New Member here..

[mike m]

Oh I'm over the limit for uploads..

[SOOTSHE]

See if you can take the photos at a lower resolution. Here's a pic of one of the drivers that was in my 19's. (An 802 - 8G). Apparently it was quite common for the factory built cabinets to have unmarked drivers in them.
If you can get a photo posted, those more knowledgable than me can tell you if it's the real deal.

[Altec Best]

OR use photobucket or Flickr they are free.You can also go back and delete some old pics in the Attachments section. It sounds like the diaghram to me. Gpa will have new ones for $90 bucks. I wouldn't use anything else like those cheapies on ebay they are garbage.Take the back cover off and inspect the diaghram but keep screwdrivers away from the "Fram" after all it is a magnetic field.Look closely at the wire leads that go through the diaghram if they are about to break this will happen either way a new diaghram is your only option really.

[SOOTSHE]

Thanks Guys !

Hi Mike here they are.This is what you need to rebuild your Crossovers.

Capacitors
a) 21uF , so you will need a 12uFand a 9uf
b) 16 uF, so you will need 2 8uF's
c) 8 uF
d) 6 uF

I used Solen 400v DC

Resistors if out of spec.
a) 3.9 ohm 10 watt 2% audio grade 2 will be needed.
b) 3.0 ohm 10 watt 2% audio grade 1 will be needed.
c) 2.0 ohm 10 watt 2% audio grade 1 will be needed

Model 19 Modifications pictures by Altec_Best - Photobucket

I was going to obtain a used set of 19 crossovers & modify them with all new components & then I searched & came up with this schematic for the 19 & I thought, well why not just build a new set from scratch. I'm curious as to the values you've given here. Attached is the schematic I found (I think from memory on this forum somewhere) & somtimes these forums raise more questions than they answer.

I have limited knowledge when it comes to taking on such a project & so I am confused by the values here & those in the parts list of the schematic.

I can follow the 8, 16, 21 & 6mfd of the capacitors (but can't you get capacitors in 21 & 16 mfd.....is that why you have to make them up from 2 different values?)

L1, L2 & L3 are the inductors?

From the schematic the resistors needed are R1 & R3 are 8 ohm L Pads, R2 & R4 are 3.9 ohms, R5 is 2 ohms & R6 is 3 ohms.
Your parts list calls for
a) 3.9 ohm 10 watt 2% audio grade 2 will be needed.
b) 3.0 ohm 10 watt 2% audio grade 2 will be needed.

So I'm confused here - I assume R1 & R3 are being deleted & replaced by fixed value resistors, R2 & R4 are the 3.9 ohm resistors, but then we have R5 at 2 ohms & R6 at 3 ohms.

So is this schematic an exact copy of the original?

Hope I haven't made this all sound too confusing & appreciate any help.

John

Sorry....this site won't let me upload the schematic N1201-8A, but here's the parts list.

C1 - 8mfd
C2 - 16mfd
C3 - 21mfd
C4 - 6mfd
L1 - 0.3mh
L2 - 2.7mh
L3 - 0.77mh
R1, R3 - 8ohm L Pad
R2, R4 - 3.9ohms
R5 - 2 ohms
R6 - 3 ohms

[SOOTSHE]

Here's the schematic.....by Jim Easley

[Panomaniac]

Thanks for the schematic, it's interesting.
Nominally, it's Butterworth with LP at 625Hz, 2nd order and HP at about 1500Hz, 3rd order. Plus adjustable high and mid EQ for the horn.

But that's just nominal. I'll have to see if I can figure it out with actual driver impedances. Wonder where the acoustical crossover point really is?

[Altec Best]

[quote]

I was going to obtain a used set of 19 crossovers & modify them with all new components & then I searched & came up with this schematic for the 19 & I thought, well why not just build a new set from scratch.

Hi John, You should have grabbed them that's what I did I bought 2 pair and still have my originals and I just rebuilt the donor sets.

I posted them for Mike M. as he was unsure if he could do it so I posted as simple as I possibly could.The values I posted are for an original Model 19 crossover that is how they came from the factory.The inductors/coils rarely go bad if ever.They can but all is needed is to check them for the most part.

Now for Jim Easley's schematic it is just a tweak,you can tweak them forever.I recommend you try to just rebuild them first to factory spec,if you don't like you can always tweak till your hearts content.But just replacing the caps & resistors cleaning the L-pads bypassing the ground lugs made such a huge difference any further tweaks will be unnecessary IMHO. I can almost guarantee you will Love the improvement.I can probably find you a dozen more schematics of tweaks of the crossover they are someone Else's preference and you may not necessarily like them.So this is why I recommend starting with the original design and then go from there.

The original crossovers will just bolt right back in this is why I recommended you snap up a pair of donors.After rebuild you can hook them right up to baffle.If you don't like how the improvements go I would be shocked.

PS.Yes the doubled up Caps values is because no one makes a 21 uF 16 uFso the ones that have 2 caps that's the reason.Well I used Solen's and they don't have them in those values.You can always have them made up but there is a quanity limit and custom values are very expensive so it is just easier and cheaper.

[SOOTSHE]

[quote=Altec Best;1828930]

Hi John, You should have grabbed them that's what I did I bought 2 pair and still have my originals and I just rebuilt the donor sets.

I posted them for Mike M. as he was unsure if he could do it so I posted as simple as I possibly could.The values I posted are for an original Model 19 crossover that is how they came from the factory.The inductors/coils rarely go bad if ever.They can but all is needed is to check them for the most part.

Now for Jim Easley's schematic it is just a tweak,you can tweak them forever.I recommend you try to just rebuild them first to factory spec,if you don't like you can always tweak till your hearts content.But just replacing the caps & resistors cleaning the L-pads bypassing the ground lugs made such a huge difference any further tweaks will be unnecessary IMHO. I can almost guarantee you will Love the improvement.I can probably find you a dozen more schematics of tweaks of the crossover they are someone Else's preference and you may not necessarily like them.So this is why I recommend starting with the original design and then go from there.

The original crossovers will just bolt right back in this is why I recommended you snap up a pair of donors.After rebuild you can hook them right up to baffle.If you don't like how the improvements go I would be shocked.

PS.Yes the doubled up Caps values is because no one makes a 21 uF 16 uFso the ones that have 2 caps that's the reason.Well I used Solen's and they don't have them in those values.You can always have them made up but there is a quanity limit and custom values are very expensive so it is just easier and cheaper.

Thanks John,
Starting to make sense now. So this "Jim Easley" schematic is not of the original....I wasn't aware of that....thought it was the original design. I agree with your comments & just want to rebuild the original crossover with newer components. I'll go ahead with that & let you know what I think.

Back to the original though......Surely there must be a schematic somewhere for us to build a brand new crossover to the original design? Is there something in this design that is an Altec patented secret????? Are there components there that are not available to anyone else??

I would imagine there would be a healthy market for someone to come up with this product, (& please don't anyone mention Iconics version as I think that lives in fairyland) as I have read countless threads from people trying to resolve this problem.

Just an observation from someone who knows nothing about electronics.

[Altec Best]

John I just rechecked my paper work and sure enough there is a typo resistors are:

3.9 ohm two will be needed
2 ohm one needed
3 ohm one needed

I'm so sorry for any confusion.It was last summer when they were done memory isn't what it used to be.

So that maybe the original schematic.

Again I'm sorry for the confusion I will go back and edit case someone else see's it I want it to be correct.

[SOOTSHE]

No problem....but if this is the original it will make things a whole lot easier for someone to build one from scratch.....I wish Jim Easley could chime in here & clarify.