Urei 811B schematic help needed

[rusty jefferson]

http://www.jblproservice.com/pdf/Vin.../UREI-813B.pdf I have a friend who is starting to build a pair of crossovers for a diy 811B project. The only schematic he could find is attached (last page) and has a few unreadable values. Does anyone have a better schematic, or if you have a pair, could you please check the value of C3 and C4 and let me know? Thanks in advance.

[stephane RAME]

The "C" version
http://www.jblproservice.com/pdf/URE...s/811C-L,R.pdf

Stéphane

[rusty jefferson]

Earl, Sorry for the delay. My friend hadn't apparently downloaded the link ESO posted but had a couple drawn out schematics. One of them matches the schematic in this link I just found and is legible. The schematic Heather posted appears to be the 813A schematic, not the 813B. Check this link and see if it looks right to you, it does appear to be the 830 network for the 811B. It might be worth a PM to ESO to see if he agrees as he's built several of these I believe. If it is right, perhaps Rob could get it into the library with a link in this thread to it?

https://www.google.com/url?sa=t&sour...vFEbrg_NCQ5AkZ

[Earl K]

Hi Rusty,

Thanks Much !! for your efforts.

What you've found here makes more sense for the C3+C4 values in the woofer section ( plus overall, it's a clearer scan of what Heather has posted > which had the added "Helper-Woofer" LP section within it ).

I'm going to model this eventually, once I get given some measurements ( which are in the works but waiting on some HF parts to arrive ).

If it doesn't model well with these updates C3+C4 values ( being 10uF and 14uF respectively ) I'll ask ESO what he in fact used.

Thanks Again!!

[rusty jefferson]

Thanks Stephane, but he is looking for the "B" version.

[stephane RAME]

http://www.jblproservice.com/pdf/Vin...s/UREI-811.pdf

Stéphane

[rusty jefferson]

I just noticed the link I posted a few minutes ago isn't to a JBL Pro or Harman server but a restoration guy in Europe I wasn't aware of.

https://robertmelchers.nl/index.php/nl/

[rusty jefferson]

Thanks again, but he is looking for the "B" version for use with the 801B Urei drivers.

[rusty jefferson]

Earl, You are correct, Heather did post the 813B, not 813A schematic. My bad. Too many UREI combinations. :-)

[Earl K]

And now:

Some more pics of eso's spectacular work ( before they get lost in the ether ).

[Mr. Widget]

Absolutely magnificent!

Thanks for sharing!!!!


Widget

[eso]

https://dl.dropboxusercontent.com/u/... crossover.pdf

While it doesn't say so, this is the 830 crossover schematic which is the correct crossover for 1 801B duplex in an 811B enclosure. The Crossovers are made in 2 parts with a large umbilcal cord connecting the sections. The time delay section is in the back panel with the signal binding screws and the high pass section, fuses, lights and trim pads are in the front panels. The light bulbs are important too. I'd really recommend going with the 813 with the helper woofer. They really kick.

This might come in handy too: https://dl.dropboxusercontent.com/u/...ver matrix.pdf

Here's my 813Bs:



And one of my hardwood horns for these:



eso

[stephane RAME]

https://dl.dropboxusercontent.com/u/...r%20matrix.pdf

Stéphane

[rusty jefferson]

ESO,

Thanks very much for the schematic. Just what he's looking for.

Your second link didn't work, however.

I'm rebuilding a pair of 813Cs right now and have been talking to a few people about wood horns for them. I'd like to discuss your horns and will pm you later. Thanks again

[eso]

ESO,

Thanks very much for the schematic. Just what he's looking for.

Your second link didn't work, however.

I'm rebuilding a pair of 813Cs right now and have been talking to a few people about wood horns for them. I'd like to discuss your horns and will pm you later. Thanks again

Try the link now. For some reason it didn't post correctly the first time.

eso