Valab 23 step

[Mordicai]

I bought one of these to put in my new stereomour build. Will this be a straight forward mod or will I need some other modification?

[feeench]

I put one in my S.E.X. 2.1 build and it's quite straightforward. I purchased the 100K version because the original pot for the S.E.X. was that value, but I've heard 50K versions work fine as well.

EDIT: You may need to modify the chassis plate slightly with a dremel tool or similar. I used a pair of pliers in a pinch to chew away some metal to get things to fit properly.

[Mordicai]

Feeech, yes I put a 100k in my Crack, but I asked the question here about the Stereomour because Paul had mentioned that it was a somewhat difficult procedure. Still waiting on my kit ordered last month.

[Chris65]

Feeech, yes I put a 100k in my Crack, but I asked the question here about the Stereomour because Paul had mentioned that it was a somewhat difficult procedure. Still waiting on my kit ordered last month.

Not sure why, looks to be plenty of room at the front of the chassis plate, maybe a larger hole needed, then just wiring.
A quick scroll through the forum & I spotted an Elma attenuator & an Alps pot in Stereomours.

[grausch]

You need to enlarge the chassis hole slightly. I used a metal file and it worked quite well.

I do not have my Stereomour at the office, but can comment that I did not join the top and bottom ground as I did in the Crack.

Just follow the instruction per the manual and ensure that all your wires are connected where they should be. Take your time and think about how you will route the shielded wire optimally. Since each bit of shielded wire has three wires inside, it does require some careful planning and measuring to ensure that a) you keep as much of the shielded portion as possible and  b) your drain wire reaches the terminal strip.

[Grainger49]

Joining the top and bottom ground makes the next step, tying the volume control to ground/chassis/safety ground more simple.  Of course, you can do it either way.

[Mordicai]

Thanks for the feedback. Sounds like it won't be much different than the Crack install. Maybe after a few years and a few more kits I might actually have some idea what Im doing.

[grausch]

@Grainger: Interesting. I replicated the wiring exactly as per the manual. The standard pot has all of its lug nice and close together, which unfortunately is not the case with the VALab. Wiring the VALab is definitely a more involved process due to that.

That being said, can I actually connect the grounds? With the stock pot in the Crack, L & R grounds are connected, but with the S.E.X. and Stereomour they are not. Would be nice if someone could explain the reasoning behind. I am sure there is a very valid reason for these design choices.

[Grainger49]

I go for simplicity.  So one wire from the attenuator to ground makes sense to me. 

Although, if I were using multiple wire cables, with shield, such as STP, I would not combine the grounds.  They would go to the same grounding lug on the plate.

Someone else will surely chime in on the SEX and Stereomour.

[mcandmar]

When i installed the attenuator and replaced the wiring in my S.E.X. i kept the stock wiring layout, grounds for each channel kept separate, and for the wiring in/out of the attenuator the shields are joined together and terminated to the chassis separately from the signal ground.

[Paul Joppa]

The important thing (IMHO) is that the grounds are connected at one point only. In Crack, that point is at the RCA jacks. In Stereomour, that point is terminal 8, which is also the single point where signal ground meets chassis ground.