Hi everyone, thanks for continuing this thread. I need time to grasp all of that bcoz as you know i'm still a novic and never designed a discrete amp before. Anyway i'm having hard time...it seems that ksc3503/a1381 completely vanished from market although a kind guy willing to help me...let's see. On the other hand i found another nice to-92 pair, ZTX 758/658(50mhz & 500ma). Although same dissipation capability like ztx558/458 (200ma), 1watt max.
I'm very much aware of cascode advantages but as of now i don't have the knowledge to design one
But i'll try my best to decode this issue. I don't want to be a copy paste guy, NEVER
I'm very much aware of cascode advantages but as of now i don't have the knowledge to design one
But i'll try my best to decode this issue. I don't want to be a copy paste guy, NEVER The datasheet of the 758 does let you run it at 2.5W (case temp=25C) which means you might be able to run it at 1W in reality with a heatsink. But bigger than the 12mm pad on the PCB which the datasheet also says you can run at 1.5W.
You could run a single-ended VAS (plus current source) at 20mA with one device (just). But take care to limit the current to 40mA max under adverse conditions.
I think I would still be tempted to use a parallel pair, but at least you have a choice.
You could run a single-ended VAS (plus current source) at 20mA with one device (just). But take care to limit the current to 40mA max under adverse conditions.
I think I would still be tempted to use a parallel pair, but at least you have a choice.
Anyway...that guy(a well known forum member) promised me he'll arrange some matched KSA1381/C3503 pair for me, so i'll wait for him. I need some good to-126 pairs for VAS 
Certainly not, time to calm down. Anyone who built the Honeybadger (and there are many...) says what a fine sounding amplifier it is. It's BOM recommends MJE15030/31/32/33's as drivers. Why should MJE15034/35's be worse that these? I'd go for them.Then i think i did a big mistake buying mje34/35
But Chinese parts? I don't know...
Best regards!
I think the “big mistake” he was referring to was paying more for MJEs before exploring availability of the other types. Neither is a mistake design wise.
ON does make a lot of their parts in China now. Remember when all the US tariffs went into effect? Half of the ON Semi parts had the “tariff applied” tag on the Digikey US website. I was surprised myself at just how many were made in China. May want to check them for conformance - depending on what middleman is involved. If they ARE fakes, Cob and Cbe will be way low, and beta will fall like a stone above half an amp or so. Easy enough to check.
ON does make a lot of their parts in China now. Remember when all the US tariffs went into effect? Half of the ON Semi parts had the “tariff applied” tag on the Digikey US website. I was surprised myself at just how many were made in China. May want to check them for conformance - depending on what middleman is involved. If they ARE fakes, Cob and Cbe will be way low, and beta will fall like a stone above half an amp or so. Easy enough to check.
I believe you. My concern was about so called 'sound quality'... & why would i spend more when i can get drivers like a1837/c4793 at a very affordable price! While ordering mje15034/35 i didn't know that i can use those drivers instead
Anyway i'm going to have 6pair of KEC c4793/a1837 soon RS never failed me, excellent quality controlBut Chinese parts? I don't know...
Best regards!
Exactly but i have no regret Sir !
I think we can trust age old RS Components & On semi without any doubt.
