output devices - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 14th August 2015, 06:04 AM   #1
diyAudio Member
 
Join Date: Nov 2013
Default output devices

Hi All
What is the best devices to output stage of a hifi audio power amplifier?
1) MJL3281 / MJL1302 On Semiconductor
2) 2SA1943 / 2SC5200 Toshiba
3) 2SJ201 / 2SK1530 Toshiba
4) 2SJ162 / 2SK1058 Hitachi.
cheers
  Reply With Quote
Old 14th August 2015, 07:14 AM   #2
diyAudio Member
 
Join Date: Apr 2010
Location: Coffs Harbour
Each pair of devices requires a different variant of a power amplifier design and power supply to suit them. You have a mixture of high and low voltage BJTs, vertical Mosfets (Hexfets) and lateral mosfets. All will require different amplifier designs and power supplies to optimise their strengths and performance.

Consequently, there is no "Best" but they are all capable of exemplary performance in designs best suited to their individual type. However, whilst there are replacements for obsolete types MJL3281/1302, you may have difficulty obtaining genuine examples of 2SJ201/K1530.
__________________
Ian
  Reply With Quote
Old 15th August 2015, 09:03 AM   #3
diyAudio Member
 
Join Date: Apr 2014
Location: US
I am using MJL3281(MJW3281)/1302. I am thinking about changing to either 2SC5200/2SA1943 or the TO-3P equivalent. Main reason is the Cob. MJL is 600pF. Usually the Ccb is proportion to Cob.

High Ccb is hard on the driver. I just posted this thread Issue with 3EF Diamond

I have waveform collapsed with higher frequency. I think it is related to Ccb holding the voltage and force the drivers to turn off. I had to increase the current of the driver to 100mA to push the collapse to higher frequency.

I have 5 pairs of MJW, I experimented cutting out 2 pairs and I can see the frequency of collapse go from 1.3MHz to 1.6MHz. I think this is due to decrease of capacitance loading. I am looking at 5200 as the capacitance is less than half and even the 1943 is only 360pF, almost half the MJW. with 5 pairs, I don't worry about the SOA at all.

The hfe graph vs collector current of 5200/1943 is just as flat as the MJW, all of them are 30MHz and hfe are comparable, so it's just as good also.

Last edited by Alan0354; 15th August 2015 at 09:06 AM.
  Reply With Quote
Old 16th August 2015, 09:21 AM   #4
CBS240 is offline CBS240  United States
diyAudio Member
 
CBS240's Avatar
 
Join Date: Aug 2005
Location: K-town
Quote:
Originally Posted by auto bias View Post
Hi All
What is the best devices to output stage of a hifi audio power amplifier?
1) MJL3281 / MJL1302 On Semiconductor
2) 2SA1943 / 2SC5200 Toshiba
3) 2SJ201 / 2SK1530 Toshiba
4) 2SJ162 / 2SK1058 Hitachi.
cheers
Any reasonable Gm sufficient planer stripe type mosfet.........providing you are using a proper gate drive circuit, proper local compensation of mosfets and that of local loops. ...........Even at less than 20mA bias.

No seriously, these devices are excellent for driving the reactive Z of a speaker(s)

Point is, any output device will suffice, just design the circuit for that particular device in order to maximize the benefits of that device and minimize the particular hindrances.
__________________
All the trouble I've ever been in started out as fun......
  Reply With Quote
Old 16th August 2015, 09:44 AM   #5
diyAudio Member
 
Join Date: Apr 2014
Location: US
I keep reading that a lot of the popular power BJT are just as good, just depend on the circuit and design. I want to compare the ON semi MJW3281/1302 vs Toshiba 2SC5200/2SA1943.

From what I studied the data sheets, other than 2SC5200 has more slant in the hfe vs current graph, they are very similar. They are have hfe about 100, fT=30MHz. The Cob of MJW is 600pF vs the Toshiba is about half. Power handling of MJW is 200W where as Toshiba is 150W.

From the data sheet, I think the Toshiba is slightly better. In fact, if you look at Fairchild, the hfe vs current is flatter than Toshiba. Toshiba is a 25% lower power handling BUT Cob is almost half. That make it much easier to drive.

Other than this, I don't see any difference in circuit design will make one or the other better. Mainly just the power handling.

If I miss something, please let me know.
  Reply With Quote
Old 16th August 2015, 07:37 PM   #6
sajti is offline sajti  Hungary
diyAudio Member
 
Join Date: Apr 2003
Location: Százhalombatta, Hungary
Quote:
Originally Posted by Alan0354 View Post
I am using MJL3281(MJW3281)/1302. I am thinking about changing to either 2SC5200/2SA1943 or the TO-3P equivalent. Main reason is the Cob. MJL is 600pF.
I am looking at 5200 as the capacitance is less than half and even the 1943 is only 360pF, almost half the MJW. with 5 pairs, I don't worry about the SOA at all.
Be careful with it! The 2SC5200 Cob is a typical value, but for MJW the 600pF is the maximum value! So it's hard to compare...

Sajti
  Reply With Quote
Old 16th August 2015, 10:38 PM   #7
diyAudio Member
 
Join Date: Apr 2014
Location: US
Quote:
Originally Posted by sajti View Post
Be careful with it! The 2SC5200 Cob is a typical value, but for MJW the 600pF is the maximum value! So it's hard to compare...

Sajti
I see what you mean. I did looked at the Cordell BJT model file CJE=11EE-9 and CJC=1.2EE-9 for both MJL

Too bad Cordell did not have the 2SA1943 and 2SC5200. I found these in the standard BJT models ( I believe from LTSpice)

2SA1943 CJE=2EE-10 and CJC=9.45EE-9
2SC5200 CJE=4.5EE-10 and CJC=8.5EE-10

MJL definitely higher, BUT I can only trust Cordell's model.
  Reply With Quote
Old 17th August 2015, 01:32 PM   #8
diyAudio Member
 
Join Date: Nov 2013
Hi Alan0354
I have very good experience with the output stage in common emitter. Emitter follower output stage always tends to parasitic oscillations. If you can accept a bigger problem in the stabilization of the bias current in the output stage I recommend you this solution.
cheers
  Reply With Quote
Old 17th August 2015, 08:07 PM   #9
diyAudio Member
 
Join Date: Apr 2014
Location: US
Quote:
Originally Posted by auto bias View Post
Hi Alan0354
I have very good experience with the output stage in common emitter. Emitter follower output stage always tends to parasitic oscillations. If you can accept a bigger problem in the stabilization of the bias current in the output stage I recommend you this solution.
cheers
I don't have oscillation problem after I move the collector of the pre-drivers to the rail. I aware of the potential problem, that's the reason I use power and ground planes, I have 0.1uF parallel with 10uF right on the collector to ground of each and every EF transistor. All have base stop point to point to the base to make sure there is no parasitic due to layout. I did square wave pulse test, the over shoot is about 10% and the ring stop after one cycle. You can see my layout in this thread:Issue with 3EF Diamond

What solution you recommend?
  Reply With Quote
Old 18th August 2015, 05:37 PM   #10
diyAudio Member
 
Join Date: Nov 2013
Hi Alan0354
I suggest you test the output stage with bipolar transistors in a common emitter.
cheers
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Output Devices ! cloud Pass Labs 11 10th November 2008 11:37 PM
Output devices? Mr Evil Class D 42 12th January 2005 02:18 PM
question on output devices! sardonx Solid State 3 2nd December 2003 10:22 PM
parelleling output devices hacknet Solid State 8 18th December 2002 11:22 PM
Aleph 3 with 4 output devices yasalam Pass Labs 2 27th March 2002 03:34 AM


New To Site? Need Help?

All times are GMT. The time now is 12:05 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright ©1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2