Sorry for the solid state question, but http://music-electronics-forum.com/t41227/ has been down lately.
This JBL amp has an internal crossover and two amp sections for HF and LF drivers. The HF channel works fine, but the LF channel does not. Speakers are OK. Since I have two units, I was able to confirm the preamp board is OK. The issue is in the power amp board.
Good schematics available. Please see attached Power amp schematic. 100Hz signal passes and looks good at TP350, which is on page 4, coordinates B2. This is the blue trace on my scope. But immediately after R331, at pin 2 of U305, the signal looks like crap. This is the yellow trace.
Suggestions on how to further subdivide and conquer?
JBL EON 515XT *repair cancelled*
Moderators: pompeiisneaks, Colossal
JBL EON 515XT *repair cancelled*
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Last edited by xtian on Tue Jul 19, 2016 8:16 pm, edited 1 time in total.
I build and repair tube amps. http://amps.monkeymatic.com
Re: JBL EON 515XT *repair cancelled*
I'd say its a transistor problem (going by the scope)
He who dies with the most tubes... wins
Re: JBL EON 515XT *repair cancelled*
Whelp, owner pulled the plug on the repair, and we're just going to replace the board with a new one from fullcompass.
I build and repair tube amps. http://amps.monkeymatic.com
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Stevem
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M
Is c319 and 323 good?
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: M
Sorry, mate, project is dead.Stevem wrote:Is c319 and 323 good?
I build and repair tube amps. http://amps.monkeymatic.com