Bug Reported for Version R1C (the current implementation), but wigger spacecadet.
Due to an impedance mismatch between the output of the flip-flop and the inverting buffer that follows it, the sub oscillator will show some ringing at the edges of its up and down transitions. To see these on the scope, dial time base down to 20uSec. This creates an overly bright result. The suggested fix is to strap a 10pf (or nearby value) ceramic cap across (in parallel to) R64/47k. It's an easy kluge if you have the right cap. The change has been incorporated into the current build document linked below, and the BOM in that document.
I don't have many of these boards left, and if I make a new run, I'll fix this in the design.
OK, where were we? Oh yeah...
The TTSH Shapers module was created to add triangle and sine wave outputs to the VCO1 and VCO3 sections. These are fully compatible and identical in function and phase to the triangle and sine wave outputs of VCO2.
UPDATE February 2020:
Synthcube is now selling complete kits. The kit and it's abbreviated build document are targeted to the V4 TTSH, but the kit and board are compatible with all versions of TTSH. If you have an older TTSH, use the build guide from the link at the bottom of this post. If you have the V4 TTSH, use this guide.
These additional waveform outputs create new timbre capabilities when used for modulation, be it FM, AM or both. With three sines to work with, additive synthesis techniques can be employed. All three VCOs become equally capable as LFOs. You can use a slow triangle LFO for PWM in VCO 2, as never before.
In addition to new waveform outputs, a sub-oscillator is also included, providing an bipolar audio output. The bass penalty for resonance in the VCF is no more!
The sub-oscillator may also be used as a clock/gate/event divider with a unipolar CV output. The sub oscillator may be built as a new, stand-alone module in the synth.
The sine shaper is adapted from one seen in many Thomas Henry VCO designs. Thomas has gracefully given his permission for me to use his shaper here - Thank You Thomas!
This is a complex modification and should only be performed by experienced builders. If you have built a working TTSH, then you qualify! For best results, use of a drill press is highly recommended. Read this post through before ordering, and look over the documentation as well.
Partial kit has been updated Sep-2018 to contain:
1 PC Board
2 NPN transistor matched pair
2 M-F hex standoff M3 nylon black
2 nylon mounts for wire dress
2 nylon cable ties
1 Electrolytic cap .1uf 50v 2.5mm LS
2 LM301 op amp DIL-8
To purchase
PM me with your:
paypal address - I will invoice you
destination country
quantity
Cost [updated Sep-2018 to reflect additional parts in the kit]:
Partial kit: $65 USD
Shipping:
US - 1-2 kits: $4.50
US - 3-5 kits: $6.00
Outside US - 1-2 kits: $15.00
Outside US - 3-5 kits: $25.00
Everything you need is in the partial kit plus this mouser cart ($51.)
... ok you will still need to provide some solder, heat shrink, epoxy glue and wire.
Shared Mouser Cart
If you would like to commission me to build your TTSH, the new waveform outputs are included in the package price! I encourage other trusted builders to purchase kits and offer modification services.
Here is a block diagram:
Nuts and Bolts:
1. Works with all versions of TTSH. The board is powered by the TTSH PSU. A method for tapping power in all TTSH versions is included in the documentation.
2. Requires complete disassembly and separation of the panel from PCB.
3. The new triangle and sine outputs on the panel are located in a manner consistent with VCO2.
4. Method and parts for mounting has been worked out for all TTSH versions.
5. Should work with (although untested) a real 2600.
6. Will be offered as only a diy partial kit group buy, and will include one PCB, two NPN matched/tested pairs for the sine shapers, and mounting hardware.
7. All remaining components in the BOM will be shared in a Mouser cart - no rare, aftermarket or expensive parts.
8. The electronic portion of the installation is fully reversible (panel drilling is not!)
9. There is some panel wiring involved.
Update 5 May 2017
1. Latest prototype built here without issue. Some resistor values were finalized.
2. Successfully stress tested using a TTSH V3 powered by Murata DC-DC converters and standard wall wart.
3. Sub-Oscillator external input successfully tested with both bipolar and unipolar sources, various waveforms.
4. The board is 70x100mm.
5. All required parts are in shared mouser cart, cost: $55US.
6. Demand: V+:40ma; V-:30ma. Added demand from +12V DC wall wart: 90ma. This has been added now to four different TTSH using various PSU schemes and no issues found thus far.
Update 17 May 2017
Its alive, its alive, its alive in my V1 Frankenmeanie.
I have prototypes out to other wigglers to get their feedback, but things are looking promising.
Update 13 June 2017
Prototype builders report success!
Update 9 July 2017
Boards are back from manufacturing and I am ready to ship. I will begin invoicing folks today. I appreciate everyone's patience here. Once you are done installing this, you will not be disappointed.
Also, unless you tell me otherwise, I will be shipping to your paypal registered address.
Pix:
Here the sub oscillator is implemented as a new, stand alone module in the synth. Across the top, left to right:
Sub Ext in jack, Octave Select Switch, Sub Out, Audio/CV switch, VCO2 Sync, VCO3 Sync (sync is a different mod and not included in this project). You hardly notice the new output jacks in VCO1 and VCO3.
Please Note: The slide switches in the pic are some I picked out for my synth because I'm weird. The switches in the mouser cart are not the same, but are Mountain sub-mini toggles (same as seen in upper left of the panel rear photo). These are much easier to install than those shown above.
Participants:
Key: Requested Invoiced Paid Shipped
Zensac:1 07/21/17
jimfowler:1 07/21/17
sanemalkavian:1 07/21/17
JanneI:1 07/22/17
hoby:1 07/22/17
heapish:1 07/21/17
groove:1 07/21/17
Sammus:7 07/21/17
nosotokarjazzy:1 07/22/177
pathosBill:1 07/21/17
olga42:1 07/22/17
Fubard:1 7/21/17
Wolfo!:1 07/22/17
Level5:2 7/21/17
gruvsyco:1 7/21/17
aread:1 7/22/17
LED-man:1 7/25/17
numan7:1 8/19/17
treseja:1 8/19/17
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