N3145 cc

[earspoiledbyjbl]

Do you need to have a 2M ohm resistor at every point of the caps witch that would be 10 per Network or just one off the + of the battery? What I'm wanting to do is using a Regulated power supply with 16vdc to run my X-overs and hooking it up with a 1.5M ohm resistor coming off the + and - of the supply that way the power is in the middle and less chance of dc volts getting where they don't belong. I have not hooked them up yet and need to know if this is something that will work?

[John W]

You need a separate resistor at each point, otherwise you will be linking all of your caps together at the junction. Signal will flow where you don't want it.

[earspoiledbyjbl]

OK that's what I was wondering. Can I still use one resistor from the - part?

[John W]

Yes, one connection from the minus side of your power supply to ground.

[earspoiledbyjbl]

Thanks for the info John.

[just4kinks]

The whole point of CC is to bias the caps with some DC. Biasing "in the middle" would defeat the purpose.

Maybe I'm misunderstanding... would you mind sketching & posting a schematic?

[earspoiledbyjbl]

I'm doing something like this schematic but with the N3145 CC network.

[grumpy]

Assuming that is what you wanted to do, you would still need three -independent- or floating
power supplies (e.g., three batteries or three non-ground-referenced power supplies).
Otherwise, as has been mentioned, you would be tying the three ground points together.

I suppose you could put a 1-2M resistor on -both- ends of the power supply...

[earspoiledbyjbl]

I've made N3145 CC for the 4345 and also one modified for the JBL 4355 and they both work perfect, a power supply for the left side and one for the right side. The first one posted on this site just used one 9v battery per X-over. You don't hook the - of the supply to the - of the X-over.

[just4kinks]

I'm doing something like this schematic but with the N3145 CC network.

I may be biased (hehehe) but I think that circuit is overkill.
- it requires 4x the number of capacitors (as opposed to 2x in 4313B's design)
- it requires 2 9V batteries (as opposed to 1) in order to pass +/- 9V
- as Grumpy pointed out, it needs 2x as many 2M resistors

If cost and size are no object, it would be interesting to try it and see if there is any sonic difference. But if you're just worried about "dc volts getting where they don't belong", then don't forget about the 2M resistor between the battery and your drivers. Even if a cap were to fail short, DC current would be insignificant. Just double check your wiring and measure for DC before you hook them up.

[earspoiledbyjbl]

The sound is a lot better from the old JBL X-overs and you get a flatter response from 30Hz to 20kHz. yes I will hook up the power supply and test the outputs.