Newbie's Model 19 journey begins

[zelgall]

I think the problem with replacing inductors is that you can get the same H value but the R is grossly different. Why do I think this - I have a box of expensive foil inductors sitting in a box and the originals back in the X-over.

[Altec Best]

If you need new L-pads I think these are better than the ones from PE it has a longer shaft 3/4" where the ones from Parts Ex. are 3/8" too short IMO, makes it tough to get the knob on and to stay on.It's from Madisound and they carry the 3.9 ohm resistors that PE doesn't have as well.


https://www.madisound.com/store/prod...roducts_id=551

Why do I think this - I have a box of expensive foil inductors sitting in a box and the originals back in the X-over.

:2thumbsup:

[Panomaniac]

I think the problem with replacing inductors is that you can get the same H value but the R is grossly different.

Yep. The Altec inductors are solid core. Likely to have a different DCR than the air core inductors that are popular as replacements.

[ZilchLab]

New GPA 902-8A measurements on 511A and MR931 using Z19 crossover posted on AK:

[ame="http://www.audiokarma.org/forums/showthread.php?p=4133787#post4133787"]Z19 Crossover - Page 3 - AudioKarma.org Home Audio Stereo Discussion Forums[/ame]





I'll borrow some 811Bs to measure, maybe next week....

[voice of the theater]

I'd love to see the 811B measurements--thanks for sharing!

[ZilchLab]

I'd love to see the 811B measurements--thanks for sharing!

511B repeated to verify measurement conditions; mic then lowered 1.5" to be on 811B axis, and same-length window advanced ~200us for its shorter horn length. All other settings are identical for both horns and drivers:

[bfish]

Thanks man! Now if you could lightly mist some 'Plas on just the surround, I think you could cure that 13k pimple...

BTW, I can't express how much I'm enjoying your new signature. :2thumbsup: :laffingassoff: Guess I'll have to fire the secretary, she never told me we'd aquired a West Coast division.

[ZilchLab]

Having no A'plas to play with, and desiring to keep this brand new 902-8A pair entirely stock, I'll likely just notch the spike out. That done, both 511 and 811 play essentially the same, +/- 1.5 dB out to 15 kHz, with a dash of 2.5 dB "forward" in the 2 - 5 kHz upper midrange, 511 kicking it in a bit lower than 811. A low-Q broadband LCR tank filter similar to what I have used on the JBL exponentials might sweeten up that part, though it'd be more fun figuring out how to do that in Z19 itself.

A slam-dunk done deal for upgrading Valencia et al., as viewed from the West Coast, original home of all that was Altec....

BTW, I can't express how much I'm enjoying your new signature. :2thumbsup: :laffingassoff: Guess I'll have to fire the secretary, she never told me we'd aquired a West Coast division.

It took a while to save up the enrollment fee....

[mekr]

i am also new to Altec club and building speaker based on Altec 19,with 416 alinico 16ohms in Onken cabinet and GPA802 HF alinico drivers and 811 horns,i wish to build a crossover for the same ,can i have the diagrams and parts required to build the crossover

[ZilchLab]

M19 or Z19?

Here's a parts list for an $80 Z19 build using Dayton caps:



Double the value for L1 and halve that for C1 for use with 16-Ohm woofers.

Install 8-Ohm diaphragms in the compression drivers.

[Tell 'em Zilch sent ya.... ]