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View Full Version : Altec model 19 owners...important info....



rontec
12-16-2009, 08:20 PM
Hello to all. I've been visiting this forum for the past six months and have found some very useful information. So, when I discovered something concerning my Altec 19's this evening, I decided to register and share this information with others. I hope this is the correct forum and that this information is not old news.
I've owned my 19's since 1985 and noticed in recent months that when comparing them to my ADS 1290/2s and my Energy Veritus 2.3's the high frequencies were not as outstanding as they used to seem, even though the dynamics and soundstage were still tremendous. Also, adjusting the HF and MF levels did not change the tone as much as it use to seem to do.
Anyway, I took the route of changing out the capacitors, but it made no improvement. Infact, I didn't like it as much. So, this evening I put the old capacitors back in and noticed that there are four ground lugs rivited to the crossover board. I began to wonder if oxidation had built up between the lugs and the board over the last 25 years. I soldered a common wire to all four lugs and then connected the wire to the negative side of the speaker wire, thus bypassing the lugs. Eureka!
The change in sound quality is unbelieveable. Everything improved, dynamics, soundstage, imageing. IMHO, if you have some 19's, before you do anything else, bypass those ground lugs by connecting them dirrectly to the neg. speaker wire. The magic is back!

TnTn
12-19-2009, 12:11 PM
This is good info. Thanks for sharing. Have you tried putting the new caps back in?

rontec
12-19-2009, 03:18 PM
This is good info. Thanks for sharing. Have you tried putting the new caps back in?

TnTn-

I haven't tried the new capacitors since making the new ground connection. Infact I didn't even measure the resistance between the lug and the crossover board. Initially , when I saw the ground lugs, I thought of soldering the lugs dirrectly to the board. But because there was little room to do so, I used a common ground wire instead. I didn't expect such a dramatic change in sound quality.
After connecting a ground wire to the lugs of the second speaker there was again a dramatic improvement in sound quality as well. I believe that you can physically stress the ground lug to make a better connection but the wire will eliminate any resistance building up through oxidation between the lug and the board.
There are four ground lugs per crossover board. If any one of those lugs developes resistance then sound quality will be degraded! After reading so many post about HF lacking in model 19's I thought maybe I too needed new capacitors. Now I do not believe my original capacitors have dimished in any way. Now when I adjust the HF and MF levels, there is a much greater change in tonal intensity. The before and after is quite dramatic.
Now I'm wondering how many other mechanical connections in other pieces of equipment such as rivited ground lugs could be oxidizing and causing sound degradation after many years?
At some point in the future I'll try the new capacitors and I'll remove the common ground wire and measure the resistance between the lugs and the board. ( ....sorry for the long post....)

TnTn
12-20-2009, 06:08 PM
Thanks for the thorough reply. I haven't opened up the crossovers of my Model 19 in a long time. I'll take a peak at it but what you wrote does make sense as a lot of the old tube equipment do the same regarding using lugs as ground points and they have them all over the amp.

rontec
12-20-2009, 07:01 PM
...since you're an owner of model 19s, you might want to check out the comments on the Altec User Board if you haven't already. I just posted the same info over there as well. Some interesting comments......

George Roland
12-24-2009, 10:44 AM
Hi,

I as a Model 19 owner and enthusiast, I am interested in any finding such as yours regarding improving these speakers.

Might you be able to post some photos of your crossover modifications so we can get a better idea of what you have done?

Many thanks,

George Roland

Dylanl
12-24-2009, 10:33 PM
I would also like to see some pictures. George when are we going to get together to listen to a few tracks together? I would love to hear your set up.

Brett

rontec
12-24-2009, 11:21 PM
Here are a few pics from the "Altec Users Board" under Altec 19 thread.

1) Model 19 crossover board with 4 ground lugs that are rivited to the board. (highlighted in green)
2) Model 19 crossover board with new caps.
3) Mod. 19 with new caps and inductors.

I began this thread because I found there was oxidation and resistance between the 4 ground lugs and the board. When I soldered a connecting wire to all 4 of the ground lugs, HF was restored to the mod. 19 without changing any componets of the crossover. I recomment grounding those lugs together first, before any other modifications.