is darlington pair is unsuitable for audio amplifier?

[boxedin]

Anyone can answer my question?. Thanks

If it is ok , then what will be the most used darlington transistor ?.

I think my guess is it is used only on power circuits for motor and stuff.

AlexK.

[Jay]

Unsuitable? I think it depends on your requirement or your definition for "suitable".

TIP47 is designed for audio (if I'm not mistaken). It's very common. Of course not in state-of-the-art amplifiers.

The "best" one is probably MJ11012-MJ11016 from Motorola. I knew a circuit that was highly praised by a serious audiophile. I built it and I didn't see any reason why it should've been praised.

[palesha]

Jay,
How about putting the circuit here?

[Praudio]

Classe Audio DR2. DR3 and VHC are all with darlington output

[lineup]

MJ11015/16
has been used as an alternative in Pass A40 amp.

All of the above parts reflect Nelson Pass's original parts list,
with the single exception of the Motorola output transistors (MJ11015 and MJ11016),
though Nelson does recommend these as one possible alternative.

http://www.passdiy.com/howto/part-sub.htm

The Lambda output devices are no longer available, and they weren't that common to begin with. Lambda appears to still be in business, but not in the business of power transistors.

Common everyday complementary power darlington transistors will substitute for these. They need to be rated at 75 watts or higher, 5 amps for higher, and 80 volts or higher.

Good examples of these are the TIP142 (NPN) and TIP147 (PNP), which are currently available from Digikey.

Another fine example, although harder to get, are the Motorola MJ11012, MJ11014, and MJ11016 (NPN) and MJ11013 and MJ11015 (PNP).

[Jay]

Originally posted by palesha
Jay,
How about putting the circuit here?

Unfortunately I don't have a softcopy. I still have the PCB with one channel still assembled with components. I had a hand drawn of the circuit but because I don't think it is special, I might have lost it.

I have ccts which were not acquired in softcopies or through the internet. I do have interest in seeking comments about the circuits but I don't know who owns the cct so I decided not to post any of them.

[AndrewT]

Hi,
just found the Sanken sap15 thread.
More views there.

[sagarverma]

built subamp (400w peak),solid punch,used darlington pairs(for output stages).
hooked up on cheapo for 'test'(to see if it plays).now working great to (super)power my sub.quality::cant say,never gave it freq>150hz

[Tekko]

Darlingtons arent usually linear enough for audio use.

[widowmaker]

I think that Jfet diff & current mirror + MOSFET SE preamp stage with current source and bias ~150-160mA or more + high current gain (>100) push pull BJT output stage (for example MJL1302/3281) with bias ~ 100mA is the better solution for class AB...
2 stages for voltage amplification + 1 for current.
More stages & open loop gain=more (not only) dynamic distortions...