Boss HC2 Handclapper project.

[FUZZZZzzzz]

Hi Guys,

Im doing a lot of projects at the moment. I probably need some guidance with some of them, so it would be great if you guys could help me out a bit if needed

But, I know the 'You show me yours i'll show you mine' rule around here. So here goes:

I want to build a Boss HC2 Handclapper:

schematic:


heres a video:

heres the manual:
http://www.synfo.nl/servicemanuals/Boss/BOSS_HC-2_SERVICE_NOTES.pdf

here's the list with some hard to get components:


here's the pcb:


heres a cool website in Japanese:
https://dothkoi.blogspot.com/search/label/HC-2

heres some additional schematic and revision from the author of that japanese website:

[iainpunk]

HOLY SH1T DUDE
this is such a cool "effect"/"synth", really close to what i was planning on building for myself,
im planning a simple 3 or 4 voice electronic drum machine. i have acquired 12 latex blocks from my girlfriend which feel adequate for drum pads.

i'm planning at least a clap, kick and tom to begin with, and maybe a snare and crash later. i have done some experimenting with heavy filters and wave folding to get a nice clap sound, but it doesn't come close to that boss HandClaper sound.

https://www.youtube.com/watch?v=TSiH9MUh4Ec
this is what im going to do for my tom sound, it already works... kinda
but i used a modded small stone from EHX

cheers,
Iain

[FUZZZZzzzz]

oh man! dont get me started!

you should also check out:

Syntom II
http://www.muzines.co.uk/articles/syntom-ii/5993

Syntom I
http://www.muzines.co.uk/articles/the-syntom-drum-synthesiser/2593

[FUZZZZzzzz]

The Syntom II was to be build with different sounding modules, that you could trigger with pad or whatever source.

Theres also the Synclap (sound of a clap) and Synbal (yes sound of a cymbal) Schematics are included. The components seem to be still available.

http://www.muzines.co.uk/articles/the-synclap/6177
http://www.muzines.co.uk/articles/synbal/5903

[bluebunny]

FYI, the Amdek version of the HC-2 can also be found at muzines in the E&MM archives (Feb '84).  Pretty sure I still have mine.  Somewhere... 

[snk]

Drumsynths ! Excellent !

[ElectricDruid]

There's a couple of bits of unobtainium in that circuit. The BA662 VCA is a Roland-only OTA that hasn't been produced in years. If you want to get really fussy, it's been cloned:

http://www.openmusiclabs.com/projects/ba662-clone/index.html

To be honest, it's just acting as a simple VCA in this circuit, so I'd just use a 13700 instead.

The other chip that's difficult to get is the 4006 shift register. That's being used as a LFSR digital noise source. Apparently there's a Russian part number that's equivalent that you can still get. But again, digital noise sources are simple to do, and I've done a load myself:
https://electricdruid.net/which-noise-chip-do-i-need/

The transistors don't look to be anything super-special and I'd be inclined to just use standard jellybean parts (BC547/548 or 2N3904/3906) instead of searching for original Japanese jellybean parts.
The only quirk is one of them is marked "gm selected" but doesn't say selected for *what* gm, unhelpfully.

Also the trigger input op-amp mentions that it is "selected for offset" but again doesn't say at what level. Probably best to choose a low-offset op-amp for that one.

Thanks for the interesting read, btw. I love the mixed digital/analog technology of Roland/Boss stuff of this era.

[iainpunk]

so i just went on a "reading vaguely relevant web pages to research an idea" binge into relaxation oscillators for a 808 bassline machine, all thanks to this thread.

im planning a analog kick sound that also turns into a single long drone note until the button is released. then ill use a boss Bass chorus for fatness and my EHX Pitchfork for all the pitch shifting needed to make thicc a$$ bass lines for hiphop/trap.  

thanks for getting me excited,
cheers,
Iain

[FUZZZZzzzz]

The BA662 is indeed the most problematic of the whole list. I found all the other stuff at little diode.

The BA662 im using is a 13700 to 662 adapter print.
this one:
https://www.ebay.co.uk/itm/Adapter-PCBs-CA3080-BA662-SSM2044-2SA798-TSSOP-SOIC-8-14-16-SOT-23-363-SC-70-SIL/163201839956?hash=item25ff967354:m:m4Z04qP4BNOgIEWQ9LVBdWA

I like these old percussion boxes. Bit cheesy but very cool with fx and to use in the studio with live drums and triggers.

There's a couple of bits of unobtainium in that circuit. The BA662 VCA is a Roland-only OTA that hasn't been produced in years. If you want to get really fussy, it's been cloned:

http://www.openmusiclabs.com/projects/ba662-clone/index.html

To be honest, it's just acting as a simple VCA in this circuit, so I'd just use a 13700 instead.

The other chip that's difficult to get is the 4006 shift register. That's being used as a LFSR digital noise source. Apparently there's a Russian part number that's equivalent that you can still get. But again, digital noise sources are simple to do, and I've done a load myself:
https://electricdruid.net/which-noise-chip-do-i-need/

The transistors don't look to be anything super-special and I'd be inclined to just use standard jellybean parts (BC547/548 or 2N3904/3906) instead of searching for original Japanese jellybean parts.
The only quirk is one of them is marked "gm selected" but doesn't say selected for *what* gm, unhelpfully.

Also the trigger input op-amp mentions that it is "selected for offset" but again doesn't say at what level. Probably best to choose a low-offset op-amp for that one.

Thanks for the interesting read, btw. I love the mixed digital/analog technology of Roland/Boss stuff of this era.

[FUZZZZzzzz]

I have an original Amdek PCK 100 in my possesion , but both the handclap Boss and Amdek are getting ridicously pricey.

FYI, the Amdek version of the HC-2 can also be found at muzines in the E&MM archives (Feb '84).  Pretty sure I still have mine.  Somewhere... 

[bluebunny]

How ridiculously pricey?  I also have the RMK-100 drum machine.  Perhaps that's my pension sorted?   

[FUZZZZzzzz]

Only if you go on a diet of canned meat or dried noodles

The Amdeks go for more then the roland counterpart. Strange really because as far as Im aware the Amdek were all cheaper and mostly kits? You can buy a Amdek RMK 100 drummachine for 350 GBP today, but I've seen them being sold on ebay up to 450 500.

https://www.ebay.com/itm/AMDEK-RMK-100-DRUM-MACHINE-JAPAN-MADE-BY-ROLAND-RMK100-VERY-RARE-LIKE-BOSS-DR-55-/183937547500

[snk]

The RMK100 is quite an oddball : it use the same sequence programing technique than the DR55, but it sounds a bit more like a TR606. And it is a bit more advanced than some other DR55 alikes.

[anotherjim]

Those Roland percussion circuits always look like they kept adding bits until it worked. I mean, if you have a digital source, why not use a simple swing VCA and do the filtering afterwards? It even looks like the "Hall" element has Q6 as a VCA/gate function working off the trigger envelope.