Search found 7 matches

by rtchau
Thu Sep 07, 2017 12:23 pm
Forum: JLM Audio Kits
Topic: JLM 60Watt Power AMP Kit
Replies: 255
Views: 306471

Re: JLM 60Watt Power AMP Kit

One other thing I've noticed is trouble with clearance between the capacitors on either side of the LM3886 and the heatsink that it's bolted to... is there a trick to mounting the LM3886 on the board that I missed, so that it has better clearance and the capacitors aren't making contact with the hea...
by rtchau
Thu Sep 07, 2017 10:14 am
Forum: JLM Audio Kits
Topic: JLM 60Watt Power AMP Kit
Replies: 255
Views: 306471

Re: JLM 60Watt Power AMP Kit

HI Richard If the volume pot is turned fully down does the amp motorboat? Hi Joe, No - it only seems to go bananas after the volume pot is turned up past 50%, prior to that it starts to hum after 10-20%, and nothing at 0%. OK what value is the volume pot? If 10k log connect a 4.7k resistor between ...
by rtchau
Sat Apr 15, 2017 7:53 pm
Forum: JLM Audio Kits
Topic: JLM 60Watt Power AMP Kit
Replies: 255
Views: 306471

Re: JLM 60Watt Power AMP Kit

Joe Malone wrote:
HI Richard
If the volume pot is turned fully down does the amp motorboat?
Hi Joe,

No - it only seems to go bananas after the volume pot is turned up past 50%, prior to that it starts to hum after 10-20%, and nothing at 0%.
by rtchau
Mon Apr 10, 2017 1:13 pm
Forum: JLM Audio Kits
Topic: JLM 60Watt Power AMP Kit
Replies: 255
Views: 306471

Re: JLM 60Watt Power AMP Kit

Is there any way to prevent oscillation in the LM3886 with no input? I made the mistake this morning of switching on the amp without checking that I had a source plugged in... BRRRRT Hi the standard AMP kit is completely stable with or without input. So your setup must be customized. So you will ha...
by rtchau
Mon Apr 10, 2017 8:44 am
Forum: JLM Audio Kits
Topic: JLM 60Watt Power AMP Kit
Replies: 255
Views: 306471

Re: JLM 60Watt Power AMP Kit

Is there any way to prevent oscillation in the LM3886 with no input? I made the mistake this morning of switching on the amp without checking that I had a source plugged in... BRRRRT
by rtchau
Fri Nov 18, 2016 2:34 pm
Forum: JLM Audio Kits
Topic: JLM 60Watt Power AMP Kit
Replies: 255
Views: 306471

Re: JLM 60Watt Power AMP Kit

One last question (hopefully) - I've done the gain mod from the diagram above, however the 10k logarithmic pot only starts attenuating below about 20% of its range, e.g. amp is full tilt after turning the knob up about 20%, and then the rest of the travel just doesn't make a difference. Is the 10k l...
by rtchau
Mon Nov 14, 2016 11:35 am
Forum: JLM Audio Kits
Topic: JLM 60Watt Power AMP Kit
Replies: 255
Views: 306471

Re: JLM 60Watt Power AMP Kit

Just finished a stereo build - the resistor delete for the gain worked a treat and it's running quite happily with unbalanced input. The only problem I had was with my little tube preamp - I think it caused a super nasty ground loop as there was a nice low hum with one channel muted, and then both c...