etheory - a bunch of projects in progress

[shot]

Yeah! We wanna play too!
;D

 

[etheory]

The e274 is still happening!
Trying to buy an apartment in Sydney and a large amount of iOS freelance work after my normal film work has been keeping me away from DIY :-[

Not to mention when I have had a little bit of free time I've just been epically distracted by the following PCB layout that I JUST finished for a VCO (Voltage Controlled Oscillator) design I've been working on for a synthesizer I am currently creating.

This VCO design has switchable oscillator reset (resets the phase at the start of each note if enabled, quite useful, and something I've never before seen on an analog oscillator), switchable hard sync, simultaneous linear and exponential frequency inputs, Frequency Modulation (FM) input, and generates Saw, Triangle, PWM and Sub (Square) outputs simultaneously. It is temperature compensated, stable, and wide-range (20Hz-20kHz and above and below):

On the simulator.... Who knows in real-life what it's like!

Anyway, more on everything soon now that I've got a little more free time.

Sorry and thanks for being patient!

 

[shot]

I saw on your blog that you did 2520 DOA on a single sided board.
Are you willing to share your layout for self-etchers?

(fingers crossed)

 

[etheory]

I saw on your blog that you did 2520 DOA on a single sided board.
Are you willing to share your layout for self-etchers?

Do you think it's a suitable thing for me to do?
My main concern is that API still sell 2520's, and Gary Barnett of Barnett Industries sells the gar2520 via ClassicAPI.
I really wouldn't want to disrespect either of them by releasing something that is, in reality, pretty damn similar to what they are doing, but for free.

 

[shot]

I don't know. Maybe some of the elders on this forum can say for sure.

The way I see it, it's only for self etching. Other DOAs that are being sold are professionally done PCBs. It's a difference.
And considering that others are releasing their layouts of API's product, and they are not affiliated with API, there's obviously no problem of using this design.

But I really don't know...

 

[etheory]

I just had the distraction of designing a fully featured analog synthesizer with 2 x VCOs a multimode filter 2 x VC ADSR's a RingMod and a bunch of crossmod stuff for a business idea I've had for ages that I just had to get out of my head and to the prototype stage - but more on that another day and in another thread.... The 8 PCBs of layout for my synth prototype have kept me busy for some time - they were easily the most complex designs I've ever done.

BUT.... They are now complete and awaiting the PCB print run, so I'm jumping straight back to my other tasks, like the compressors. So the e274 diode comp is back in the mix, more soon.... I opened up the file last night for a quick look and I'll dust of my two prototypes so I can take them all the way to a proper PCB.

 

[etheory]

Here are a couple of the CNC PCB's a mate of mine created for me as a part of my stash of prototype PCBs for the analog synthesizer - more soon once I've finished moving house:

Left to right - 12 channel VCA, Analog Ring Modulator, VCADSR

 

[Landins]

Wow. Modulars are the Greatest! Did the yusynth last year with great result. Been used in studio frequently. What is your inspiration for this gig? Moogish or the more askew buchla, Ken Stone serge school?

 

[etheory]

This isn't going to be a modular.
I'm building it in a modular fashion only for testing.
The final result will be a single PCB for the analog portion of a whole voice, and another separate one for the digital control board, so you can control every single parameter digitally with 16-bit resolution.

The designs are a custom blend between all sorts of different places.

The RingMod is totally custom but loosely inspired by the Roland SH-5
The VCO is based on the Moog Source but with a whole bunch of mods thrown in, and a more reliable and advanced core, with saw/pwm/triangle and sub outputs simultaneously, along with frequency modulation, amplitude modulation and cross-mod capabilities with hard sync and note-on phase-reset capabilities.
The Filter is completely custom but the broad topology is largely based on the SEM (multi-mode VCF).
The LFO is like nothing I've ever seen before, but is a triangle-core VCO with square output also and phase reset.
The VCA is just a simple SSM2164 x 3, hence 12 channels per VCO pair.
The VCADSR was largely my modifications and simplifications to the OldCrow crOwBX synth ADSR (mine can have much faster Moog-like attack times), which was based in turn on the VCADSR of Jurgen Haible.

Everything has been heavily modified from the original source, and very very heavily simulated.
But nothing built for real. So now it's coming time to build up all of these circuits and see if they actually work as they should, which is needless to say ridiculously exciting.

 

[kooma]

This isn't going to be a modular.
I'm building it in a modular fashion only for testing.
The final result will be a single PCB for the analog portion of a whole voice, and another separate one for the digital control board, so you can control every single parameter digitally with 16-bit resolution.

The designs are a custom blend between all sorts of different places.

The RingMod is totally custom but loosely inspired by the Roland SH-5
The VCO is based on the Moog Source but with a whole bunch of mods thrown in, and a more reliable and advanced core, with saw/pwm/triangle and sub outputs simultaneously, along with frequency modulation, amplitude modulation and cross-mod capabilities with hard sync and note-on phase-reset capabilities.
The Filter is completely custom but the broad topology is largely based on the SEM (multi-mode VCF).
The LFO is like nothing I've ever seen before, but is a triangle-core VCO with square output also and phase reset.
The VCA is just a simple SSM2164 x 3, hence 12 channels per VCO pair.
The VCADSR was largely my modifications and simplifications to the OldCrow crOwBX synth ADSR (mine can have much faster Moog-like attack times), which was based in turn on the VCADSR of Jurgen Haible.

Everything has been heavily modified from the original source, and very very heavily simulated.
But nothing built for real. So now it's coming time to build up all of these circuits and see if they actually work as they should, which is needless to say ridiculously exciting.

NICE!!!
Are you making more of those final pcb's? 

 

[Landins]

Jeebus! That is a nice sauce!
If you put up for sale I'm interested.

 

[etheory]

NICE!!!
Are you making more of those final pcb's? 

At this point my plan is to actually sell final units instead of PCBs, but I'm open to all suggestions.

The initial plan was to sell a combination of a desktop box containing the synth, with options for USB/Cat5/Wireless MIDI connection to your computer, along with PC/Mac VST plugin with full support for automation of all parameters/presets/full recall/full GUI.

So an entire solution as one commercially available package. At least that's the dream.

I'll keep you posted on how likely that actually is.

I was considering selling DIY PCBs also, but I fear the insane complexity of this project would have my support work cut out for me....

 

[etheory]

A few more PCBs fresh off the CNC:

 

[evilcat]

And what about your FET compressor??? I'd love to put a bunch of simple but effective comp in 1 box!

 

[etheory]

I know it looks all over the place at the moment, and it is. Sorry you all have to be so patient.
I haven't stopped any of the projects, but for this year I've been between spending any spare moment on this stuff, and the rest trying to buy an apartment in Sydney, which, thankfully, I was just able to do.
Due to organizing that (i.e. driving around to do at least 5 inspections per day every weekend) and now the move (I move in early June), I've not had much time for these projects .
Also I freelance a lot after work as a computer programmer for a few extra bucks (which I'll need now!), however, once I've finished the move, and I have my man-cave back again and all set up (I have a great space ready to be electroniced-up), it'll be full steam ahead!

I hope to FINALLY have some great things happening a little later in the year that you'll actually be able to get your hands on.

 

[JoshuaUnitt]

Hi etheory,
Just wanted to share my enthusiasm for your upcoming PCBs/kits. With your permission I'd be more than happy to link to them in the DIYRecordingEquipment.com directory when they're finished and available to the public

I'm especially intrigued to see your take on the 2510. It seems like an interesting undertaking and the DIY world has more or less neglected the 2510 in its original state (perhaps because of its original operating voltage and pinout?). As far as I've been able to tell, API has used it in some console modules as a balanced receiver (in the place of an input xformer), is that correct?

 

[etheory]

Hi etheory,
Just wanted to share my enthusiasm for your upcoming PCBs/kits. With your permission I'd be more than happy to link to them in the DIYRecordingEquipment.com directory when they're finished and available to the public

Yes, of course, no problem, thank you.

I'm especially intrigued to see your take on the 2510. It seems like an interesting undertaking and the DIY world has more or less neglected the 2510 in its original state (perhaps because of its original operating voltage and pinout?).

Also because, as with the 2520, most of the schematics out there available in the public domain contain rather large errors, so you really have to fill in the gaps yourself, which isn't as easy as with some other designs. The operating voltage is +-15V, so pretty standard stuff. And yes, the original pinout is weird, hence my 2520-style pinout re-design.

As far as I've been able to tell, API has used it in some console modules as a balanced receiver (in the place of an input xformer), is that correct?

Yes, to my knowledge it's main use is in the 225L compressor, where it is used as a class A/B balanced receiver, and potentially many other electrically-balanced API designs.

The main traits of the original version are low distortion, low DC offset (about 1mV) and low current draw. So it's really good as an input, but doesn't have the guts to drive a transformer.
The version I've created does have the guts to drive a transformer, whilst retaining the original low distortion and low output offset, and I've had a couple of forum members build them and tell me that they can drive a transformer easily, and don't even heat up when driven hard (due to their class B operation mode being quite power-efficient). Once I've completed my house move and settled in, the 2510 is one of the first things on my list to produce in DIY form as PCBs + kits.

 

[L´Andratté]

The e274 is still happening!

Man, I´m so looking forward to that one.
I want to try it with electric bass/di. I had the original and loved it, but sold it, because I rather want to mod it
and feel immoral to solder around inside such a museum piece!

This post was triggered by reading your

Sorry...

-****.

To put that into perspective, I have to say I´m really stunned by your energy and productivity,
(or the part of it on display here). And anticipation is half the pleasure...

 

[etheory]

Man, I´m so looking forward to that one.

Awesome! That makes me very happy 8)

I had the original and loved it, but sold it, because I rather want to mod it
and feel immoral to solder around inside such a museum piece!

I know exactly what you mean, I have a pair of them I want to recap, but I almost don't want to touch it it's so old and pretty!

To put that into perspective, I have to say I´m really stunned by your energy and productivity,
(or the part of it on display here). And anticipation is half the pleasure...

That's so nice of you to say, thank you!

Well, I REALLY love what I do, so I'll keep doing it ;-)

We move this weekend into our new apartment, so probably the week after that I should have my man-cave set up again and ready to roll. I will also have LOADS more space (cause our new apartment is much bigger, and since we own it now, I can build stuff into it properly for a change!), so I should be able to have everything nicely laid out ready for assembling some of these prototypes. I also took delivery today from a mate of mine in Japan who has a killer CNC machine, and he's delivered me my second batch of synthesizer PCBs ;-)

Not long now! Thanks for all the encouragement, I really appreciate it.

 

[etheory]

by the way....

Did anyone end up seeing The LEGO Movie by any chance?

The company I work for in my day-job (Animal Logic) in Sydney, did all the CG (Computer Graphics) for it, and I was involved heavily in the software development on that show for all the image generation and rendering.

I would love to know if you all loved it as much as we loved working on it!