Settings on phono stage

 Here is the instructions:


Cartridge loading is achieved via internal dip-switches. Factory setting is 100 ohm, zero capacitance.


Two 6-row dip switch banks are located on the board. Loading is as follows:


  • Dip Switch 1 up = 100 ohm; Dip Switch 2 up = 100 ohm.
  • Dip Switch 1 & 2 up = 50 ohm.
  • Dip Switch 3 up = 1K; Dip Switch 4 up = 1K.
  • Dip Switch 3 & 4 up = 500 ohm.
  • Dip Switch 5 up = 47K; Dip Switch 6 up = 100pf.
  My cartridge is Clearaudio Concept MM.  Specs say:  Loading impedance :  47kw   Loading capacity : 100pf.. I put dipswitch 5 up,should 6 be up ? It sounds good,but I have some hum and my woofers seem to be fluttering quite a bit also. If anyone could help  it would be much appreciated. I did email manuf. but havent heard back yet.
Switch 6 is just giving you added capacitance which your cartridge may or may not need to sound it's best.
Just listen but I doubt you'll hear much difference in which case leave it switched down.
Switches 1-4 are for moving coil cartridges.  Keep all them down.

Set 5 & 6 to the up position.
Agree. 5 and 6 in the up position, all others down.
 Appreciate the help guys. Thank you
Apparently putting switch 6 up adds 100 pf to whatever the input capacitance of the phono stage is when switch 6 is down (which will be greater than zero, and perhaps a few tens of pf’s). As you indicated a load capacitance of 100 pf is recommended for your cartridge. Unless your phono cable is exceptionally short its capacitance together with the capacitance of the tonearm wiring and the input capacitance of the phono stage with switch 6 down will almost certainly total around 100 pf, and very possibly more. Therefore the most accurate performance of your cartridge will most likely occur with switch 6 down, although it is possible that having switch 6 up may be subjectively preferable, or as Halcro said it may not make much difference either way.

Whatever difference load capacitance may make will occur mainly in the treble region.

Switch 5 should be up and 1-4 down, of course.

None of this will affect the hum or fluttering woofer issues you mentioned. Is there a ground wire connected between the turntable and the phono stage?

-- Al

 Al, the phono stage is built in to the pre amp ( Modwright LS100) The ground from the TT lead is connected to the pre amp. I just got this 2 days ago and havent really had much time with it. I will try moving cords,flipping plug polarity where possible.I will also try re-seating the tubes in the phono stage. Thanks for your input.
Hum is not coming from the dip switches....sounds like a ground issue, or too you may need shielded cable if you aren't using it now.  Although shielded cable closes in the sound, it may be your answer for the hum.