User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 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
 9th May 2012, 08:24 PM #1 diyAudio Member     Join Date: Oct 2010 ADS A/D/S P640 Repairing this amp for a friend because it was poping 30A fuses. I found one of the two rectifiers shorted internally so I replaced both of them. Amp now powers and plays on all channels, but the rail voltage is just a meer +-22vDC. Is that too low for this amp? Regulated voltage is ok (about +-15V) __________________ | Fluke 10 | Ramsey BS-601 | Topward 8102 | RS MiniAmp | Pyramid PS-15KX | DieHard |Big A\$\$ Resitor | Last edited by Dr Zeus; 9th May 2012 at 08:26 PM.
 9th May 2012, 11:13 PM #2 diyAudio Member   Join Date: Dec 2005 Location: Northern California ADS wasn't known for high voltage power amps, so unless the replacement diodes have some unusual Voltage drop issues its likely a acceptable rail supply for a 6 times 40 watt amp. If in doubt you could always setup a simple resistive test loads and scope the output of the amps channels into those loads driven by a clean sine wave just below clipping on the scope and measure the RMS AC voltage across the loads and use ohms law to calculate its power level. Here is a link to a online ohms law math calculator: Ohm's Law Calculators P = E 2 / R
 12th May 2012, 05:43 AM #3 diyAudio Member     Join Date: Apr 2005 Location: Indianapolis, IN That's about right for a 40Wrms per channel amp. Since it is a class A/B amp you can only get within about 4 volts of each rail before clipping sets in. So this is what I come up with for +/-22V rails: (44V - 8V) = 36Vpp 36Vpp = 12.7278Vrms 12.7278Vrms/4 ohms = 3.18195Arms 12.7278Vrms*3.18195Arms = 40.499Wrms Looks about right to me. __________________ Ah, how beautifully the orchestra sounds before a rain! In a dry sunny day there is no way for the instruments to sound this way!

 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 OffTrackbacks are Off Pingbacks are Off Refbacks are Off Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post mike49504 Car Audio 27 1st March 2010 08:34 AM mike49504 Car Audio 8 8th October 2008 09:25 PM mike49504 Car Audio 1 5th September 2008 08:07 PM mike49504 Car Audio 3 8th August 2007 02:11 AM markp Multi-Way 0 15th December 2004 11:16 PM

 New To Site? Need Help?

All times are GMT. The time now is 05:18 PM.