JoaMat

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?

Nice!! Especially the form of top plate at the screws against the heat sinks.

Could it be the LT1021 that is the problem? It's supposed to be 10 volts as long as the regulated voltage is some 20V or higher.

I want to add that I use the Raspberry with piCorePlayer and a iPad with iPeng and Squeezepad apps. I’m very happy with the piCorePlayer and the iPad apps - Internet radio (I listen to BBC3 HD every day) Tidal, ripped things on hard disk, Met Opera, Berliner Philarmoniker. Pretty magic, isn’t it? Everything works terrific until batteries fade.

Touch screen to the right. Who needs Pokémon?

I’ve had a great time the last couple of weeks building the mini Dynalo designed by Kerry. Here is the Dynalo with a finished (almost) board. Side panels from Modushop, internal height 40 mm. Front and rear panel are copper clad boards milled myself and the top cover is an aluminum net for better ventilation. Now, this amplifier turned to be a very nice one, so I started to modify it for my own personal preferences. I want a small portable amplifier to be used in my garden under a cheery tree - resulting in this. Switching power supplies, all connectors at the rear panel and some other stuff not needed removed to give room for Raspberry Pi 3 with a HiFiBerry DAC+ Pro on top. Changed front panel (easily done with a mill and copper clad board) and rear panel has two holes for connectors for the batteries and a wlan antenna. Today I got a heat sink for the output transistors. Below is a picture showing them, they are just resting on some soft pad – have to figure out the best way to get them fastened. I don’t think the sinks are needed but they are very much preferable. Many thanks to Kerry for an excellent work.