ADS L-1290/2 Help/Advice needed

[minnesotatv]

Hello:

I recently acquired a pair of L-1290/2 loudspeakers.
There are issues with them.

In one speaker the tweeter output is muted. Swapping
channels makes no difference. Tested DC resistance for
both tweeters, and its comparable - 3.5 ohms each.
Tweeter attenuation switch and circuit seem to be
working properly.

Also bass is muddy.

Pulling the crossovers, I tested the DCR of the
thermistors. Each measures 0.5 ohms.

3 of the 4 caps on the circuit board are electrolytics. I
think the one in series with the tweeter is a polyester
film cap.

Do you have any other suggestions what might be the
trouble with these loudspeakers?

I'm considering replacing all the caps. Poly caps in
series and electrolytics for the parallel circuits.

Any suggestions which replacement caps might
work best with these old ADS loudspeakers?

Thanks,
TV

 

[movingcoilguy]

RE. ADS speaker trouble

Well you may have more of a grip on the situation then I do but you have tested things well so far. I have one question did you try switching the bad tweeter to the cabinet that has the good tweeter? in not thats what I would try sure its a pain but it will tell you for sure if its crossover trouble? If the drivers like the tweeter and bass unit are faulty I may have some spares I will part with as I have many ADS drivers around. I hope this helps and best of luck solving your troubles. Daren

 

[TerryO]

I was going to suggest you check Audio Karma.org for info on the ADS speakers, but I see that you've already posted there as well.
Those are wonderful speakers and you're going to be pretty happy when you finally get them sorted out.

Good luck on your project!

Best Regards,
TerryO

 

[minnesotatv]

movingcoilguy:

thanks.

I appreciate you letting me know that you've got some
spares. I'm still trying to identify the problem. If you
have any ideas, I'd love to hear them.

TV