April 16, 201115 yr you have to touch together 2 bare wires to make a change in volume You totally beat me to this one. I think it should also require morse code be used.
April 16, 201115 yr you have to touch together 2 bare wires to make a change in volume I would rather rig up a set of switches to look like Hello Kitty.
April 16, 201115 yr ... with rotary optical encoder being worked on soon. 4dsystems thing being worked on also. Excellent!
April 16, 201115 yr Author max williams should be joining us soon. His entire thing was 3 pages of code. And one entire page of the code is to control the preamp inputs (of which there aren't any in the volume control only version) and to flip the MSB and LSB because he got the bits upside down. How someone else can turn this into 10k+ lines of code, i just cannot fathom Now as to morse code, we can certainly do that as long as you have 2 keys. One for clock and the other for data. Edited April 16, 201115 yr by kevin gilmore
April 17, 201115 yr max williams should be joining us soon. And here I am! His entire thing was 3 pages of code. My code is here: http://nospecifictop...eamp-relay.html Feel free to use it! I don't claim to be good at coding though, I just learn enough to get what I need done. And one entire page of the code is to control the preamp inputs (of which there aren't any in the volume control only version) and to flip the MSB and LSB because he got the bits upside down. That was by design, not a mistake Interesting project! I'm curious why you chose that resistor package? Isn't it hard to get all the values right from the same range and make? I used 1206 sized which also fits MMA0204 (both pretty common) and it was still tough to get the right values all within one range/make! I settled for +/-2.5% of the correct value using 1% metal film resistors: Also someone mentioned using thick film resistors, wouldn't metal film be a better choice?
April 17, 201115 yr Please sign me up for 4 bare boards. I may or may not be interested in a parts group buy......
April 17, 201115 yr Glad you're here Max! I'm currently looking at thin film resistors in a 1206 package (similar to GoldPoint). The boards will support both 2512 and 1206 sizes. I'm not against metal film either. I'm actually on vacation now, but will sneak in some geek time and see if I can find the required values I know this is opening up a can of worms, but it might be possible to have a 10K version and one other like a 50K or 100K. Could possibly impact price a bit, but I just wanted to float this out there to get some feedback.
April 17, 201115 yr Well, it's just swapping the resistor set for another one. It shouldn't be too hard if we include some preset values on the BOM for people with blank boards. OTOH, for people with assembled boards maybe we should have a single version to keep the price down? What do people think?
April 17, 201115 yr PLEASE SEE POST FOR THE LATEST COUNTS. Another updated list: Name - Assembled - Bare Boards grawk - 4 - 0 Driftwood - 4 - 2 luvdunhill - 0 - 2 ujamerstand - 4 - 0 deepak - 2 - 0 cetoole - 0 - 10 manaox2 - 2 - 0 el_doug - 2 - 0 DouglasQuaid - 2 - 2 jgazal - 2 - 0 Lil Knight - 4 - 0 nattonrice - 0 - 4 kevin gilmore - 4 - 0 looser101 - 4 - 0 chinsettawong - 2 - 0 Kerry - 2 - 4 Fing - 4 - 0 blubliss - 4 - 0 n3rdling - 4 - 0 guzziguy - 2 - 0 Pars - 0 - 2 Nebby - 4 - 0 Flyingsparks - 0 - 4 morphsci - 4 - 0 dwhat - 4 - 0 minivan - 2 - 0 Craig Sawyers - 2 - 4 MASantos - 2 - 0 Vortex - 0 - 10 Beefy - 0 - 4 Samuel - 2 - 0 deadlylover - 0 - 6 TOTAL - 72 - 54 Again, if anyone is interested please PM me and I'll add you to the list. Edited April 19, 201115 yr by Kerry
April 17, 201115 yr Well, it's just swapping the resistor set for another one. It shouldn't be too hard if we include some preset values on the BOM for people with blank boards. OTOH, for people with assembled boards maybe we should have a single version to keep the price down? What do people think? I am ok with what the majority want for assembled boards. Guessing 10k?
April 17, 201115 yr Hi everyone, this is my first post here, though I have been reading Head-Case for quite some time. Would you consider shipping to France? If yes, I am definitely in for 2 boards assembled, plus relays. regards, sam
April 17, 201115 yr you could possibly alter the overall impedance with the programming, even make it user selectable.
April 17, 201115 yr Make sure you're looking at the latest version from post. The resistor values were removed from the silk and replaced by references.
April 17, 201115 yr Hi everyone, this is my first post here, though I have been reading Head-Case for quite some time. Would you consider shipping to France? If yes, I am definitely in for 2 boards assembled, plus relays. regards, sam I don't want to speak for Kerry, but I would assume that won't be a problem as I'm in Europe as well.
April 17, 201115 yr The boards will support both 2512 and 1206 sizes. I'm not against metal film either. So you will have pads for both? Nice! I know this is opening up a can of worms, but it might be possible to have a 10K version and one other like a 50K or 100K. Could possibly impact price a bit, but I just wanted to float this out there to get some feedback. That will depend on what people are using for sources and whether they are happing driving 10K. Folks could always use an input buffer though, or buy their own resistors! This calculator is handy for calculating values: http://www.amb.org/a.../delta1/r2r.cgi
April 17, 201115 yr 2050/38.3k (silk has 38.8k) 3650/16.9k (silk has 3050) This http://www.charcroft.com/site/pdf/data/Charcroft.SCAR.04.09.Is2.pdf could be an interesting resistor option - the SM form of the Vishay/Charcroft Z-foil resistors. Not sure about availability though. Unless anyone knows of an easy source already, I'll make enquiries.
April 17, 201115 yr Author ok, 2 final versions. 4 layer version with 99.9% controlled impedances http://gilmore.chem.northwestern.edu/attenuatorsmt10.pdf and 6 layer version with 100.0% matched impedances (2 ground planes added) http://gilmore.chem.northwestern.edu/attenuatorsmt11.pdf
April 17, 201115 yr This http://www.charcroft...R.04.09.Is2.pdf could be an interesting resistor option - the SM form of the Vishay/Charcroft Z-foil resistors. Not sure about availability though. Unless anyone knows of an easy source already, I'll make enquiries. They look amazing but foil resistors are usually really expensive, for example: http://uk.farnell.com/vishay-foil-resistors-vpg/s102c-20k000-0-01/resistor-metal-foil-0-6w-20k/dp/1692579?Ntt=1692579
April 17, 201115 yr ok, 2 final versions. 4 layer version with 99.9% controlled impedances http://gilmore.chem....nuatorsmt10.pdf and 6 layer version with 100.0% matched impedances (2 ground planes added) http://gilmore.chem....nuatorsmt11.pdf Perhaps the process of exporting to PDF messes with the clearances? It looks like some clearances are inconsistent, example attached!
April 17, 201115 yr They look amazing but foil resistors are usually really expensive, for example: http://uk.farnell.com/vishay-foil-resistors-vpg/s102c-20k000-0-01/resistor-metal-foil-0-6w-20k/dp/1692579?Ntt=1692579 Well, yes - the Z-foil resistors with leads from (eg) Parts Connexion are $16 to $17 each. So the SM versions are likely to be about that too. But if this attenuator is to match up to the KG Blowtorch, it's gonna need some pretty fancy resistors. I'll get a quote and see how nuts this option is likely to be.
April 17, 201115 yr Author Conversion to PDF is filled with accuracy errors. Don't know any other way to show 4 or 6 layers. If you have a gerber viewer i can supply the real files.
April 17, 201115 yr I will check to see what the price difference is for 6 sided boards I'm guessing it won't be more than a couple of bucks if that. Edited April 17, 201115 yr by Kerry
April 17, 201115 yr I might have missed it but, does the kgitsojc still have the attenuator onboard or is it now moved off using this one?
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now