Has anyone used these gems? - 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 26th December 2006, 11:03 PM   #1
jgedde is offline jgedde  United States
diyAudio Member
 
jgedde's Avatar
 
Join Date: Dec 2006
Default Has anyone used these gems?

HN3C51F and HN3A51F NPN and PNP matched pairs from Toshiba. So far they seem to be unobtainium, but worth pursuing.

150V VCbo, high and linear Hfe, and a whopping 1 db noise figure! JFET territory for sure...

Here are links to the datasheets:

http://www.bestweb.net/~jgedde/HN3C51.PDF
http://www.bestweb.net/~jgedde/HN3A51.PDF
  Reply With Quote
Old 26th December 2006, 11:41 PM   #2
diyAudio Member
 
darkfenriz's Avatar
 
Join Date: Jun 2004
Location: Warsaw
They seem very similar to popular 2sa970 and 2sc2240 in to-92 case.
  Reply With Quote
Old 26th December 2006, 11:51 PM   #3
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Quote:
Originally posted by darkfenriz
They seem very similar to popular 2sa970 and 2sc2240 in TO92 case.
... and 2SC2240 - 2SA970 are just great low noise transistors
and even though rather low power is recommended
they can take 120 Volt Collector-Emitter !!
Which makes them suitable, without cascoding,
as higher power amplifier input differential dual pair.

Compared to other common TO92, like BC550 - BC560 'only' 45 Volt C-E


Lineup Audio Lab
... uses both BC550 and 2SC2240 in circuits, frequently
... and results are very rarely disappointing
__________________
lineup
  Reply With Quote
Old 27th December 2006, 10:55 PM   #4
jgedde is offline jgedde  United States
diyAudio Member
 
jgedde's Avatar
 
Join Date: Dec 2006
For the ones I found low power is the word of the day also.

Note that the HN3*** beats the noise figure of the 2sa970 by 2db. Better yet, they are matched pairs (3%) matching. This means it is possible (a good idea?) to not use emitter degeneration resistors.

Since they are also Hfe matched, it means reductions in THD without having to go through the trouble of matching discrete transistors by hand.

I'm designing an amplifier that will use these (if I can find any). I was curious about opinions from those you have reviewed the datasheets.
  Reply With Quote
Old 28th December 2006, 12:10 AM   #5
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Quote:
Originally posted by jgedde
For the ones I found low power is the word of the day also.

Note that the HN3*** beats the noise figure of the 2sa970 by 2db. Better yet, they are matched pairs (3%) matching. This means it is possible (a good idea?) to not use emitter degeneration resistors.

Since they are also Hfe matched, it means reductions in THD without having to go through the trouble of matching discrete transistors by hand.

I'm designing an amplifier that will use these (if I can find any). I was curious about opinions from those you have reviewed the datasheets.
from what you say,
it has to be excellent transistors for input pair in any amplifier
because, there are not too many that can beat up 2SC2240 - 2SA970
or even come out even

but as you wish
I will download and have a look into datasheets
__________________
lineup
  Reply With Quote
Old 28th December 2006, 12:24 AM   #6
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
i did have a look at datasheet
and test diagrams

i must say it all look very nice and good

I would say, even though Toshiba have used 1mA for to get good data
I think they work the absolute best between like: 0.5 - 1.0 mA

It is a bit depending on the resistance at the input of your circuits.
Source resistance will a have some little effect due to some little bias current noise in resistors.

But also, of course one factor is what collector load you need to drive with input pair.

Sometimes we need more than 1mA to get good drive of collector loading.
__________________
lineup
  Reply With Quote
Old 15th June 2007, 12:02 PM   #7
diyAudio Member
 
Jose Hidalgo's Avatar
 
Join Date: Mar 2007
Question : I'm looking for these two components (Toshiba HN3A51F and HN3C51F). I need about 50 pairs. Do you have any URL where I can buy them ? (Europe, US or elsewhere, I don't care).

BTW, I'm also looking for Toshiba 2SA1349 and 2SC3381 (same qty, about 50 pairs).

Thanks in advance.
  Reply With Quote
Old 15th June 2007, 12:36 PM   #8
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
If the voltage is not so important BC847BS is quite OK as a pair, very cheap also, less than a 1/4 dollar.
http://sjostromaudio.com/hifi_pics/h...363_detail.jpg

http://sjostromaudio.com/hifi_pics/h...L6toSOT363.jpg
__________________
/Per-Anders (my first name) or P-A as my friends call me
Tube Buffered Gainclone in work |Thread || Diamond buffer |Thread for the group buy | Wiki
  Reply With Quote
Old 25th March 2011, 12:08 PM   #9
diyAudio Member
 
winhill2's Avatar
 
Join Date: Aug 2008
Location: Cambridge, MA USA
Default 2SC2240 and 2SA970 - RIP. Replacements and dual versionss

Quote:
Originally Posted by lineup View Post
from what you say,
it has to be excellent transistors for input pair in any amplifier
because, there are not too many that can beat up 2SC2240 - 2SA970
or even come out even...
This line of parts are in my estimation the lowest-noise BJTs now available (lowest r_bb') that have official low-noise specs**, now that Rohm's 2SD786 and 2SB737 have disappeared.

Sadly the 2SC2240 and 2SA970 (npn, pnp) super-low-noise trannies in TO-92 packages no longer appear on Toshiba's Bipolar Transistors Product List, and have been designated NRND by Toshiba (Not Recommended for New Designs). [link] This means the factory is presumably still taking (large) orders, but they are destined for the dust-bin of history. FYI, last chance, B&D still has some inventory.

But, not to fear, Toshiba offers what appears to be the same (or better) die in SOT-23 packages, the 2SC3324 and 2SA1312. These are stocked by Mouser, and cost only 15 cents qty 100. Their datasheets are fairly complete, including two NF contour plots. The 1kHz plot shows the 3dB contour dropping 35 ohms at 1mA and below 20 ohms at 10mA. That corresponds to voltage noise levels e_n of 1.4, 0.75 and 0.56nV at 0.1, 1 and 10mA. Using the 100Hz plots, we can calculate that the 1/f corner frequencies are about 14Hz, 35Hz and 170Hz, not too bad.

The hn3c51F and hn3a51F dual transistors, original subject of this thread, also appear on Toshiba's official Bipolar Transistors Product List. They come in easy-to-solder SC-74 (6-pin SOT-23) packages, and apparently use the same dies as the 2sc3324 and 2sa1312. Their datasheets have the same two impressive noise-figure contour plots. But even though several years have gone past since this thread started, no distributors have picked up these parts. If we want to use them, we'll have to make a large group purchase. A standard reel is 3000 parts.
Attached Images
File Type: jpg 2sc3324_NF-plot(1kHz).jpg (46.9 KB, 325 views)
  Reply With Quote
Old 11th April 2013, 11:02 AM   #10
diyAudio Member
 
Join Date: Apr 2004
Location: BE/NL/RW/ZA
Not sure where the claim comes from that the parts are matched to 3%. Most will probably be reasonably well matched because most units will come from adjacent spots on a silicon wafer (after all, it would take special effort to mix them up) but unless the manufacturer takes explicit care not to pair one unit from the end of a row with another from the start of the next row, occasional badly matched parts will turn up.
Toshiba makes no mention of taking any care at all with regards to this.

Anyhow. I tested 10 parts for hfe matching. Two were at 3%, the remaining eight were below 0.5%. Frustrating, because it means the majority are really good, but the nongood ones are still a substantial minority.
__________________
There's a time for everything, and this is not it.
  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



New To Site? Need Help?

All times are GMT. The time now is 07:50 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2