2 Attachment(s)
Charge-coupled 3144/3145 network schematic for JBL 4344 and 4345 Studio Monitors.
Here's a Solen/Mills parts list along with the schematic from post 100.
You can substitute the Solen resistors if you wish.
They run something like $0.50 instead of $3.50 (Mills).
Please deal with that 52uf cap!
Hi Jean
- About the middle of last month ( Apr. ) Guido & Giskard revealed that the audio signal on the way to the horn & tweeter network passed through the 52uf midrange capacitor. Did you explore these statements to find out if they applied to your network or not ? ( to do so, simply unsolder one 52uf cap and take note of what components won't reproduce any sound, ie ; what "turns off" . )
- If your horn & tweeter network legs are being funneled through that 52uf cap / you'll be waiting until "Hades freezes-over" for your new Solen Film & Foil caps to start sounding even OK. Believe me ; the sound of an old 52uf NPE will completely dominate/mask any quality resolution that might be residing in any quality 2uf capacitor. It's a simple matter of ratios .
- My point ? do as Gerard stated in the thread on Capacitors and get rid of those stock 52uf caps.
At the very least , wire around them the parts of the circuitry that feed into the compression driver & UHF portions of your networks.
- This critical info ( relating to HF & UHF resolution & sound quality ) was laid out in posts 54, 56, 59, 63 thru 71, & 79 of this thread. Please pay special attention to posts 71 & 79 / and follow the advice offered.
- By not dealing with this 52uf cap question , I believe any meaningful upgrade of your network ,,, "is still on hold " .
- & Yes, By all means, build some DC-biased networks according to the latest network info, as laid out by Giskard .
- I would also suggest building new networks into external boxes so that micro-vibrations can be more effectively dealt with .
- regarding Solens' "Fast-Caps" & your latest picture of "pulses". Actual, measurable, capacitor speed is never going to make those pulses merge into one. The physical offsets/distances between the voicecoils will always dominate a "pulse picture" no matter which capacitors are used in a circuit.
:cheers: