Yamaha MVS-1 Passive preamp

[belgianbrain]

I bought a Yamaha MVS-1 passive preamp to put between my Lampizator DAC and my Yamaha M2 power amp.

Opened it up.

Alps 8K pot. Thumbs up.

20k resistors and capacitors (unknown value, won't measure in circuit, but presumably small) shunt all inputs to ground. Circuit then proceeds through selector switches, through coupler, through alps unit, and to output where there are the same capacitors to ground and 460 Ohm resistors in series with the output.

:dammit:

There only conceivable purpose for the caps in my mind is to shunt high frequencies to ground? I'm not sure I understand the purpose of the resistors.

I'd like to see my signal go only through the selector switches and the alps unit and be otherwise unmolested.

Can anyone think of good reasons why I shouldn't snip all the caps and resistors off the board and short the 460 Ohm output resistors?

 

[Martin.Ca]

Are you sure those aren't for filtering the levels for the "surround" / "presence" speakers? It wasn't simply a passive pre-amp.

 

[belgianbrain]

These resistors on are the input selector for the main. After the resistors/caps/input selector, you have the main out on the back, which is jumpered back to the main in on the back alongside the surround inputs and then the main/surround inputs are subject to the pot attenuation.