+mytek Posted July 21, 2016 Author Share Posted July 21, 2016 Connector Interface Board is done. The spacing for the PS/2 connectors and the mounting brackets remains the same as the interface board that was made for the TK-II-PIGGYBACK board. So the good news is if you drilled holes and mounted that in your A8 then all you need to do is drill one more hole for the 3.5mm audio jack -or- leave that jack off of the board assembly and interface whatever you want through J4. - Michael 3 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 22, 2016 Author Share Posted July 22, 2016 TK-II-STEREO first board run ordered from OSH Park. 12 pieces @ $7.43 each (with free shipping) When I've confirmed that the board works properly I'll post a shared buy link for the PCB, and also upload the design files to the AtariBits website (soon I'll be creating an entirely new page for this project). I ordered 12 boards because I have high confidence in the PCB layout. Hopefully that confidence is well placed . - Michael 3 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 22, 2016 Author Share Posted July 22, 2016 Developing the TK-II-STEREO board. I thought you guys might like to see what the R&D looked like on this project. ZYBEX was my Stereo Sound Check Thanks to some tall male/female pin headers and Lotharek's Stereo board I was able to create the Pokey test interface Because whatever happens on proto board gets messy real fast (switching and analog circuits) Scoping things out (ZYBEX really blasts the sound out reaching +/- 0.4v peaks) - Michael 4 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 22, 2016 Author Share Posted July 22, 2016 (edited) TK-II-STEREO Connector Interface first board run ordered from OSH Park. 12 pieces @ $3.48 each (with free shipping) Since this is the mating board to the main one, I matched the same number of units as placed on that order. Now all I have to do is just wait and then when my boards arrive - Michael Edited July 22, 2016 by mytekcontrols 1 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 22, 2016 Author Share Posted July 22, 2016 (edited) The 3.5 mm Stereo Audio Jack that is utilized on the connector interface board is something I picked up on eBay for dirt cheap. It's the perfect connector for this application, having vertical orientation and a small foot print, and only requiring a single hole. 20pcs green 5PIN 3.5MM Stereo Socket PC PCB $3.99 (includes free shipping) -or- in other words $0.20 each eBay Store: cao19961023 I don't think the source is going away anytime soon, since I purchased my 20 back in January of this year, and he is still selling them on eBay 6 months later. But if anyone is contemplating making some of these boards, it would probably be wise to buy some of these now while you still can. Otherwise it might take some searching to come up with a suitable replacement. What I love about using this type of connector, is that there are all kinds of adapters and powered speakers that are compatible with it. And for use with old school RCA audio connectors, this cable is very cheap. 3.5mm 1/8" Plug Male to 2 RCA Male Stereo Audio Splitter Cable Adapter 4.3FT Only $1.51 (includes free shipping) And for the PS/2 jacks, I found these purple ones that really work great. 20PCS MINI 6PIN FEMALE PCB MOUNT PS2 JACK Only $4.56 (+ $2.00 shipping) And for the original Pokey piggy-back, these headers are perfect and at a great price: 40 Position Single Row Round Male Pin Header Five of them for $1.81 (includes free shipping) Just snap it apart into two 20 position pin headers for use on the TK-II-STEREO Main board. - Michael Edited July 22, 2016 by mytekcontrols 2 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 22, 2016 Author Share Posted July 22, 2016 TK-II-STEREO Connector Interface (revised) first board run ordered from OSH Park. On the surface it looks almost the same as the first version, but when digging deeper a not so subtle change has occurred. Notice the term 'SWITCHED' being used for the auxiliary audio output connector. The not so smart part of me initially missed the fact that there were 5 connections on the 3.5 mm Stereo Audio Jack. After thinking more about it, I suddenly realized that those must be switched outputs. So I then had another thought, why not put those to work . Well here is the result of that idea... So the basic thinking is to have the 'Switched Audio Out' connector have the option of being used for feeding an amplified speaker set-up. Then if you plug into the 3.5 mm jack, this aspect gets switched off, and the audio gets fed to an external audio input, such as what exists on a monitor. BTW, the PAM 8403 chip can be purchased as part of a complete board assembly with a volume control for about $1.00 from GearBest. If you want to use a separate power supply for this, then don't tie VSS to the common and just run the +5 and GND directly from the external supply. - Michael 2 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 23, 2016 Author Share Posted July 23, 2016 Opps I accidentally deleted the schematic image on that last post. So here it is again, only I've added some manufacturer part numbers as well to make it even better. The manufacturer's listed would be for high quality components, so the cost will be higher. Some things like the pin headers can be bought much cheaper from China, but you'll have to weigh your options. I also discovered that those cheap 3.5 mm Stereo Line Out jacks from China don't all have reliable switches, so I found a cross match for it in the SwitchCraft product line that should be of a much better quality. Mouser Electronics and Digi-Key carry these, but they're not going to be $0.20 each (more like $1.80 each instead). - Michael 1 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 24, 2016 Author Share Posted July 24, 2016 (edited) Just a slight revision to the TK-II-STEREO connector interface schematic. Nothing's really changed circuitry wise, just added a few more notes, increased font size on example part numbers, and created a better representation of the the 3.5 mm stereo jack, now showing the proper switching action (switches open when inserting the plug). Image coming soon...And here's a video talking about and demoing the PAM8403 audio amp module that I've recommended for use as an internal solution for amplifying the dual Pokey stereo output. It's a very amazing and effective stereo amplifier.https://www.youtube.com/watch?v=oB-k0tA1G2M And if you guessed correctly, yes I'm getting bored waiting for my boards to arrive - Michael Edited July 24, 2016 by mytekcontrols Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 24, 2016 Author Share Posted July 24, 2016 (edited) Drats I took too long to edit my previous post!!! Well here is the revised version. ------- Just a slight revision to the TK-II-STEREO connector interface diagram (which also affects the PCB). Added a pin on the switched audio output connector for a +5 V source for an external amplifier such as the PAM8403 Module, increased font size on example part numbers, and created a better representation of the the 3.5 mm stereo jack, now showing the proper switching action (switches open when inserting the plug).Yes unfortunately for me this means another batch of these connector boards needs to get fabricated . This whole scenario of going back and redesigning what should have been the simplest part of this project, reminds me of how misplaced our attention can get when something is considered insignificant. But I promise this will be the last change - Michael Edited July 24, 2016 by mytekcontrols Quote Link to comment Share on other sites More sharing options...
Van Posted July 24, 2016 Share Posted July 24, 2016 Wow, very cool. So much happens when I'm elsewhere. Will def be building a couple of these Pokey boards If you will have some of the 'first' batch PS2 boards unused because of the design change, I'll gladly buy a few. These would work very well with a Raspberry Pi case project I'm messing with ATM. Yogi Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 24, 2016 Author Share Posted July 24, 2016 Wow, very cool. So much happens when I'm elsewhere. Will def be building a couple of these Pokey boards If you will have some of the 'first' batch PS2 boards unused because of the design change, I'll gladly buy a few. These would work very well with a Raspberry Pi case project I'm messing with ATM. Yogi The 3.5 mm jack on those first run boards is not going to work as is. Do you still want some? If so you can have as many as you need for free. Do I have your address? PM me. - Michael Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 24, 2016 Author Share Posted July 24, 2016 (edited) Here's some cool little speakers that could certainly work in a re-cased Atari and be a good match for the PAM8403 Amplifier Module. Gikfun 2" 8Ohm 5W Full Range Audio Speaker Stereo Woofer Loudspeaker - Michael Edited July 24, 2016 by mytekcontrols Quote Link to comment Share on other sites More sharing options...
Van Posted July 25, 2016 Share Posted July 25, 2016 The 3.5 mm jack on those first run boards is not going to work as is. Do you still want some? If so you can have as many as you need for free. Do I have your address? PM me. - Michael Very good, mainly just need some PS2 breakout for a panel (have a USB to KB/Mouse cable for the Pi but want to get away from all the dongles hanging off the board or rather put them all in a old WebTV case). Have some mini-dins with the panel flange but they aren't nicely color coded like 'PS2' sockets. So Thank You and will PM you Quote Link to comment Share on other sites More sharing options...
adam242 Posted July 25, 2016 Share Posted July 25, 2016 (edited) Here's some cool little speakers that could certainly work in a re-cased Atari and be a good match for the PAM8403 Amplifier Module. Gikfun 2" 8Ohm 5W Full Range Audio Speaker Stereo Woofer Loudspeaker - Michael The 400 and 800 already have one internal speaker and the 'vents' in the case for it... If one were careful, a matching set of slots could be cut into the other side of the case, and two of these babies installed, one in place of the original speaker. Very subtle and almost stock appearance. THAT would be slick. Did I mention I'd really like to see a 400/800/1200xl version of this board? Edited July 25, 2016 by adam242 2 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 25, 2016 Author Share Posted July 25, 2016 Yep I still plan on creating a 400/800 version board, but only after I'm satisfied with how the XL/XE one works first. As for the 1200XL, just so people don't assume the wrong thing, you are specifically referring to a 1200XL with something blocking space above Pokey such as the 32-in-1 OS board. Otherwise the XL/XE version stereo board works just fine. I like your idea of installing those 2" speakers in an 800. That would be a real sleeper installation that would blow people away when activated. - Michael 1 Quote Link to comment Share on other sites More sharing options...
adam242 Posted July 25, 2016 Share Posted July 25, 2016 As for the 1200XL, just so people don't assume the wrong thing, you are specifically referring to a 1200XL with something blocking space above Pokey such as the 32-in-1 OS board. Otherwise the XL/XE version stereo board works just fine. My apologies. I should have worded that more carefully. Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 25, 2016 Author Share Posted July 25, 2016 My apologies. I should have worded that more carefully. Shame on you But seriously I thank you for pointing out the problem with the 1200XL in regards to space above Pokey with certain upgrades. It's good stuff to know when laying out boards. - Michael Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 27, 2016 Author Share Posted July 27, 2016 Line level outputs will be hotter, as in a higher Vpp (total voltage span from - to +) then the typical A8 or Lotharek's Stereo Board. But in my opinion I think it'll be much closer to the -10 dBv Consumer Audio Device Line Level Standard of 0.894 Vpp (0.447x2). TK-II-STEREO O-Scope Capture showing maximum Vpp signal while the game music of Zybex is playing Looking at the O-Scope image you can see that a Vpp of 1 volt is hit at maximum volume. The normal Atari (although this greatly varies on some machines such as the 1200XL) is normally around half that, and the same seems to apply to Lotharek's Stereo Board. For reference: typically today's MP3 players run a Vpp of around 1.5 volts. Also the wave form coming out of the TK-II-STEREO board's analog mixing amps appears to be a bit more symmetrical or true to what is going in from Pokey. When I look at the original audio output on my XEGS, the waveform appears to have a higher peak on the front edge of a given sound which then tapers off over time. WARNING This new Stereo Board will be much louder using the same volume setting as used with your original setup. However not so loud that it will cause clipping problems with a properly design audio input circuit. 2 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 27, 2016 Author Share Posted July 27, 2016 Final Version TK-II-STEREO Connector Interface board ordered from OSH Park today. Yes this really is the final version - Michael 1 Quote Link to comment Share on other sites More sharing options...
Dropcheck Posted July 27, 2016 Share Posted July 27, 2016 Final Version TK-II-STEREO Connector Interface board ordered from OSH Park today. Yes this really is the final version - Michael Are you really..... really sure? If so, are you thinking about a completed board run or a unsodered kit or the customer orders all from various suppliers? I'd like one. 2 Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 27, 2016 Author Share Posted July 27, 2016 Are you really..... really sure? If so, are you thinking about a completed board run or a unsodered kit or the customer orders all from various suppliers? I'd like one. LOL yep I'm really, really... sure I won't be doing any board runs myself (I'm just the design guy), but there are a couple of people here on AA that have done assembled versions for sale of the TK-II PS/2 keyboard adapter boards in the past, and I'm thinking they might do the same for this new project. Of course I'll be posting 'buy links' that will send anyone directly to OSH Park to purchase just the unassembled boards. And on my website I'll have the Gerber board files, schematics, and hopefully a decent BOM as downloads available soon. Currently you can go there to get the PIC16F1847 firmware code for the keyboard aspect (ataribits.weebly.com/design). The cost to buy the board set is about $33.00 a batch (a batch is the minimum order that OSH Park will do, which is 3 boards of each type). So in other words $11 gets you both the Main and Connector Interface board, and you'll still need to come up with the other components (2 IC's and some misc resistors, capacitors, and connectors). So for you it would perhaps make sense to buy the board sets and components, assemble them, keep one for yourself and sell the other two for a profit thereby making your's a freebie. Just a thought Thank you for your interest - Michael Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 29, 2016 Author Share Posted July 29, 2016 I revised the schematic once again just for purposes of authenticity. The PAM8403 Modules that are being made and sold now days are a bit different then the one I drew the schematic symbol for, and I figured to avoid any confusion and smoke, it was a good idea to update it. I also removed the connector part numbers from this schematic as well, since that should actually appear in a separate BOM for ease of updating where necessary. So to be clear, the circuit for the connector interface has not changed since the last version (nor will it in the foreseeable future), this is only a correction of how it hooks into the PAM8403 Module. Cheers - Michael Quote Link to comment Share on other sites More sharing options...
Frankie Posted July 29, 2016 Share Posted July 29, 2016 (edited) Developing the TK-II-STEREO board. I thought you guys might like to see what the R&D looked like on this project. ZYBEX was my Stereo Sound Check Thanks to some tall male/female pin headers and Lotharek's Stereo board I was able to create the Pokey test interface Because whatever happens on proto board gets messy real fast (switching and analog circuits) Scoping things out (ZYBEX really blasts the sound out reaching +/- 0.4v peaks) - Michael Are all versions of Zybex stereo? I have Lotharek's simple stereo board and I use Yoomp! to test it. Zybex only plays from one speaker for me. Edited July 29, 2016 by Frankie Quote Link to comment Share on other sites More sharing options...
+orpheuswaking Posted July 29, 2016 Share Posted July 29, 2016 Are all versions of Zybex stereo? I have Lotharek's simple stereo board and I use Yoomp! to test it. Zybex only plays from one speaker for me. I believe the original release was not stereo. It was later patched to be stero Quote Link to comment Share on other sites More sharing options...
+mytek Posted July 29, 2016 Author Share Posted July 29, 2016 Are all versions of Zybex stereo? I have Lotharek's simple stereo board and I use Yoomp! to test it. Zybex only plays from one speaker for me. Yes as orpheuswaking pointed out it was patched. Only the theme music was modified. And here is the modified version: Zybex _ stereo.atr - Michael Quote Link to comment Share on other sites More sharing options...
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