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Oneminde 13th August 2019 03:22 PM

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same calculus for inner ring of current mirror bjts - Q5,6,7,8 - same Iq as previous , figure out CE voltages for dissipation calculus
Maximum voltage swing is 25V peak-to-peak, that as +12,5V and -12,5V.

The core is the SuSy, the rest is interpretation just like the paralleled version which N.Pass liked. (see attachment)

I have no clue on the differences in sound, but no matter, it will be the best I've ever owned :)

Zen Mod 13th August 2019 03:26 PM

try harder ..... when dealing with technical things , being precise is beneficial .....

so , define CE voltage for each bjt , write it down , do dissipation calc - both static and peak

you don't need doing that for me ......


Oneminde 13th August 2019 03:35 PM

I will need to go over all the notes and do sim. Remember, I have no idea what I'm doing, I'm a n00b, so steep learning curve here. :)

The BC850/860 has a Pd of 310mW which I am sure is more than adequate. The [hfe] target is a different story. I know the recommendation is more than 100, but HOW much more.

Zen Mod 13th August 2019 04:05 PM

I did told you - ignore Hfe

Oneminde 13th August 2019 04:26 PM

But ideally you want the FETs to be matched, it is a mantra repeated over and over when you read about these things. Hfe on the other hand, well... I will investigate it a bit further. I just wana make sure that everything is done properly. If that mean 1% or 13% or whatever, that I don't know. But it can't harm to match

Oneminde 13th August 2019 06:31 PM

Two places that sell the SOT-23 version. Both of them can deliver the LSJ74B if you send them an email.

US; LSK170B SOT-23 3L | Linear Integrated Systems | Trendsetter Electronics
Europe: Micross Components Ecommerce System


Oneminde 13th August 2019 06:58 PM

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Oneminde 13th August 2019 09:55 PM

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One of the reasons I am doing this project - besides the volume wheel :D - is my passion for loudspeakers. That too has been a long journey but I am finally ready to start prototyping soon. So when the need for a really nice stereo system became a serious task, I knew I had to find something fully capable of delivering effortless rendition of music. In case anyone wonder if I had more reasons than electronics and music, here is a picture of the concept rendition for 1 of 2 2-way's which is part of a series of loudspeakers.


Oneminde 14th August 2019 01:31 AM

Nelson Pass on learning his craft, then starting Threshold, Pass Labs, First Watt.

Oneminde 14th August 2019 07:46 PM

Important question.
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I was inspecting the motherboard sch and found something that I can't understand. So maybe someone can jump in an explain.

In the MUSES 72320 datasheet, pin 8 & 9, labeled DCCAP_L/DCCAP_R (Switching Noise Rejection Capacitor) has a 100uF capacitor in place in all of their test and example circuits.
Checking the UGS MUSES sch, pin 8 & 9 is pulled to gnd via 0 ohm resistor.

Why does the schematic not use a capacitor but rather a resistor ?

(see attached image)

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