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?

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. 

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.

I would be interested in a couple boards as well if someone more versed in managing the process ends up doing one.

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, 201312 yr by Kerry

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...

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.

Sadly it's all the electrostatic amps eating up my time.  This will be finished at some point though... 

Thanks.  Is anyone doing a board run?  I'd like to piggyback on for two pairs.

I'd like to piggypiggyback for two pairs.

Thanks for the quick reply and update! I'll look forward to whenever you are able to put this back on the front burner.

I thought spritzer was selling some prototype boards

Edited March 9, 201412 yr by nopants

Yup I have some prototype boards for sale. 

will the krell psu board work for those?

Yeah, pretty much any bipolar PSU will do. 

sorry but why this board cannot run L+R ?

 

I see ckt on both sides are identical from my untrained eyes.  

 

 

thanks !

only one set of input devices.

this is unbalanced/balanced in, balanced out

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

this is the production version

http://gilmore.chem.northwestern.edu/ssdynalobal.jpg

Where did the film caps go?

I didn't do the final layout of the that board... 

Fine, I will squeeze the expensive 4.7uf film caps in...

 

done

Edited August 10, 201411 yr by kevin gilmore

http://gilmore.chem.northwestern.edu/ssdynalobal2.jpg

 

loving it with he6

This does look like a fun build. What's it swing VRMS?

Nice!

 

This one is on my list.  Might take a bit to get there.

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