Maybe I am. What is the point?
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They are a perfectly normal BJT and fairly quiet at the bias used. A lot are used in this design. To match properly you need to do it at the conditions seen in the circuit. Matching them with the Hfe setting on a multimeter will not do! Potentially, several matching jigs or one adjustable one will be needed. I can't be arsed to count them but there's probably something like 30 transistors per channel in this design and most need matching. You wouldn't need to match for example all the BC327 to each other, more a case of pnp and npn opposites to each other. To get enough matched pairs with close enough matching you may well need to buy say 500 to build one unit and it will take hours of work to do.... Even though I would agree that the price of the pre-matched ones above is well steep!
I haven't seen a circuit diagram from this design but when I'm designing something I prefer not to rely on transistors having any specific performance. I thought that's what good design was all about.
Well one thing is they will charge 550 even if they can not match them :lol:
On semi sez that they can screen the PNP but not the NPN but advertise them as complementary Case for advertising standard ombudsman ?
Other quoted that to get screened transistor the minimum Purchase Quantity would be 250000 units Maybe around £16000 (possibly much less )
Group buy any one?
I had the R2 built and believe me it is one of the best around
Simon did ear it for about an hour or so and ended up building 23 of those
One thing that I found was that Salas Simplistic had much more accurate staging and I am sure that this is not a Paradise related problem but due to my build whit poor transistor matching
I have the DCA pro (best money ever spent) now and I am sure I can do much better than before but trust me when I tell you testing 5000 transistor will give you sore back
Quite agree whit you I wish I could design circuits I am much better at hammering and welding
That you have not seen the circuit is lets say not good just a few resistor values to change and use Toshibas complementary pairs may be the answer but this is way above what I can do
I'd like to try one of these stages but it would need to be built for me or are there any demo ones available? I'm assuming not but I live in hope.