It's 2010 and what's your fav VAS transistor?

First of all its Workhorse.....!!!😡😀
😕
my apologize😉

My favourite VAS driver is THS4631.😀

It is strange.. I am felling that Workhorse (<-this one is correct🙂) schematic are faster than this controversial one. It is real controversing (or whatever I don't know😀) and waste much components.
What is the goal of this amplifier?
 
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What is the goal of this amplifier?

This is an example of extremely good sounding amp of course if you put some of the perfect OP amps in the input circuit and it can be much faster than the one you mentioned. You probably know only traditional approach topologies but this one is a mind blowing, believe me ... you sadly comprehend it as a waste of components, too bad for you. 🙄
 
This is an example of extremely good sounding amp ......... this one is a mind blowing
So... the goal is extremely good sounding amp.
That one is not mind blowing😛, but this one IS real mind bowling amplifier😱.
 

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Actually my amplifier is working as normal, but then I found a problem with it, not really has affecting its sound, but it is unsolved.
If you really could read my schematic, you'll find out what that problem.

Nothing special in this schematic, but at least it is reasonable and not controversing or whatever (my spell checking says no controversing word).
ULTRA Fast 😱 , but it is ultra slow😛

I found this from google, nice picture collections.
48 Mind-Blowing Ideas and Designs - Noupe Design Blog
 
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Onto,

I'm not sure why you would criticize Workhorse. His drive circuit, which he has shared on this forum with all of us, is a flash of brilliance.

Kenapa?

Because he drives the gate of the output mosfets, a significant capacitive load, with an emitter follower. This sort of drive is unusual in audio and brings slew rate benefits, which in turn prevents cross conduction.

We are lucky to have Workhorse. You must not let convention blind you to innovation.

Hugh
 
Hi Hugh,
I am not.
In this case workhorse floating drivers is OK, but better if sense resistors not sensing Igs and the driver may have less compensator.
Look at LazyCat's shematic.
It has superfast expensive instrumentation-grade opamp and many power transistors to just converting voltage into current, to be used in low feedback current feedback amplifier.
In this low feedback, tl061 has major effect in overall amplifier, and what is that IGBT, and also those quality opamps used for?
Any way ofcourse, It is OK if the sound is extremely good.😉
 
Forget about TL061 and overall sound from it, it's here just for an example. You can read again my posts as I noted that you can put some of the best OP amps in the input, whichever is the best choice for you, of course with a little necessary modification, which, you as an expert will solve in no time. The whole story about Controversial Power Amp is exactly what you've stated, story about transforming "voltage into current" with very good impedance match. 🙂

For instance I successfully use AD797 in the input circuit. And the sound mmmmm ... :cloud9:
 
Yes, that's true, no one answering with this original question at post#1


It's 2010 and what's your fav VAS transistor?

The requirements might be:
high Vce (rail-to-rail) say 120V-200V, Ic ~ 1A
high linearity
medium power dissipation, say <25W
medium Ft say 15Mhz up

Higher Ic and PDiss mean larger (slower) junctions, so the TO-220 packaged parts are out. I usually see the TO-126 (TO-225) package for these parts. TO-92 is too tiny.

Not many North American offerings. On-Semi offers the venerable MJE340/350, ST the 2N3439/5415 in the old TO-5 can. The BD139/140 are low in Vce like the 2N4921/23. The TIP series are dogs, IMHO.

I haven't looked at the Japanese (Sanyo/Toshiba) offerings, which are surely superior but tough to procure as originals.


Ok, it is my answer, coming from local market dealers about now days choice, it is 2SB1186A-E / 2SD1763A-E. I don't much experienced with it, but I got 2pair samples. Sadly I am not use it for my amplifier, but my tesla coil circuit.
160V with TO220F(isolated)
 
If there available 150V-200V version of BD139/140, it must be good choice. It is 2010 and still they not showing out.
The best I ever have is 2SA1111/2SC2591, now they are discontinued, the others are 2SA1696/2SC4473, 2SA1475/2SC3781, but not available.🙁
 
It's 2010 and what's your fav VAS transistor?

The requirements might be:
high Vce (rail-to-rail) say 120V-200V, Ic ~ 1A
high linearity
medium power dissipation, say <25W
medium Ft say 15Mhz up

Higher Ic and PDiss mean larger (slower) junctions, so the TO-220 packaged parts are out. I usually see the TO-126 (TO-225) package for these parts. TO-92 is too tiny.

Not many North American offerings. On-Semi offers the venerable MJE340/350, ST the 2N3439/5415 in the old TO-5 can. The BD139/140 are low in Vce like the 2N4921/23. The TIP series are dogs, IMHO.

I haven't looked at the Japanese (Sanyo/Toshiba) offerings, which are surely superior but tough to procure as originals.

I got it, not excellent in linearity:
KSC2690/2690A - KSA1220/1220A 😉