Behringer MS-1 Review

I used to have a SH-101 from Roland. I loved it. I traded it for my n0nx0x x0xb0x, which was an awesome trade. The guy who got the old SH-101 got kinda shafted though. The SH-101 was begging to be reissued, and Behringer of all people have done exactly that… For under 400$, with a metal chassis. Fuckin a, man. I guess that’s what buying a whole city in China to do your fabrication results in: low cost high quality product. Behringer should be proud of itself for creating such a huge line up of re-issued hardware from Yesteryear. Roland, Korg, and the other companies fucked up: they could have re-monetized their old designs again, and pleased fans. Instead they said “no, we’re doing different stuff now.” Oops. Uli Behringer might be kind of a ruthless corporate cut throat, but he’s not stupid. He did what Roland, Korg, Dave Smith, and the rest wouldn’t: apply modern fab techniques and MIDI technology to old synthesizer designs. And honestly? I applaud him. The vintage synth market needs to be annihilated. Most vintage gear is not well made. In fact, most of my favorite gear is badly (cheaply!) made. Having Behringer release these new devices, with MIDI and USB capabilities, for dirt cheap is going to be good for synth innovation in the long run.

People have not been innovating in the synth realm, for the most part. It’s a copy and paste world where schematics are cut into constituent circuits and pasted together to form new products. While this is totally fine, and occasionally produces awesome results, there have been few breakthroughs in new synthesis technology over the last 20 years of increasing synthesizer popularity. Granular synthesis is now possible with hardware. Chowning’s through zero FM synthesis was accomplished with analog circuitry (See the MacBeth synthesizers or Cynthia’s through zero FM module.) There is innovation, but not in big new ways. It’s mostly re-hashing of older concepts in synthesis with new software, or maybe a few analog re-issues with more interfacing. The cutting edge, like a MacBeth analog, or a Cynthia designed through zero FM analog oscillator, or Dave Rossum’s Assimil8or are all state of the art and innovative, but very expensive.

My personal hope is that as Behringer makes the technology of the Curtis ICs and their sounds available again, the numbers of boutique copies of the SH101, TB-303, and similar old products will decrease as users turn to Behringer gear over boutique re-issues at much higher cost. The good news is that designers for these audio companies will have to become more creative about new products instead of re-hgashing old concepts to death.

I love the purely analog. There is something elegant at the electron level about a system kept in near perfect balance by proper analog engineering. Reaching that point in a design can be maddening, or even impossible without elements of digital control introduced into the system. Such is life. Digital control architecture is mostly superior to analog control and routing, although it lacks some of the weird-ness produced by using analog control circuitry. I also love the digital- the ability to save patches, the ability to do sequencing, complex sequencing (like recording parameter changes), the ability to route Control Voltages almost anyhere (like in the Moog Sub37 for example), and so much more is possible with digital architecture piggybacking on the analog circuitry.

I am getting distracted! This is supposed to be a review! I’m going to uscientifically rate between 0-10 some of the immediately noticeable things about the MS-1:

MIDI implementation: 3/10. MIDI implementation in the MS-1 sucks. Why is that NOT a big deal? MIDI implementation, the sequencer, etc. can all be updated with a new FW update down the road. Bahringer! Fix the MIDI note implementation. The notes just go “off” seemingly at random.

CV implementation: 10/10. All CV functions work properly as far as I can tell. I’ve tested the CV I/O with my Eurorack sequencer, an ARP Odyssey re-issue, and my MS-20 desktop.

Sequencer implementation: 5/10. The sequencer is not as easy to use as the former SH101 sequencer, which is legendary for being easy and also just working. Since my MS-1 had no manual with it, I don’t know how the sequencer is supposed to work. Mine does weird shit; but I assume if it doesn’t work, the next FW update will fix it (or attempt to.) I really need a manual.

Keys: 10/10. HUGE improvement over SH101. Semi-weighted. See below.

Panel: 11/10. HUGE improvement over SH101. The Behringer engineers just included the mods that end users usually did to their SH101 as a standard featureset. Love it.

Chassis: 10/10. Metal and injection molded plastic. Far superior to old SH101 chassis.

Warrantee: 0/10. I can’t figure out how to even sign up with Zendesk or whatever their terrible customer service app is. Irritating too because I could give Behringer’s engineers bug reports and tell them how to reproduce the problem I’m seeing if they’d let me register my product.

Sound: 10/10. And then some- the addition of the oscillator wave to filter modulation with the “amount” knob adds radically different realm of sound to this instrument’s palette.

All and all, even with the midi, manual, and warrantee issues, I’d give this product an overall 7/10, as long as you aren’t relying on MIDI. Why not a better score? The customer service is so confusing- I can’t even start my warrantees because I can’t figure out their registration system. The addition of some Firmware Fixes, a manual, a working warrantee system, and a clearer way to interact with the sequencer would make this product a 10/10. For the sound palette, and for what it is, it’s an impressive product for 300$ or so. Pretty dope!

Something absurd this way comes

That is a synthesizer. It is knee height, so it’s huge. Made of wood, wrapped in orange, with an acrylic faceplate. This is the monstrous creation of my good friend and partner in hooliganism and design, Ben Mandberg. I have been doing basic design consulting with him for the analog portions of his projects for a couple of years, and he dropped this off just before my 32nd birthday. This is a silly and fucking awesome project. Thanks Ben. You a true homie.

He announced to me that it was almost completed in college, but he never finished panelizing the PCB. Yay. I love to panelize stuff. <–That is sarcasm. Wiring panels sucks. That’s why Eurorack panels are so convenient to produce- everything is PCB mounted. However, before I could wire the panel, he also told me that the knurled knobs, small switches, and phone plugs were not to his aesthetic liking. I laughed. He is a chassis designer, afterall. Aesthetics are his thing. They’re mine, too, but only after function. He thinks of the way something looks from the start. He let me know he’d be buying our favorite Marquardt switches, black faced plastic phone plugs to match the switches, and the new pots (with their knobs.) So I waited and like magic they appeared the day after I turned 32.

What exactly is to be panelized? A Ray Wilson SoundLab MkII of course, which fits the theme of PCB’s we’ve been exploring (see the vocoder posts.) The MANLY question is, of course, “How big is your PCB?” The answer is, in true MANLY fashion, “THIS BIG!”

Oh, wait, when you look at it, the size of the PCB is no longer that masculine… I guess the chassis will have to be masculine enough for now. It is in fact as large as the rack full of MoogerFoogers, minus a few inches, which is still impressive if not manly. The vocoder PCB, though? Now that will show them how big your soldering iron is.

Enough with the size jokes already. This was Ben’s 5U style “Semi-modular” that he conceived as a vehicle for a digital pattern generator he designed in college. The thought behind making the bottom section so big is that when he finishes the pattern generator, he can assemble it and add it to the front bottom section of the synth, I imagine something like the EMS Synthi VCS3, a sort of L shape. He hasn’t given me much of an idea of how the pattern generator will work, but I’m sure he will. He always does. At the moment, I’m just wiring it and making it work. After I drill out the front panel and try not to destroy it in the process.

The Marquardt Switches are huge in mounting hole diameter compered to the Eurorack sized mounting holes for the switches on the front panel. Ugh. Its cool. I can do it. The potentiometers will be easier. I believe I can leave the 1/4 phone plug holes intact as is. Dope. The new pots are all 1/2 watt Alpha brand, nice and big with solid shafts for proper knobbing action. Thats a technical term, by the way.

This mothafucka will be beautiful when it’s re-faced with new hardware, and the hardware on the front all matches. No doubt. With an innovative pattern generator it’ll be super useful. I’m also going to ask Ben if we wants to do a D-Sub or some other kind of interface to the pattern generator so he could use the panel I/O to interface with other instruments, which might be totally dope.

Wiring the PCB is different though. It has nearly 100 wires to the panel. This will actually be made far easier by replacing the hardware. I actually didn’t account for that in the beginning. The larger parts have larger lugs and are easier to solder. I could even use crimps to connect to the panel if I get the right ones. This is a welcome development. The circuit bender in me wants to also break out every knob wiper to an input jack too. I’m thinking thats too much work in this case.

Ben supplied a bipolar 12v power supply to be used with this project. It’s Ray Wilson’s wall wart power supply. I think I can adapt it to an IEC inlet, but I’m not sure if I want to. I’ll just Wall-Wart it. The design is basically to take a 12v AC supply, stepped down from the wall’s 120v or so, and make a PSU stage out of each phase. Meaning the output of one phase is rectified half wave before being fed to a regulator, which keeps it steady and quiet with the help of decoupling capacitors. I’ll have to add a DC barrel jack on the front panel to accommodate the PSU, but it aught to be fine.

My girlfriend looked over my shoulder and pointed out I’d missed the chassis hole for the PSU. Its here:

As you can see above, this hole is to accommodate a DC barrel style jack, in this case to an AC PSU.

Font panel removed. Conductive Tape is used to create a shield against noise sources, and act as a ground plane. And, sigh of relief, 11 of the pots are already the size of the new ones. They will not need further machining. The other 10 pot holes will need to be slightly larger. –2019, unfinished post

———————–

Well, that was written months ago. My girlfriend’s constant mental illness issues have monopolized my time, and as I have lacked the training to deal with her codependency and anorexia, I have been distracted from what is important, which is making an impact on this God forsaken rock before I give my other foot to the cool embrace of the grave. Impact ahoy! I’m going to finish this project this month.

Poor Ben. One of my only homies, one of my best homies, is so very sick. He has officially gone deaf above 8kHz according to tests. It’s such a fucking shame that a gifted designer, engineer, and musician has to contend with tinnitus so bad that he can’t sleep only later to find the ringing in the hears has ruined all human interaction, music appreciation, the ability to read, and even the most basic human activity, which is sleep. I love Ben. I hope he recovers. If I have to learn ASL I will if it means I can still talk to my friend. Ugh. Life is unfair.

Although he bought me the new hardware, the front panel can’t be modified. It’s too fragile and the holes are too close to be drilled out. Such is life! I’ll be simply wiring it up, so I can play with it and hopefully design a digital sequencer to pair with it as a tribute to Ben’s original dream and vision. I will do the project justice. Stay tuned!

MKS-80 LCD Odyssey

The Roland MKS80 has a 1×16 character LCD screen that uses original Hitachi LCD drivers, the HD44100H and HD44780A00H. It’s backlit with EL tape, which sucks ass. It’s not bright, requires power rails that introduce noise into analog circuitry, and the color of the backlight which is a kind of dim sickly green blue is also just kinda awful. The old days were rough for LCD screens: the MKS80 was made before the 14/16 pin pinout for the LCD displays were standards, so it has 15 pins for data, and an additional two for the backlight, for a total of 17 pins, not 16 like on a modern standard LCD bought from China or Newhaven Display.

What is the 15th pin for? According to the schematics for the unit, it’s a line called “data” but that didn’t tell me much. So, what then? First thing first, trace out the pin on the old Roland OEM screen. I found it went to the “D” pin on the HD44780, which is labeled on the datasheet at “data output.” It also leads to SHL1 on the HD44100, which controls the direction of the shift registers on channels one and two. SHL1 controls the direction of the DL1 and DR1 registers on the HD44100 chip. Below is a photo taken after I overzealously pulled the old display by cutting it out of circuit. The bare wire at the bottom right was the white “data” wire. I fucked up by not doing these tests before I cut the old screen out. OOPS. I figure if it’s a lost cause to replace this thing, at least I can resolder it all together, but damn what a mistake and what a risk. I could fuck the whole thing up and be left with no screen for my hotrod synth… I really made a potential mess here…

But given that the LCD’s “data” line is tapped by something on the CPU board, and we can see on the datasheet it’s and Output, not an input, we can make an assumption: the data line is being broken out to the cpu board as a kind of sensor that has something to do with the screen. I think the line for “data” is being used by the cpu as a kind of sense line to sense screen state, or it might even be part of the contrast control circuit, which I think was designed to prevent ghosting or flickering on the EL illuminated screen.

I tried a new LCD and no luck when I simply left the 15th pin (white wire) off of the LCD. Leaving it not connected yielded a blank screen. D’oh! Ok, so the two aren’t directly compatible… What happens, though, if I hold the data wire high, at 5v? Well, unfortunately, not much. No characters, backlight doesn’t seem to change with contrast knob. Damn. I almost thought I was outta luck. Then before putting the old LCD back on, I figured I’d try grounding the data pin just for kicks. It worked! Sort of. The LCD’s contrast is all fucked up (because of the contrast control circuit) and it’s only displaying one line, because the old LCD was a one line display.

As you can see, there is only one line being scanned to the screen. As is also visible, the contrast is all f’d up. The contrast weirdness is caused by there being a “contrast control circuit” in the CPU board. It’s basically an opamp with some schmidt triggers in circuit with it. I can easily disconnect the pot from the circuit by pulling the wiring harness for the potentiometer, and removing the wire for the wiper of the pot, and rerouting it to the contrast pin on the LCD. There is a series resistor for the wpot’s wiper pin on the board too, which is convenient. Next I just connect the other two wires in the harness to a ground and 5v source on the CPU PCB, and I’ll have an aruduino style voltage divider for the LCD backlight, which will make the characters more visible.

If this doesn’t work, there is the possibility that I could trace pin 15 of the original to find it’s interconnecting via between the HD4100H and HD44780AH. Once found and probed with an oscilloscope, on the original board, I can locate it to the new display by probing vias until I find one that matches the “Data” line’s scope image, and tie the white 15th wire to the via in the new screen where the “Data” signal via is located on the new LCD.

Another answer is for me to contact Newhaven Display and ask them to provide a schematic with labeled vias of their LCD’s so I can find the via for the “D” pin and break it out myself as mentioned above. The other answer is of course to inquire about a custom run of 50 or so LCD’s from Newhaven and see what it could cost to add the 15th pin for Data to the header on the order of 50 boards. Even if it were expensive, I could sell the rest to people who want the new screens, so it could work financially if the price were right from Newhaven.

But having said all of that, I’m hoping It’ll just work properly. I won’t be able to say until I’m done with the restoration job, but I’m confident it’ll be just fine. I don’t mind the smaller text for now. I’ll have to locate a suitable 1×16 replacement. Even if I can’t, the better backlighting makes the data more visible than it was before. I’m pleased. Now I can also remove the high frequency transformer used to light up the EL tape from the circuit altogether, which will improve the quality of the unit’s sound or at least cut the HF noise I can hear it produce when it’s switched on. Success!

…Fast forward 90 days or so of girl drama, job drama, and family drama, and my mod is not yet complete. After I found a way to get the D pin issue solved, and I mounted this beauty… I was confronted with the tight spacing of the wiring harnesses that all come through the front panel cutout. Fuckin a, Roland. I know the Roland MKS series was super cheaply made by today’s standards just like their racks that I love so much. But dammit, Roland could have used the Hitachi brand 2×8 LCD displays with LEDs instead of the EL tape if they’d just made the front panel a two sided PCB instead of a single sided, easily broken, and super cheap phenolic PCB. It would have meant that the front panel cutout would have only had to house the wire assembly from the screen, instead of all of the wire to PCB connectos on the front panel. Plus it eould have made room for the eventual screen mod. Or a different OEM. I digress.

Next thing to do was to remove the wire to PCB connectors used to connect the front panel to the CPU board. You can see above there are several bundles of wires snaking their way through the buttons and lightpipes. They all go back behind the screen to the CPU board, through the panel cutout that sits behind the new screen. This means it is not possible to put the new screen in without very very carefully removing these wire-to-board headers from the PCB. How? Solder sucker and wick, and patiently. The phenolic board is easy to damage. As are the pins holding the harnesses in place. With the right temperature for the solder, some patience, and care, we have success:

Above is one of several of these wire-to-pcb headers that must be judiciously removed before it’s carefully repositioned on the solder side of the PCB and carefully soldered back onto the “wrong side” of the PCB, with the pins making solid contact with the base of the through holes. Ideally, some kind of strain relief could be used to make sure the solder joints don’t experience shearing stress if someone dropped the unit or did something else unforgivably stupid. Below you can see how the harnesses were resoldered, although in the photo no new solder is applied yet.

Below another photo, this time of the critical-to-change header, labeled on the silkscreen as P6. Without removing this header and replacing it on the opposite side, the new screen will not fit well enough to put the face back on when we’re done. This project sucks lol. It’s just one uncomfortable, challenging thing to have to do after another, on a 3000$ piece of rack history, and I was supposed to be able to play the damn thing already. I digress. Im committed now: the old EL tape transformer is gone, and so is the old screen (that I couldn’t see anyhow.) So on we go.

Once completed, I was surprised by how little it seemed to matter that the harnesses were on the other side. They all fit fine, even with my battery mod.

Reassembly will now go smoothly, after I double up my safety precautions and wrap my screen’s back PCB with kapton tape. This should prevent the LCD from shorting to the chassis, even if the unit is bumped around. It should also be a basic sort of strain relief on the wires soldered directly to the LCD board.

Now that she’s wrapped up, and we can see there is no possability for the screen to short to something, we’re going to put ‘er back in circuit. To make the old contrast knob work, which was emitting pulses too high to effectively control the LED backlight, a simple voltage divider was used to cut the pulses meant for the EL tape based backlight down to size For the LED. I use a 27k resistor in series with the contrast control knob’s wiper, and use a 10k resistor to ground from the contrast input pin. This creates a little voltage divider that gives the screen it’s contrast back. Yay! Problems a plenty solved. Now I just have to find the right OEM with a 1×8 LCD display and I’ll be golden.

Wow. She looks fantastic. Love it. Only issue? Print is only on the top line, making it a little hard to see unless your rack is level or up high. I can fix that no problem though, it shouldn’t be hard to fins an 1×16 LED LCD screen from Newhaven or whoever. This initial screen-job was mostly a proof of concept, and something for me to (significantly) challenge myself with. I wont ever have to dick around with that “EL foil restoration kit” jive either, now that there is an actual LED display on the unit. Plus the high voltage high frequency switching supply for the EL illumination has been removed, which is an added bonus. Less noise inside to be capacitively coupled through the wires. This whole odyssey took months. Glad to be done, vindicated, and assured that my baby still works just fine after the face lift.

Replacement of old MKS80 LCD displays is now a service I can supply to clients who need a new LCD or just want a less shitty backlight. Email me for details!

Deckard’s Dream, a Bill Of Materials critique

Photo above thanks to the Deckard’s Dream manufacturer, the Tokyo, Japan based Black Corporation. I love the sound of this device; I have seen Youtube videos and read much about the performance orientation of the MIDI implementation and analog parameters. This is essentially a Yamaha CS-80 replicant. They have done an excellent job in creating a patch storage system for this fader based interface, which is impressive. As is the fact that they have productized this monstrosity at a 3750$ price point. Only one word for that, folks: impressive. Hats off to Black Corporation for bringing the masses a kit for 1000$ (Plus BOM cost and enclosure) that can hold it’s own against the venerated Yamaha CS-80. It also has a better compliment of MIDI implementation and I/O than the original Yamaha. Naturally, I saw, I heard, and I wanted one for me. Like, now. I’ve never thought I could have an analog polysynth the likes of this. So I began to break down the cost and time for the kit. Here is where my criticism begins, and I hope the good people at Black Corporation will take this in stride as I am a fan of their work and I respect Japanese manufacturing quite a bit. Just read my Hifi writings about Japanese Hifi. I love the Japanese audio industry.

To get critical, now: the BOM they list for the kit is pretty crappy. In many ways. Let’s break them down, shall we?

First, the BOM has eBay listed as a source for several items. Holy shit. You could never sell a product in ANY serious capacity for any serious use, like a power supply, with parts sourced from eBay. Full stop. No acceptions. You cannot pass any kind of safety or production verification, like an ISO standard for example, or UL for that matter, without accounting for the purchase of all components from a verified reputable distributor like Digikey, Arrow, Mouser, Element14, Delta Electronics, etc. That way you as the manufacturer can verify the longevity of your product. How are you supposed to know about End Of Life status updates from the manufacturer if your distributor is eBay? A real component distributor makes the documents your team need available, so that you all know you have to accommodate upcoming supply chain drama. It helps the accountants predict the amortization of component purchases for ongoing production over time (because they know when the components are approaching End Of Life.)

So, what do they suggest you source from eBay? First: 15mm tact switches. Why, gentlemen? Where is that Japanese precision? The quality of tact switches on eBay will be shit. No Doubt. No matter what the datasheet might say. eBay & Amazon are both notorious for counterfeit sales. They have 15mm tact switches of every conceivable kind shape and footprint at Mouser and Digikey alone, I have no idea why these are supposed to be sourced from eBay, where thete is no QA accountability.

Next up? .96″ 128×64 OLED display. Whoa, man. This is kind of a dealbreaker. Heres why: First of all, the link to eBay takes us to a seller selling them for 2$. That’s really, really cheap, even for something so small and relatively simple. That is suspicious to me. Why are they 2$? There is no way to pay for adequate QA at a price of 2$. They come from China. Shenzhen or Hong Kong usually. I don’t like to support the Chinese, as their government and cultural mindset of “China at the cost of everything and everyone on Earth” is frightening to me. But nonetheless, there should be an alternative to the “No Name” brand Chinese screens they link to on the BOM. I’m surprised Black Corporation didn’t approach Noritake Itron in Japan to make the displays- Noritake Itron is already making NuTubes for KORG, and usually the Japanese are proud to support other Japanese companies. Plus a VFD would have looked way cooler. Just sayin. I’ll locate a better display later in the article here.

Next. “Card Edge Connector.” Ok, whoever put this BOM together is not an engineer. Straight up. Who forgets to list the OEM# for the component, in this case, LW-S22A2G is the OEM#, which is in the title of the eBay sale. What the Hell, Black Corporation? Y’all just lazy? I found them at a distributor called LinoLama, 5 pcs for 7$. I don’t know about them as a company but they have to be more consistent than eBay. It looks like the person who made the BOM just looked to eBay as their front for Chinese and Taiwanese parts they didn’t want to locate from reputable dealers.

Next? DIP Sockets. Fuckin a, guys. They want you to buy second hand shit box sockets with no QA from eBay instead of buying Milli-Max brand, like someone who has some respect for the hardware they’re ALREADY SPENDING 1000$ JUST TO GET PCBS FOR. Like, ok, for a Jaspersynth or something, I can see buying something from Shenming electronics. But the PCBs cost 1000$ for this synth. Why would someone cheap out on any damn part of the build? They already spent 1000$. The sockets see every element of the signal when they’re populated with ICs. Why take chances with contact quality in a synth that will take you weeks to build and cost close to 2000$?

Then, they want you to SOURCE THE HARDWARE from eBay too. Holy shit. Why? McMaster Carr is already on the BOM. And as I have delineated, there is no QA on eBay. There is no product traceability on eBay. What if you, like me, ordered two bags of the same screws, and half of them in each bag stripped or cammed out within a few turns, when the rest were fine? If you get your hardware from eBay, you’re taking chances with the structural integrity of your newly built, 2k$+ in cost, super sexy new synthesizer. Why in God’s name would any self respecting hobbyest take such an unnecessary risk to save 1$-9$ on the hardware? They want you to buy wire from eBay too. Fuck that. It’s a stupid idea. Buy real wire from AlphaWire or another reputable company.

So, folks, in closing, the 4000$ finished product uses a display that has no brand. No brand means no Mean Time Between Failure data, and no Quality Assurance. Deckard’s Dream, a 4000$ synth, uses hardware rejected from assembly lines in China (as that is how the screws, nuts, and bolts end up on eBay- they’re rejected by Chinese QA and put on eBay to recoop cost.) They suggest we use no name standoffs, wire, USB adaptors, and imitation Milli-Max sockets. They suggest buying card edge connectors from mystery fabricators too. What could go wrong? It’s only the interface for the voices to the synth, for Christs’ sake.

These missteps are critical when it comes to the supply chain. The end user of a kit that costs 1000$ should not have to do the legwork of finding the “real thing” from McMaster Carr, Mouser, Digikey and the rest when the manufacturer is offering completed kits. It’s only appropriate that the Black Corporation shares with us where they OEM the parts from for the cost of a 1000$ set of PCBs. In this case their BOM makes them look like they buy components for their finished units from eBay, which is stricly a no-no in any real design application. Is it just bad Public Relations, and lazy BOM keeping by the company? Probably. May not even be a deal breaker in the end.

An example of a good BOM would be Jaspersynth. It’s totally complete as far as BOMs for kits that do not include parts go. It tells us where the original designers sourced their parts, with caveats about where to order depending on where you are on Earth. They also leave it to the end builder to choose if they want to buy things from eBay or Amazon, but crucially, Jaspersynth does not reccommend to the end user to source from eBay or Amazon. It makes it clear that the unit was meant to be made with Quality Controlled parts, not Chinese crap.

The dealbreaker, in the end, will likely be Behringer. I’m considering starting a Church of Uli. Jesus had nothin on Uli Behringer. “Oh, Roland, you don’t want to re-issue your best hardware? That’s ok. Behringer will blow your asses out of the water.” Uli’s released clones of the SH-101, DR-808, VP-330 vocoder, and he is rumored to be working on a CS-80 clone. The DS-80, 3rd design revision, released courtesy of Behringer earlier this year is shown below. You can see Deckard’s Dream inside of this larger, sexier piece of hardware. I’ll get into Behringer’s Blitzkreig on the synth industry on another post soon. I will also say this: It is an inapt comparison to compare the work of Behringer, who employs a city full of people, to that of Black Corporation, who certainly lack the kind of infrastructure, cash flow, market presence, and pricing for quality that Behringer now offers. I know that.

Punch line? If you’re an aspiring synthesizer designer, and you’re making your BOM after initially sourcing the parts wherever you could get them in time for the prototype, go the extra mile for your kit customers, and tell them where you (the Original Equipment Manufacturer) got the electrical components, wire, hardware and screen. If you are an OEM making “high quality” hand made electronics, definitely avoid sourcing parts from eBay. If you’re an OEM getting parts supplied by eBay, slap your inventory manager before firing them for gross negligence, then throw out the hardware your idiot employee was buying from eBay.

Your customers will thank you when their screws don’t strip and their screens have been Quality Assured.

…and yet, until I can play a DS-80, I’m still considering Deckard’s Dream. The Black Corporation Elka Synthex clone looks stunning, as does their Polykobol polyphonic rack. They do great work. I hope they and their fans don’t hate me for the criticism, I’m only trying to assure that everyone gets good shit.

KORG Polysix, with Kiwisix Mod

Aaaahhhh… Bad photography. Unlike my father, bad photography seems to be my contribution to the world.

The KORG Polysix is a masterpiece of pre digital ’80s synth engineering and design. At that point in the history of synths, every synth had what was at the heart of it, essentially a monosynth. Monophonic blocks each with VCO, VCF, and VCA (sometimes also having individual Envelope Generators as well) were all arranged like in a series of “Voice Strips” in the PCB layout. Each was a full synth voice. This would have been mercilessly unstable and exhausting to tune if the circuits (VCO, VCF, VCA) were all made with discrete transistor designs like the Buchla 100, or the original Moog devices. How did manufacturers get around having to hand match thousands of transistors?

Enter the SSM, Curtis, and Roland “All in One” Integrated Circuits. Yamaha also had ICs for VCO, VCF, & VCA- they were notibly used in the Yamaha CS series (like the CS-5 from my collection, seen above.) These ICs were chips that held all of the analog components necessary to create exponential responses to the control voltages (necessary to accommodate the human logarithmic scale we use to hear things,) the matched transistor pairs for generating waves and filtering them, and the matched transistor pair devices used to amplify current called Voltage Controlled Amplifiers. These chips were a one chip solution to costly and PCB real estate intensive discrete transistor designs.

This is still true of most modern synthesizers in the analog family: one IC will often be the VCO, with a few external components, of course. Another IC will comprise a VCA, often an IC from the Operation Transconductance Amplifier family, or OTA these days. They act like op-amps but they only deal with current instead of voltage. Fun lil bastards. Many modern VCFs are also OTA based, like the Wasp VCF or any number of DIY designs. But there are plenty of integrated VCF ICs still out there too, which make the construction of a VCF as simple as using 4 caps and selecting a few resistors. If you compare that to an ARP 4035 filter module from the Odyssey, which consists of 4x LM3086 monolithic transistor arrays, you can see a huge cost and space savings available with using IC based building blocks for your polysynth.

How do we use these ICs for a convenient analog polysynth? Simple, actually. Design one voice thats fucking awesome. Like, for example, in the Roland Juno or the KORG Polysix: both would sound pretty dope and be fairly versatile as a monosynth. Then, copy and paste that single voice 6 times on the PCB, each one identical. In the case of the Roland Juno and the KORG Polysix, each voice has more than one VCO as well. Some synth companies made polyphonic analog synths with 3 or more VCOs in each voice. Damn, son!

Anyhow, once you have some sweet ass sounding voices laid out on a PCB, you have to control how they’re assigned to different keys when the player plays a chord. Seems simple, right? Not really. Most manufacturers settled on the simple-ish way of doing it which is to assign each voice in succession to each key pressed in succession. That means several things from a design stand point: you need a polyphonic keyboard, a keyscanner that can control the data coming from the keybed, and then a CPU to handle voice assignment and any other fun things like LFO parallel routing and other stuff. So not only does there have to be a polyphonic keybed, but the hardware and software to route it’s data and control periphals with it’s output. Complicated stuff! But all of it follows more or less monosynth architecture except you get a harmonically tuned voice on each key, up to 6, for a 6 note polyphonic analog synthesizer. Below are a few photos of the mighty Roland MKS-80 channel strips, which make liberal use of Curtis CEM ICs for basically every circuit block in the synth.

Fun Fact for the Roland MKS-80: The character of the analog voices comes from the CEM3340 IC’s used in the VCO of each channel, but the real “character” of this synth’s voice structure came from the Single In-Line Packages (SIPs) used to process the voices. Roland rolled some custom ICs and breakout boards in the MKS-80 that beefed up the bass response of each voice, among other things. It’s modulation character came primarily from the CEM3360 driven “X-Mod” section of the circuit. You can see the uniformity and compact nature that using pre-fabbed ICs afforded designers when you look at the silkscreen. The IR3109 ICs are Roland proprietary single chip filters.

For this service call my lovely girlfriend was making me crazy the whole way to Santa Cruz where I did the repair in front of a bunch of people who wanted to talk to me while I did it, so it was a cluster fuck. I didn’t get any photos of the outside of the keyboard, and I was rude to my host.

Oops. Why am I a dick? …and other profound thoughts.

Moving along. The Polysix is also exemplary of 80s engineering in that the fucking RAM battery always leaked in people’s storage units or closets, and would melt the CPU board with battery acid. This is a common killer of keyboards, antique computers, and pretty much any rack with a RAM battery on the PCB. Why is there a 3.3v battery on the PCB for the RAM chips? Simple! In the 80s RAM needed to have a voltage so it could hold your presets! I know, in today’s world of pennies cheap flash, this seems asinine. Why not write the data to flash? Also, simple: the CPUs were not integrated to that level yet, and flash memory was still a pipe dream. So writing it to RAM, and simply making the amount of current needed to perpetuate the data negligible, the manufacturers found a way to sustain your data. Pretty cool. They thought, “put the battery by the RAM, which should be by the CPU and the ROM,” which made sense.

…Unless the battery leaks acid all over the CPU, which contains the mask ROM inside, like the Roland Juno series. Or when the whole CPU board gets ruined like the Peavey keyboards of the 90’s or, yes, our humble subject, the KORG Polysix. This design flaw was common across Yamaha, Moog, Sequential Circuits, Roland, KORG, and basically every synthesizer manufacturer during the 80s and 90s. The battery acid leakage on the PCBs from these glorious synths has caused many to simply get thrown out due to the lack of new parts availability.

Enter the Kiwi6 Mod. It’s a fully new fabrication of the old CPU board with SMT components instead of the old style through hole logic. It’s in a bright red color, and they seem to work pretty well. The only drawback to using this board is that it causes bleedthrough of the LFO into the audio path. The Poly6 always had a signal bleed problem, but for most users it was never audible. Hitting the signal with a shit load of gain will yield bleedthrough, though, as many guitar amp-carrying synthesists discovered. The Kiwisix board makes the bleedthrough immediately obvious on the “High” volume setting. At “Medium” output volume it’s barely audible, however. Considering the the alternative is to part out the Poly6 and let it die, the Kiwi6 is good hardware. They also provide an upgraded PSU unit that is beautifully engineered, and easy to install and tune. Bravo, gentlemen. The power supply rails are rock solid under load. There is even space for a hand wired star ground on the PSU PCB. The star ground is supposed to reduce bleedthrough. It doesn’t. Lol. Below is my shitty photo of the PSU.

One repair I did manage to do was to reflow the solder to the pins on the output jack’s wire-to-board connector. You can barely see it above on the right of the spotlight, with white wires perpendicular to the rest of the board. The white plastic housing had been manhandled to the point where it’s solder joints had developed visible cracks when I pulled the PCB. A quick reflow fixed it.

The next thing was to tune the voices, which I did adequately, but it reminded me I need to go back to oscilloscope school. I did however, finally get them tuned, and it was time to try to take care of the bleedthrough. The Kiwisix instructions recommend making a star ground after joining the digital and analog grounds at the output jacks in order to reduce noise. After doing exactly what their instructions recommended, there was no change in noise floor or bleedthrough from the LFO. Oops. Kiwi6 is still dope, though. It’s clearly preferable to trashing the synth. And if you play it on Medium Output, and add gain later, it should be quiet enough not to need a noise gate (depending on your style of play, etc.)

Last thing worthy of note here:

Ever see an old-school style LED? Above you can see it illuminated. They look like signal diodes! I though it was a signal diode, but when I looked at the schematics I could see it is in fact supposed to be a Light Emitting Diode. Super cool to see the glass plastivised PN junction glow like that. Electrons, ahoy! It tells the person servicing the unit which voice they’re hearing by lighting up the LED. Thanks, KORG. It makes my life easier.

Hope you enjoyed my disorganized, exhausted post. I’m crying right now. I’ve had a long couple of weeks. I turned 32. I’m grateful. I’m fed up with my job and life. And I’m excited to burn it to the ground so I can create a new ash sculpture.

Love y’all. Go build some cool shit.

DIY Synth: Jasper (Electronic Dream Plant Wasp clone) Part II

Finally complete. It was an odyssey that lasted a month. These drafts have been in my box on WordPress for weeks. Why? I made a mistake and ordered my pots from Germany. Why would I do that? I figured I could get all of the stuff I couldn’t source from Mouser from Musicding.de because they were recommended by the Jaspersynth website. I also thought that if I could get em all in one place that I’d save fuel and shipping, etc. I was trying to be responsible as a consumer, and figured with rushed DHL delivery, even at 45$ for shipping it would be worth it.

Musicding.de gave my package to DHL, and had them deliver it to USPS. Which is slow and not readily reliable. Their customs checks take forever. Musicding.de ripped me off for shipping, so it took 3 weeks for the pots to arrive, and they showed up damaged because apparently nobody in Germany knows how to ship international packages. I’m lodging a complain with Paypal. I could have gotten the pots from BuildYourOwnClone.com, I later realized. Or I could have made my own by simply wiring solder lug pots from the panel to the PCB. There is really no necessity to having PCB mounted pots for most of the panel.

I had a hard time getting the MTA100 headers as they come in one million flavors. I finally fuigured it out. I got the pot knobs and some of the 4000 series ICs from Jameco here in San Carlos. I neglected to get the MTA100 Feedthrough punch tool, which meant I had to solder stripped wire to the headers instead of making them clean, but the work fine. I had to reverse my wiring for the mixer section pots initially, too, as there was no telling which end was which in the PDF. Oops. Such is the hazard with a kit: little details not provided often cause one to have to backtrack and try again. It’s time consuming.

However, after all of the drama with cutting wire lengths, changing orientations of components, making wire headers, and the like, she’s a beauty. It sounds gnarly. It plays beautifully. The keybed is responsive. The filter is super flexible, and the DCOs are rock steady stable. I love this machine. It’s simple, but so heavy sounding. The only things it’s missing are the full modular compliment of CV I/Os and some oscillator sync-ability, and this thing would make a great modular system.

The timbre of this synth is different from My Moog, Arp, Roland, and Yamaha synthesizers. It’s a little buzzier, and a little more hard edged sounding. It lacks the creamy sort of analog sound that one would expect from an American designed analog synth. The filter can be driven up and down by the modulation controls, which can make for ridiculously complex tones. The synth really could benefit by one more LFO, and maybe a second filter and third oscillator. But it’s a beast: heavy, hard edged and slightly harsh, this synth is surprisingly musical and easy to get along with. It would be a monstrosity if one were to take the guts of two Wasp synthseizers and put them into a modular system as a semimodular stand-alone unit: 4x oscillators, 2x filters, 4x EGs, 2x LFOs, and CV input outputs for each section. With MIDI added, you’d have a far beefier version of something like the Pixie Attaché (which is in fact another Wasp inspired piece of gear.)

Was it worth it? Yes! I’ll be making another one, which will be modified to be fully modular-ed out. I’m not sure when. I also plan to make a real enclosure for this thing sometime soon. I’m sure I’ll post about it. When I do my enclosure I’ll also be looking at possible mods that I can include space for in the new enclosure. I’ll need room for my MIDI breakout board too. Then I’ll have to add the Ext Trigger input as well. I’d like a DCO sync switch, CV input for the Filter Cutoff, CV inputs for the Oscillator pitch, and maybe even a CV input for filter resonance. We’ll see.

DIY Synth: Jasper (Electronic Dream Plant Wasp clone)

Fresh from the UK I have acquired a Jaspersynth.co.uk made Wasp clone. The original Wasp had the look of a kids’ toy, and this one does just a little bit too, but nonetheless, it’s a titan of early synthesizer engineering. They were treated as a serious synth because of the multimode filter and the ease of making patches with it. The original Wasp was originally made by Electronic Dream Plant, or EDP for short. The circuit employs few analog ICs and transistors, and a ton of the early CMOS 4000 series ICs. These had an advantage over their later, “more advanced” TTL compatible devices: they could operate well when interfacing with analog circuitry. They also have a switching threshold of exactly 2.5v, half of their rail voltage of 5v. The oscillators are 555 timer based. The filter is multimode. The keybed is capacitive touch based. I got the MIDI kit with the Jaspersynth kit too, which will make the capacitive keys a less irritating limitation than they tend to be.

The PCB photos above were done after I got started stuffing the PCB, of course, as my enthusiasm usually causes me to start ASAP instead of taking my nice blog photos. Oh well. Such is life.

I bought this kit because I have no home made synths. I got inspired by the vocoder build, which as of yet is not racked and paneled, and thought it would be fun to have a kit synth to build too. I remember being very high and smoking a lot of grass about 10 years ago somewhere in Humboldt County, and someone had a Wasp with batteries that I was goin to town on. The one I’d played was in bad shape but it sounded great. Or was it at a funeral? I can’t remember. I saw the Jasper kit and thought “Perfect!”

The PCB I ordered came with the switched pots and MIDI IC and other stuff that Jasper offers as their “kit.” The kit included the switched pots, a 4006 IC, the Jasper MIDI board, 2 8-pin mini DINs, and some other stuff. This is no normal kit though: they didn’t include most of the parts and there is no easy order-in-one-place BOM to just click “order” with. Having said that, I fear no kit. If it’s a proven piece of hardware, I can build a nice one. So I just put my “advanced kit” hat on and got to work. The parts have to come from Mouser.com, musikding.de, Jameco.com, and Jaspersynth themselves. It was actually harder to source all of the old 4000 series ICs than I expected, and Jameco saved the day. I bought their kit with a faceplate for the unit too. All and all I was surprised it took over an hour to buy the parts available, to cross-spec suitable parts for the Mouser order, and to locate the remaining parts at Jameco. An hour is much much more time investment to source parts than I had to do with my vocoder (thanks, Ben!) or my kits from Pete Millett which took about 1 minute to order.

The quality of the PCB is superb. I intend to eventually to have an acrylic and 3D Printed case made with the files Jasper provides on their website. That will prove to be an adventure, I’m sure. The front panel too is of supreme quality. I am totally impressed that this whole thing, without the acrylic/3D printed enclosure, will cost me approximately 300$ (+/- 20$) and that includes the shipping. For all that I’ll be getting a MIDI enabled EDP Wasp Synth made with 1% tolerant 20ppm TE Connectivity resistors. I will see how they stack up against the sound of the others I’ve used. I prefer Vishay/Dale or Koa-Speer, but I’ve never tried these. “Hearing” resistors is not really something most can actually do, in my opinion, and I am not sure if I can hear it or if I imagine I hear it. It’s difficult to tell.

I also purchased the Jasper MIDI PCB kit, which should give the Jasper the ability to use a MIDI In to control it and a MIDI Out for the capacitive keys. The kit is like the PCB for the main unit: well made with a clear silkscreen and a (for it’s size) simple BOM. No difficult to source parts for the MIDI board, unlike the main unit that uses the 4006 ICs which are (apparently) at End of Life. Sad. Those ICs work well and sound cool. Thankfully I have a pile em. The only parts I needed for the MIDI kit were the crystal, voltage regulator IC, and the 8-pin mini DIN. I had the rest of the parts sitting around. I socketed the ICs because I believe it to be best practice.

Ill be posting pics on the assembly and my impressions playing it for the first time. I guess I’ll have to record some music again now too!