holland Posted June 27, 2013 Report Posted June 27, 2013 This amp looks very interesting. Are there any plans to distribute this more widely? The old Dynalo was a starter build for many, I'm not sure if they are still available from djgardner with the transistors and all. Sorry about that, I had the thought of modifying the board so the same one could be setup for L+R instead of just balanced while writing the post. Stock it can't be done but I'll see about changing it. Might just change the board and offer a single ended one as well as I'm not really a fan of cryptic jumpers etc. It should just have all the parts on the PCB, stuff it and it works. Couldn't one just use O+ and IG for SE, and 2 boards still? Or O+ and IG and O- and IG for 2 SE outputs, one inverted? Power rails still at 16.4V (or up to 20V IIRC with the old Dynalo), or has it bumped up higher?
spritzer Posted June 27, 2013 Author Report Posted June 27, 2013 The board will always output balanced regardless of the input. Not really intended for SE but you could just leave the - leg not connected for SE. We are not concerned about the distribution as that is up to the people who want to build these. I have enough boards for my own use but the Gerber's will be available to all. The parts are all in stock at Mouser so that side is covered. PSU is +/-20V.
holland Posted June 27, 2013 Report Posted June 27, 2013 The board will always output balanced regardless of the input. Not really intended for SE but you could just leave the - leg not connected for SE. We are not concerned about the distribution as that is up to the people who want to build these. I have enough boards for my own use but the Gerber's will be available to all. The parts are all in stock at Mouser so that side is covered. PSU is +/-20V. Thanks. Is anyone doing a board run? I'd like to piggyback on for two pairs.
FraGGleR Posted July 3, 2013 Report Posted July 3, 2013 I would be interested in a couple boards as well if someone more versed in managing the process ends up doing one.
Kerry Posted September 2, 2013 Report Posted September 2, 2013 (edited) Hi Birgir - Any progress? I was inspired and took the original version of the board and modified it so the servo is the same as yours. I used a 2uF cap instead of the 10uF. Also lowed the resistor coming from the opamp to 20k. works well. now looking at an SMD version. Thinking about the sot23 version. At 15 mA per should support it. Could use the sot223 version instead. Edited September 3, 2013 by Kerry
spritzer Posted September 2, 2013 Author Report Posted September 2, 2013 Nope, nothing yet. Everything was pushed aside for KGSSHV work... SMD version would be very cool given how bloddy small we could make it. Hell let's make a portable one which would last for about 5 minutes on a set of batteries. But what glorious 5 minutes it would be...
dubiousmike Posted March 8, 2014 Report Posted March 8, 2014 Hi spritzer. Any chance you've had the time and inclination to pick this project back up? I'm still very interested in attempting a build once green lit.
spritzer Posted March 8, 2014 Author Report Posted March 8, 2014 Sadly it's all the electrostatic amps eating up my time. This will be finished at some point though... 1
lkong Posted March 9, 2014 Report Posted March 9, 2014 Thanks. Is anyone doing a board run? I'd like to piggyback on for two pairs. I'd like to piggypiggyback for two pairs.
dubiousmike Posted March 9, 2014 Report Posted March 9, 2014 Thanks for the quick reply and update! I'll look forward to whenever you are able to put this back on the front burner.
nopants Posted March 9, 2014 Report Posted March 9, 2014 (edited) I thought spritzer was selling some prototype boards Edited March 9, 2014 by nopants
spritzer Posted March 9, 2014 Author Report Posted March 9, 2014 Yup I have some prototype boards for sale.
spritzer Posted March 9, 2014 Author Report Posted March 9, 2014 Yeah, pretty much any bipolar PSU will do.
ang728 Posted August 9, 2014 Report Posted August 9, 2014 sorry but why this board cannot run L+R ? I see ckt on both sides are identical from my untrained eyes. thanks !
kevin gilmore Posted August 9, 2014 Report Posted August 9, 2014 only one set of input devices. this is unbalanced/balanced in, balanced out
ang728 Posted August 9, 2014 Report Posted August 9, 2014 AH I got it ,didn't notice only one set of input stage Thanks Dr.Gilmore only one set of input devices. this is unbalanced/balanced in, balanced out
kevin gilmore Posted August 10, 2014 Report Posted August 10, 2014 this is the production version http://gilmore.chem.northwestern.edu/ssdynalobal.jpg
spritzer Posted August 10, 2014 Author Report Posted August 10, 2014 I didn't do the final layout of the that board...
kevin gilmore Posted August 10, 2014 Report Posted August 10, 2014 (edited) Fine, I will squeeze the expensive 4.7uf film caps in... done Edited August 10, 2014 by kevin gilmore
kevin gilmore Posted August 17, 2014 Report Posted August 17, 2014 http://gilmore.chem.northwestern.edu/ssdynalobal2.jpg loving it with he6
GrindingThud Posted August 17, 2014 Report Posted August 17, 2014 This does look like a fun build. What's it swing VRMS?
Kerry Posted August 18, 2014 Report Posted August 18, 2014 Nice! This one is on my list. Might take a bit to get there.
kevin gilmore Posted August 18, 2014 Report Posted August 18, 2014 on +-15V power supplies it will do about 30vpp balanced on +/-20v power supplies it will do about 40vpp balanced on +/-15v power supplies its 200ma per channel. would need to adjust the bias resistors to reduce the current for 20v. works out to at least 2.5 watts rms pure class A into 50 ohms 1
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