SIDbox PCBs and/or Kits

[c0nsumer]

TK,

Since I've put together the SIDbox PCB design, I'm thinking that others might be interested in purchasing the PCBs (for which they will have to source most of the components -- likely from Mouser) or kits. If I do sell the kits they will include everything except the enclosure. The enclosure the board is sized for is available from Mouser, and the front / rear panels can be ordered from Front Panel Express or Schaeffer Apparatebau KG. I would include them in the kit, but people will likely want a vareity of silver / black / whatever parts. Additionally, the cost of the enclosure and panels would likely more than double the final cost of the kits. And, some people just might not want to use my enclosure.

If sold as kits, the proper components for using either a 6581 or 8580 synth would be provided.

My desire would be to sell the PCBs (or kits), have the parts list (BOM), schematic, and .FPD (Front Panel Designer) files be freely downloadable. After I've sold through all the PCBs (or kits) I'll release the Gerber / Excellon files and the actual board layouts so others can order (or etch at home) boards if they so desire.

'Licensing' for my work would be a general Creative Commons license which permits unrestricted usage. Basically, I'd just want to let it go so that others may use it as they desire.

To recap, the 'SIDbox' that I've been working on for myself and a few friends is the MBHP_CORE, MBHP_SID, MBHP_IIC_MIDI, and MBHP_BANKSTICK all implemented on a single 158mm x 70mm board. As the my intention is to have everything controlled remotely, I've stripped off a good portion of the MBHP_CORE in my implementation. I've also added a MIDI THRU. This is designed to be used with the newer PIC18F4620 and provides a header to allow ICSP while the chip is socketed in the SIDbox.

More information (including the schematic and board layout) which I currently have being produced (the 'prototype', as it were) is available at http://www.nuxx.net/gallery/v/stuffivemade/sidbox/. If these are sold as either PCBs or kits, I would change a few things on the board, most notably clarifying the layout in a few places, and adding screw-sized through-holes should someone wish to mount the board in another enclosure.

If you have any other questions about this, please let me know...

Thanks!

-Steve

[TK.]

Hi Steve,

I will propably accept this, but only under following circumstances:

• rename the project to MIDIbox SID <your abbreviation like -LC for low-cost) in order to make the origin of the design clear
  
• add the URL www.midibox.org (not only your own - this is like hijacking the IP of somebody else and not a good style)
  
• replace the oscillator by a direct clock connection to the core due to this issue http://www.midibox.org/forum/index.php?topic=5748.0
  
• add R10 to the PIC - even it might currently not be required, it could be used for any purpose in future
  
• allow to add more banksticks for MBSID V2 (the subsystems require different BankSticks, see wishlist) - optionally just add a pin header for extensions
  
• consider to change the layout, so that the pin headers for DIN/DOUT and LCD could be mounted
  
• test your board intensively before offering it to other people to avoid additional support effort in the forum
  

I can only make a final descition once you were able to get the board successfully running.

Best Regards, Thorsten.

[c0nsumer]

Thorsten,

Thanks for replying. At this point I'm not certain if I want to invest the time into the kits, but I'll go ahead and add the changes you suggested. I'll reply to this thread if/when I have new information for your review.

Thanks...

-Steve

[illogik]

My desire would be to sell the PCBs (or kits), have the parts list (BOM), schematic, and .FPD (Front Panel Designer) files be freely downloadable. After I've sold through all the PCBs (or kits) I'll release the Gerber / Excellon files and the actual board layouts so others can order (or etch at home) boards if they so desire.

why not publish everything right away when you are ready, there are enough people who don't want to etch and are very happy with a nice pre drilled ready to go pcb.

cheers, marcel

[c0nsumer]

why not publish everything right away when you are ready, there are enough people who don't want to etch and are very happy with a nice pre drilled ready to go pcb.

Unless I'm misunderstanding what you are asking for, that's exactly what I would be planning.

-Steve

[DrBunsen]

I would probably interested in a PCB, if the board has the option of mounting the parts needed for the control surface.  Which I guess is the change that TK suggested.

Have you thought about working with SmashTV or Mike to produce this board?

[c0nsumer]

I would probably interested in a PCB, if the board has the option of mounting the parts needed for the control surface.  Which I guess is the change that TK suggested.

Have you thought about working with SmashTV or Mike to produce this board?

No, this will be done on my own. I'm just taking a short break from the project for a vacation and the time needed to get ready. I should have more info in the first week of May...

And yes, my current design is to have all the DIN/DOUT headers, the LCD header, and even a 8-input digital input (DINX1) on the board as well. This is because I want to stick the board in a small enclosure with an LCD and two buttons for switching patches. I'm wanting this to be very usable live, but without making a whole control surface.

-Steve

[c0nsumer]

In case anyone is interested, I'm back working on this project after a bit of a break. My first prototype boards arrived and everything is now working great. I've finished a first draft of the layout for what I hope will be sold as either kits or stand-alone PCBs. After I'm happy with this layout, I'll order another 5 boards. If these check out, I still have the motivation, and TK is fine with it all, I'll probably go ahead from there.

Just so everyone knows, this is everything needed for a single-SID MIDIbox SID with a Step A control surface (up to 8 buttons and an LCD). That is, it's the MIDIbox Core, SID, LTC (LEDs only), DINX1, IIC_MIDI, and Bankstick modules, with headers for adding more DIN/DOUT/Bankstick modules and an LCD. There is also an ICSP header for the core PIC.

This board is designed to be used with a PIC18F4620, and thusly it uses the IIC_MIDI module / software for MIDI out.

Oh, and a power supply which expects ~12VAC or ~15VDC. For good measure I also made all the headers pin-compatible with SmashTV's boards.

A PNG showing the this draft is available here: Small - 300dpi

The board is currently 160mm x 80mm and is designed to slide right into a Hammond 1455T1601 (warning: PDF) enclosure. (Actually, it'll fit right into any of Hammond's 6.30" wide enclosures... But I digress...)

Anyway, that's it for now. I thought you all may be interested in an update of where this Proposal / Sale Request stands.

-Steve

[Jaicen]

Hey man, that all looks good to me, should save me a little effort doing it myself! Put me down for one of them if you ever go into production.

Have you had any chance to test for noise or whatever in the circuit? Also how many bankstick chips are supported by the layout itself?

[Tanstaafl]

ditto !

[c0nsumer]

Hey man, that all looks good to me, should save me a little effort doing it myself! Put me down for one of them if you ever go into production.

Have you had any chance to test for noise or whatever in the circuit? Also how many bankstick chips are supported by the layout itself?

Thank you. If I do, I'll be sure to make enough that there are plenty to go around... Just curious, would you be more interested in purchasing just a PCB, or a whole kit? Currently I'm thinking that kits would sell best...

As far as noise goes, the design is similar to the previous prototype I made. That is, except for crossing themselves at one point, absolutely nothing else crosses the audio lines. You can see this cross-over the 300 dpi view of the board at R28 just above the AUDIO_IN jack.

The only noise I've heard thus far is the standard SID bug where one can hear the VCA (I believe) when the levels are turned up rather high. As expexted, this is more pronounced in the 6581 than the 8580. If you are interested, I've posted a recording of the Airwolf theme played via ASID XP and the MIOS sidplayer app over here: sid_airwolf_clip.mp3. This is with a MOS 6581 CBM as seen here.

Oh, yeah... The BankSticks. The current plan (and layout) is for it to support one Microchip 24LC256 (standard bankstick). A four-pin header (called J4A) will allow one to connect up to seven more banksticks. I would envision this being done (if the user desires it) with a board similar the one laid out by Mike which can be seen on the MBHP BankStick page.

I'll probably lay out something like this out and post it with the other docs for the board. That is, a board which could plug in to the MIDIbox SID-LC board and nestle nicely amongst the other components. That way if someone wants one, they can make one...

Hope that answers your questions...

-Steve

[Tanstaafl]

As to PCB or Kits, I guess it is our respective locations.  I am in the U.S. and have access to many parts vendors locally.  So a PCB would be my best bet if you are located outside of the lower 48.  I have 4 old C64 systems so don't really need the SID's or power supply.

On a complete tangent..... I also have a few Amiga's.... did they not have a kick butt sound chip also?  I wonder.....?

TK?

;)

[c0nsumer]

As to PCB or Kits, I guess it is our respective locations.  I am in the U.S. and have access to many parts vendors locally.  So a PCB would be my best bet if you are located outside of the lower 48.  I have 4 old C64 systems so don't really need the SID's or power supply.

Thanks, that's good to hear. The reason I'm thinking of doing full parts kits is because everyone will need a programmed PIC16F88 and a PIC18F4620 bootstrapped for IIC_MIDI. Since most people don't have PIC programmers, I figured at least these chips have to be provided. Since the power supply is built on the board here, there's really no way to leave that out. It'd just be fed from a wall wart.

Oh, for what it's worth, I'm in the Detroit area.

I'm going to try and work up some pricing today, so hopefully I'll have a rough estimate of full-kit costs today.

-Steve

[Tanstaafl]

Kewl, looking forward to pricing.

I burn my own PICs / etch my own PCBs also... forgot to mention that.

anyway, been thinking about building a MidiBox SID since I have most of the parts, but a prefab would save a week or two of dev time  :)

gb

[Wilba]

Good work...

It looks like the ground isn't connected to the pins... are you intending to use wires under the PCB? If so, it's a good idea, as I believe you get less noise if the SID's ground is connected directly back to the ground of the 7809 or 7812 (as per SID datasheet). I'd be interested to know what ground wiring produces the least noise (i.e. how you wire SID's ground, audio out ground, the mini-amp circuit ground, etc.)

Also, a direct connection of the +5v supply to the 7805 is recommended by the SID datasheet, maybe you should put the track from C4 straight up to C28 instead of joining the +5v track connected to the shift registers.

[c0nsumer]

Good work...

Thank you. :)

It looks like the ground isn't connected to the pins... are you intending to use wires under the PCB? If so, it's a good idea, as I believe you get less noise if the SID's ground is connected directly back to the ground of the 7809 or 7812 (as per SID datasheet). I'd be interested to know what ground wiring produces the least noise (i.e. how you wire SID's ground, audio out ground, the mini-amp circuit ground, etc.)

Also, a direct connection of the +5v supply to the 7805 is recommended by the SID datasheet, maybe you should put the track from C4 straight up to C28 instead of joining the +5v track connected to the shift registers.

Ground is currently being handled by a ground plane on the top of the board. I generally leave this out of exported images for clarity. I may still add some extra ground runs around the audio in/out on the bottom of the board (or possibly another ground plane there) but that's still up in the air.

I see what you are saying about the Vcc, Vdd, and GND specs in the 6581's datasheet. I need to think about this a bit... I'm not sure that running this as separate traces will be that useful. For what it's worth, my routing of these lines is quite similar to that done by both TK and SmashTV, and neither of these boards have issues.

Also, there's no mini-amp in there. If you are talking about the extra circuitry on the output, that's to keep the SID from being cooked accidently if fairly hot audio is accidently fed into the Audio Out.

[c0nsumer]

Okay, I just worked up the BOM and ordered a set of parts for final confirmation of sizes before ordering the prototype boards.

Based on my calculations the kits will likely cost around US$100 plus postage (should be cheap).

The complete kit will include:

• PCB
  
• All board-mounted components
  
• Turned-Pin Sockets
  
• All ICs
  
• Parts to support either an 6581 or 8580 SID
  
• Wall-wart type power supply (110VAC)
  
• Programming of PIC16F88 (IIC_MIDI) and PIC18F4620 (MIOS Bootstrap)

So, now I'm just waiting for the parts to arrive from Mouser to I can confirm the footprints, finalize the layout, and order the prototype boards.

TK, if I may ask, what are your thoughts on this project / sale request as it stands now? Is there any more information I can provide to you?

Thanks...

-Steve

[TK.]

US $100 is a high price when you consider, that the core and SID kit are available in SmashTV's shop for ca. US $40, thats less than the half, and I think that even a MBHP_IIC_MIDI module, a PIC18F4620 and a wall wart won't raise the costs to more than US $50..$60.

Therefore I'm currently not sure if I can recomment your venture with a good feeling, because people could assume that this is the best price for a "low-cost MIDIbox SID", which is just not correct... :-/

I've to sleep some nights of this...

Best Regards, Thorsten.

[c0nsumer]

Thorsten,

I fully understand these concerns. As such, I'd like to explain how I came up with the estimated US$100 figure. First, here are my rough costs:

All on-board parts from Mouser: US$35 - US$38, depending on if I order enough parts for 50 or 100 kits. I'll include the BOM in an attachment.

Wall Wart Power Supply from Jameco: ~US$4.50

PCB: US$9 - US$12 (after tooling charge), depending on 50 or 100 boards ordered. (Double sided, with soldermask and silkscreen, 160mm x 80mm, non-leaded solder. Using a soldermask color other than green would increase this cost US$1.50 - US$2/board.)

Packaging (anti-static bags, plastic bags, box, chip tubes, etc): I'm guessing this will total US$3 - US$4 per kit.

Postage from vendors to me for all aforementioned parts: An estimated US$2 - $3 per kit.

As you can see, my total cost per unit would be somewhere around US$60. With the time I would spend putting in programming the PICs, kitting the parts, re-shipping them, and simply handling the order, I do not feel that this is an unreasonable markup. My understanding is that markup for electronics kits is typically greater than 100%, and this is far below that.

However, there is another option which I am beginning to think would be better for everyone involved. That is, I could simply produce and sell the PCBs along with a programmed PIC16F88 and bootstrapped PIC18F4620. In quantities of 50 the cost would be around US$10 (plus a bit for postage) for the PICs. Board cost would be the same as above. Then, along with all the other documentation, I would just provide a parts list individuals could use to order the components themselves from either Mouser or whatever other vendor they prefer to use.

After checking SmashTV's site, I see that the total for one each of the Core, DIN, LTC, and SID modules (PCBs only, not kits) and a PIC18F452 is US$31.95. Additionally, my board / PIC set includes the newer (and more expensive) core PIC (via Mouser the PIC18F4620-I/P costs US$1.50 more than the PIC18F452-I/P), a PIC16F88 (cost at Mouser of $2.60), and the IIC_MIDI module (for which a pre-made board currently is unavailable). Combine this with the simplified assembly, I feel that a price of around US$35 for my PCB and programmed 18F4620 and 16F88 PICs would be in line with the spirit of name MIDIbox SID-LC -- a "low-cost MIDIbox SID".

While writing this reply, I've come to believe that it would be in the best interest of everyone involved (you, those purchasing the kits, and myself) if I were to produce and sell just the PCBs with the two programmed PICs.

I see the following as some of the additional benefits from my sale of PCB+PICs sets as opposed to full kits:

• I do not have to invest almost US$3000 to initially make the kits available.
  
• Individuals purchasing the PCBs will see a lower overall cost because I wouldn't be spending time kitting the parts.
  
• Individuals not wishing to use all aspects of the board may choose to leave some parts out. I would envision parts such as those needed for the LCD display, MIDI LEDs, and DINX1 being left out by some. This would lower the overall cost even further.
  
• Individuals in areas which don't use 60Hz/~110VAC will not end up with an unneeded wall-wart power supply.
  
• Greatly decreased packaging costs. I could likely reuse all antistatic packaging from original parts shipment, and packaging for PCB and chip tubes would be < US$1.
  
• Lower postage costs (and potentially lower customs charges) to ship from myself to individual purchasers.

So, Thorsten, may I ask your opinion of this new idea for me to sell just a PCB and pre-programmed PICs for around US$35?

Also, is the MIDIbox-related labeling / copyright notice on the proposed PCBs acceptable to you? If these PCBs are produced, it will generally read as follows:

[tt]MIDIbox SID-LC

    ©2006 T.Klose // ©2006 S.Vigneau

www.midibox.org // www.nuxx.net

v1.0[/tt]

Thanks again. I look forward to your response.

-Steve

bom_for_mouser.txt

bom_for_mouser.txt

[TK.]

I will give you the final answer next thursday (Currently I don't find much time to answer all postings and emails...)

Best Regards, Thorsten.

[c0nsumer]

I will give you the final answer next thursday

Thanks very much. I won't be able to have the layout and part footprints validated before then (Mouser order arrives on Wednesday) so this should work out very well.

-Steve

[c0nsumer]

Earler in this thread Wilba suggested that Vcc, Vdd, and GND for the SID be run back to the power supply on their own. Well, this seems a bit silly on this board, but I went ahead and did that anyway. I also added some shielding around the audio lines.

To see the current state of the layout (this is likely very, very close to the final one) either check the link above, or here: Small - Large

The only thing left to do is validate the physical dimensions of the parts, give everything one last going over, and then I'll order the prototype boards.

-Steve

[Wilba]

It wasn't really a suggestion... I'm no audio electronics expert at all, only quoting the SID datasheet. Perhaps someone else can suggest whether a ground plane would be better, i.e. even less noisy.

I was hoping that your experience with this PCB design would help me in my own, so I could decide whether to join the SID's ground to a ground plane or use an explicit track.

[c0nsumer]

It wasn't really a suggestion... I'm no audio electronics expert at all, only quoting the SID datasheet. Perhaps someone else can suggest whether a ground plane would be better, i.e. even less noisy.

I was hoping that your experience with this PCB design would help me in my own, so I could decide whether to join the SID's ground to a ground plane or use an explicit track.

I understand. I'm learning here as well... That's a big part of this project for me. After reading the datasheet, I decided to go for it. It also allowed me to clear up a few other areas as I shuffled things around. I also went with a ground plane encircling the audio lines as more of a safety measure. I've seen it done on other audio gear, so I put it here as well.

To be honest with you, I don't see how the special routing of Vcc, Vdd, and GND could help much, but I figured that it can't hurt.

I've also put up yet another version of the image. Provided all the parts footprints check out (they should) and my checking once again (triple? quadruple?) versus the reference schematics is good, this is the layout I'll have made into the prototypes.

-Steve

[TK.]

It's still difficult for me to make the final decision, there are many pros and cons, some of them will be propably mentioned later once I'm very sure...

However, I've an important question: are you using a legal copy of Eagle? Because the freeware version is limited to 100x80 mm size and only allowed for non-profit projects. The commercial version is very expensive.

Best Regards, Thorsten.