.bc.ca/~jc/tubeData.html

KK.Ho

[quote:6475a7d2ef="kk_ho"]Do you need ORCAD(PSPICE) for analysis ?

http://www.lynx.bc.ca/~jc/tubeData.html

KK.Ho[/quote]

Of course, please help.

I'm confused.  From the schematics, the two tubes should be either 12AX7 or 5751.  But why we are using one 12AX7 and one 12AT7?

[quote:d2aecddf1f="hpn"]I'm confused.  From the schematics, the two tubes should be either 12AX7 or 5751.  But why we are using one 12AX7 and one 12AT7?[/quote]

I simply pick one schematic to show the measured voltage. I am using 12AX7EH for the 1st stage and 12AT7EH for the 2nd stage to build the PV3

muka

Any reason for not following the original PV3 design, i.e. use two 12AX7 or two 5751?

[quote:8250dc7dec="hpn"]muka

Any reason for not following the original PV3 design, i.e. use two 12AX7 or two 5751?[/quote]

I think the schematic that I picked up is not correct. The 2nd stage should be 12AT7 because based on the schematic diagram to calculate the idle cathode current is 2ma and bias is -2V that match with the specification of 12AT7.

muka,

Thanks for explaining.  

Probably it is not you who picked the incorrect schematic diagram.  In fact, I've seen in various other ocassions that the same 12AX7/5751 schematic was stated for PV3.  So, just wonder whether the PV3 DIY course conducted by HiFi Fever was the original design/circuitry.

[quote:805ff012a4="hpn"]muka,

Thanks for explaining.  

Probably it is not you who picked the incorrect schematic diagram.  In fact, I've seen in various other ocassions that the same 12AX7/5751 schematic was stated for PV3.  So, just wonder whether the PV3 DIY course conducted by HiFi Fever was the original design/circuitry.[/quote]


The DIY course of HiFi Fever is using 12AX7 and 12AT7.