high rail voltage chip amps? - 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 27th November 2012, 06:53 PM   #1
diyAudio Member
 
Join Date: Jun 2002
Location: non
Default high rail voltage chip amps?

Are there any amplifier ICs that can handle +/-58V? I have a bookshelf stereo that is sentimental to someone, unfortunately since STKs arnt made anymore, they are hard to find unless chinese clones which are garbage. I tried, and it blew 3 times already.

So i am going to build an amp module retrofit, But i need to find a chip that can handle the rail voltages this thing puts out.

any ideas?
  Reply With Quote
Old 27th November 2012, 06:56 PM   #2
Banned
 
Join Date: Jan 2005
The highest voltage one i know of is the TDA7293, but it specs 100V max between the rails.
  Reply With Quote
Old 27th November 2012, 09:41 PM   #3
diyAudio Member
 
Rundmaus's Avatar
 
Join Date: Aug 2005
... what about looking ebay&co for a used unit using the same STK as donor?

Greetings,
Andreas
  Reply With Quote
Old 27th November 2012, 10:12 PM   #4
diyAudio Member
 
Join Date: Jan 2011
Location: Fosser, Aurskog-Holand, Akershus, Norway.
I really don't understand what ST is trying to tell us here,
But this one: http://www.st.com/internet/com/TECHN...CD00001887.pdf
Can be supplied with 120V when there is no signal.
Easiest way to fix Your problem is in fact to rebuild Your power supply to a regulated one, with +/-60V? Will provide some loss, but it should be good still?
Probably easier than finding a genuine STK-amp I guess.
__________________
Sooner or later you end up with TANDBERG
  Reply With Quote
Old 27th November 2012, 10:24 PM   #5
diyAudio Member
 
bobodioulasso's Avatar
 
Join Date: May 2008
LME49811, LME49810, LME49830, though you have to add some outputs.
  Reply With Quote
Old 28th November 2012, 05:14 AM   #6
diyAudio Member
 
Join Date: Jun 2002
Location: non
I tried building a transistor amp using the UPC2581 I had hanging around, following a sony schematic and turned out to be a disaster. distorted, oscillating like mad, etc...

I eventually got it tame, but it still had low level oscillation (couldnt hear) and it got hotter than hell.

So i gave up and want to go with a chip solution.
  Reply With Quote
Old 28th November 2012, 06:22 AM   #7
jcx is offline jcx  United States
diyAudio Member
 
Join Date: Feb 2003
Location: ..
http://www.edn.com/contents/images/45890.pdf

not saying you can do this trivially with power op amps but it may be one approach - need to heatsink the pass transistors, compensation may be squirrelly

would need to reduce the divider R values to supply worst case base current for the bootstrap Q
  Reply With Quote
Old 28th November 2012, 12:43 PM   #8
diyAudio Member
 
Michael Chua's Avatar
 
Join Date: Jul 2006
Location: Calais, ME
Quote:
Originally Posted by mbates14 View Post
Are there any amplifier ICs that can handle +/-58V? I have a bookshelf stereo that is sentimental to someone, unfortunately since STKs arnt made anymore, they are hard to find unless chinese clones which are garbage. I tried, and it blew 3 times already.
Yes, some of the Chinese made STK are not exactly to Sanyo specs. They do blow up when you power up.

You can use the OEM STK4050V that I have. With the modifications I did, the STK4050V is stable. I tested them at +/- 65V for 200W full power. Should work at your voltages.

These mods are only applicable for my STK4050V.

Regards
Mike
Attached Images
File Type: jpg STK4050mod.jpg (49.4 KB, 172 views)
__________________
AmpsLab.com
  Reply With Quote
Old 29th November 2012, 01:14 AM   #9
diyAudio Member
 
Join Date: Jun 2002
Location: non
This unit used the STK-4221V, Yes and the junk ones do tend to spontaneously combust. Your STK is mono so it really isnt going to help considering the heatsink is very small, Fan cooled. Only enough room to fit 1 STK, I just barely managed to fit 4 TIP35/36 transistors on the heatsink, and they were packed side by side like sardines. Using TIP35/36 outputs with the UPC2581 worked ok, but it oscillated like a chinese bandwagon and the heatsink got way too hot way too quick.

I tried a couple already, one from MCM and one from Electronix online, they blew up. one on powerup, one after a little while.

I found an STK, which was way underpowered, but same pinout from an Optimus car amp from the mid 90s. Used that one, and it lasted a long time and eventually jamming it blew it.

So i have to find another option.. FAST.

Last edited by mbates14; 29th November 2012 at 01:17 AM.
  Reply With Quote
Old 29th November 2012, 01:36 AM   #10
diyAudio Member
 
Join Date: Jun 2002
Location: non
Ah, i like the boostrapping idea (never understood that term, still dont, only in the digital world).

So, If i use the TDA7293/TDA7294, I could bootstrap these?

I read the document and the math is over my head. So, what type of transistors would i need? how much heat would they dissipate?
  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
Please suggest a high rail voltage (160V) amplifier Jay Solid State 19 3rd May 2012 07:32 PM
Rail Voltage chart for Amps axperion2 Solid State 10 18th November 2010 11:46 AM
Chip amps - referencing input to negative rail? Circlotron Chip Amps 21 12th June 2004 12:16 PM
high-voltage chip amp xplod1236 Chip Amps 7 2nd June 2004 04:09 AM


New To Site? Need Help?

All times are GMT. The time now is 12:45 PM.


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