Question:
I just received some of MJL4281 and MJL4302 samples from on semi.
In what amplifier configuration they coould be used(schematic or link)?
How many devices per channel (for 4 and 8 ohms) on +/- 42V(what power could I expect?
Quality of MJL's?
MJL's or MOSFET's?
Regards
I just received some of MJL4281 and MJL4302 samples from on semi.
In what amplifier configuration they coould be used(schematic or link)?
How many devices per channel (for 4 and 8 ohms) on +/- 42V(what power could I expect?
Quality of MJL's?
MJL's or MOSFET's?
Regards
http://www.onsemi.com/pub/Collateral/MJL4281A-D.PDF
NPN / PNP transistor pair for output stage solid state amp. These are not MOSFET or JFET at all, just "oridinary" silicon transistors and can be quite good in the right, "push / pull", Class A or A/B amp design. (Difficult to exactly balance in production and elimination or reduction of the 0 Volt crossing point.)
NPN / PNP transistor pair for output stage solid state amp. These are not MOSFET or JFET at all, just "oridinary" silicon transistors and can be quite good in the right, "push / pull", Class A or A/B amp design. (Difficult to exactly balance in production and elimination or reduction of the 0 Volt crossing point.)
Did you order from onsemi.com, or some other way?
I'm obviously not in a big hurry (I can't use them yet anyway), or I'd have bought them from Mouser or Digikey. I'm just puzzled, since the people at onsemi told me this delay was normal. Oh well, beggars can't be whiners.
Reid
I'm obviously not in a big hurry (I can't use them yet anyway), or I'd have bought them from Mouser or Digikey. I'm just puzzled, since the people at onsemi told me this delay was normal. Oh well, beggars can't be whiners.
Reid
Hi Zox,
1pair will drive 8ohm to about 75W @ 60degree phase angle.
2pair will drive 4ohm to about 140W @ 60degree phase angle.
+-42Vdc is your limiting factor for maximum peak output voltage.
These predictions were checked for continuous operation below 60degC. Music type duty at home would demand much less from the amp (Tc=60degC allows a heatsink of about 50degC which is pretty hot) will not trouble either arrangement.
You will need a stiff power supply that holds up well under load to produce these powers. I suggest 500VA and 4 by 30mF for a stereo amplifier.
nearly.Am I will be able to get 150W on 4 ohms with 4 of these devices(+/-42V).
1pair will drive 8ohm to about 75W @ 60degree phase angle.
2pair will drive 4ohm to about 140W @ 60degree phase angle.
+-42Vdc is your limiting factor for maximum peak output voltage.
These predictions were checked for continuous operation below 60degC. Music type duty at home would demand much less from the amp (Tc=60degC allows a heatsink of about 50degC which is pretty hot) will not trouble either arrangement.
You will need a stiff power supply that holds up well under load to produce these powers. I suggest 500VA and 4 by 30mF for a stereo amplifier.
You might be able to derive a decent schematic from this Wiki kit: http://www.diyaudio.com/wiki/index.php?page=Add+your+names+join+the+group+buy ... or ... http://home.ca.inter.net/~lloyd.maclean/Krell/Krell.htm
The diagram above (Rod Elliot's @ http://sound.westhost.com/p3a-f1.gif ) is great ... except that you will have to find suitable complimentary pairs for the first stage of the Darlington out put ...
....
The diagram above (Rod Elliot's @ http://sound.westhost.com/p3a-f1.gif ) is great ... except that you will have to find suitable complimentary pairs for the first stage of the Darlington out put ...
....
Though I'm impressed that he pulled off the CF triplet, that amp has some basic design flaws. Some which save a few cents (shared CCS reference), some which are just plain stupid (the fixed LTP collector resistor).
As I recall, we discussed this designer's work in the past and someone said he designs for "sound" (including intentional distortion), so these may not be mistakes.
I don't think I've ever seen a bias circuit quite like it.
As I recall, we discussed this designer's work in the past and someone said he designs for "sound" (including intentional distortion), so these may not be mistakes.
I don't think I've ever seen a bias circuit quite like it.
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