Valab Stepped Attenuator and Speedball PCB Space Clearance?

[senpai3330]

Hi everyone!

I sprang for one of those Valab stepped attenuators on eBay since they looked cheap and a few members here have reported pretty good results with them.

What I forgot to check was whether they could coexist with the Speedball boards installed. Does anyone have any experience with these in their Crack?

[Paul Birkeland]

They are physically pretty well separated, I wouldn't expect any issues.

[senpai3330]

I can't find any verification on this at the moment. Might be safer to just cancel.

[Paul Birkeland]

If you run into trouble, you can buy a pair of nylon 4-40 x 1-1/2" standoffs and a pair of tin snips.  This would allow you to mount the smaller PC boards up higher (above the attenuator), and you can use the tin snips to nibble off the bits of the board that aren't used but are in the way.

-PB

[serpent68]

I have the Valab installed together with the speedball.  Definitely enough space, still have about 3-5mm space left.

[senpai3330]

Serpent, that's a relief!

PB that sounds like a good backup if it doesn't work out. I was already wondering why the whole board wasn't populated and considered cutting it, thanks 

[Chiratas]

I have the Valab installed together with the speedball.  Definitely enough space, still have about 3-5mm space left.

Serpent, was the Valab a straight replacement or did you need to cut the top plate to fit?

[mcandmar]

I installed one into the S.E.X amp, the chassis hole is the perfect size however the locating pin needed filed down a tad to fit into the slot in the top plate.   In the end i didn't actually need to as i added washers to space it down to get my volume knob flush with the top plate, but you may have to give it a little trim.  Its only plastic anyway so easy to do.

[serpent68]

I had to do some minor filing on the top plate to enlarge the hole for the Valab.  It was a quick job, the hole only needs to be enlarged slightly to fit the Valab shaft.

[senpai3330]

Just to clarify, are these series type or ladder type we're talking about? I think the ladder type steppers are significantly larger in terms of height.

[mcandmar]

They are smaller than they look in the pics, the ladder version is only about 2" tall.

Pic of mine installed here ..http://www.bottlehead.com/smf/index.php?action=dlattach;topic=5252.0;attach=4370;image

[serpent68]

I'm using the ladder type.  Its physically quite big, but I have no problems with clearance.  Just need to pay some attention to proper routing of wires - do allow for some slack in the wire to route around the speedball PCBs to the terminal points.

Valab 23 Step Ladder Type Attenuator Potentiometer 100K Log Stereo
http://www.ebay.com/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-100K-Log-Stereo-/251293582926?pt=US_Amplifier_Parts_Components&hash=item3a8243c64e

[JamieMcC]

I have one on the way also for my Crack, how has your installation gone some thoughts and a pic in if possible would be great.

[serpent68]

Installation is quite straight forward.

1. The hole on the top plate needs to be filed slightly to accomodate the larger shaft of the Valab.  A minutes work, no sweat.
2. The length of the wires need to be longer than what is stated in the manual because of the added height of the Valab. 

Here's a picture of my crack with Valab pot + speedball upgrade.  I used neotech 7N silver wires which comes in 1 color only.  Quite a messy job, but it works perfect.