I have an amp that uses 2 of each of the 2sc5200/2sa1943 per channel. Are the mjl21193/4 direct replacements? I've read here that the mjl are possibly better sounding. 
By the way, this amp is rated 100wpc into 8r, but has +-50v rails? That seems awful high. I guess it would allow some high peaks before clipping. The power supply has 4 6800uf caps, I am looking to upgrade them.
Thanks,
David
By the way, this amp is rated 100wpc into 8r, but has +-50v rails? That seems awful high. I guess it would allow some high peaks before clipping. The power supply has 4 6800uf caps, I am looking to upgrade them.
Thanks,
David
Probably won't sound different one way or the other, however they have lower fT and higher capacitance than the 2sa1943/2sc5200. What this means (I think) is that they (the mjl's) may be just a little noiser. Get confirmation on my interpretation as I'm no expert. The base-collecter junction is sort of like a diode. When a diode switches off there is a tiny blip of high frequency noise generated, a small charge that gets realeased, hence the the term "capacitance". In Class B operation the transistor switrches off once each cycle and generates this small "blip". As I understand it, a higher fT correcsponds to lower capacitance, a smaller "blip" and less noise.
Like I said, don't rely on this explanation. Get a second opiniuon.
Anyway, the 2sa1943/2sc5200 are new parts and seem to be pretty much top of the heap for power BJT's. At leask in flat-pack. TO-3 may be another story.
Of course if the amp is Class A, the transitors don't swith off so I presume there is no "blip".
Like I said, don't rely on this explanation. Get a second opiniuon.
Anyway, the 2sa1943/2sc5200 are new parts and seem to be pretty much top of the heap for power BJT's. At leask in flat-pack. TO-3 may be another story.
Of course if the amp is Class A, the transitors don't swith off so I presume there is no "blip".
Thanks for the reply. I did notice the fT of the 2S is 30MHz vs 4Mhz for the MJL. I guess I shouldn't mess with them.
I am still curious about the high rail voltage. Most amps I've seen with this output configuration have 35-40v rails.
Is there an easy way to figure the biasing of the amp from the schematic? Or, do I need to try and model the circuit?
David
I am still curious about the high rail voltage. Most amps I've seen with this output configuration have 35-40v rails.
Is there an easy way to figure the biasing of the amp from the schematic? Or, do I need to try and model the circuit?
David
Hi,
I use MJL21193/94 in my power amplifier. I tried some other devices such as Sanken 2SC385/2SA1494, and I prefer Motorolas. Unfortunately I can't compare them with 3281/1302, because it's very hard ot get in my country.
I also prefer MJLs over the 15022/23/24/25 series.
MJL21193/94 is the only output device I know, which is specified for harmonic distortion!
Sajti
I use MJL21193/94 in my power amplifier. I tried some other devices such as Sanken 2SC385/2SA1494, and I prefer Motorolas. Unfortunately I can't compare them with 3281/1302, because it's very hard ot get in my country.
I also prefer MJLs over the 15022/23/24/25 series.
MJL21193/94 is the only output device I know, which is specified for harmonic distortion!
Sajti
Rail voltages of +/- 50V for a 100 watt amp at idle are about what would be expected. The peak voltage swing into 8 ohms would be 40V. Allow for 3-6V drop across the output stage (depending on topology) and some sag at full power and the extra 10V is eaten up.
I have used the MLJ1302A and MJL3281A in the Leach amp with excellent results.
I have used the MLJ1302A and MJL3281A in the Leach amp with excellent results.
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