Hafler TA 1100

[tylerrussell]

Hi, all. Very new(bie) here. Hope there's some input available. My Hafler TA 1100 started distorting some in one of the channels. A post from 2006 indicated this:

Ok, this was a weird one! I emailed Hafler yesterday and a tech emailed me back and said to remove C21 and C22, and put a .47uF between pins 6 and 7 of U2B, and to duplicate the mod on the other channel before it goes bad as well. I only had one .47 lying around, so I gave it a try on the defective channel and it WORKS! Looks like a design flaw, huh?  :thumb:​

I'd like to try this, since when I opened the top of the unit one of the caps fell off the board! Getting C21 and C22 off is no problem (one's gone anyways) My question is~is this a polarized cap? And where is "between pins 6 and 7"? Here's someone's link to the schematic: http://mywebpages.comcast.net/tamron1958/Schematic.pdf    Since the schematic is not clear to me; does the .47 go from the + of the now removed C22 connection point to the - of the C21 connection point? Since the unit is un-usable as is. thought I'd give this a shot. I have a soldering station and have done minor R&R on guitar amps successfully. Thank you for your time!

 

[mjrippe]

C21 and C22 are two polarized caps arranged back to back in order to form a non-polar cap.  You would solder your .47 non-polar (probably a film cap) from the + of C21 to the + of C22.

 

[tylerrussell]

I'd just like to thank everyone for their input! The Hafler is now running very good. Caps removed/changed and distortion is gone. I appreciate all who took the time to help a true newbie out.  ;D