Introduction: Building the Muffsy Phono Preamp PP-2
This instructable is outdated, visit Muffsy Home Page for Muffsy PP-4.
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This instructable is outdated, visit Muffsy Home Page for Muffsy PP-4.
Participated in the
DIY Audio and Music Contest
9 Comments
7 years ago
Hi skrodahl, great project! :-)
I'd like to ask you one thing: how is important the capacitance tolerance of the capacitors used in this preamp? I refer especially to the polyester capacitors - which are responsible for the equalization if I'm not wrong. Should I choose M (20%), K (10%) or J (5%)? Thanks in advance!
Reply 7 years ago
The 47 and 68 nF capacitors form the RIAA filter. I'd choose 5% or better. The other capacitors can be 20%, with no ill effects.
Reply 7 years ago
Many thanks for your response :-)
7 years ago on Introduction
Going to try this as sson as possible. One question though - is it possible to set an adjustable gain through a potentiometer knob?
Reply 7 years ago on Introduction
It could be done, but I don't recommend it.
The high amplification of the (very low) signal from your turntable, means that any small variations between the two potentiometers will become quite noticeable. This is especially true if you use a stereo potentiometer.
Since this is DIY, you can adapt the gain to suit your needs:
https://hackaday.io/project/4788-muffsy-phono-preamp-pp-2/log/15926-more-gain-less-gain
Reply 7 years ago on Introduction
Thank you for your reply... Indeed that was what I suspected, however I saw that you used switches to vary the gain and it got me wondering. Maybe if I find a way to limit the pot's range to the same values you set with the switches (just wondering, probably going to try the PCB as is first)
7 years ago on Introduction
Snyggt jobbat Håvard :) Göran låvorda den, men själv har jag lämnat vinylspelare bakom mig.
Reply 7 years ago on Introduction
Jag hörde du var mer inne på lasrar och sånt numera. :)
7 years ago on Introduction
This kit looks really fun to work with!