| Ultrasimple MM/MC RIAA Preamp mkIII - Click HERE for Original Thread |
| GlidingDutchman |
A friend of mine (Ludo) tweaked the circuit by Mads K.
I a having trouble getting it to work so I thought I post it here for some discussion. |
|
|
| peranders |
| Have you checked the working points for all three JFET's? Are the JFET's capable of 12 mA Id? |
|
|
| GlidingDutchman |
| quote: | Originally posted by peranders
Have you checked the working points for all three JFET's? Are the JFET's capable of 12 mA Id? |
20mA max...
D |
|
|
| Conrad Hoffman |
| You're at the mercy of whatever current flows with the gates grounded (Idss?, I forget), and this can vary. You might have to adjust the upper three resistors to get the voltage drop you want. Other than that, it looks like it should work fine. I assume the gain is rather low and another gain stage has to follow this. |
|
|
| GlidingDutchman |
| quote: | Originally posted by Conrad Hoffman
You're at the mercy of whatever current flows with the gates grounded (Idss?, I forget), and this can vary. You might have to adjust the upper three resistors to get the voltage drop you want. Other than that, it looks like it should work fine. I assume the gain is rather low and another gain stage has to follow this. |
I guess so...
Conrad - this design stems from here: http://www.diyaudio.com/forums/show...&postid=1550522
and the unit, as designed by Mads K works just fine as it stands with my Kiseiki Purpleheart Sapphire low output MC cartridge...!
D |
|
|
|
|
