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.
But ZTX758/658 costs as much as MJE150xx
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 😎
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.
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 control 🙄
Exactly but i have no regret Sir ! 🙂
I think we can trust age old RS Components & On semi without any doubt.
...but I didn't know where you sourced these devices in those Made in China bags from 🙂.
Best regards!
Best regards!
Ok, so what’s PHILIPS here? Don’t tell me KEC is Philips now too - I didn’t think they operated out of the Far East.
2SC5200 & A1943
More power transistors but this time from Toshiba 😉
Mr. Wg_ski@ Now don't tell me that these transistor are from Casio 🙄 😀
Anyway still waiting for VAS transistors
More power transistors but this time from Toshiba 😉
Mr. Wg_ski@ Now don't tell me that these transistor are from Casio 🙄 😀
Anyway still waiting for VAS transistors
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Gotta keep that PHILIPS symbol off your work bench, lest it’s ‘quality’ starts to rub off on your work. Unless you like amplifiers that burst into flames and take your speaker with it.
