Driver transistors for 2SC5200&1943

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I notice that the Toshiba 2SC5200&1943 are very popular o/p transistors and sound good as well.

I have bought 2 pairs to try and I realise I need the driver transistors as well.

After some initial search here I found that 2 types of drivers that are very popular in driving these o/p transistors. They are the TIP41 and 42 OR BD149 and 140. I notice Destroyer uses them.

My question is is there any advantage(s) of 1 set over the other.

Any comments welcomed.

Thanks.
 
Zero Cool said:
I see these driven with 2SC2238 / 2SA968 often.

Those are good lowpower transistors.
I suppose they are almost same as 2SC2240 / 2SA970 TO-92, lownoise.

For driving output stage 2SC5200 & 2SA1943 or other devices,
I would often want TO-126 or even TO-220.
How much power such drivers need to cope with
if very much a descision from case to case.

Current x Supply Voltage = Power & Heat.

I would think of using TO-126:
BD139 / BD140 .. the good and old couple. Proven in AUDIO.

And some of the best TO-220 there is!:
MJE15030 / MJE15031 ( MJE15028 / MJE15029, too )
======================================

As often, what we should use, is very dependent on the actual circuit.
Higher Output power and Supply voltage = 'Stronger drivers'.

Better if having a margin upwards.
When transistors get too hot for their rating, they will not work well,
even if they do not actually BURN OUT :)

Regards
 
ttan98 said:
I notice that the Toshiba 2SC5200&1943 are very popular o/p transistors and sound good as well.

I have bought 2 pairs to try and I realise I need the driver transistors as well.


Pavel 'PMA' Macura version of SymaSym as I recall it, uses 2SC5200 & 2SA1943.
PMA:
'I have to add that my output devices are Toshiba 2SC5200/2SA1943, ... '
http://web.telecom.cz/macura/symasym.html

You may have a look at what he and SymaSym-MikeB use for drivers.
PMA are among the best we have regarding DIY Amplifier designs :cool:


Lineup :)
 
ttan98 said:
TIP41 and 42 OR BD139 and 140.

Not much choice if that's about all what is available.

BD139/140 are great if they are the original parts, what's for sale in the stores nowadays are totally different animals.
2SA968/2SC2238 are obsolete, "current" Toshiba numbers are much better, might as well ad A1306/C3298 to the list.
All ramblings that have been chewed to death many times before on this dork parade.

As for MJE1503* drivers, if i had the ambition to assemble a mega-power output stage i'd pick any hunk of a ringemitter before cheapskating with OnSemi drivers. Only a fool would skip a pre-driver stage on a sick +250W BJT amp, therefore the high capacitance of the driver is not an issue.
 
Following the thread with interest.

Originally posted by jacco vermeulen
As for MJE1503* drivers, if i had the ambition to assemble a mega-power output stage i'd pick any hunk of a ringemitter before cheapskating with OnSemi drivers. Only a fool would skip a pre-driver stage on a sick +250W BJT amp, therefore the high capacitance of the driver is not an issue.

Jacco, would you care to break this down for me? Are the OnSemi devices deficient?
 
Of course not, just that for real high power amps with high-fT output devices there are driver devices which are better, stronger,....and much more expensive.
Not my ideas, there have been a number of commercial power amps with fast Japanese output devices with such driver stages.

Suppose you were thinking of assembling a 500W/8 power amp with 12 pairs of A1943/C5200, then you'd be better off with exotic drivers and they'd be worth the extra cost.
At the cost level of the MJEs, OnSemi TO220s are really cool.

(I is driver dissipation phobic, no insulated package drivers on high power amps. A1306/C3298 are fully encapsulated items too )

As for BD139/BD140, different ball game : datasheet
How many would you like to see ? =>
 

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jacco vermeulen said:

Only a fool would skip a pre-driver stage on a sick +250W BJT amp, therefore the high capacitance of the driver is not an issue.

Tell that to the "fools" that sell pro amps commercially. The ones with only two stages of current gain driven directly by an op-amp. Running out of beta appears to be a perfectly valid short term current limiting mechanism.

I for one thought the C5200/A1943 *were* drivers - for a stack of MJL's :D. For pre-drivers I like the C4793/1837 or the C2344/A1011 (which are getting hard to find).

And anyone who uses TIP devices to drive sustained-beta outputs (of any type) needs to have their head examined. Sort of defeats the purpose....
 
Hey Shaun, I have a built up DX precision board you are welcome to audition for a while and test your output transistors on... I'd like to get some input on how it performs with other outputs... It will fall just a bit short of your 200W into 8 ohm requirement, but this thing is a beast... I think it will still eat 300W speakers... You know where I stay... and how to contact me... you will need supplies in the range of about 2x45VAC or a centretapped 90VAC one... I did test the board on about 50VAC per rail.
 
I think this amp concept will be the last amp I work on for a while (but not anytime soon). I just got myself a pair of Denon POA-6600 monoblocks tonight, and I'm rather enjoying them. Why don't I lend you my Load Invariant amps, and you can do a comparison with the DX? I actually want to wean myself off amp building to concentrate on speaker building (even though I have a string of electronics projects I could be doing).

I know someone who might be interested in auditioning your DX amp (say, over a weekend). Do you have any completed?
 
Well, I only have one channel of the precision ready... needs a PSU as I used my HRII supply to run it off... I need to make my PSU a little more user safe, then I will arrange for you to get the HRII to from me..., freshly modified on Sunday, but I want to dail back the modification just a little bit... just have to swap out two resistors but my cube case is susch a big job to work on.

I'd also like to get involved with some speaker building, but am only finding run of the mill inefficient speakers around here... Jose's stuff is OK though, I want to get some of those potted midranges he has.
This weekend is full, but maybe we can make an afternoon of some auditioning next weekend... :D
 
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