JoaMat

Yes, it’s 2-layer. I think homemade inner layers is too complicated. Making vias is not that funny either. My board is a bit smaller than the original, no terminal blocks and one ground plane for the entirely board. Kevin’s board have solid inner ground planes which is preferred, but I can’t do that in my kitchen. By the way I'm retired, gives some additional time for funny things.

Relays clicking.

Excellent work you are doing with the controllers, Kerry. I’m trying to learn how to program the Arduino. Below is an Arduino UNO with an OLED and a rotating encoder. Turning the encoder - volume goes up/down. Encoder knob pushed toggles mute. If rotation while in mute the volume is changed, but takes effect first when mute is off again. Last volume value is stored in EEPROM and is called back next time controller is powered on and it starts with mute on. I don’t know if this really works - I don’t have a digital attenuator.

I used this link for programming the ATTiny with Arduino Uno. Maybe you have to change the supply voltage on Volumite so it works with the digital attenuator. Edit: Consulting MAX4820 datasheet - looks that 3.3V at Volymite should be sufficient??

Thank you. Programming – that’s my problem. I’ve to keep it simple. With ATMega328 you will have lots of opportunities – motorized pots., OLEDs, remote control etc. etc.. An AMB OLEDuino version would be great. If you just are able to program it. Excited to see what’s coming.

May I jump in and quote myself? Volumite consists of ATtiny85, potentiometer and voltage regulator. At picture above there is a ATtiny on the breadboard, power supply and potentiometer. The microprocessor is programmed and it seems that I get the correct signals to control the digital attenuator. I don't believe you can use Twisted Pear Audio's codes with Kevin's digital attenuator.

@Kerry, any good part number for the crystal Q1?

Yep, 8 bit digital attenuator is the future.

I just held the chip with one hand and with a small pliers I carefully bent the pin. After bending 30 degrees or so I took a new grip with pliers moving it a few tenths of a mm to avoid a to sharp bent. Well, try it – I did ten pieces and all successfully - maybe beginners luck…

I did consider tubing, but the min distance between pins is about the same as for those without crossed legs. As long as I don’t try to stick some test pins in there I think it’s safe.

IMO it's fairly easy to build a nice case for this board without the need for standoffs.

Happy Birthday!

One could say that the legs of BJT is shifted one step to the right. So I just bent the legs accordingly and put a pin header in the left hole and then mount the transistor with desired torque . As I do it the pin header is hold in place by the crossed leg. Solder and it’s done. Few pictures below. Hope they show how I did it. I've modified one T2 and one Blue Hawaii this way. And it works fine.

It's a test board. I like natural colored PCBs.

Very nice indeed.

Indeed a most elegant amplifier. Impressive chassis work - like a Maserati.

Managed to squeeze the code in ATtiny85. I do think it will be able to control the balanced digital attenuator... ...maybe.

Bought a Saleae Logic thing years ago. Eventually I got some use of it.

Wanted! Anyone willing to sell me a balanced digital attenuator board? or two?

Wow, absolutely amazing!

I consider my T2 to be absolutely silent. I can't hear any noise, might be because my old ears though.

May I help? Q1/Q3/Q13 - MMBTA56 Q2/Q4/Q14 - MMBTA06

Happy birthday!

Superb. And it has your signature… one could see from far distance that it’s a John William McClean coming, something like Mercedes S Class.

Kerry, how long time does your machine need to mill the amplifier top plate?