Are the 52-5140 cards unobtainium?

[martin2395]

Guys, is there any place to get the 52-5140 cards for 4343's or are they totally unobtainium? I think I've searched everywhere but I couldn't even find a pic or a schematic of the 5140.

I got two Urei 5235's today, one was equipped with 51-5333 (18dB, 800Hz FFBREQ for 2380 series horns), the other one has a 51-5232 (18dB, 500Hz CCBREQ for use with 2360 series horns) mounted.
Can I convert one of these to 52-5140?

[stephane RAME]

Yes, you can change the components (resistors and capacitors)

http://www.jblproservice.com/pdf/Vin...A%20manual.pdf
http://www.jblproservice.com/pdf/vin...5%20manual.pdf

Stéphane

[martin2395]

Wow, that would be great.
So can I assume that both have the same PCB layout?

[Guido]

Wow, that would be great.
So can I assume that both have the same PCB layout?

The 4343 cards are 12dB cards. You have 18dB cards.
You can build a 12dB card from a 18db card (I did it) but that isn't easy !!!

I'm sure some members will sell you a pair of 12dB pcb's or even swap with your 18's

[martin2395]

Hi Guido,

Do you have a schematic of a 12dB card? I've searched but could only find the the layout of the 18dB ones.
If it's not possible to change the slope to 12dB I think I will try to make the correct 52-5140 from a blank custom PCB.

I wonder what would happen if I place all the parts of a 12dB 52-5140 on my 18dB card


By the way: how did you deal with inverted polarity of the XLR's on the 5235?

[Guido]

Hi Guido,

Do you have a schematic of a 12dB card?

schematic
http://www.audioheritage.org/vbullet...ull=1#post4797

pic
http://www.audioheritage.org/vbullet...l=1#post126606

[martin2395]

Thanks Guido!
I'm going to compare it right away to my 18dB ones to see if it's not easier to build such a card from scratch, rather than converting an 18dB one.

[4343]

...


By the way: how did you deal with inverted polarity of the XLR's on the 5235?

Personally, (having lots of experience with circuit board re-work) I just cut the two traces and reversed them with a pair of jumpers. Put a big label on the rear stating "XLR PIN 2 HOT!"...

[4343]

BTW, I have a pair of 52-5120 boards I made. Completely empty, not even drilled, but available.

I found it advisable to upgrade the op-amps while I had mine apart. I used LME49740NA for the quads and LME49860NA (which is also called LM4562).

[martin2395]

Hi 4343, thank you for the pics. I send both to the guy who is going to convert the cards for me and give the 5235 a check-up as it turned out to have some clumsy soldering jobs done in the past and I don't want to take any risk of blowing up my speakers when that thing breaks down.

I gave him all the info I could find about the cards and the crossover itself and according to him, it's perfectly doable to convert my 18dB cards to 12dB 290Hz. I'm curious what he will think about that XLR conversion :P

[stephane RAME]

This can be used, but the page is under construction.
http://www.bunneraudio.com/Products/jbl-5235

Stéphane

[martin2395]

I called the tech today and he says they are finished He only needs to test them and the 5235 to be sure they work 100% properly.

[martin2395]

I don't know what I do wrong but it sounds much worse active than fullly passive....

[hjames]

I don't know what I do wrong but it sounds much worse active than fullly passive....

What is the Polarity of the Woofers, relative to the other drivers?

When I ran my 4341s in Biamp mode, I had to connect the woofer in REVERSE polarity, relative to the other 3 drivers, to get the correct crossover cutoff between drivers and get the right sound.

Is it possible that is your problem?

[martin2395]

Hmm, that could be it. In passive mode everything was connected like this: solid color - red terminal, color+black - black terminal.
Just as Kenrick sound advised and it sounded the best to my ears.