PMI,
My thinking exactly. It is no different than what is the best topology or the best type of speakers, with a hundred people you will get two hundred answers, there always seems to be an alternative for everything.
My thinking exactly. It is no different than what is the best topology or the best type of speakers, with a hundred people you will get two hundred answers, there always seems to be an alternative for everything.
You rang? 😀
http://www.diyaudio.com/forums/solid-state/132471-national-opamp-inflation.html
I also had a very short, and personal, email conversation with Mark. He basically repeated what he said in his posts. I think he did remark that he was always a big fan of the AD811 and that is what drove him to push for such a CFB type opamp at National Semi. If anyone here is not familiar with Mark (Audioman54), he established MSB Tech in the 80's and sold his DAC designs and then later moving on to National Semiconductor. I believe he is now with TI and still working on audio designs.
Matching of transistors
Hi
I can match bc547c and bc557c for HFE within less than 3%, is that ok?
For the 2sc3502E and 2sa1380E Stock I have I can only match HFE within 15%, is that ok?
Thanks
Fab
Hi
I can match bc547c and bc557c for HFE within less than 3%, is that ok?
For the 2sc3502E and 2sa1380E Stock I have I can only match HFE within 15%, is that ok?
Thanks
Fab
PDTA115
Just a reminder, so nobody is surprised...
"PDTA115ET215, NXP Semiconductor, one of the resistor biased SMD transistors in the over-current circuit, is not available as a stocked part on cut tape (i.e., in small quantity), at least not from Mouser or Newark."
Long leadtime, limited quantity, etc, etc...
Just a reminder, so nobody is surprised...
"PDTA115ET215, NXP Semiconductor, one of the resistor biased SMD transistors in the over-current circuit, is not available as a stocked part on cut tape (i.e., in small quantity), at least not from Mouser or Newark."
Long leadtime, limited quantity, etc, etc...
KSC3503E
Another diyaudio member is looking into ordering these in quantity, and will share with us when they arrive. Since this is a small group, there will be plenty for everyone.
Basically, he and I will split his lot buy, and I will pass them on to anyone who is interested at the quantity price, around $0.15/ea.
Another diyaudio member is looking into ordering these in quantity, and will share with us when they arrive. Since this is a small group, there will be plenty for everyone.
Basically, he and I will split his lot buy, and I will pass them on to anyone who is interested at the quantity price, around $0.15/ea.
I have ordered 755-DTA115EKAT146 from Mouser to substitute for the NXP part. The case is not a SOT23 but it is very close and I expect it to fit the board without problems.
Regarding the KSC3503E, at $0.15 I will buy as many as you are willing to sell.
If you do get some BC556C's, I'll buy some of those too.
At what current?
I recently tested KSA1381E, purchased together from Mouser, hfe at around 14mA (tested for VSSA): 180-195
For comparison, I also tested two pair of original Fairchild 1381E/3503E, which tested quite close around hfe~192 and 185, respectively.
I do not think you will get a close hfe match, to be honest. better than using D and E ranked parts though.
Drivers
I know that 3503/1831 are very good for VAS but for drivers can I use 2sb1086a-Q/2sd1563a-Q with matched HFE of 205 instead (to spare my 3502/1380)?
Thanks
Fab
I know that 3503/1831 are very good for VAS but for drivers can I use 2sb1086a-Q/2sd1563a-Q with matched HFE of 205 instead (to spare my 3502/1380)?
Thanks
Fab