Modular in a tool case

I had a day free on Saturday and set about putting a modular in a tool case. To be exact it is a Doepfer A-100 DIY kit #1 fitted to a Halfords engineers tool case. The point of this was to have an easily transportable demo system so I can take to shows, meets etc in order to show how lovely my CV Tools module is and to let people have a play.

In a follow-on to my cheap DIY store front panels post a few weeks back I used anodised aluminium angle strips in the construction from Homebase - the case is bigger than the 6U 84HP of the rack kit.
(Note to non-UK readers Halfords is a motor accessories store and Homebase is a DIY store)

Here's the case

Prep the case - remove separators, tool panel and unecessary fixings.

All done, ready to start serious modding

This will be powered by a 15VAC supply so a nice big hole for an XLR connector

XLR in place (EDIT: this is eventually replaced by a plug version as a power lead with exposed pins is bad karma)

A bit of judiscious foam cutting to neaten it up

Markout and drill the regulator boards fixing points - 4 x M3

Regulator screwed in place

I used M3 washers to spread the load - the case is just hardboard with a thin aluminium veneer

Position the bus boards and drill mounting holes - long M3 screws with tapped spacers fitted

All electrics now in place. Note this is temporary - there will be wiring to a front panel power switch on the next installment!

Next make the rack end pieces out of 10mm x 20mm anodised aluminium angle strip. These make the rack the perfect width to fit the case.

Similar to above I made top and bottom strips to fill the gap - I used 25mm x 25mm anodised angle, again an almost exact height fit - starting to look good.

Here's a view showing the fixings (ok I drilled a hole in the wrong place. Motto: measure twice, cut once!!!).

As I said a near perfect fit in the case. At this point just resting on the foam and not screwed in. That's in the next installment.

Loaded with modules and powered up. Take no notice of the modules selection, I've since changed it to a more coherent set.

Even a nifty scope showing VCOs, Synovatron DioDe and CV Tools in operation - now that's a waveform!

 Next installment will add a power switch and fixings to anchor the rack to the case. It will also make use of all that front panel space top and bottom for passive and buffered mults, bus access, simple LFOs, gate logic, 3.5mm to 6.25mm/RCA adaptors, etc etc (the thought of the lovely goodies that will get built in is going to keep me awake a night - so sad!!)

Here's a short clip of it working:-

CV Tools arrives in the USA

Finally after many trials and tribulations a batch of CV Tools Modules has arrived at Analogue Haven in Santa Monica USA.

Watch this space for a distributer in Australia too.

Having sold all of the first batch of CV Tools I'm now hastily preparing the next batch of 50 of which 10-20 will be allocated as kits. 

Some may also remember my DioDe module, well that took a back seat to lots of things, but am actively completing the design and will announce some news soon.

First review comments and user's video for the CV Tools Module

Over half of the first batch of CV Tools have been sold, many in kit form. Here is some feedback from a few kit builders and module users:-

"Finished the CV Tools module. It works as advertised ;) No warts!

I must compliment you on your kit. The packing and organisation of components are as good as I've ever seen. Documentation is on the money for newbies ... All in all, I'm extremely satisfied ..." Steven H (VICMOD)

"An excellent simple tool. Great for cascading polyrhythms. Really easy to use and very surprising differences depending on where you tap the signal." Stephen R (VICMOD)

"...I was really impressed with the documentation and the way everything (in the kit) was bagged/labelled...CV Tools seems like a real Swiss Army Knife. I can already think of countless ways I'll be using it with my Oberheim SEM ... and humble modular." Alex M

"Tinkerbell lives!  Tonight I patched a triangle wave LFO into channel 3 of CV Tools and took the slew output into a quantizer (A156) set up to run minor arpeggios.  I can control the range of the arpeggiaic ascend/descend and even build in rhythm just using pots 3 & 4 - then out to two VCO's tuned apart. Out through a digital delay and reverb in ProTools and  . . . instant magic - fairy dust!  What fun . . " George B

Also check out this thread on Muff's entitled Some thoughts on the Synovatron CV Tools
 

Just to keep things balanced some people have expressed a lack of enthusiasm for the front panel, some about the font and some about the fact that the graphics is on a matt laminated laser printed vinyl overlay. The beauty of the overlay is that multiple colours, shades and fading effects can be easily implemented, the down-side (for me) is they are expensive and difficult to fit accurately. 

The solution is that the second batch of CV Tools will have a standard screen printed front panel (something like TipTop Audio quality). I will be offering either a very low cost swappout or a low-cost retro-purchase to existing users who would prefer a more conventional graphic - I prefer happy customers over a few extra £. Hopefully you'll come back for more!

Here is the current overlay panel next to the artwork that will be taken to the screen printers (where there is grey it will be the brushed anodised aluminium showing through so it will look a bit better). Any comments, likes and dislikes gratefully received - I will give the artwork to the screen printer in just over a week's time.

CV Tools Modules are now in production

It's been a while in coming but CV Tools Modules are now coming off the production line and going through a burn-in and test process to weed out any faults. The launch date is just over a week away - 9th April. The user manual is nearly done too. Details of distributors and price will be available very shortly.

So what's taken all this time? Well I just wanted to get the design right and pack all the features I could into it that make sense - I had several good suggestions from Muffs and other places and have built the best ideas into the design - the main one being the signal polarity LEDs to replace the channel routing LEDs (they really didn't add a great deal). There are jumper selectable coarse and fine normalled offsets for each channel and Channel 4 can be jumper configured to pass an accurate normalled bus CV into the mix for mixing VCO CVs. Check out the preliminary spec below.

Someone asked about these being available in kit form - if you would prefer to do this then please contact me.

Here is a preliminary spec:-

CV Tools Specification (updated 08.04.2011)

4-channel Polarizing Cascade Mixer

Channel 1

Input: 3.5mm jack IN1

Input impedance: 100kΩ (±1%)

Normalled input: VREF - jumper selectable to +5V, 0.5V-2.5V or none

Bandwidth: DC-15kHz (-3db)

Gain: LEVEL control variable 0 to ±2 (±3%)

Output: 3.5mm jack OUT1 - Normalled to Channel 2 output mixer

Output impedance: 1kΩ (±1%)

Output indication: ±LEDs

Channel 2

Input: 3.5mm jack IN2

Input impedance: 100kΩ (±1%)

Normalled input: VREF - jumper selectable to +5V, 0.5V-2.5V or none

Bandwidth: DC-16kHz (-3db)

Gain: LEVEL control variable 0 to ±2 (±3%)

Output: 3.5mm jack OUT2 - Normalled to Channel 3 output mixer

Output impedance: 1kΩ (±1%)

Output indication: ±LEDs

Channel 3

Input: 3.5mm jack IN3

Input impedance: 100kΩ (±1%)

Normalled input: VREF - jumper selectable to +5V, 0.5V-2.5V or none

Bandwidth: DC-15kHz (-3db)

Gain: LEVEL control variable 0 to ±2 (±3%)

Output: 3.5mm jack OUT3 - Normalled to Channel 4 output mixer

Output impedance: 1kΩ (±1%)

Output indication: ±LEDs

Channel 4

Input: 3.5mm jack IN4

Input impedance: 100kΩ (±1%)

Normalled input: VREF - jumper selectable to +5V, A-100 Bus CV or none

Bandwidth: DC-15kHz (-3db)

Gain: LEVEL control variable - jumper selectable to ±2 (±3%) or 1 (set by RV7)

Output: 3.5mm jack OUT4 and Slew Limiter input

Output impedance: 1kΩ (±1%)

Output indication: ±LEDs

Slew Limiter

Input: 3.5mm jack IN

Input impedance: 1MΩ (±1%)

Normalled input: Channel 4 output OUT4

Slew range: 0.5ms-1s

Gain: 1

Output: 3.5mm jack OUT

Output impedance: 100Ω (±1%)

General

Dimensions

3U x 12HP (128.5mm x 60.6mm).

Power consumption

+12V @ 20mA max, -12V @ 20mA max, +5V is not used.

Reference voltage (VREF)

Jumper selectable at each mixer input. Channels 1-3: 5.00V (set by RV6), 0.5V-2.5V (set by RV8), Channel 4: 5.00V (set by RV6), CV from A-100 bus.

A-100 Bus utilisation

±12V, 0V, CV used; +5V and Gate are not used.

Contents

CV Tools Module, 200mm long 16-way ribbon cable, 4 sets of M3 cap head socket screws, nylon washers and a 2.5mm hex key.