Interesting that just a 2 device VAS can whup them ALL (below- 60ppm @10k 40v p-p). To me and any who have heard it , IT is the "best sounding amplifier in the world" (Blame ES/mongrel BX). I keep this one in my house , i'm hooked 🙂🙂
simplicity rules...
OS
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If it was only for THD, certainly that i would go blameless
style, but other parameters are to be accounted for such
as symetrical slew rate or stability and so on..
True that the blameless fashion has an unbeatable
complexity/perfs ratio as pointed by your graph,
and further, by this one.
As for Hitachi s lateral fets, whoever did build a worthy
design using them , probably didn t went back to bipolars.
Hope that you ll have soon an occasion to test them.
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Krisfr and Jaycee - I'm not sure what experience you guys have in military electronics, but I have quite a bit... The military does not use plastic transistors, at least 99% of the time. The military almost always uses metal can transistors. This is just simply a fact.
Little OT, but Hitachi non the less. Guys have you simulated my JLH lateral by any chance in the past or have an opinion? Talking of the CCT in this link: http://www.tcaas.btinternet.co.uk/WW8-82.gif
The last time I looked, the military do not make power amplifiers. I'd take a stab at the reason they use TO-3 is because these can be made with inbuilt shielding against radiation and such like.
You still haven't technically justified your "sounds better" comment.
That one in the graph is the blameless with a bootstrapped VAS ,TMC, and with input cascode , low noise mpsa18/ss9014 LTP. The strait blameless ran nice and had PPM THD but did not sound as good (most likely CCS related).
I do have 2 pair of SK134/J49 (to-3) , and will try all these voltage stages on them , the TRUTH will be heard.
OS
Jaycee - Did I ever said the military made audio amplifiers? Military almost always uses metal transistors. I'm just simply stating a fact. Metal transistors are significantly superior to the plastic ones. That's another fact 🙂
I will give you that they have better thermal dissipation, but that is it. You have not technically justified "sounds better". The only thing that would make them "sound better" is if the die was somehow different - and these days, they use the same die in TO-3 packaging that they use in TO-247/264 packaging.
Inside the device there's some stray capacitance between the bonding wires etc. The metal can ones have air dielectric, whereas the plastic ones have that horrible black plastic for dielectric. If the plastic ones were packaged in teflon instead of whatever the black stuff is they would no doubt sound better but then you'd have to worry about burn-in of your transistors.
:randomsmiley:
:randomsmiley:
yeah, plastic is bad, it really is
but its everywhere in any amp
and some say teflon is the worst of all
but it doesnt burn, and why its "military"
but its true, some do believe metal devices are better
whatever it is, they wont save a bad design
and "plastic" types wont make a good amp sound bad either
you may laugh now, but I have heard changes in sound, depending on how much you tighten the mounting screw
but its everywhere in any amp
and some say teflon is the worst of all
but it doesnt burn, and why its "military"
but its true, some do believe metal devices are better
whatever it is, they wont save a bad design
and "plastic" types wont make a good amp sound bad either
you may laugh now, but I have heard changes in sound, depending on how much you tighten the mounting screw
Well, it s better to have at least two pairs per channel,
but for let say 2X40W/8R , a pair will do it, but no 4R loading
even if these devices are very rugged and would undoubtly
stand it.
Hey, they are pricey if ever you manage to find some
which are not faked..!
It is the same thinking that says a $100 speaker cable sounds better than a lamp cord. Utterly subjective , purely psychological. Akin to the Bybee "quantum purifier" or other audiophool mumbo jumbo. 🙁
Realistically, the plastic device would have almost no micro-phonic tendencies as opposed to the metal can.
OS
Critical listening on efficient speakers would not need more than 40-50w. If I want to see how it does on the nuclear level , I can plug the voltage stage into my 200W BJT OPS. I had another member ship some to me ... he assured me they were authentic.
OS
I have driven 2ohm Infinity Kappa9 with one pair of MJL21193/94
and they guy had never heard his speakers sound that good
from memory, supply voltage is about 30Vdc
but it needs a very good heatsink
No doubt the bjts you re talking about are rugged as well,
but we re talking of 2SJ48/49/50 and their complementaries
2SK133/134/135 which are rated 7A/100W.