I'm trying to find out which are the best sounding TO-220 darlingtons. Some of you might have experience with them. I'd like to use them in a mid and high amplifier in an active speaker system. Minimum requirements are 80V and 8A.
Any one any suggestions?
Any one any suggestions?
Loooooong time ago I worked with stuff that had BDX53C/ 54C complementary pairs. Fast and easy stuff, but they did not sound too bad to me.
We had a lot of them around and sometimes, of course they came back for repairs. I do remeber that at the time the BDX53C from Motorola (now ONSEMI) were the toughest.
BDX53C
We had a lot of them around and sometimes, of course they came back for repairs. I do remeber that at the time the BDX53C from Motorola (now ONSEMI) were the toughest.
BDX53C
They all sound the same.
The sound is in the design, not the parts, as long as they are used within their ratings, i.e. not abused
The sound is in the design, not the parts, as long as they are used within their ratings, i.e. not abused
integrated Darlington's remove very useful degrees of freedom, choices in driver speed and bias
if you want "infinite hfe" use a Mosfet pair - at the cost of not swinging as close to the rails
if you want "infinite hfe" use a Mosfet pair - at the cost of not swinging as close to the rails
Sanken has some very good darlingtons.
Audio ?Sanken Electric
Exemples :
2SD2401 ?Sanken Electric
2SB1570 ?Sanken Electric
Audio ?Sanken Electric
Exemples :
2SD2401 ?Sanken Electric
2SB1570 ?Sanken Electric
I keep reading on DIYAUDIO about connectors, wires and capacitors that sound better so why not Darlington's ?
lol
Not entirely, some will be more linear (less beta droop), some will be more stable/faster ( lower COB ) etc. The sound is in the design and the parts. Better design with better parts. The thing most device rollers don't get is you can't separate the device from the design. A "better" device will not necessarily make a certain design better. Often it will make it worse. The design should have been optimized for the part. Change the part, the design is no,longer optimized. (most transistors hfe is most linear at a certain bias current, you change transistors but the bias remains and is probably not right anymore. ). I believe most designers will pick the best devices they can get for the application and then design around the devices.
So the question is not what sounds best but what is the best transistor for this particular application. And that will get you the best sound.
The most important bottleneck in darlington for audio amplifier is the fixed resistors (R1 and R2) connecting the bases to output. This makes it hard to design for the best possible result, especially for class B.
If you have a darlington in mind, check their datasheet. You want R1 and R2 to be very high. R1=8K is the standard as is found in TIP147, MJ11016 used in modern amplifiers (Classe Audio DR3 uses MJ11016 TO3). R2=50 is suitable in class A. I expect more than 50 Ohm here. Sanken is unique as they design exclusively for audio with R=infinite/R2=70. But in class B I couldn't make the Sanken sound better than discrete either.
For mid-hi application of course you want sufficient high fT and Cob, but I think TO-220 wont have issue here. So you can probably judge from R1/R2:
BDX53C 8k4/300
BDW42 8k/150 (4M, 200pF)
TIP120 8k/120 (100kHz)
TIP131 8k/120 (lower fT)
TIP147 8k/40 (TO-247 for comparison, is a standard in audio)
So as I can see it, BDX53 is the best. For TO-220 I'm using old Motorola BD243 with gold plated pin (R is unknown). For TO-3 I'm using Motorola 2N6284.
ST 2N6284 8k/60k for audio. Too good to be true?
ON 2N6284 8k/50 (4M) for audio, better than 11016.
ON MJ11016 8k/40 (4M) general purpose amps
But remember that consistency is hard to achieve with darlingtons. Batch to batch, manufacturer to manufacturer, NPN to PNP, all have big variations.
BDV 66 and BDV 67 (TO 247):
http://www.farnell.com/datasheets/296700.pdf
Used in NVA amp, very good sounding amp.
http://www.nvahifi.co.uk/power-amplifiers/
http://www.farnell.com/datasheets/296700.pdf
Used in NVA amp, very good sounding amp.
http://www.nvahifi.co.uk/power-amplifiers/
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If it is necessary to detail (and this is only my opinion). I compared listening with jlh 1969 monster Hiraga, single ended 300b, copland CTA 505, it is still very subjective too, but the NVA amps are very good and recognized and have a sound comparable to tube amps. I listened to the AP30 and AP 50 models I had in repair.
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I have been for many years hunting and studying how to design the best sounding amplifiers. Amplifier like this makes me want to cry... :_(
That's not what I mean...
This P30, could be turned all the time because the bias current is so low, in the edge of instability such that no other cable (or interconnect) is allowed except for the one from NVA, using such darlington output, yet it is better than class-A amps like the JLH, Hiraga or SE 300B...
My be I should study marketing instead of electronics? :_(
Or may be we should compare the amp with audio analog Puccini?
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I can not find the AP 30 or 50 necessarily better than the others I have mentioned. Personally, I prefer class A (it 's a matter of taste). But i find NVA amp very good especially for class B and I was surprised to be able to listen to classical music at high volume without having stressed ears.
You're right, the capacitance of the speaker cables should be as low as possible on these amps if not, the output transistors are destroyed easily. That's why I have the repair.
It does not necessarily need the NVA cables, This one, for example, is ok :
http://www.erni-hifi.ch/contents/media/vovox%20initio%20ls%20single.jpg
TO-220 is under-powered. The more common ones are TIP 142/147. But like jcx said, mosfets are a better choice.
For simplicity, I would consider the STK442-130. It's a fairly powerful stereo amp IC, just right for mid and high use. Uses darlingtons for outputs. Very easy to construct, just a few a few parts.
Regards
Mike
Mike, such a change is not an option... I'm only looking for the best TO-220 Darlingtons to do the job..
Besides, I do not have the luxury of a symmetrical PSU..
Greetz,
Edwin
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