Stk4142ii - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 18th June 2005, 04:00 PM   #1
kinser is offline kinser  Israel
diyAudio Member
 
kinser's Avatar
 
Join Date: Jan 2004
Location: R'aanana
Send a message via ICQ to kinser Send a message via MSN to kinser
Default Stk4142ii

Hi all,

Panning on starting a new sub amp, and found an STK4142II in an old amp.. thougt it would be good to bridge! BUT... the recomended power supply is 26Vdc+/-.. and all i have is 35Vdc+/-.. the max Vcc on the STK4142II is 39Vdc+/-.. so can I use 35Vdc?

Second thing is that the amp outputs a minimum of 25watts x2 @ 8 ohms.. so at 4 ohms it will be 50watts right? and i wanna bridge it using an 8 ohm driver.. so can i run each amp at a 4 ohm load with 35Vcd? and if i can get hold of a 4 ohm driver can I use it with this amp? Becasue i dont think these amp will handel 2 ohm loads at 35Vdc.. unless i add some extra tansistor 2 the output?

Thanks,
Kinser!
  Reply With Quote
Old 18th June 2005, 04:39 PM   #2
diyAudio Member
 
metal's Avatar
 
Join Date: Jan 2004
Hello

If you connect 4 Ohm to the output it will not be 50 watt @ 26+/- cuz there are things that I have no idea about till I started studying electronics, I am talking about my self.

The efficiency is 70 % for class B amplifier when connected to 8 Ohm resistor, and 63 % when connected to 4 Ohm resistor, so don't expect to get more the 30 to 35 watt @ 4 Ohm speaker.

Also the impedance of power output transistors plays a considerable role here, when using 4 Ohm speaker the current increases, meaning that I have larger voltage drop across output transistors, limiting the maximum possible output voltage swing, hence limiting the power output.

Regarding how to bridge amplifiers, you better go to :

Bridging STK4048XI module is the best.

and see you there...
  Reply With Quote
Old 18th June 2005, 04:53 PM   #3
kinser is offline kinser  Israel
diyAudio Member
 
kinser's Avatar
 
Join Date: Jan 2004
Location: R'aanana
Send a message via ICQ to kinser Send a message via MSN to kinser
metal,
Im not using 26vdc... i only have 35vdc.. so the output will be abit higher right?
about bridging.. i know how.. i have done it befor..

i just wanna know how much power i can get using a 8ohm driver, and a 4ohm driver, if possible to bridge into 4 ohms(2 ohms an amp..) and if i add some MJL's to the outputs can i bridge using a 4 ohm driver? i mean i know that adding transistors 2 the output wont increas power.. cuse that dependes on rail voltage.. but the extra transistors will help will driving low loads, right?(please correct me if im wrong)
Sorry for asking so many Q's.. im learing myself to... heheh!

Thanks,
Kinser
  Reply With Quote
Old 18th June 2005, 04:55 PM   #4
diyAudio Member
 
metal's Avatar
 
Join Date: Jan 2004
I am on line titaniumoash@hotmail.com
  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
Need circuit board layout for STK4142II plaese steve101 Chip Amps 1 2nd August 2005 10:35 AM


New To Site? Need Help?

All times are GMT. The time now is 02:00 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