The ultimate DIY? A Stax SRM-T2!

[micon21]

Today I received the main part for T2, the boards. I drew the boards taking into account that changes have occurred in radio components over the past ten years.

 I fit into the dimensions of 300x150mm with power supply units.

[micon21]

 I'm not in the mass production business, so I'm not going to BUY expensive devices, meters, analyzers, for basic hFE determination. Over the last ten years, I've built many different versions of electrostat amplifiers. Yes, not all of them worked. Yes, I didn't like all of them. For example, the mini T2 really disappointed me.

assembled version called carbon, I am happy for two years. But many music lovers always want something better. I hope  that T2 will outplay Carbon. 

Edited Wednesday at 10:42 PM by micon21

[simmconn]

On 7/15/2025 at 2:52 PM, micon21 said:

 I showed three samples, one of the demonstrated ones, the device defines as IGBT.

I assumed that I was not the only one who encountered fakes...

Thanks. I guess nobody likes to receive fake parts. But if it’s a low-current, 1200V or better grade IGBT, its characteristics can come very close to the SiCFET we use in threshold voltage, transconductance and even input/output capacitance. It might actually work, at least in the GRHV. I’d be interested to try it out. Well, we should probably stop talking about SicFET or IGBTin this thread, as they are irrelevant to T2.

[micon21]

 When I was looking for 2SA1968, I also got PNP. I couldn't make a claim to the seller, because according to the Toshiba datasheet, there is such a version too. Model 1968, one for the whole world, n-p-n and p-n-p

Edited 9 hours ago by micon21

[kevin gilmore]

2sa1968 is in fact a PNP 900v.  2sc1968 is a 500mhz rf amplifier.

Edited Friday at 09:28 PM by kevin gilmore

[micon21]

1 hour ago, kevin gilmore said:

2sa1968 is in fact a PNP 900v.  2sc1968 is a 500mhz rf amplifier.

sorry,  I have one 100% original and 10

fakes, many do not know who the original is.

Edited Friday at 10:49 PM by micon21

[spritzer]

The original is on the right... the left one is clearly a fake