old device specs - 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 1st January 2006, 10:26 AM   #1
diyAudio Member
 
Join Date: Sep 2003
Location: Fort Bragg CA
Default old device specs

Hi,

I'm restoring an old early 70's one-of-a-kind amp made by a talented friend (now deceased) and am looking for the specs for these devices.

Motorola

SJ3679
SJ3678
SJ3681
SJ3680

Knowing the guy who built it, the devices are probably hand selected for CEv. Likely also selected as full SOA devices in that I*V=P where P is a constant up to the current limit. (that's how this fellow built his personal stuff) But I know not P or I. It uses 6 of the SJ3679/8 devices per channel w/ a 40V regulated supply. Runs in class A for 8 ohm load ~ 1.5A bias per side. The other devices are the drivers.

Just trying to get a better idea of what I'm working with. The amp works just fine, (better than many 'modern' amps - i.e. clean power bandwidth to over 100K, even with these old devices) and not I'm planning on replacing these devices unless it's necessary. I've been unable to find these as they are so old and my library doesn't go back that far.

This is a very advanced amp for its time.

Thanks for any info,

~ Sorabji
  Reply With Quote
Old 1st January 2006, 10:37 AM   #2
Netlist is offline Netlist  Belgium
diyAudio Moderator Emeritus
 
Netlist's Avatar
 
Join Date: Jan 2003
I have no indication of the existence of these devices.
Not by number and not by Motorola Xref.
2SC36XX is possible but these would be Sanken or for the 2SC3681, Sanyo.
Could you provide a picture?

/Hugo
  Reply With Quote
Old 1st January 2006, 11:21 AM   #3
Onra is offline Onra  Germany
diyAudio Member
 
Join Date: Jul 2005
Location: near Frankfurt/M
Hi,
i looked up an older ECG-list and found ECG-replacements for three of them:
SJ3678 is NPN replaced by ECG130 (maybe a 2N3055), TO3,
SJ3679 is PNP replaced by ECG219 (complementary type of ECG130), TO3;

SJ3680 is NPN replaced by ECG175 high voltage audio in case TO66
SJ3681 not found in this list, but ECG´s complementary type to ECG175 is ECG 38 in same case and voltage range.
Onra
  Reply With Quote
Old 1st January 2006, 11:53 AM   #4
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
$orabji!, if you by any chance have a schematic I'm pretty sure that the gathered expertize here can find suitable replacements.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 1st January 2006, 12:44 PM   #5
Netlist is offline Netlist  Belgium
diyAudio Moderator Emeritus
 
Netlist's Avatar
 
Join Date: Jan 2003
Onra made me dig a little deeper.
So, for the SJ3678 we have:
VCB:100
VCE:60
VEB:7
IC: 15
PD: 115
ft: 800Khz
Hfe: 40

SJ3679:
VCB:100
VCE:70
VEB:7
IC: 15
PD: 150
ft: 4Mhz min.
Hfe: 20 min.

SJ3680:
VCB:500
VCE:300
VEB: 6
IC: 3
PD: 40
ft: 10Mhz
Hfe: 50 typ

ECG38 (no SJ3681 here as well)
VCB:400
VCE:350
VEB:6
IC: 2 cont. 5 peak
PD: 35
ft: 20Mhz
Hfe: 50typ

/Hugo
  Reply With Quote
Old 2nd January 2006, 01:19 AM   #6
diyAudio Member
 
Join Date: Sep 2003
Location: Fort Bragg CA
Many thanks!
  Reply With Quote
Old 2nd January 2006, 03:24 AM   #7
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Hi $orabji!,
Those do sound like old Motorola part numbers for "factory numbered" devices. Motorola will have no specs on these numbers. They are like a state secret.

Be very cautious of subs listed by ECG or NTE. Do not cross in and out of these manuals.

Hugo,
Where did you find listings for those? Just curious. These numbers remind me of older Marantz part numbers.

-Chris
  Reply With Quote
Old 2nd January 2006, 08:35 AM   #8
Netlist is offline Netlist  Belgium
diyAudio Moderator Emeritus
 
Netlist's Avatar
 
Join Date: Jan 2003
Data comes from an old '89 ECG catalogue.
Indeed, one can only hope the info is reliable.
http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/$$Search?OpenForm already lists different specs for some devices parameters when looking at the datasheets.

/Hugo
  Reply With Quote
Old 2nd January 2006, 10:53 AM   #9
djk is online now djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
Chris is right, they look like house numbers used by Marantz.

The outputs are the 2N5631(NPN), and the 2N6031(PNP).

The drivers are the 2N3584(NPN) and 2N6421(PNP)
  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
ESL AMT device... moray james Planars & Exotics 8 16th January 2007 02:45 AM
Device like upc1298 palesha Solid State 5 26th January 2006 12:09 AM
IC Echo device Ubijoux Instruments and Amps 5 6th December 2005 10:51 AM
Tuning Device sma Multi-Way 1 12th October 2004 08:59 AM
Single device (BJT/FET?) amp? RichardJones Solid State 2 19th April 2003 10:06 AM


New To Site? Need Help?

All times are GMT. The time now is 07:43 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