Dear Mr. Z,
Would you like me to send you these 846a components and N800-f xovers for testing?
I am not doing anything with them at this time.
I am just finshing up the 2nd pair of subwoofer cabs for the club.
Always willing to help!
Scott.
Dear Mr. Z,
Would you like me to send you these 846a components and N800-f xovers for testing?
I am not doing anything with them at this time.
I am just finshing up the 2nd pair of subwoofer cabs for the club.
Always willing to help!
Scott.
Sure, Scott. HF drivers (no horns) and crossovers only, please. Address via PM.
They'll get us closer to "Definitive...."
Check to see if the larger section 10.5 uF isn't in the HF circuit, Jack.
If I swap them, it's much better....
Yes, maximum attenuation (lowest HF level) would be full clockwise:Originally Posted by sourceoneaudio
Reverse engineering's soooo much easier. You can tell where they were aiming by the location of the bullet holes. The only requirement is assurance that the DUT performs within design tolerances, the liklihood of which decreases signifigantly as the item wears/ages. None of us wanna admit it, but to everyone else, these things are antiques.
I wouldn't assume the Lpad flipping necessarily a design change since it's not integral to the XO. Could've been a production flip, or for many other reasons since then. I remember when we replaced pads 'steada' spraying them.Sometimes the owner simply had to have them reversed. Lotsa stuff got built in/hardwired to the house with custom pads and switching (bell wire through the rock wool in the attic, none of that Monster crap, nosir). Lafayette Radio Supply and McGee Electronics...sniff.. I gotta go guys... gettin' a little misty here....sniff...
(hick reduction of Meyers' "talk among yourselves, I'm getting a little verklept")
Yer a card, Moldy. I'm gonna fly to Fayetteville just for old times sake and to go fishin' with ya....
It'll be interesting if Jack'll tell us what the control legend says on the ones that have max level CW. I'm bettin' it says "HF Level."
Zilch, you would lose that bet. Every one of them says "HF ATT" and are numbered from 0 at CCW to 10 at CW. At least that shows some consistency at Altec.
Yeah, that makes a lot more sense doesn't it? I was so careful measuring the inductors since I expected them to be different values. The caps pretty much matched the expected values as printed on the box, so I didn't pay as much attention to what I was doing. Hopefully I did make a mistake in noting the caps wire colors, and the big guy is the HF cap. That would make me happier with Altec, but shake my faith in my own abilities. Maybe CRS is catching up to me. I will need to make another trip to the company in a couple of hours, so will post results ASAP.Check to see if the larger section 10.5 uF isn't in the HF circuit, Jack.
If I swap them, it's much better....
If you are going to get N800F's from Scott, maybe I will hold off tearing another one apart. You should be able to check whether the response is indeed 800 HZ, and the actual values probably don't matter much, if the net result is indeed the 800 HZ that Altec advertised.
Thanks, Jack Gifford
You'll need a 'chute to land in F'ville now, Helen Walton pulled some strings and got us a new regional 'port (XNA). Be glad to give you the tour including fishing, but would really like to finish a project first so you can critique. Well, might need a few days with the shopvac after completion to be presentable, so at least another month anyway. Too bad, cause I expect an explosion of green here any day now.
Zilch,
0 is flat and 10 is minus 10db correct? (de-attenuation)
J/S-S1A
Jeff-S1A
Wow. One post about tweeters being added to a pair of Valencias and then this...
I am amazed at how this topic has evolved. Great job guys!
All this tech stuff is going over my head.
Can someone just let me know if I should keep the tweeter or not?
Thanks.
-Storm.
Keep your tweeters until instructed otherwise, Storm.
We're not there yet....
Well, they're certainly not flat, and it don't say "dB" there. "Balanced" would be somewhere in the middle, probably.
I'll know the actual adjustability after I measure Scott's crossovers....
Keep your tweeters until instructed otherwise, Storm.
We're not there yet....
Well, they're certainly not flat, and it don't say "dB" there. "Balanced" would be somewhere in the middle, probably.
I'll know the actual adjustability after I measure Scott's crossovers....
Once it is all figured out Zilch can give me the ideal x-over point and I can build you a couple of new networks to replace the 6db's in there now. We can do a 12 or 18 db network and it will really smooth them out, and it improve the sound quality greatly. I think he has mentioned around 5k is the perfect point.
J/S-S1A
Jeff-S1A
I was really hoping that I had made a mistake, and the caps were backwards, but it is not to be. The 4 Microfarad cap has the red wires, and it is the one feeding the HF section. The black wired one is across the woofer.
Score: Jack---1, Altec---0.
I measured the caps on the cheapee capacitor tester in the repair department. They read 4.61 and 14.5 microfarads, essentially confirming my reading yesterday on the LCR meter. The LCR meter is the much more accurate measuring device, being the companies standard for measuring the inductance of the wound search coil windings.
Zilch, I know you want to see the open crossover and retest the parts values, but I can't imagine that you could have a more accurate measuring device. I could send you the one not opened yet for measuring if you like. You could compare it's function to one of Scotts. That might be interesting. This one is very fragile by now, and I hope to get it repotted so I can restore the original Vals to whatever condition they are now in. I could build a pair of crossovers to replace them, but then they wouldn't be original.
So where do we go from here, Kemo Sabe?
Jack Gifford
S1A,Zilch,
0 is flat and 10 is minus 10db correct? (de-attenuation)
J/S-S1A
The calibration of their dial simply means no attenuation at 0 and max attenuation at 10. Here is a picture of the back panel of the one which had the crossover I opened. Of course the description is wrong for that crossover, but correct for the rest of them apparently. I typically set the ones in my bedroom system at 3.
Jack Gifford
Jack's rear label pic also mentions the 8-16 input option. Can't help but think that has something to do with the unexpected values.
Just noticed the label part #, while proven not to suit all situations, by their normal standards, the -2 indicates the second version of the item.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote