Vulcan-74 - A 6502 Powered Retro MegaProject

[Oneironaut]

It was a great time to be into music and tech!
Had a Moog in 1980 and also messed around with it, adding a line in to the filter section so I could pump drums from my VIC-20 into the mix.
Written in basic of course, but still bleeding edge for the day.

Originally I gutted a dead Roland 88 key piano for the hammer action and velocity sensitive board but after some time realized that I didn't like it for synth playing.
I have a nice weighted digital piano and a synth action board in my studio, and prefer the zero weight basic keys for the synth and weight for piano.
It took some time to track down a non weighted 88 key unit for parts, but finally I have the non velocity and zero weight board I prefer for shredding on the synth.

I will be able to add the nuances of volume on each track though as I have individual adc controlled filters on all 12 channels - volume, low pass, resonance, and overdrive.
All FX are pure analog (Buchla style LPF + Res), but all recordable via ADC for playback via 8 bit digital DAC back to said filters.

There are also 4 patchable FX channels that include spring reverb, digital reverb and others yet to be determined.
So if I want an epic volume swell on a track, I just hit record on that tracks volume FX and it will record the action of the ADC knob with whatever FX is assigned.

Each of the 12 audio channels are quite complex, which is why I have an individual 6502 for each of them.
Actually, each channel is basically a complete instrument on it's own, at least as capable as Octamed on Amiga was.
The main 6502 running the OS only has to tell each channel what to do, so it can keep up to all of the track data being send and recorded.

I should probably buy a bunch more 65C02s for spare parts while I can still get the DIP format. I want to be able to keep this beast running until they burry me with it in 40 years!

https://www.youtube.com/watch?v=m1s5ktZVFxw

barnacle wrote:

I assume the keyboard has velocity sensing (or whatever the term is: how hard you hit it, basically).

You're reminding me of an additive synthesizer I designed, um, forty years ago for a friend in the music business; stuffed full of TI DSPs. In context, they were expensive parts and initially I simulated them using a 6502. It _did not_ run at full speed!

Neil

[Oneironaut]

Wow, it has been 6 years since I did any real form of accurate welding, but it came back to me after a while.
Last thing I built with any real precision was my electric tractor, and that was in 2018.

I had half a day to spend in the old shack out back and managed to get the entire top segment of the frame together.
Welds are not complete or smoothed out yet, but it makes the project feel real to finally see it come together.

Here is what I am aiming for....

And here is the top frame segment...

A few stills from the many videos I took today...

It probably took more time to get all of the action shots than to actually cut and weld the frame.
I am making a very detailed video series of this build later, so there can never be enough video.
Even made a head mounted iphone holder so I can do POV welding and grinding.
It will also come in handy when I start soldering the 1000 or so ICs on those massive perf boards.

Later!
Radical Brad

[BigDumbDinosaur]

Over the years, I have found a number of uses for a pallet.  Acting as a welding table wasn’t one of them.    I’d be afraid of setting the damned thing on fire. 

When I need to build a weldment such as what you are doing, I get out this big hunk of aluminum tooling plate that I’ve been using for some 50 years.  I just set it on some jackstands, which puts the work at a height that is comfortable for welding while I’m seated.  In the below photo, I have it set up with a welding jig on top of it.

Makeshift Welding Table

The tooling plate is four feet in length, 3/4 inch thick and despite being aluminum, weighs over 100 pounds.  Back when I was a young whippersnapper, I’d just pick it up.  Nowadays, I use the cherry-picker to lift it and thus avoid making an unscheduled visit to the nearest emergency room. 

Here’s another view of it in use.

Makeshift Welding Table

[Oneironaut]

Nice shop, and certainly a durable and flat table to work on.
My current shop is the great outdoors, and my clients... "whatever breaks on the farm"!
It was a chore to make that complex frame true, but I managed to do it, using a lot of shims on that old pallet.
Also did catch the grass on fire a few times, but that's usually what happens.

[barnacle]

The last use I had for a pallet was firewood: the 'real' firewood was delivered in pallet crates with instructions for disposal being 'add to firewood pile' (And then I moved next door, which doesn't have a fireplace, but SWMBO insisted the wood came with us so now it gets burnt a few logs at a time for barbecues.)

Quote:

It will also come in handy when I start soldering the 1000 or so ICs on those massive perf boards.

Eeh! Hand wiring? Point to point? That may be taking authenticity too far - I think I would seriously consider circuit boards, given how cheap they are these days. (I might think about a homebrew wave soldering system too... how hard can it be? What could possibly go wrong?)

Neil

[Oneironaut]

I don't want to give up the enjoyment I will get from hand soldering 16000 wires to 1000 ICs.
I get great rewards from these seemingly huge tasks for some reason.

Similar to how I walk deep into the back 40 and cut 10 cords of wood every year for for heating the house.
It may seem like a daunting task, but each day a bit more gets done and by fall, the woodshed is full.
Very rewarding!

I don't think the P2P wiring will be all that difficult really. Since each channel is identical, I basically just need to hand wire this 12 times...

I am going to use the same CAT-5 wiring I use on by breadboards as well.
I am really looking forward to it!

barnacle wrote:

The last use I had for a pallet was firewood: the 'real' firewood was delivered in pallet crates with instructions for disposal being 'add to firewood pile' (And then I moved next door, which doesn't have a fireplace, but SWMBO insisted the wood came with us so now it gets burnt a few logs at a time for barbecues.)

Quote:

It will also come in handy when I start soldering the 1000 or so ICs on those massive perf boards.

Eeh! Hand wiring? Point to point? That may be taking authenticity too far - I think I would seriously consider circuit boards, given how cheap they are these days. (I might think about a homebrew wave soldering system too... how hard can it be? What could possibly go wrong?)

Neil

[BigDumbDinosaur]

Oneironaut wrote:

I don't want to give up the enjoyment I will get from hand soldering 16000 wires to 1000 ICs.

“Enjoyment?"  Soldering 16K wires sounds as enjoyable as getting a lower GI exam. 

I'm not sure at this stage in my life that I would live long enough to do that much soldering.  I’m with Neil on this one: PCB, baby!

[Oneironaut]

There are times when I wish my cross-wired brain could take the path more travelled, but after 55 years I realize that it will never happen!
Hell, if I could mine the silicon and smelt the metal myself I would probably make the ICs too.
No way I am going to let some machine in China make my boards.... hand wired or death!

To me this kind of hard core prototyping is a true work of art, and I want my Synth to give off this aura as well...

https://bigbookofamigahardware.com/bboa ... e_vignette

This is why everything is standing vertical and behind a glass window. It will be about the music and the machine.


The more this world trends towards instant gratification, the more I gravitate towards the seemingly impossible.


I am fitting up the 88 key piano hardware today, one of the last "precision" parts of the frame.
I hope that old pallet I am using as a workbench hasn't warped too much in last night's rain.

Base frame with the 88 key assembly...

Found some spare 1 inch by 2 inch tubing that was exactly what I needed to make the side supports...

Now I need to adjust the frame model to support this small change in design.
I always build using recycled parts, so the "plan" is always just a guide.

Later!
Radical Brad

BigDumbDinosaur wrote:

Oneironaut wrote:

I don't want to give up the enjoyment I will get from hand soldering 16000 wires to 1000 ICs.

“Enjoyment?"  Soldering 16K wires sounds as enjoyable as getting a lower GI exam. 

I'm not sure at this stage in my life that I would live long enough to do that much soldering.  I’m with Neil on this one: PCB, baby!

[Oneironaut]

Some adjustments to the base frame and front plating.
I like this better, plus the 1x2 square tube will make a great mounting point for the removeable caster/legs, putting the load on the strongest part of the frame.
Time to get that buzz-box sparking again!

[barnacle]

Some bicycle wheels on the ends would give it a pleasingly baroque air...

Neil

[BigDumbDinosaur]

barnacle wrote:

Some bicycle wheels on the ends would give it a pleasingly baroque air...

...with some bike pedals to run a generator to power the contraption. 

[Oneironaut]

The trees are shedding their leaves and the sun is setting at 7:30 now so I am in a hurry to get the basic frame done before the snow hits the ground.
I am not worrying about the final weld and grind work, just the basic frame with all bars and plates installed.
If I have the skeleton sitting inside all winter, it will be motivation for all that wiring that is coming soon.

Started by framing in the keyboard with the 1x2 square tubing.
This will allow an attach point for the stand as well as ensuring that there is no flex in the frame around the keyboard.

Cutting the front plate. This will join the top and bottom parts of the frame and is the place where the VIC-20 keyboard & mixer controls live.
I will cut the keyboard access later once I can bring the frame indoors for fine dremel cutting.

Welding the front plate to the top and bottom half of the frame. It was starting to rain, so I put it into overdrive tonight.

Here is the frame now. Still needs the speaker grill plates and side plates, but almost completed.
It is actually not as heavy as I figure it would be, bust is still not your average plastic synthesizer frame!

Made a small adjustment to the front of the frame where the keyboard edge meets the front corner.

If the weather holds up, then perhaps I will get the other smaller plates installed this weekend.
Well... depends on the farm chore list too.

Later!
Radical Brad

[BigDumbDinosaur]

Oneironaut wrote:

Started by framing in the keyboard with the 1x2 square tubing.

It’s starting to shape up!

I can’t begin to count how many feet of 1" × 2" tubing I’ve used over the years to make things.  There’s just something about that size...

Quote:

Cutting the front plate...Welding the front plate to the top and bottom half of the frame.

Given the amount of metal work you are doing, and have done with the bikes, I’m surprised you don’t have a plasma cutter and GMAW (MIG) welder.  Stick welding is okay—I still use my old Lincoln buzz box for some jobs, but it’s possible to work faster with MIG, as well as produce much smoother welds.  Plus there’s no slag to chip, and with the right shielding gas (I use 75/25 argon/CO2) and wire, it’s easy to weld thin sections and keep warpage and spatter to a minimum.  Only thing with MIG is welding outdoors can be a challenge if there is anything more than a very gentle breeze.

As for cutting sheet metal with an angle grinder and stone, I haven’t done that since the 1970s.  When it comes to dicing and slicing sheet metal, a plasma setup is the way to go if you don’t have access to a shear.

[Oneironaut]

Thanks!

I made a vow (in 1998 when I started AZ / ChopZone) never to own any metal working tools besides an angle grinder, hand drill and basic AC buzzbox.
All 43 vehicles on my site were made using only those tools, so anyone can do what I do.
I live for doing the most complex things I can using the most basic tools possible... not sure why, but I really enjoy it!

Probably the reason I plan to do a point-2-point circuit board with 1000+ ICs to go along with this project.
Oh, and all that assembly programming and cycle counting... the only way to code!

BigDumbDinosaur wrote:

Oneironaut wrote:

Started by framing in the keyboard with the 1x2 square tubing.

It’s starting to shape up!

I can’t begin to count how many feet of 1" × 2" tubing I’ve used over the years to make things.  There’s just something about that size...

Quote:

Cutting the front plate...Welding the front plate to the top and bottom half of the frame.

Given the amount of metal work you are doing, and have done with the bikes, I’m surprised you don’t have a plasma cutter and GMAW (MIG) welder.  Stick welding is okay—I still use my old Lincoln buzz box for some jobs, but it’s possible to work faster with MIG, as well as produce much smoother welds.  Plus there’s no slag to chip, and with the right shielding gas (I use 75/25 argon/CO2) and wire, it’s easy to weld thin sections and keep warpage and spatter to a minimum.  Only thing with MIG is welding outdoors can be a challenge if there is anything more than a very gentle breeze.

As for cutting sheet metal with an angle grinder and stone, I haven’t done that since the 1970s.  When it comes to dicing and slicing sheet metal, a plasma setup is the way to go if you don’t have access to a shear.

[BigDumbDinosaur]

Oneironaut wrote:

Thanks!

I made a vow (in 1998 when I started AZ / ChopZone) never to own any metal working tools besides an angle grinder, hand drill and basic AC buzzbox.
All 43 vehicles on my site were made using only those tools, so anyone can do what I do.
I live for doing the most complex things I can using the most basic tools possible... not sure why, but I really enjoy it!

My main concern has always been the time required to get something done.  I built most of my first race car’s chassis with a buzz box, and basic tools to cut and fit steel.  However, it was a very time-consuming process to get things right—about three years from when I started to when the car made its first run.

So when I decided to build the next car—which was expected to go a *lot* faster than the first one, I thought about the problems of building a frame that was square, straight and strong.  I also thought about the importance of having a roll cage that could withstand a high-speed crash.  A tertiary thought was about how much time would be involved with all the cutting, fitting and welding, especially when my job had me constantly on the road.

All considered, I decided being proud of being able to build a race car using basic tools wasn’t nearly as important as being able to build a car that would perform, be survivable in a crash, and not require a huge amount of time to complete.  Those factors led to me acquiring better tools, especially the MIG welder.  The build took about two years, start to finish, despite being significantly more complicated than its predecessor.  I credit a lot of that to having better tools at my disposal, as well as some experience gained from the first build.