BPA300 Round 2 - Page 122

tryonziess · 4th October 2011, 11:18 AM

Can anyone offer up a method for adjusting the bias trimmers on the BPA300. In the past I was not able to get much real change while turning the Bourns resistor. Alexw88 in his original article was able to get overall bias to less than .09 volts total.

Does anyone know why Jeff Rowland choose the inverted mode on this amp.

I have my old boards completely stuffed except for the trimmers which I forgot to order, duh. I will add this into a tri-amp setup and see, or listen, to what happens.

Tad

AndrewT · 4th October 2011, 11:20 AM

Do you mean output offsets?

As far as I know the bias inside a chipamp is not adjustable.

panson_hk · 4th October 2011, 11:44 AM

Quote:

Originally Posted by tryonziess

Does anyone know why Jeff Rowland choose the inverted mode on this amp.

I believe they want to avoid common mode distortion.

The trimmer of each 3886 is used to adjust output offset.

regiregi22 · 4th October 2011, 12:39 PM

Quote:

Originally Posted by tryonziess

Can anyone offer up a method for adjusting the bias trimmers on the BPA300.

Tad

Look at post 1136#
BPA300 Round 2

mrsavage · 17th January 2012, 05:15 PM

Can I still get four (4) of the PA150 latest group buy? Let me know.

4th October 2011, 11:18 AM	#1211
tryonziess diyAudio Member Join Date: Apr 2007	Adjusting individual bias on BPA300 Can anyone offer up a method for adjusting the bias trimmers on the BPA300. In the past I was not able to get much real change while turning the Bourns resistor. Alexw88 in his original article was able to get overall bias to less than .09 volts total. Does anyone know why Jeff Rowland choose the inverted mode on this amp. I have my old boards completely stuffed except for the trimmers which I forgot to order, duh. I will add this into a tri-amp setup and see, or listen, to what happens. Tad

4th October 2011, 11:20 AM	#1212
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Do you mean output offsets? As far as I know the bias inside a chipamp is not adjustable. __________________ regards Andrew T.

17th January 2012, 05:15 PM	#1215
mrsavage diyAudio Member Join Date: Nov 2011 Location: Columbus, Ohio	Order PA150 circuit boards Can I still get four (4) of the PA150 latest group buy? Let me know.

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

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)