JoaMat

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?

This? kgbhultraminipsv4.zip

@starcat I have boards. Ping me if still interested. Location Sweden.

Most, if not all, public published GRHV boards are with c2m1000170d but if a bit creative you might use fqpf8n80c. If you do - please tell us how it turned out. We have to find ways to tackle unavailable parts.

Eventually I managed to dig up some money. I also had a brand new pair of Stax pads at hand. Thanks for the advice. I’m really happy with this Headphone.