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just modded my V-LPS

cyto

cyto

Super Member
I added a 6 position switch and some resistors to allow adjustable input impedance. I was an electronics tech in the 70s so I figured what the heck.
It works! :thmbsp: Now I can experiment with my AT440mla and M97xe.

Thanks for the info from this site and thanks to catman :thmbsp: :thmbsp:

The finished product
VLPSandswitch.jpg


Installed
VLPSandswitchinstalled.jpg


Inside the V-LPS
inside2.jpg


Inside the switch (not really as neat as I would like, but it works)
switchinbox4.jpg
 
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While you were in there did you notice what the input capacitance is on the V-LPS? 100pF? 220pF? This spec seems to be impossible to find.
 
Shunt loading/'tuning' capacitance is of primary interest to Shure cart users, resistance is more 'universally' adaptable. It's be no prob to add another 2-pole/6 position R/S switch and some plastic film caps to make the shunt capacitance adjustable up from that of the rest of the system's baseline value.
 
Pio1980 said:
Shunt loading/'tuning' capacitance is of primary interest to Shure cart users, resistance is more 'universally' adaptable.
Click to expand...

I was thinking of Audio Technica cartridges, most of which have a spec'ed total load capacitance of 150pF (including tonearm wiring and interconnect). The less input capacitance the better it seems, at least for Audio Technicas. I suppose that could be compensated for by adjusting the resistance, as cyto has done.
 
a multi position rotary for R and another for C. sounds like an idea.
I was entertaining useing some mini toggles to switch a few Rs around. The external box seems good way to go, just cliping the internal parts from their circuits leaving all the RCAs in place for normal use.

how far from TT and preamp?
 
Last edited:
ferninando said:
a multi position rotary for R and another for C. sounds like an idea.
I was entertaining useing some mini toggles to switch a few Rs around. The external box seems good way to go, just cliping the internal parts from their circuits leaving all the RCAs in place for normal use.

how far from TT and preamp?
Click to expand...

It is right behind the TT, a few inches, about 18 inches from the Yaqin MS-20L. The mod has not added any hum or interference (so far). I am always careful about making sure things are properly grounded.
 
After playing several LPs with my AT440MLa and M97xe I came to the conclusion that cartridge loading does work. The AT440MLa seemd to sound best at 32K and the M97xe at 62K. The differences were not monumental, but noticeable. Just my observations. Here is the end result, I have it right behind the TT for easy reach.
installcompletecomp.jpg
 
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