Mod thoughts, regarding stock ALTEC Model 19 crossovers.

[LowOhms]

Hi ALL,

On Friday, I bought a pair of Model 19s advantageously, off of Craigslist, and have been looking it over today. I have a few ideas, that I wanted to share or voice for other's input.

On the stock crossover, if one is KEEPING the stock three inductors: (a) why not turn the middle one 90 degrees, for less field interaction.? ALSO, why not space the two "outer" inductors, each about 3/8ths of an inch closer to the edges on the stock ALTEC Model 19's metal plate, for less interaction??

On the " grounding the rivets mod ", It appears to me, only the Input rivet, and the two Output rivets, are electrically in the ground path. Instead of wiring all four rivets together as previously shown on this forum, ( a large " C " ) why not take the input ground, and STAR wire two ground runs, to individually run the output grounds...?? That way, the tweeter will not be sharing the woofer's ground run currents.

Oh well, have a good day

Regards,

Jeff.......... Low Ohms

[Phil-G]

nice find Jeff.

I myself would leave it as stock as possible, but that's my preference.

[RonSSS]

Jeff,

You bought just the crossovers correct?

I have 2 sets. One just used the rivets as grounds. The other had all the grounds wired together.
So Altec either thought it was important at some time, or cheaped out and saved a foot of wire by leaving them out.......
Who knows.

The set that I used to have that came in the A7X speakers I bought actually had a box around them, and spade connectors on the back. They were N1201 but were the same circuit as the M19.

The two I have now that actually say Model 19 are just flat plates with the input and output wires just soldered to the terminal strips.

Only the LF inductor handles and real current, so maybe turn that one. I forget though which one it is.

Separating grounds is never a bad idea. Will you hear it? Hard to say.

BTW, those pots get noisy. The covers come off for cleaning though.

Enjoy

[mah]

Jeff, Classic domestic Altecs. If they weren't as rare as hens teeth Down-Under they would have been my choice.

Orientation of air-cored inductors is much less important than for iron-core ones. Air-cored inductors can be much closer together than iron cored inductors. X,Y,Z axis arrangement can be beneficial if desired component placement is constrained by space considerations. This arrangement looks better than the one in the link, below: Altec Lansing Model 19 Crossover NEW ?€? $178.00 - PicClick , but may give a different result to the original.

Grounding: If joints are in good fettle there is no audible difference between a short bus-ground and a star-ground in an LV passive crossover.
One version of the M19 crossover appears to use riveted connections to ground-plane These would be OK if welded but if solely riveted may suffer oxidation over time.
See here: help with m19 crossover wires - Mod. shown.
(Inductor layout would disturb purists but it worked well).

The high-pass filter prevents LF 'sharing'.


The Model 19 is possibly the most discussed Altec system on this forum and there are several crossover alternatives and mods. posted by forum members. I frequently find Google more useful than Hostboard Search.

Enjoy, as they used to say.

[LowOhms]

Jeff,

You bought just the crossovers correct?

I have 2 sets. One just used the rivets as grounds. The other had all the grounds wired together.
So Altec either thought it was important at some time, or cheaped out and saved a foot of wire by leaving them out.......
Who knows.

The set that I used to have that came in the A7X speakers I bought actually had a box around them, and spade connectors on the back. They were N1201 but were the same circuit as the M19.

The two I have now that actually say Model 19 are just flat plates with the input and output wires just soldered to the terminal strips.

Only the LF inductor handles and real current, so maybe turn that one. I forget though which one it is.

Separating grounds is never a bad idea. Will you hear it? Hard to say.

BTW, those pots get noisy. The covers come off for cleaning though.

Enjoy

Thanks, I appreciated your comments. No, I bought a whole pair of Model 19s on Friday. Missing one 802.

Since I like my A7-800 VOTTs, ( mass loaded and rewired ) and don't have the room, I will have to re-sell these in my area ( Kansas City ). Onto Craigslist !!

Jeff .... Low Ohms

[RonSSS]

Ah. In that case, I'd just leave them be and let the new owner muck with them if he chooses.

[BillWojo]

Your not going to at least give them a chance? For many the Model 19 is the end game. Not sure of the drivers on your VOTT but if it uses 802's I'd do some swapping and give them an honest try.
Do some research on what you have before being so hasty to unload them.

BillWojo

[Altec Best]

Jeff can you post some pics ? Don't use hostboard to do it though. Use Photobucket,Flickr,or Image shack.. Something like that or any image hosting site.. and just post the IMG links. Hostboard resizes them to thumbnails practically.

[LowOhms]

Jeff can you post some pics ? Don't use hostboard to do it though. Use Photobucket,Flickr,or Image shack.. Something like that or any image hosting site.. and just post the IMG links. Hostboard resizes them to thumbnails practically.

I am so sorry, but the M19s were sold about four hours ago. I HAD lotsa photos in the Craigslist Kansas City ad, which I referred to you folks in this post, but I have since deleted the ad. Had the drivers been correct and matching, I would possibly have not " flipped" the purchase.

As it was, it was a LOT of fun to buy and sell it .

The new owner is a typical ALTEC fan, but , like many I see, he knows NADA about correct / best possible amps. He is an Electronics Technician, says he can build a DIY tube amp if I give him a schematic, so, I will have him over in 90 days, when I get my two monaural Direct Coupled 2A3 amps finished, just to see if I can blow him away ! Would be fun to witness his listening response, and also very instructive to me. Will he recognize and hear what " I " hear. I think he might.


Jeff .... Low Ohms

[Elitopus1]

OT: Speaking of hearing, checkout this site. The "blind test" section is good. Take the tests and then tell us how you did! Some of the tests have very small changes that are hard to hear.

Free Online Audio Tests, Test Tones and Tone Generators