Charge Couple - 250TiLE.

[JBL_620]

Hello CC Guru's,,
I am planning and wanting to CC the crossover and have a quick question wrt the attached schematic. I understand from reading the threads here that I need to double the value of the capacitors then add one identical to make pairs.

I need clarification on whether I need to do this on ALL the capacitors - meaning including the bypass ones like 0.01uF and 0.005uF or just the higher value ones?

Your help is much appreciated.:thmbsup:

53515

[Allanvh5150]

Hi, Generally you would not worry about installing the bypass caps at all. Some however, do. If you choose to do so, just use the bypass caps as they are now. I.E. bypass each group of capacitors.

Allan.

[JBL_620]

Hi, Generally you would not worry about installing the bypass caps at all. Some however, do. If you choose to do so, just use the bypass caps as they are now. I.E. bypass each group of capacitors.

Allan.
Thanks much Allan for the advice. So I went ahead and modified the diagrams as shown below with the bypass caps removed from the circuits.

Does everything look correct? Any other suggestions before I start shopping for the parts?

Thanks.

[Amnes]

Looks good to me. Might do it in mine some time too.

[JBL_620]

Looks good to me. Might do it in mine some time too.
Thank you Amnes for the confirmation of the modified circuits. Come on and lets do it.:D
I'll be biamping the speakers as well.

[Hey19]

Thank you Amnes for the confirmation of the modified circuits. Come on and lets do it.:D
I'll be biamping the speakers as well.

will you be using?

[Uncle Paul]

Thank you Amnes for the confirmation of the modified circuits. Come on and lets do it.:D
I'll be biamping the speakers as well.

Are you using an active crossover? If so you can eliminate much of the larger and more expensive components. Also, others with much experience have recommended using Solen caps without the need for bypass caps. There is a really, really good build thread here by 4313b somewhere, though for the version that uses bars to select padding. Still, much to be learned there due to the excellent construction technique.

[Uncle Paul]

Almost forgot.... If you are building from scratch and using new inductors, make sure you get the dc resistance (DCR) from the existing inductors. This resistance does affect the crossover, and you may need to provide additional resistance.

[grey]

Thread on 250ti CC network:
http://www.audioheritage.org/vbulletin/showthread.php?289

I have been warned that the bi-amping quest can lead to a redesign of the network.:dont-know:

[Allanvh5150]

Thread on 250ti CC network:
http://www.audioheritage.org/vbulletin/showthread.php?289

I have been warned that the bi-amping quest can lead to a redesign of the network.:dont-know:

Not really. This cabinet was made to be bi amped in the first instance.

Allan.

[JBL_620]

Are you using an active crossover? If so you can eliminate much of the larger and more expensive components. Also, others with much experience have recommended using Solen caps without the need for bypass caps. There is a really, really good build thread here by 4313b somewhere, though for the version that uses bars to select padding. Still, much to be learned there due to the excellent construction technique.
Yes, Uncle Paul, I'll be using an active XO (main reason is to experiment and learn). I am currently putting together a part list with price and got about 40% done and I am already at ~$600 (for both speakers). I anticipate the toal for parts alone is about $1K at minimum. I am only shopping at Parts Express as I don't know anyone else.

Looks like I am looking at two different and separated projects here: Charge Coupled and Biamp.
My plan is to keep the original passive XO's and build new ones from scratch to play with. I'll use the original passive XO when biamping (bypassing the low but still use the passive network for the mid's and hi's). I'll using the Behringer DCX2496 as an active XO for the experiment. Once I learn more about the biamp, I will shop for more hi end unit then but for now the DCX2496 should be sufficient.

The question I have for the experts here is:

Can I still biamp with the CC passive network that I will be building? I was not planning to run both simultaneously though as I don't know if you can do that or what the advantages are from that.

Thank you.

[JBL_620]

Almost forgot.... If you are building from scratch and using new inductors, make sure you get the dc resistance (DCR) from the existing inductors. This resistance does affect the crossover, and you may need to provide additional resistance.
Uncle Paul, can you elaborate more on this?
I will be building from the scratch and will buy all the components and construct the circuit as shown on the CC schematic. Does not work like that?:confused: Thanks.

[JBL_620]

Need help on finding the right values for these parts.

Seems they don't make the inductors in these exact values, What equivalent are you using to get these values:

0.03mH
0.18mH
0.5mH

Same for the 3.9 Ohm 10W resistor, can I use a 4 ohm resistor, or four 1 ohm resistors in series? With 5% tolerance, I think this should work.

Your advice and guidance is much appreciated. Thanks.

[Robh3606]

When I built my Jubilees I just purchased a coil size a bit larger and then just wound off some coils. For the resistor you can use 4 ohms

Rob:)

[Uncle Paul]

You can absolutely biamp using cc networks - that should be the ultimate. Once again for the biamped network you can drop much of the network components (everything to the LE-14-1 but add a zobel, and the high pass portion going to the 108H) since the electronic crossover will be doing the low pass to the woofer and the high pass to the mid woofer. Or you can leave it stock.

[QUOTE=JBL_620;322608]Uncle Paul, can you elaborate more on this?
I will be building from the scratch and will buy all the components and construct the circuit as shown on the CC schematic. Does not work like that?:confused: Thanks.

Basically, measure the DC resistance of the original inductor, then measure the DC resistance of the replacement. The use a series resistor to make up the difference. (I'm making an assumption here that the new inductor has less DC resistance, which is usually true) This gives the new inductor effectively the same electrical characteristics of the new one, so it's behavior in the circuit is effectively unchanged.

[Robh3606]

Once again for the biamped network you can drop much of the network components (everything to the LE-14-1 but add a zobel, and the high pass portion going to the 108H) since the electronic crossover will be doing the low pass to the woofer and the high pass to the mid woofer. Or you can leave it stock.


You can't just drop out the components. You have to check the changes to the 108H voltage drive and then make changes in the balance of the network to match the original voltage drive. The changes can be significant so you can't ignore them.



Rob:)

[JBL_620]

You can't just drop out the components. You have to check the changes to the 108H voltage drive and then make changes in the balance of the network to match the original voltage drive. The changes can be significant so you can't ignore them.


Rob:)
Thanks much Rob for the pointer on the coil values.

Since I am a newbie to this hobby, so are you saying I need to measure the stock voltage of the 108H at the drive terminals then make sure the CC circuit matches this voltage? Do I need to do the same for other HF drivers or just the 108H only?

Also, while doing my parts shopping, I've noticed most of the components (Iron core inductors and the caps) are physically big. I am starting to be concerned of the breadboard size required. Maybe I need to have two separate boards and piggy-bag them?

Do you or can you please show some photos of your CC Julibee(if you still have some)? Perhaps I can learn or get some ideas from them like the size/diimension of the breadboard/s.




Basically, measure the DC resistance of the original inductor, then measure the DC resistance of the replacement. The use a series resistor to make up the difference. (I'm making an assumption here that the new inductor has less DC resistance, which is usually true) This gives the new inductor effectively the same electrical characteristics of the new one, so it's behavior in the circuit is effectively unchanged.

Thanks again Uncle Paul. I understand now. This whole thing seems already to be more involved and detailed than I had anticipated (probably and very likely due to the fact that I've never done anything like this before). The pain is part of the game I guess.

[Robh3606]

Since I am a newbie to this hobby, so are you saying I need to measure the stock voltage of the 108H at the drive terminals then make sure the CC circuit matches this voltage? Do I need to do the same for other HF drivers or just the 108H only?


Hello

No you are fine with the CC network. You would only have to check if you changed from the stock network beyond the CC that you plan on doing. For example if you decided to biamp with an active crossover and took out a section of the network on the 108H then you would have to do some measurement of you could do it in a simulator like LEAP.

Here is a link to my Biamp Jubilee build.

http://www.audioheritage.org/vbulletin/showthread.php?21421-Biamped-L250ti-Jubilee-Clone&highlight=l250ti+jubilee

Rob:)

[Uncle Paul]

You can't just drop out the components. You have to check the changes to the 108H voltage drive and then make changes in the balance of the network to match the original voltage drive. The changes can be significant so you can't ignore them.



Rob:)

You are correct, sir! If the voltage drive can be duplicated by the crossover it would be my preference to do it there, but otherwise I'd stick with the network as designed but with CC'd caps.

[JBL_620]

Thanks Robh3606 for your link to the CC Jubilee. I have read through them and good job on the speaker cloning. Do you have own the pair?


So here's the BOM with price for one speaker. Since I am going to be using an active XO, I will likely not order the parts for the LF portion (or maybe I should in case at the end of the day I will just stick to the CC network only - without the biamp. I am not sure yet).




Obviously, the shown price doesn't include the required misc parts like (this is what I can thing of at the moment):

9V battery and connectors
PCB's (I will stack the PCB's similar to how Robh3606 did on his CC Juliee)
Stand-offs, washers and screws
2-position toggle switches
speaker terminals
etc...
Do these prices seem about right in today's market? These are all from the Parts Express.

Any concerns of the listed brands or specs?

Any suggestion or recommendation on the PCB's? Use MDF cardboard from Home Depot?
Thanks again.