Rebuilding a JBL N7000. Possible?

[qcautosports]

Are the internal parts of the N7000 replaceable? Are there replacement parts readily available to freshen up the old cross over?

[Bruno GINARD]

HI

THere are only 2 caps and 2 inductors........you can change it easily, and use better quality models...

Regards

[Bruno GINARD]

original circuit...........

[qcautosports]

So do I just go to any electronics store and show them the diagram? This is not a thing that I really do so please bear with me.:)

[Bruno GINARD]

Hello,

In fact , you need :

2 capacitors, Like SOLEN or equivalent , value of 1,5 Uf, see :

http://www.partsexpress.com/crossover-capacitor-index.cfm

quality is important for HF... i use Paper OIled caps for my 2405, but they cost a lot, and are very big and heavy... you can't use them in the box of the N7000 !( but.......you can put all in another box or near the speaker...)

and if necessary 2 inductors of 0,6 M h :

http://www.partsexpress.com/air-core-inductors.cfm

In my opinion, the quality of the caps is very important in the serial circuit :the cap on the line to go to the HF output

For the inductor, it's the inductor on the line to go to LF output...

If you have problem of scratches with the pad, try this :
http://www.partsexpress.com/webpage.cfm?webpage_id=3&CAT_ID=48&ObjectGroup_ID=196

model : 260-248 OR 260-262

the 262 are big ones !




Warmest regards

Bruno

[qcautosports]

Hello,

In fact , you need :

2 capacitors, Like SOLEN or equivalent , value of 1,5 Uf, see :

http://www.partsexpress.com/crossover-capacitor-index.cfm

quality is important for HF... i use Paper OIled caps for my 2405, but they cost a lot, and are very big and heavy... you can't use them in the box of the N7000 !( but.......you can put all in another box or near the speaker...)

and if necessary 2 inductors of 0,6 M h :

http://www.partsexpress.com/air-core-inductors.cfm

In my opinion, the quality of the caps is very important in the serial circuit :the cap on the line to go to the HF output

For the inductor, it's the inductor on the line to go to LF output...

If you have problem of scratches with the pad, try this :
http://www.partsexpress.com/webpage.cfm?webpage_id=3&CAT_ID=48&ObjectGroup_ID=196

model : 260-248 OR 260-262

the 262 are big ones !




Warmest regards

BrunoDo you have an idea on how ,much the big caps cost? The size will not mater as they are inside the baffle. And if they will give a better soud, thaen I'll go for that.

[qcautosports]

And which inductor do I need if ever I need one? Do you have a part number? So basically there are only 4 items that I have to replace internally, correct?

[Bruno GINARD]

THat s right, you need 4 caps, 4 inductors,2 L pads for a pair of spkrs, plus a good quality wire...........

For inductors it depends the price ( like for caps !)
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=255-412&DID=7
is a good choice

what speakers do you use for HF/ and LF ?

[Bruno GINARD]

i have used this kind of caps, good choice for the price :

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=027-528

YOu can try 1 uf + 0.47 uf in parallel to minimise serial resistance, and to mix caps technology ( 1 Uf solen+ O,47 Kimber cap)

JBL recommends in hf filtering a couple of caps in parallel...

Look the serial caps on the followed scheme :

[qcautosports]

THat s right, you need 4 caps, 4 inductors,2 L pads for a pair of spkrs, plus a good quality wire...........

For inductors it depends the price ( like for caps !)
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=255-412&DID=7
is a good choice

what speakers do you use for HF/ and LF ?It is a home brew Olympus with all the blueprint mailed from JBL 37 years ago.
LE15A
375
075

Working condition is a Conrad Johnson CJ7 Tube preamp, a CROWN DC300A amplifier, Empire troubador 598 II turn table, Forte Audio Phono Preamp.

Can you also help me with the LX5 parts? My dad told me it's not hard to take the wax or that icky stuff off of the XO.
They have tried replacing parts years ago and they used taiwan or Japanese parts. It never sounded the same. Now the sound is too bright / forwrd and a bit sharp. You wont last 15 minutes listening to it. Will these parts make difference? I don't mind using the big paperoiled caps you were talking about, as long as they will produce good sound, I'll go for it.

Here are some pictures.
http://i104.photobucket.com/albums/m172/qctirecenter/JBL%20L88/DSCF6668.jpg
http://i104.photobucket.com/albums/m172/qctirecenter/JBL%20L88/DSCF66631.jpg
http://i104.photobucket.com/albums/m172/qctirecenter/JBL%20L88/DSCF6671.jpg

[Bruno GINARD]

Hi

I have several ideas to realize a better filter, based on LX 5 and N 7OOO...

I will look the LX 5 scheme and will be back to you.

My first opinion : try to change the HF to a pair of 2405....better for music at home. I have tried 2402 ( lemon squeezer !) and 2405, 2402 sounded too hard for me.

SEcond : we can realize a more simple filter for the hf ...

regards

[qcautosports]

Hi

I have several ideas to realize a better filter, based on LX 5 and N 7OOO...

I will look the LX 5 scheme and will be back to you.

My first opinion : try to change the HF to a pair of 2405....better for music at home. I have tried 2402 ( lemon squeezer !) and 2405, 2402 sounded too hard for me.

SEcond : we can realize a more simple filter for the hf ...

regardsI think, switching to another model is not an option for my dad. First of, he is in the Philippines and I am in California. I just buy the parts here and send them there. He ahs been using that system since day one and he loves them. He only stopped when his SG520 pre broke. I will be starting a thread regarding that soon. He was using an all JBL arsenal. I remember the sound still. It sounded so...I don't even know hoew to describe it but you can listen to it all day without fatigue. Let me know of other updates. Also, another thread fro the SE408S repair.

[Bruno GINARD]

simple circuit based on the LX5/3115 for bass/mid, and a single cap in the high to use 2402 only as a complement of the 375.

N 7000 isn(t necessary in a domestical use

I have a similar circuit on my 376/2405

TRy it,

references are parts express ones

[qcautosports]

N 7000 isn(t necessary in a domestical use

I don't understand what you mean.

[Bruno GINARD]

You have two cell in the N 7000 :

One cell is a low-pass circuit, ( where the inductor is in the serial line of the signal) for the 375. It means that above 7 Khz the signal will decrease at 12 db per octave

THe second cell is the high pass circuit, for the 2402 (the capacitor is in the line.) it means that the signal will decrease below 7 KHZ 12 db per octave.
IN a professional use, this filter will protect your tweeter for high current below 7 KHZ; thus you can drive the lspk with a lot of power.

THe circuit on my paper is :

-A Lx 5 Circuit for the bass spkrs ( low pass) and for the connexion at 500 Hz for the375 (high pass above 500 Hz). The switch/transformer assembly is substituted by a 16Ohms L Pad ( but you can re-use the original assembly).

The 375 has NO filter in the high, because the natural cut-off of the speaker about 12 Khz, and the phase turnover inducted by a 12db/octave filter.

The bullet tweeter have only a capacitor to have a natural and sweet slope around 8/10 khz.

My english is'nt as good as it used to be, but i hope you shall understand!:)

Rgds

[qcautosports]

You have two cell in the N 7000 :

One cell is a low-pass circuit, ( where the inductor is in the serial line of the signal) for the 375. It means that above 7 Khz the signal will decrease at 12 db per octave

THe second cell is the high pass circuit, for the 2402 (the capacitor is in the line.) it means that the signal will decrease below 7 KHZ 12 db per octave.
IN a professional use, this filter will protect your tweeter for high current below 7 KHZ; thus you can drive the lspk with a lot of power.

THe circuit on my paper is :

-A Lx 5 Circuit for the bass spkrs ( low pass) and for the connexion at 500 Hz for the375 (high pass above 500 Hz). The switch/transformer assembly is substituted by a 16Ohms L Pad ( but you can re-use the original assembly).

The 375 has NO filter in the high, because the natural cut-off of the speaker about 12 Khz, and the phase turnover inducted by a 12db/octave filter.

The bullet tweeter have only a capacitor to have a natural and sweet slope around 8/10 khz.

My english is'nt as good as it used to be, but i hope you shall understand!:)

RgdsThanks. I will print out all the infos you gave me. And regarding the big caps the you mentioned early in the thread, do you have any photos?

[Bruno GINARD]

pics of my first filter....

you can use Paper oiled caps for the 16.5 AND 1.5 UF in the circuit, Solen"s are sufficient for the 3 X 13.5 Uf

[Bruno GINARD]

don't forgot to change the wire ( all)

an exemple :

http://www.partsexpress.com/pe/showdetl.cfm?Partnumber=100-028&vReviewShow=1&vReviewRand=5337156#reviews

[Bruno GINARD]

an example on the bay..

http://cgi.befr.ebay.be/Audiophile-Cornell-Dubilier-Paper-Oil-caps-10-f-1000v_W0QQitemZ250233688194QQihZ015QQcategoryZ3276 QQcmdZViewItem

[Oslo Ole]

Hi

I have several ideas to realize a better filter, based on LX 5 and N 7OOO...

I will look the LX 5 scheme and will be back to you.

My first opinion : try to change the HF to a pair of 2405....better for music at home. I have tried 2402 ( lemon squeezer !) and 2405, 2402 sounded too hard for me.

SEcond : we can realize a more simple filter for the hf ...

regards

I have a similar challenge.

I want to expand the range of my homebuilt S7R with a 077 tweeter. I bought the L65 Jubal at the end of the 70s and they have been playing load and clear every day since after refoaming the woofers 10 years ago. I want the 077 of the L65 to play together with the S7R.

1. May I simply divide the signal using the 7000Hz N7000 dividing network, letting the low frequency go to the S7R and the high to the L65s? All speakers are 8 ohm. My main concern is the 6 dB difference in the efficiency of the speakers. The S7R are much more efficient (91 db / 1 meter) than my small speakers (http://www.tomshardware.com/forum/57053-6-marantz-2385-european-version#).

2. I have not been able to purchase the N7000 dividing network. Does anyone know of replacement networks;
Alternatively does anyone know of companies building replacement networks using good components?

Best regards and thanks in advance!

[yggdrasil]

N8000 will work better with the 077. The L-pad will in the network is there to adjust levels. The 077 is ~105dB@1W.

A new network with better components will sound better.

Wiring: You take the signal out of the LX-5 that now goes into your LE-85 and feed it into the N-7000/N-8000 network. The output of the N-7000/N-8000 is wired directly to the LE-85 and 077.

[caddisgeek]

Hi all, I know I'm digging up an old thread here, but has anyone else built Bruno's crossover? I'm thinking of tackling this one myself for my S8 Olympus

Cheers
Steve