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Dynaco A10 Help potentially blown woofer

pjrengineer

pjrengineer

Quality of work is a lasting trait
Subscriber
Hello

I recently had my turntable playing on my amp and was figeting with the turntable ground wire connection. A “pop” noise was heard through the speakers and one of the dynacos stopped working correctly and completely went out. I decided rather than try to fix them I want to upgrade them. Drivers and all. I have little electronic experience but have a lot of friends who can help me with the replacement work. Can someone help me with a list of what’s needed to fully upgrade these? I really like these speakers.

Let me also say that they play Paul McCartneys voice better than any speaker I own which isn’t much for some of you on here but I have about 10 pairs.

Thanks
 
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Sorry to hear about the problem. We have all done lame things to our gear over the years.

Curious why if you love their sound so much you want to change them. Are you talking replacing the drivers with different new speakers all together?

I would keep them original and either repair or replace the bad driver(s) but that is me.

Replacing the drivers will kill their collectibility too. They are not making any more A-10's.

Remove the woofer and go from there. Take pictures and describe exactly what they are doing. Both speakers out that sort of thing. Post pictures too of the inside and the cross over etc.

Just my unprofessional opinion. :biggrin:
 
I agree with Fairlane. Your best course is a simple repair of whatever crapped out on your A10 - for a bunch of reasons.

As suggested, pull the woofer and tweeter out and we'll help you diagnose the problem.

GeeDeeEmm



From the interweb - the Dynaco A-10

118975-dynaco_a10_speakers.jpg
 
Thanks I was told there are upgraded seas tweeters available. Do you guys have any info on these?
 
vinylkid58 said:
Here's the replacement tweeter for the A25. The internet says the same tweeter was used for the whole Dynaco line.

http://www.madisoundspeakerstore.co...s-prestige-27tffc-h0881-textile-dome-tweeter/

jeff
Click to expand...

Well, that is not correct. There are several tweeters that were used in the Dynaco line. H086 and H087 are two of them (Seas), but there were also Scanspeak drivers used (I do not know the numbers for those). I would also be concerned about using the Seas 27TFFC on a simple 6db per octave slope.
 
WaynerN said:
Well, that is not correct. There are several tweeters that were used in the Dynaco line.
Click to expand...

I meant to say the 2-way line, A10/A25 etc.

WaynerN said:
I would also be concerned about using the Seas 27TFFC on a simple 6db per octave slope.
Click to expand...

Well, it has a higher power rating and a lower Fs that the Seas H087, so it may survive ok. I pushed my A10's "hard" back in the day, and never had an issue with the tweeters.:biggrin:

jeff
 
Fairlane said:
Sorry to hear about the problem. We have all done lame things to our gear over the years.

Curious why if you love their sound so much you want to change them. Are you talking replacing the drivers with different new speakers all together?

I would keep them original and either repair or replace the bad driver(s) but that is me.

Replacing the drivers will kill their collectibility too. They are not making any more A-10's.

Remove the woofer and go from there. Take pictures and describe exactly what they are doing. Both speakers out that sort of thing. Post pictures too of the inside and the cross over etc.

Just my unprofessional opinion. :biggrin:
Click to expand...

Is it possible I just blew a fuse? Do these speakers have fuses? The drivers look glued down more than the grille and may try to use a heat gun to loosen them. I just don’t want to do any damage.
 
If I remember correctly, the A10 had only a 5uf cap on the tweeter, so that put the cross-over at 4k. At 2k, its only down 6db, at 1k its only down 12db and at 500, its only down 18db. Tweeters are not designed to produce 500 cycles. If it were a 12db per octave slop it would be down 36 db at 500.
 
I believe that A10 has a different crossover than the A25 from what I can remember from the pair i had 10 years ago. I'll have to pull up pics on my laptop later. Hard to believe it totally took one out. Do you have a DMM to check the drivers with?

I could have sworn it was a 12db/Oct crossover. Maybe those old electrolytic caps popped.
 
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I have no idea, but are you sure it's your speaker that you heard go "pop"? I would guess there was something wrong with the amp personally. I just can't imagine what would make the Dynaco completely go out as you describe. Doesn't make sense.
 
WaynerN said:
Does the amp not work on the same channel if you swap the speakers around?
Click to expand...

Wayner et all,A912FD24-C33D-470E-BFA8-863F2C8DE7B9.jpeg9CFFB771-0AFB-41F7-9A11-C54946805496.jpeg

Please see pics. Does this look good to you? When I put the multimeter on ohm setting and leads against the wires coming out of the terminals that connect to the crossover I get no sound and a reading of 1. When I put the multimeter leads against the thin bare wire coming out of the woofer to the terminal I get a reading of 7.5-9.5 then it jumps up to 100+ and during this time there is a very slight static noise coming from the woofer.

Again this happened when I was messing with the turntable wires and a loud pop happened when the amp was turned on.

Thanks.
 
The wire looks as if it is frayed and broken where I've drawn the arrow.
You could scrape off the yellow glue around the rivet, de-solder the wire
and reinforce it with some solid similar sized wire, then re-solder it.
I'd leave 1/8" extra length so that it doesn't get damaged at full excursion
again.
Dyna-A10.jpeg
 
The Seas 27TFFC is noted as being a very robust tweeter that will in fact take
a 6dB/oct crossover. Zaph tested it for distortion, and many others have also
noted it, it is a good replacement.
 
Thanks man. I have a friend who will help with this on Saturday and will post results.
 
Pete B said:
The Seas 27TFFC is noted as being a very robust tweeter that will in fact take
a 6dB/oct crossover. Zaph tested it for distortion, and many others have also
noted it, it is a good replacement.
Click to expand...

I was looking for a woofer and not a tweeter. But maybe your fix will resolve it. I don’t want to buy an ugly replacement from ebay that’s all black and obviously not an original.
 
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