alexd15z6 Posted January 22, 2014 Report Share Posted January 22, 2014 Clear - thanks a lot Kevin . With respect Alex Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted May 15, 2014 Author Report Share Posted May 15, 2014 (edited) actually we should rename this thread KGITSOCH because this input section is virtually the kx-r with a few mods that make it even lower distortion, lower noise, and faster. No feedback of any kind. Should be doing a test run of boards very soon http://gilmore.chem.northwestern.edu/ubaltobal2.jpg Edited May 15, 2014 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted May 30, 2014 Author Report Share Posted May 30, 2014 (edited) http://gilmore.chem.northwestern.edu/ubaltobal.jpg rest of the parts on monday Edited May 30, 2014 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
nopants Posted May 30, 2014 Report Share Posted May 30, 2014 does eBay sell zchannel devices? I am not seeing them when I look them up at RadioShack Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 2, 2014 Author Report Share Posted June 2, 2014 nopants you are fucking idiot. birgir and I spend hundreds of hours on this stuff and you make a stupid joke. not funny input board complete and works perfect. thd less than the base of my ancient test gear (<.002% thd, and absolutely flat) picture later. Quote Link to comment Share on other sites More sharing options...
nopants Posted June 2, 2014 Report Share Posted June 2, 2014 I apologize, I wasn't undermining your effort in any way Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 3, 2014 Author Report Share Posted June 3, 2014 http://gilmore.chem.northwestern.edu/ubaltobal1.jpg Quote Link to comment Share on other sites More sharing options...
Kerry Posted June 4, 2014 Report Share Posted June 4, 2014 Looking good. Have you had a chance to test this yet? Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 4, 2014 Author Report Share Posted June 4, 2014 I have tested it, listened to it, works great. offset is 1.5mv going to swap out the opa445 for op27 and then remove the offset pots. and probably add a pot on the pnp current source to do a final trim. input impedance with the bipolars is 10k. replace them with the jfets and it works better Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 4, 2014 Author Report Share Posted June 4, 2014 should be final rev's of these two boards unbalanced/balanced to balanced http://gilmore.chem.northwestern.edu/ubaltobald3.zip ss dynalo balanced http://gilmore.chem.northwestern.edu/kgdynalobal5.zip Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 20, 2014 Author Report Share Posted June 20, 2014 (edited) http://gilmore.chem.northwestern.edu/dsc_0585.jpg http://gilmore.chem.northwestern.edu/dsc_0586.jpg on +/-15v power supplies maximum output is 16 volts peak to peak balanced into 50 ohms on +/-20v power supplies maximum output is 22 volts peak to peak balanced into 50 ohms Edited June 20, 2014 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
Algar_emi Posted August 31, 2014 Report Share Posted August 31, 2014 Hi. I'm very interested in a group buy for this preamp. Keep me posted. Thanks SB Quote Link to comment Share on other sites More sharing options...
Algar_emi Posted September 22, 2014 Report Share Posted September 22, 2014 Can I find the power supply you used in one of the posts, or it was not posted yet? Thanks SB Quote Link to comment Share on other sites More sharing options...
mypasswordis Posted September 30, 2014 Report Share Posted September 30, 2014 Input JFETs just came in the mail. Most of them look real, there are a couple 2sk170s that have funky looking printing on them that I'm not sure about. Will measure IDSS later. Finally the project can move forward! Actually, I still need to get a few more things. Just ordered the amp and PS cases yesterday, and am about to put in a final mouser order for some other parts. I'm going to be out of town this weekend but should have the attenuator boards and Multi Amp up and running fairly soon, and breadboarding the ubal to bal and phono boards will shortly follow. 1 Quote Link to comment Share on other sites More sharing options...
nopants Posted November 18, 2014 Report Share Posted November 18, 2014 So the poverty version of the KGITSOJC would be the ubal to bal (stuffed with jfets) driving the dynalo boards? And I guess a switch between pre and headphone outs? I'm curious about this dynamic piece of equipment, but Iv'e only got k401s and some random onkyo I found lying around. Quote Link to comment Share on other sites More sharing options...
mypasswordis Posted November 18, 2014 Report Share Posted November 18, 2014 If you're interested, have the KG or similar digital attenuator boards, and are willing to wait a couple more months (really sorry about that, I'm pretty busy these days and don't have enough time to do much except sleep by the time I get home), I'll hopefully have finished the microprocessor and touchscreen code, and the android app code to implement in the KGITSOCH so you can build the full version. I aim to finish soldering most if not all the amp hardware this weekend but not sure about the next time I'll have some free time. My Nexus 4 should be getting the Lollipop update sometime next week and I think I'm planning on getting the Nexus 6 anyway (verdict still out on whether or not it's too big) so I can use them to test the app. The only dynamic headphones I still have are a couple of vintage orthos. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted November 18, 2014 Author Report Share Posted November 18, 2014 i've started working on the 4dsystems 3.2 inch touch lcd again. I think its the right answer whether you use it standalone, hooked to a arduino, or raspbery pi, beagleboard etc. still looking for an easy solution that combines this display with a wifi enabled web page controller. (yep i'm lazy) will publish the 4dsystems standalone code when i have time to test it. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted November 23, 2014 Author Report Share Posted November 23, 2014 volume and balance now working with the real attenuators http://gilmore.chem.northwestern.edu/dsc_0626.jpg something else could be used to feed the serial port with an infrared or web based controller. Quote Link to comment Share on other sites More sharing options...
G600 Posted July 16, 2015 Report Share Posted July 16, 2015 Any finished system here ? I also would like to know if mpsa are OK for the ubal to bal boards ? And what is the proper way to use them with dynalo mk2 ? Thanks Quote Link to comment Share on other sites More sharing options...
mtoc Posted April 27, 2016 Report Share Posted April 27, 2016 i ve bought several so called new old stock mpsw06 from ebay and waiting for the jfet version... Quote Link to comment Share on other sites More sharing options...
purrinn Posted May 30, 2016 Report Share Posted May 30, 2016 Hello, what're these things? Quote Link to comment Share on other sites More sharing options...
G600 Posted May 30, 2016 Report Share Posted May 30, 2016 LEDs Quote Link to comment Share on other sites More sharing options...
starcat Posted February 19, 2021 Report Share Posted February 19, 2021 Hey Kevin, is there a new continuation thread to this somewhere, or did you just stopped this project? Hope you are well. Quote Link to comment Share on other sites More sharing options...
starcat Posted June 28, 2021 Report Share Posted June 28, 2021 (edited) No pictures, not even posts anymore... c'mon guys, don't be shy and show off your work 🙂 Edited June 28, 2021 by starcat Quote Link to comment Share on other sites More sharing options...
TC1980 Posted October 8, 2022 Report Share Posted October 8, 2022 Hi Could somebody help me out please? I have started building the KGITSOJC, got the boards and the components. What resistor value should I use for resistors labed RF on the silkscreen? For the power supply I'm building GRLV, is it okay to use +/-15V or should I use +/-20V? I have a suitable transformer for 15V output already, but I can get a new one if it is better to use 20V rails. Quote Link to comment Share on other sites More sharing options...
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