Hello
The 2SA1943 and 2SC5200 transistor are use in a lot of diy power amp.
What is the sonic quality and and linearity of the MJ15003 AND MJ15004 compared to the 2SA1943 and 2SC5200 ?
Thank
Gaetan
The 2SA1943 and 2SC5200 transistor are use in a lot of diy power amp.
What is the sonic quality and and linearity of the MJ15003 AND MJ15004 compared to the 2SA1943 and 2SC5200 ?
Thank
Gaetan
Hi,
two completely different beasts.
Surprisingly, when the amp for each is optimised, they can sound very similar (but only when driven within spec).
two completely different beasts.
Surprisingly, when the amp for each is optimised, they can sound very similar (but only when driven within spec).
Hello
If we would use MJ15003 and MJ15004 transistors for those amps; Dx amp, GEM100 amp, SymAsym, or the partial AKSA55 amp. What would be the sonic quality difference ?
Thank
Gaetan
If we would use MJ15003 and MJ15004 transistors for those amps; Dx amp, GEM100 amp, SymAsym, or the partial AKSA55 amp. What would be the sonic quality difference ?
Thank
Gaetan
The MJ15003 is a TO3 part; has anyone had any good results using the similar MJL21196 or MJL21194 which are similar Audio Bipolars, but in easier to use TO-264 cases. I ask because I'm building a John Linsley-Hood Class-A amp, and the MJ15003 is reckoned to be very good with the JLH design.
(I'd rather use TO-264 packages for ease of construction)
(I'd rather use TO-264 packages for ease of construction)
I used those in mine
Yes, I used MJ15003 in my JHL amplifier, 6 transistors in each channel. They are excellent in that design.
Yes, I used MJ15003 in my JHL amplifier, 6 transistors in each channel. They are excellent in that design.
Re: I used those in mine
Hello
Why 6 transistors in parallel in each channel ?
If I remember, the original plans do not use 6 transistors.
Thank
Gaetan
jmateus said:
Hello
Why 6 transistors in parallel in each channel ?
If I remember, the original plans do not use 6 transistors.
Thank
Gaetan
Hello
Btw, normally we use output transistors who have a vce of 1/2 the rail voltage.
So, for any amp, wen we put many output transistors in parallel, how much higher rail voltage we can go with the same output transistors ?
So to get more output power.
Thank
Gaetan
Btw, normally we use output transistors who have a vce of 1/2 the rail voltage.
So, for any amp, wen we put many output transistors in parallel, how much higher rail voltage we can go with the same output transistors ?
So to get more output power.
Thank
Gaetan
No the heatsink must be the same size as it still has to get rid of all the same heat.
When you parallel transistors the voltage handling stays the same, so you cannot use higher rails. It is the current handling that increases.
When you parallel transistors the voltage handling stays the same, so you cannot use higher rails. It is the current handling that increases.
absolutely right, and the MJ15003 can dissipate a LOT of heat (200W IIRC). Paralleling the OP transistors just enables more heat to be dissipated, needing even more heatsinking.
But, I'd still rather use a couple of plastic H-PAK style devices in my JLH, because they are easier to work with (for me). Has anyone used a plastic equivalent to the venerable MJ15003 in a JLH class-A amp?
But, I'd still rather use a couple of plastic H-PAK style devices in my JLH, because they are easier to work with (for me). Has anyone used a plastic equivalent to the venerable MJ15003 in a JLH class-A amp?
6 transistors
Hi Gaetan8888
No in fact the original JLH doesn't use 6 outputs. However, if you go
to Geoff's web site you'll see another version of the same amplifier
intended for electrostatic speakers and this one has many more,
I can't remember how many.
But I used 6 and the amplifier works like a charm despite a lot of heat
that dissipates, this the reason I don't use it in summer time although
it has humangus heat sinks.
Hi Gaetan8888
No in fact the original JLH doesn't use 6 outputs. However, if you go
to Geoff's web site you'll see another version of the same amplifier
intended for electrostatic speakers and this one has many more,
I can't remember how many.
But I used 6 and the amplifier works like a charm despite a lot of heat
that dissipates, this the reason I don't use it in summer time although
it has humangus heat sinks.
hi
the more output transistors the more current it will carry..but it doesnt mean the Vload would increase.. increasing Vrail also increases the output power..but! too much Vrail may damage your amp especially during short circuit of load(if you dont have protect)..
in adding more power. will it be increase its quality?..
the more output transistors the more current it will carry..but it doesnt mean the Vload would increase.. increasing Vrail also increases the output power..but! too much Vrail may damage your amp especially during short circuit of load(if you dont have protect)..
in adding more power. will it be increase its quality?..
I can name a few good commercial amp models with MJ15003/15004 output stages, but the smallest of 100 watts or more has 4 pairs of devices per channel.
A 50 watts ML29 has a 2-pair metal can output stage, but those are/were different type devices with improved linearity/fT.
I can also think of a few good higher than 50 watts amp designs/models with just a single pair of Japanese plastic devices.
Anyone who can think up a decent design with a single pair 15003/4 output stage ?
A 50 watts ML29 has a 2-pair metal can output stage, but those are/were different type devices with improved linearity/fT.
I can also think of a few good higher than 50 watts amp designs/models with just a single pair of Japanese plastic devices.
Anyone who can think up a decent design with a single pair 15003/4 output stage ?
Hi,
Aaron use a single pair of MJ15003/4 in their 100W into 8r0 power amps.
They claim enormous output power into 4r0, 2r0 and even 1r0, but fail to specify the duty cycle, using this same output stage.
They substantially remove the markings on the output devices, but sufficent fragments of characters were left on the four devices in the stereo amp to identify the devices.
BTW,
it sounds quite nice, but does not like high frequency testing. 50kHz blew it up!!!!
Aaron use a single pair of MJ15003/4 in their 100W into 8r0 power amps.
They claim enormous output power into 4r0, 2r0 and even 1r0, but fail to specify the duty cycle, using this same output stage.
They substantially remove the markings on the output devices, but sufficent fragments of characters were left on the four devices in the stereo amp to identify the devices.
BTW,
it sounds quite nice, but does not like high frequency testing. 50kHz blew it up!!!!
Hi,
if substituting MJL21193/4 for MJ15003/4 then do take account of the differing temperature derating factor between the types as well as the reduced power and reduced heat dissipation through the plastic package.
You may find that 2pair of MJ (=4 250W To3 devices) can be replaced by 3pair (=6 200W To264 devices) of MJL and turn out to be equivalent.
The advantage of 3pair is the reduced current through each device holding up the gain into a low impedance load.
if substituting MJL21193/4 for MJ15003/4 then do take account of the differing temperature derating factor between the types as well as the reduced power and reduced heat dissipation through the plastic package.
You may find that 2pair of MJ (=4 250W To3 devices) can be replaced by 3pair (=6 200W To264 devices) of MJL and turn out to be equivalent.
The advantage of 3pair is the reduced current through each device holding up the gain into a low impedance load.
Exactly the one i was waiting to hear, Thomas Höhne himself tried to flog me the nipple button Aaron amp.
In a year from now, Mr. and Mrs. Höhne have also been producing a power amplifier duo with a huge number of TO3 cans for 20 years, to this day the largest size power amplifiers in the world.
Sovereign Reference power amp picture :
HERE , the tall tower thingies with the goldplated inserts in the bottom pic.
In a year from now, Mr. and Mrs. Höhne have also been producing a power amplifier duo with a huge number of TO3 cans for 20 years, to this day the largest size power amplifiers in the world.
Sovereign Reference power amp picture :
HERE , the tall tower thingies with the goldplated inserts in the bottom pic.
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