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Finished up cabinet #7 in my modular system today. I've been working on this for a number of years, and have posted pics of various types over time, but figured some closeups were due.

It all started with some lovely anodized aluminum plates, 4" x 2.5", that a local surplus place was selling 4 for a buck, some years back. I thought I might have a use for them, so I bought about 30, I think (although 30 suggests they may have been 3 for a buck). I was getting a little tired of spending more on the enclosure for pedals than for all the guts inside, and thought "Hell, if it's for ME, and not for sale, I can make 'em any way I want to". So I went for a modular system, with each cabinet holding 12 modules, like you see here. In/out jacks are cheap 1/8" mini phone jacks, and I use plain old DPDT toggle switches instead of stompswitches. Because they're small, and I don't have to leave any room to step on a stompswitch without accidentally stepping on a control or toggle, I can use a lot more of the surface area of the plate. NO need for a status LED, because the position of the toggle handle tells me what I need to know.. And, as the pics show, I have a LOT more space behind the faceplate than I might have in a conventional enclosure, so I can stuff a lot behind there.

Here's #7 from the front. It's a dog's breakfast of golden oldies, DIY things, and 3rd party designs. I etch the circuit boards from layouts that generous and industrious people have posted. The glossiness of the different faceplates seems to vary with time of year that I sprayed them with clear lacquer (to protect the legending). For some reason, cooler temperatures in the garage is leaving them dry very matte.
Computer keyboard Peripheral Input device Audio equipment Electronic instrument

Here's the backside, that I've never really shown before. You can see the boards are just hanging off their respective controls. Two of the modules are using the original anodized faceplates, and the rest are making use of some aluminum siding scrap that the contractors left here at the end of winter.
Electrical wiring Audio equipment Glass Electronic device Electronic instrument

Power is provided to individual modules via Molex connectors on a homebrew power bus. The 2.1mm jack off to the right lets me plug in a regulated wallwart to power the entire cab, and the Molex connectors allow me to simply unplug any given module from the power bus, undo the 4 machine screws holding it to the aluminum brackets, and remove it so I can either stick it in another cabinet, modify it, or troubleshoot and repair it if it's misbehaving.
Circuit component Passive circuit component Hardware programmer Electrical wiring Audio equipment

There are 6 other fully-stocked cabinets of identical size and construction, one of which has its own bipolar (+/-9vdc) power supply for the odd thing that requires both voltages, and I've started working on things to stuff into #8, after which I think I'll knock it off for a bit. While, mathematically, 7 cabs = 84 effects, a few of the modules in other cabs are double width, and are essentially "utility" modules (e.g., switching modules, EQ), rather than effects, per se, so I think we're up to about 74 actual effect modules. In most instances, I have at least 2 variations on any given type of effect. So, for instance, 3 different compressor modules, 2 different cabinet simulators, a couple of noise gates, etc. The only thing I have one of is a ring modulator, but that may change with cab #8. Naturally, there are more drive-type modules than anything else. Five of the 12 in this cab are drives of various types, which is fairly representative. And clearly, this is NOT a gigging setup.

There are two clear advantages to this setup. One is that I can both condense a lot into a small space and can also SEE it all at once. The other is that building these modules is "cheap like borscht" as the saying goes. The jacks, bypass toggle, and Molex connectors cost about $1.30 altogether. The pots are about [email protected], and the knobs are about [email protected] I etch my own boards, rather than buy them. So many of the modules have cost me <$10 apiece, and sometimes half that. The cabinets themselves probably cost about $10 in materials, when you factor in the aluminum angle material, lumber, and paint. So, all told, the 7 cabs and 80-ish modules have probably cost me about $650.

Patching uses the same sorts of cables one would use for Eurorack synths. And while I have plenty of homemade cables for patching, I think I'll need to buy some more of those moulded colour cables they sell for big synth setups, so I can rely on the colour-coding to help me visually follow the signal path.
 

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Finished up cabinet #7 in my modular system today. I've been working on this for a number of years, and have posted pics of various types over time, but figured some closeups were due.

It all started with some lovely anodized aluminum plates, 4" x 2.5", that a local surplus place was selling 4 for a buck, some years back. I thought I might have a use for them, so I bought about 30, I think (although 30 suggests they may have been 3 for a buck). I was getting a little tired of spending more on the enclosure for pedals than for all the guts inside, and thought "Hell, if it's for ME, and not for sale, I can make 'em any way I want to". So I went for a modular system, with each cabinet holding 12 modules, like you see here. In/out jacks are cheap 1/8" mini phone jacks, and I use plain old DPDT toggle switches instead of stompswitches. Because they're small, and I don't have to leave any room to step on a stompswitch without accidentally stepping on a control or toggle, I can use a lot more of the surface area of the plate. NO need for a status LED, because the position of the toggle handle tells me what I need to know.. And, as the pics show, I have a LOT more space behind the faceplate than I might have in a conventional enclosure, so I can stuff a lot behind there.

Here's #7 from the front. It's a dog's breakfast of golden oldies, DIY things, and 3rd party designs. I etch the circuit boards from layouts that generous and industrious people have posted. The glossiness of the different faceplates seems to vary with time of year that I sprayed them with clear lacquer (to protect the legending). For some reason, cooler temperatures in the garage is leaving them dry very matte.
View attachment 450550
Here's the backside, that I've never really shown before. You can see the boards are just hanging off their respective controls. Two of the modules are using the original anodized faceplates, and the rest are making use of some aluminum siding scrap that the contractors left here at the end of winter.
View attachment 450555
Power is provided to individual modules via Molex connectors on a homebrew power bus. The 2.1mm jack off to the right lets me plug in a regulated wallwart to power the entire cab, and the Molex connectors allow me to simply unplug any given module from the power bus, undo the 4 machine screws holding it to the aluminum brackets, and remove it so I can either stick it in another cabinet, modify it, or troubleshoot and repair it if it's misbehaving.
View attachment 450557
There are 6 other fully-stocked cabinets of identical size and construction, one of which has its own bipolar (+/-9vdc) power supply for the odd thing that requires both voltages, and I've started working on things to stuff into #8, after which I think I'll knock it off for a bit. While, mathematically, 7 cabs = 84 effects, a few of the modules in other cabs are double width, and are essentially "utility" modules (e.g., switching modules, EQ), rather than effects, per se, so I think we're up to about 74 actual effect modules. In most instances, I have at least 2 variations on any given type of effect. So, for instance, 3 different compressor modules, 2 different cabinet simulators, a couple of noise gates, etc. The only thing I have one of is a ring modulator, but that may change with cab #8. Naturally, there are more drive-type modules than anything else. Five of the 12 in this cab are drives of various types, which is fairly representative. And clearly, this is NOT a gigging setup.

There are two clear advantages to this setup. One is that I can both condense a lot into a small space and can also SEE it all at once. The other is that building these modules is "cheap like borscht" as the saying goes. The jacks, bypass toggle, and Molex connectors cost about $1.30 altogether. The pots are about [email protected], and the knobs are about [email protected] I etch my own boards, rather than buy them. So many of the modules have cost me <$10 apiece, and sometimes half that. The cabinets themselves probably cost about $10 in materials, when you factor in the aluminum angle material, lumber, and paint. So, all told, the 7 cabs and 80-ish modules have probably cost me about $650.

Patching uses the same sorts of cables one would use for Eurorack synths. And while I have plenty of homemade cables for patching, I think I'll need to buy some more of those moulded colour cables they sell for big synth setups, so I can rely on the colour-coding to help me visually follow the signal path.
WOW! I can’t even... just… yeah. Holy cow.

PS… have you started the sackbut project yet Mark? I hope you keep us posted on the adventure.
 

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Discussion Starter · #5 ·
WOW! I can’t even... just… yeah. Holy cow.

PS… have you started the sackbut project yet Mark? I hope you keep us posted on the adventure.
1) Thanks.

2) The sackbut project is underway. The first mission was to get the keyboard working. Like many mono synths from the '60s and '70s, it uses what is termed a "resistor ladder. So a string of precision resistors are wired end to end, and the key one presses essentially makes contact at some point along the ladder. In a sense, it functions like a 49-step potentiometer. Much later synths, and many organs, would use little wiggly dangling springs as their contacts, such that when you pressed a key, it forced the end of the spring into contact with something else, and "allowed" it to break contact when you lifted your finger off the key. In the case of the sackbut, the mechanism LeCaine used was the opposite, making it more labour-intensive to get working. When a key is not pressed, it forces the contact out of the way, and "allows" it to make contact when you press down.

As an essentially homebrew device, I can understand how LeCaine came up with it, but that didn't make it any easier to get going. I'll see if I can convey what's involved using a hastily-drawn cross-section diagram. A brass bolt (A) extends upwards through a block of hardwood (B). The 1% resistors connect each of the 49 bolts underneath the hardwood block at the head. The bolts are screwed in tight. The copper strip (D) slips over the end of the bolt, and is screwed in place by a hex nut (C). We realized the the holes drilled through the copper strips, to let them slide over the bolt-end, were slightly bigger than the bolt diameter, compromising the contact with the bolt. The tarnish on the copper strips didn't help either. So I brought in a bunch of small locking washers (F) that would increase contact with the hex nut and copper.

The keyboard keys are spring-loaded, and when they return to the upright position, each key pushes a piece of wood dowelling (E) up through a hole in the hardwood block, that forces the copper strip out of contact with the common contact (G) which is simply a steel plate across the entire front of the keyboard. Everything rests on the gap between the end of the copper strip and the "common" being big enough to break the connection, but small enough that "relaxing" the strip by pulling the dowel down (i.e., letting the dowel fall down) lets D make contact with G. Each of the copper strips used as contacts for the 49 keys is annealed, making it softer and more pliable. My diagram suggests they are all perfectly flat, which is certainly NOT the case. My task these past few weeks has been to hand-bend each of those copper strips, to compensate for their individual "springiness", such that they would make and break contact appropriately. Let me emphasize, they are NOT uniform in those properties, and the critical gap to achieve was not easy to see, given the setup. So there was a lot of bend-it-a-wee-bit-and-measure. I was able to get the resistance from hex nut to steel plate down below a few ohms for the 49 keys. T'weren't easy. Again, there are MUCH easier ways to do this, but the goal/mission was to repllicate what was originally used. That's done and I await further instructions next week.
Thanks for the interest.
Parallel Font Rectangle Drawing Balance
 

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This is what NASA should have been doing this whole time!
 
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