How to set idle current with old STK modules

Orit · 25th October 2010, 01:12 PM

Hello,
after replacing the output modules on the amplifier as attachment, I noticed that idle current is too low. Am I right saying that idle current depends on voltage difference between pins 0 and 1 of the output modules, hence on VAS collector current ?
Thanks in advance, have a good day

Orit

sregor · 25th October 2010, 05:08 PM

Yes - but the bias circuit is internal to the module and inaccessible. I suppose increasing the VAS current would increase the idle current, but would affect other things too. There is no simple fix to adjust the current. Are you measuring the current by the voltages on the output resistors? Is it different from the other channel? Have you checked the value of the .22 resistors? Parts change in the thirty years since this amp was originally range. Good luck with it.

Orit · 26th October 2010, 08:34 AM

Steve,
thank you for your reply. Yes, there should be 20 mV on each output resistor, but I measure only 6 mV, and the resistor values are Ok.
Orit

EchoWars · 26th October 2010, 05:11 PM

There's a lot of bogus STK modules out there (probably from China) that have virtually no bias circuitry (or at least circuitry that isn't doing what it's supposed to).

25th October 2010, 05:08 PM	#2
sregor diyAudio Member Join Date: Jan 2006 Location: massachusetts	Yes - but the bias circuit is internal to the module and inaccessible. I suppose increasing the VAS current would increase the idle current, but would affect other things too. There is no simple fix to adjust the current. Are you measuring the current by the voltages on the output resistors? Is it different from the other channel? Have you checked the value of the .22 resistors? Parts change in the thirty years since this amp was originally range. Good luck with it. __________________ Steve

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
help setting up idle current	lensmanMk2	Solid State	31	10th March 2010 11:48 PM
STK Modules FS	4bassman4	Chip Amps	0	20th October 2009 06:27 PM
STK series amp modules- any good?	flyingtele	Chip Amps	7	1st July 2009 12:22 PM
Comparison between STK modules	Tekko	Chip Amps	2	13th July 2005 01:13 PM
SMPS Idle Current	cm961	Parts	2	20th February 2004 05:56 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

26th October 2010, 08:34 AM	#3
Orit diyAudio Member Join Date: Feb 2007 Location: Milano	Steve, thank you for your reply. Yes, there should be 20 mV on each output resistor, but I measure only 6 mV, and the resistor values are Ok. Orit

26th October 2010, 05:11 PM	#4
EchoWars diyAudio Member Join Date: Dec 2002 Location: Left of the Dial	There's a lot of bogus STK modules out there (probably from China) that have virtually no bias circuitry (or at least circuitry that isn't doing what it's supposed to).

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