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Bottlehead Kits => Crack => Topic started by: senpai3330 on December 11, 2013, 02:45:58 PM

Title: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: senpai3330 on December 11, 2013, 02:45:58 PM
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?
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: Paul Birkeland on December 11, 2013, 05:12:39 PM
They are physically pretty well separated, I wouldn't expect any issues.
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: senpai3330 on December 11, 2013, 05:46:41 PM
I can't find any verification on this at the moment. Might be safer to just cancel.
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: Paul Birkeland on December 11, 2013, 05:50:42 PM
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
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: serpent68 on December 11, 2013, 06:16:50 PM
I have the Valab installed together with the speedball.  Definitely enough space, still have about 3-5mm space left.
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: senpai3330 on December 12, 2013, 02:18:49 AM
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  :)

Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: Chiratas on December 17, 2013, 01:17:02 AM
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?
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: mcandmar on December 17, 2013, 03:57:30 AM
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.
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: serpent68 on December 17, 2013, 04:21:47 AM
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.
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: senpai3330 on December 17, 2013, 12:41:19 PM
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.
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: mcandmar on December 17, 2013, 12:54:43 PM
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 (http://www.bottlehead.com/smf/index.php?action=dlattach;topic=5252.0;attach=4370;image)
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: serpent68 on December 17, 2013, 09:36:31 PM
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
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: JamieMcC on December 19, 2013, 10:21:54 PM
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.
Title: Re: Valab Stepped Attenuator and Speedball PCB Space Clearance?
Post by: serpent68 on December 19, 2013, 10:54:07 PM
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.