JoaMat

squirrels on Iceland? didn't know that...

The squirrels sits on them.

Lots of converters at Mouser – just have to find a suitable one in stock. Alternatively 9 volts cells....

this one, 12V to 12V and 1/4W

Can a DC/DC converter be used as it is or is some filtering needed?

Very nice indeed.

I like the way Skooby attachs the heat sinks. It’s a Fischer SK 81 - 100 x 37.5 x 15 mm. Found it at a local dealer. Cut it in two halves and it fitted quite nicely. I also use an aluminum net for top cover. Heat sink or nor the heat has get out of the cabinet. At 74 degree Celsius the PTZA06 is good for some 450 mW.

Take a look at this 3M product. 3m8810[1].pdf I use it and I'm confident it will hold the heat sinks safely in place.

Long time since I did this kind of calculations. Try this: (12V/7V * 1.5kOhm) – 1.5kOhm = 1.07kOhm. If I’m wrong you get something else.

Milled a couple of small board 0.8 x 1.15 in. Put a cheap USB microscope on CNC machine. Easy to move microscope over the board. Took this picture, optical magnification x40.

nope

Actually a new airline. SAS was kind of not interested. Operation is planned to commence next week. Free electrostatic earspeakers. Proud to announce our new Head of Flight Operation. Here is a link to the interview with him, a very experienced guy. CV interview

Flying three-layers on single malt is a criminal act in Sweden, no matter how shrinked I am.

Yes, same as the T2 current sources except 2SC4686 instead of 2SC3675. Two LEDs and emitter resistors on bottom side. Today I visited a fantastic DIYer. He designs and builds his own small metal airplanes. He let me use his equipment to cut 1/16 aluminum sheet. Thoff thoff and I had perfect fitting top and bottom covers.

Carbon with 2SC4686 current source at the left. Inspired by works of Soren, Kerry and the team behind the DIY T2. Original design by Stax (I believe). No more speed ticket for violating the 450 limit.

You seem to have a very fruitful collaboration, ang728 and jeohpj. Congratulation to really nice amplifiers.

Wow, very nice!

Interesting topic this inlet AC controlling. Found this board in my closet. Small power supply with a PIC 10F202. Input IR and toggle momentary switch. Out to SS relay and two color LED for on/off indication. This board has served in a T2 power supply. For some reason it didn’t work when I used it for BH and Megatron. Those amplifiers draw more current than the T2 and the control powered up just to fall back to off within a second. So I took it out. I’ve a similar board with SS relay onboard in a KGSShv power supply and that works OK. Mean Well has small power modules that might be used to power the control unit. Like this. Correction: not toggle switch - it is a momentary switch.

Nice! Is there a trimmer on the vertical board? Looks so to me.

Went back and looked at this again; a lot to like here! Agree. I like the small boards close to power inlet. @sorenb I guess the power switch on front panel is a toggle type? Is the switch just an elegant black one or is there light in it?

Thanks everyone for all the kind words and encouragement along the building of the Carbon. I think it turned out very well. In previous post I said it sounded all right – that’s an understatement, it sounds fantastic. But of course everything you just built is the best sounding ever built never trust a DIYer. George, I wish you hadn’t asked me about the 500 V. Yep, I run it at 500 V. I’ve read the datasheets but I haven’t told the amplifier.

Today I’ve shorten in the front and back panels. Makes the three layer Carbon looking neater. Dual power connectors on the back. Using the T2 power supply, too lazy to build a new one. Still more work to. But it works as it is and it sound all right.

I’ve used the method described by Soren for a quite a while. Found it reliable and easy to use and it’s an advantage not to do the measurements on a live amplifier. While I did this on my latest board I got some funny readings on one current source. Increasing the voltage (I use lab power supplies) the current increased to a much higher value then expected. It turned out that when increasing voltage above some 15 volts the other current source start to provide current. At about 70 V it provided full current. Didn’t understand how this could happen unless I did something wrong. Checked my board layout for more errors, changing components etc.etc., but I didn’t found anything explaining this issue. Finally, after two days of investigations, I decided to just power it up and hoping for the best. OK flipped feedbacks. When corrected the board worked all right.

I’ve a bad habit. I want my boards to be symmetrical. Take the first board turn it 180 degrees and flip it. Next I’ve to tidy it up to get it working. This time I missed a couple of things. Kevin once told me this method – maybe there was something I didn’t understood.

A picture from my kitchen. My dear is away for a few days and will be back on Friday evening so I have time to fix this mess. Anyhow, a second board of three layer Carbon is done. This one’s offset is as good as the first board after fixing an error. Mixed up the feed backs so first offset was +440V and -440V. First board was free from errors but this one have some serious errors. Glad I didn’t sent it to a board house for manufacturing.