Careful now!
That is a very large can of worms you just opened up there. Two camps:
1) All amps have charicteristic "sound" and some are distinguishable from others.
2) All amps that are properly built will sound the same when operated in their linear region of operation
...confusing the matter are the studies done that prove both camps to be right, and some prove both right at the same time, depending on who is explaining the results...
How fast can a thread get hijacked? Maybe you will find out if you watch this space!
That is a very large can of worms you just opened up there. Two camps:
1) All amps have charicteristic "sound" and some are distinguishable from others.
2) All amps that are properly built will sound the same when operated in their linear region of operation
...confusing the matter are the studies done that prove both camps to be right, and some prove both right at the same time, depending on who is explaining the results...
How fast can a thread get hijacked? Maybe you will find out if you watch this space!
That is a very large can of worms you just opened up there. Two camps:
1) All amps have charicteristic "sound" and some are distinguishable from others.
2) All amps that are properly built will sound the same when operated in their linear region of operation
...confusing the matter are the studies done that prove both camps to be right, and some prove both right at the same time, depending on who is explaining the results...
How fast can a thread get hijacked? Maybe you will find out if you watch this space!
Hmm... I am need to studying something from this too.
One thing which has not been mentioned is that RET (and other similar technologies, for example see Sanyo 2SB817/2SD1047) have substantial emitter resistance 'built in' because of the many parallel transistor cells.
This is evident on the Vbe-Ic graphs in the datasheets, which show practically linear behavior once the Vbe=0.6V or so knee is reached. This means bias current setup is will vary compared to some established rules (see D. Self treatise on optimum bias). The 'internal emitter resistors' are sometimes sufficient even to operate the devices without external resistors while still maintaining temperature stability, if the thermal interface to the bias servo is done right. The approximate equivalent value of the internal resistance is usually on the order of what you would minimally use externally, about 0.1 ohms - however, depending on type, it may be different for the PNP and NPN counterparts, which means there will be transfer function asymetry around the crossover point in a complementary amp. True, there are many other mechanisms that cause many such asymetrical behaviors, inherent in the differences between P and N doped silicon but this is one that can actually be corrected by using asymetrical external emitter resistors.
This is evident on the Vbe-Ic graphs in the datasheets, which show practically linear behavior once the Vbe=0.6V or so knee is reached. This means bias current setup is will vary compared to some established rules (see D. Self treatise on optimum bias). The 'internal emitter resistors' are sometimes sufficient even to operate the devices without external resistors while still maintaining temperature stability, if the thermal interface to the bias servo is done right. The approximate equivalent value of the internal resistance is usually on the order of what you would minimally use externally, about 0.1 ohms - however, depending on type, it may be different for the PNP and NPN counterparts, which means there will be transfer function asymetry around the crossover point in a complementary amp. True, there are many other mechanisms that cause many such asymetrical behaviors, inherent in the differences between P and N doped silicon but this is one that can actually be corrected by using asymetrical external emitter resistors.
is there a way us poorly equipped amateurs can identify the internal Re asymmetry and from there calculate and/or measure the asymmetry in the external Re?
Can the correction thus applied be confirmed as correct or in need of more adjustment?
Simple answer is NO. Sanken produce the best high power transistors at the moment.
Homemodder, have you done comparisons, measurements etc. I would expect subtle differences?
Sankens. These are USA made "clones" of the Symphonic Line RG11, currently selling for Euro 3,500.
http://e-shop.highendstudios.de/AMP....html?XTCsid=0e1467734afa6c0c1b6a3b68612d06c5
A1215/C2921 > A1216/C2922 > A1295/C3264 > MJL4302/MJL4281
(for tech spec lovers : compare the 5Vce beta graph of the MJL with the one of the Sanken at 4Vce)
Each of the Marantz MM70** series has the Sanken MT200 devices, amusing that Marantz stepped up to silent-running blower cooling.
2-channel MM7025 =>
(for tech spec lovers : compare the 5Vce beta graph of the MJL with the one of the Sanken at 4Vce)
Each of the Marantz MM70** series has the Sanken MT200 devices, amusing that Marantz stepped up to silent-running blower cooling.
2-channel MM7025 =>
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