Driver transistors for 2SC5200&1943

[Leolabs]

If it isn't related to high power design,some TO92s will do the job as the 2SA1943/2SC5200 are high beta devices,at least 100 of HFE.

[ttan98]

Originally posted by Leolabs
If it isn't related to high power design,some TO92s will do the job as the 2SA1943/2SC5200 are high beta devices,at least 100 of HFE.

Hello fellow Malaysian, it is good to see you here regularly.

Both o/p trans. have a min. hfe of 55, strictly speaking you really should design to the lower end not norminal hfe of 100. Furthermore, thes are "fast" devices due to lower input and miller cap. I think the drivers like 2SC4793 and 2SA1837 and o/p transistors make an excellent combo or synergy.

I am trying to build a power/integrated amp about 50-100w/channel based on these combo. I believe my chipamp(whatever model) and yours too will not come close to the performance(*) I can get from these devices when I finished building it. Similarly this applies to other amp. that are based on these o/p devices, there many excellent DIY ones on these sites, all of them based on discrete devices.

It will not be designed from ground up, I use short cuts like using the LME49810 driver chip and ready made power module. That will cut down the amount of design work and testing time and also cheap to construct eg. parts and PCB alone about US$26-$40 per channel without heatsink of course. If you interested leave a message here I will follow up with more detailed descriptions.

* I mean it will give the drive(speed) and slam to produce a large soundstage than any chipamp, esp. the BASS end. The smoothness and graininess is more a function of the type of components used.

Wish me luck.

[jacco vermeulen]

Originally posted by roender
MJE15034/15035, true hfe and ft

Ouch.
Mihai, did you measure the hFe number of the 34/35 yourself ?

[roender]

Originally posted by jacco vermeulen


Ouch.
Mihai, did you measure the hFe number of the 34/35 yourself ?

Hello Jacco

hfe, yes
ft, no, not myself but a friend of mine who work at O2micro.
34/35 driver transistors are very different than the 30/31 and 32/33 series.

Mihai

[Leolabs]

Hi,ttan98!Unfortunately the 2SA1943/2SC5200 cant perform well with only one pair at high power,ie 100W at 8 ohms only.Really lack of slam at the lower frequency end.Only will perform well with a few pairs,prefer the MJL1302/MJL3281 under these circumstances.

[ttan98]

Originally posted by Leolabs
Hi,ttan98!Unfortunately the 2SA1943/2SC5200 cant perform well with only one pair at high power,ie 100W at 8 ohms only.Really lack of slam at the lower frequency end.Only will perform well with a few pairs,prefer the MJL1302/MJL3281 under these circumstances.

If you read my posting I said 50-100W, I mean 50W for 8 ohm and 100W for 4ohm, rating I think it is convervative rated for 45V rail.

I heard from most people that the 2SA1943/2SC5200 combo is fairly dynamic. Have you tried MJL1302/MJL3281 combo to make the comment you made, or just based on experience of others?

Also a pair of the discrete SA1943/2SC5200 will still give better performance esp. at the Bass end over any chipamp watt for watt say comparing a pair of SA1943/2SC5200 with LM3886. I read from a no. of amp reviews that that chipamp does not give you dynamic bass performance(my experience as well). I think it it because the die on the chipamp is too small to delivery PEAK current necessary for good bass performance. Hence I am going along the direction as explained in the previous post. I will compare it with LM3886 to see what I suspect is correct. If it works I may parrallel a no. of SA1943/2SC5200 together if necessary.

[homemodder]

I agree with sandyK, 2sc5171/2sa1930 and 2sa1507/3902 are about the best you can find, 2sb631/2sd600 and 2sb649/2sd669 very good too.

Alex

[Leolabs]

Hi ttan98!Yes,I did compare both:under +/- 50V,the Toshiba sounds better in term of mid and high,a little attractive too at the vocal and the
OnSemi sounds well balance at each band,more slam at the lower end.

But seen that u r running them at lower supply voltages,so the result should be different from my experience.

And of course,sure they are perform better than normal chipamp,esp the bass.

[ttan98]

Originally posted by Leolabs
Hi ttan98!Yes,I did compare both:under +/- 50V,the Toshiba sounds better in term of mid and high,a little attractive too at the vocal and the
OnSemi sounds well balance at each band,more slam at the lower end.

But seen that u r running them at lower supply voltages,so the result should be different from my experience.

And of course,sure they are perform better than normal chipamp,esp the bass.

understood...thanks.

[sam9]

An additional reason for 2sc4793/2SA1837 is that they are readily available from Digikey. Same page as 2SA1943/2SC5200.

Apart from specs and performance, for DIY availability is important. Doesn't do much good to layout the perfect amplifier only to find the components you need are not to be had.