4ch. Ma Audio p.s. Subsitution question....

amc32 · 19th December 2011, 10:30 PM

I have this amp in for repair. PowerSupply fets have been pulled previously by owner. The amp has dual powersupplies, total of 8 fets, 2 in each bank. Here is the question! The TL494 is driving all fets directly thru 70ohm resistors. There are NO drive trans between the TL494 and powersupply fets. I have verified that the drive signal is present with a scope. Seems to me to be a poor design thay would overly tax a tl494. But what I need to know is what p.s. Fet would make a good sub. Already ruined 4 irf3205's before I noticed the drive circuit...... Thanax in advance for any and all help!

Perry Babin · 19th December 2011, 10:49 PM

What is the value of the pulldown resistor from pins 9/10 to ground on the 494?

19th December 2011, 10:30 PM	#1
amc32 diyAudio Member Join Date: Mar 2008	4ch. Ma Audio p.s. Subsitution question.... I have this amp in for repair. PowerSupply fets have been pulled previously by owner. The amp has dual powersupplies, total of 8 fets, 2 in each bank. Here is the question! The TL494 is driving all fets directly thru 70ohm resistors. There are NO drive trans between the TL494 and powersupply fets. I have verified that the drive signal is present with a scope. Seems to me to be a poor design thay would overly tax a tl494. But what I need to know is what p.s. Fet would make a good sub. Already ruined 4 irf3205's before I noticed the drive circuit...... Thanax in advance for any and all help! __________________ ...............I Hear in color.................

19th December 2011, 10:49 PM	#2
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	What is the value of the pulldown resistor from pins 9/10 to ground on the 494? __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Crown MA-12000i / MA-5000i / MA-9000i	jack2040	Solid State	4	8th March 2011 01:21 PM
ma audio hk-4000 ,no sound to subs ?MA AUDIO HK-4000,NO OUTPUT TO SUBS	WRENCH030380	Class D	2	7th March 2011 11:38 PM
MA Audio	Tom7227	Class D	0	31st August 2010 08:18 PM
MA Audio 802sx help	judtoff	Car Audio	2	12th November 2007 02:25 PM
MA Audio vs. Dayton	ZuMbAiU	Subwoofers	7	30th January 2006 01:29 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	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

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)