I wonder what it would do with a buffer on each input. and what can be done with the Tz port.
THx-RNMarsh
Lottery--- too bad people are willing to give hundreds of millions of dollars for a gamble but not want their taxes increased or donate to a good cause.
-RM
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Pretty easy to DIY, just add a diamond buffer. Unfortunately most multiple discrete pnp/npn devices are in micro SOT.
You will probably find an inverse relationship between lottery spending and tax rate.
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who makes a good stand-alone diamond buffer in a single ic package? The popular one is bal for dc and not ac so its thd is high.
-RNM
I never said CFA is better, don't put that in my mouth. I just enjoy to design some amps, CFA lately, and some of the things is simpler to achieve, at least to me.
Damir
Those are decent parts. I wish they made a package that brought out all of the connections to the 8-transistor die.
We have gone over what it is we like about CFA in some great detail in other forums. I dont want to play these games with people who havent followed and thus we have to go back over old material again and again.
I challenged SW to make a simple but super linear line stage...... he did and it is a wonderful circuit. Damir took up the challenge to produce an CFA with the characteristics I wanted to see. His result is also a wonderful circuit. I'm not a reviewer so I havnet heard everything.... just that the Damir amp is the best I have heard to date. And measures as well, also.
The other arm chair critics need not apply or do a circuit and put it out there.
A lot of people who hear these CFA topology amps think they are superiour and that includes many of the top Japanese mfrers. I have said before, it isnt a cooincidence and wondered why. I am still refining that question and looking deeper when time allows.
Snide/sniping remarks and fluff contrary remarks from suppressive personalities were at first taken seriously. Now its just a sad annoyance to not get excited about.
THx-RNMarsh
Is there are large MOQ on the die? Or is getting the thing mounted in small quantities for sensible $$$ the killer?
They do sell the die. Now just look on eBay for a wire bonder. There are several for under $1,000.00.
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There is no problem to find good replacement for small power transistors(BC types or higher voltage types as 2SA970/2SC2240) in SMD even in pairs and complementary pairs. Problem is with those high voltage low Cob, made for CRT displays used as VAS/TIS and predrivers/drivers transistors. Those should be THT to be on a heat sink mountable. One example are 2SA1381/2SC3503.
BF720/BF723 in SOT223 can be efficiently cooled on a copper area and heat relief holes and have Vcemax=300V and Cob=1.6pF, great for the VAS and pre-drivers. Lower Early voltage compared to your favourite TH parts, though.
Yes I know it, but how you are going to thermally connect the drivers with the Vbe multiplier, normally they are fixed on the same heat sink?
They can be used for VAS/TIS actually.
Normally you don't thermally connect the pre-drivers with the vbe multiplier. OTOH, the bf720/723 won't work as drivers, Icmax is way to low.
I my CFA mosfet I would use them as a drivers with collector current between 13 and 15 mA, no pre-drivers used of course. Now I use BF471/BF472 in that position and I think those a equivalent in THT. With standard drivers as MJE15032/15033 I get much worst result.
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