# NAD: Does anyone recognize this Marshall 1987x?



## Nino Rafanelli (Jan 24, 2018)

Picked this up off of Kijiji last week. Has a few mods done and I'm trying to find out more about it.

Front view. Pre PI master volume installed where there pilot light used to be. New indicator LED (purple) installed above the MKII logo.









View inside.









V2a cathode bypass cap - 330uf if I'm not mistaken.









Adjustable high cut filter attached to the High Treble volume pot. 









Pre-Phase invertor master volume, connected after the effects loop between the effects loop card and BN4 on the PCB.


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## Nino Rafanelli (Jan 24, 2018)

Hum balance removed at VR2 (used for the high cut filter above?) and replaced with 2 resistors attached to 2 caps spanning across W1, W2 and W3.









78k resistor along with a 68k at each input.









Does anyone recognize this amp? I would love to get more information on the above modifications.

I'm considering bringing it back to stock and replacing the pre-PI mv with a LarMar post-PI configuration. Any thoughts on the pro's/con's of this change?

I have already removed the adjustable high cut filter on the High Treble volume control, as seen here.









Next I'm considering replacing the 78k resistor at the input with a 68k and the hum balance trim pot back to original configuration.

Thanks!


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## sammyr (May 7, 2013)

Personally I prefer the lar/mar. If you're changing the resistor on the input you may want to consider mounting those resistors at the tube socket pin. If the amp isn't noisy then I wouldn't bother. It does look like the clearance on the effects loop is pretty tight.


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## Nino Rafanelli (Jan 24, 2018)

Are you aware of any place in the area which stocks the LarMar parts (PEC pot, etc.)?


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