Hi everobody,
I just bought the k4306 vu-meter kit and would know if it’s possible to substitute the two IC3/IC4 LM3916 with two LM3915, to got a full scale 40db range, just as suggeted form National LM3916 diagrams…
The K4306 project has a 28db High res range but I’d like to extend it to a 40db because my amp has two big full scale vu meters and I’m going for a repair, so I’d like to reflect the original scale 
I guess the two LM3915 aren’t enought to got the goal and I need also other (little?) mods to make… so please can you help me?
Sorry, no modifications.
All worked flawlessy but accidentally I put the pcb on a metal conductor plane and now right channel is broken 
What can be causes that fire (it’s very hot) R22 resistor? I’d like to repair it without change all parts 
Thanks in advance everybody.
If R22 get very hot, the leds must be on.
Most likely, the driver IC is defective.
Check with IC from other channel.
Many thanks for fast answer.
I already swapped both ICs and four Lm3916, the sx channel works ok but rx channel is still broken, leds are all power off.
Degrading voltage to 3v with the help of a tester i looked for different voltages between left and righr side.
My conclusion is: R16 is broken (no current pass), could this be the problem? Tnx!
R16 and R13 changed with new one, still no good news!
…Any other ideas? …Do you think could be some diode or C3/C4 capacitors?
I just reswapped the ICs but nothing…
Substituted both IC UA741CP with new ones, again no good news 
So please, before I became crazy and change every piece on the pcb, can you suggest me something else to try?
Sorry, we have no clue at this time.
You can mail us your kit for inspection and repair.
Velleman Projects Tech. Dept.
Legen Heirweg 33
9890 Gavere
Belgium