Yes, I want to go all-out with the Carbon. Will start serious work on it once I wrap up the KGST and mini stereo KGSSHV — all parts now ordered and inbound for those two.

Are there discernible advantages over the fqp supply? It seems like you'd only want to use the sic supply only if you're going to bump the current above the default(?) 14ma.

I want to build a Carbon so badly...

Are there discernible advantages over the fqp supply? It seems like you'd only want to use the sic supply only if you're going to bump the current above the default(?) 14ma.

 

I'm not expecting any profound difference, it's mostly that we can do away with the current limiting and that the amp will be mostly SiC fet.  Including the rectifiers...   

- do you do your own Stax jacks? ...looks like that from your pic??

 

 

 

Made some research. Back in 2011/2012 I bought jacks from ujamerstand and PCIaudio. Both made very good Stax jacks.

I have some jacks printed out by my 3D printer. Wanna try?

I certainly want to!

You'll need to get some CMC 8P Tube Sockets like this:

 

 

I use them on my recently built KGST and they are working very well. 

 

 

Please PM me your address and I'll send a few to you.

 

Wachara C.

Those jacks look very nice and your enclosure is gorgeous. What filament are you using?

I use ABS filament for printing the jack.  The melting point is aorund 200 C.  For normal solder jobs, it's been OK.

I recently noticed a strange behaviour of my good old KGSSHV which has probably been there from the beginning, but has gone unnoticed with the 009. Now I have the 007 and I had to turn up the volume a few clicks (elma stepper). I now also notice it with the 009, because I now what to listen for. During the warmup phase, one channel presents a sizzling noise which is clearly noticeable but not loud. After the amp has been running for some time, it dissappears. 

 

Does anyone have an idea?

i would open up the top and take a look in complete darkness and see if something

is arcing to somewhere

 

or you hear a physical noise in the amp

I have removed the amp board and visually checked it. Also used the opportunity to add 100ohm input resistors. 

The problem still persists. The sizzling changes in volume when I turn the volume pot. 

If the sizzling originated from some arcing, changing the volume should not have and impact? yes?

There is no audible physical noise coming from the amp.

Edited June 7, 201511 yr by insanity

Is it sizzling, or a crackly static sound? Also what are your measurements for offset and balance?

The first thing I did was checking balance and offset. Both were good. I will try my best to describe what I hear. Its a noise similar to what you hear, when you push the headphone cups against the head but less loud/less pronounced. It is not continous, more like there one second, gone the other. The volume of the sound becomes louder when I turn the stepper to increase the volume. 

So I take it that it is not a noise you hear from the amp itself, but only from the headphones. Does touching your case at all affect the sound or its intensity? What is your grounding scheme for your XLRs and pot as well as your amp/psu boards ?

Yes I hear it only through the headphones. Touching the case has no effect. My XLR input jacks are both directly connected to the chassis. Chassis is connected to earth. 

 

The amp boards are connected to ground through the psu board. 

 

I just turned on the amp again and this time the problem did not appear (the amp was off for 1h). hmmm. I guess I will watch it and report back. 

http://gilmore.chem.northwestern.edu/circlotronps.pdf

 

birgir seems afraid.  birgir is NEVER afraid.

 

uses the 550V caps which are $32 each, and you need 10

plus 10 of the 500V versions

Edited June 7, 201511 yr by kevin gilmore

So when will boards be available?

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

 

!!!

 

no ground plane on that one, everything floats

 

It fits in the 5U pesante amplifier chassis with room to spare.

 

3 x power transformers mounted to the back panel

 

hv power supply mounts vertically, one on each side

 

kgsshv power supply mounts vertically on the bottom

(not a lot of heat because less current draw for the gain stages)

 

either gain stage board, 1 each side mounting vertically

and output stage board, 1 each side mounting vertically

 

of possibly gain and output stage on the same board.

(going to be close)

Edited June 8, 201511 yr by kevin gilmore

Sweet Jesus!

Fascinating. For those of us a little late to this party, what is the purpose of this..? I found on this thread from 2010, which makes it sound like the purpose of the Cyclotron is to make a fully-complementary, fully-symmetrical electrostatic amplifier. Is that right?

The parts cost sounds insane

Are you trying to power a small city with it?

Edited June 8, 201511 yr by eggil

Kevin listening to his Stax on the new amp.