JoaMat

We all know what KGSSHV Carbon is. But why was it baptized Carbon?

This is probably pushing it too far. Changed ksc2690 for 2sc3324. Board size now 99mm x 112mm or 3.95in x 4.44in. Looking at the 3D visualizer it seems doable. I've found a way to lay down the transistors flat but not how to bend the legs. Anyhow it’s fun working in Proteus. You can create the most odd things.

Schematic a few posts up is updated and now reflects what I’ve built. Changes: R21 – R23 and Q3,Q4. Picture from top. Carbon board to the right with ceramic insulators. New thing to the left. All transistors (2SA1968 and 2SA4686) on bracket are insulated and don’t need ceramic insulators.

Milling process went smooth. Here is the board populated with components I had at hand and it works alright I would say. It is playing in pair with a Carbon I built three years ago. The Carbon to the left but its actually the right channel. Amplifier is upside down. I put the trimmer on bottom side – I forgot that this isn’t a tube amplifier with none component side facing upwards. In schematic posted earlier there is a couple of 2SA1486 but I took a pair of KSA1156 instead which is OK as HV is +/-400V.

Yes, I use a small CNC machine. Just made a file for the CNC machine for top side of the board. Below you can see the route (red lines) for a 15th or 0.38 mm end mill. I’ll try to make a board in the next few days - if no unexpected happens…

Seems R21 – R23 string is upside down. Lucky I discovered it before milling/etching boards.

I think a welcome message in YouTube format would work better.

I would say it’s a modified KGSShv or Carbon with T2 style current sources at outputs. My intention is +/-400V but +/-450V will be OK as 2SA1968 is a 900V device (I think). Schematically it looks like this. I’ve saved the old, now hard to find, transistors from my first built electrostatic amplifier - an onboard heat sinks KGSShv.

Nor sure where to post this. Sorry for polluting. 4 x 2SC4686, 2 x 2SA1968 and 2 x 2SA1486. Rest of the parts from Mouser except LSK389. Two trimmers, no servos. Does it work? – that is to be seen, or heard.

To be a DIYer gives you the privilege to do what ever you like (maybe not to break federal laws). I think a proper torque considering the thermal aspect is more important than the recommendation by Aavid in this case. And the shoulder washer will stand a higher torque than recommended. Thank you, I like the Wiha a lot. It even counts the clicks.

Got myself a pair of these. So I’m very much prepared for a battery powered amp.

Be aware. Recommended torque for 10PPSG is 0.565Nm to 0.678Nm. See attached Page from Aavid-Board-Level-Heatsinks-Catalog-2018-1507171.pdf for reference. I use this setting ...and I don’t know how to convert Ncm from Nm 😢

Anyone feels like taking care of three Golden Reference boards version .44? Then ping me.

Proxxon microclicker – nice. What torque setting will you use for transistors at brackets?

Stumbled over this… …what opera house might that been?

My guess is both cases are 2U… optical visual illusion makes them 1U?

Happy Birthday!

Datasheets are nice.

Thanks guys. Now I know I don’t understand… hopefully I’ll learn something later...

0.4A at 11.1V suggests … something like 3mA each channel?

Check this partco.fi/en. They claim they have 8 pieces of 2SK216 in stock at EUR 4.28 each. I don’t know anything about Partco. But Finnish people tend to be reliable. 03/01/2021. They seem to be gone.

Very nice headphone amplifier indeed. Please don’t wait too long with your next project. We want more.

Nice! So with one 5000mA 3S LiPo pack I’m ready for a 10 hours hike? Lovely. P.S. I want one now.

@Blueman2 Have you tried any of the alternative devices to C2M000170D in a Carbon amplifier?