RobRoy
It's just stuff - but fun
Guess I should have read the entire thread.
Dynaco a25 Speakers!! Should I get em?
- Thread starter TheWolf82
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- dynaco a25 speakers vintage
Blue Shadow
Waiting for Vintage Gear from this century
The site is mentioned a number of times on AK but just sliding it into a thread like this, under appropriate comments about those magazines gets the info out to more folks. Glad we got you something to do on a rainy day in front of the computer.
Blue Shadow
Waiting for Vintage Gear from this century
There is so much written about the A25, not discussing public deals until they are done and such that the thread did get long. More than many want in one sitting. Gotta check in regularly to keep up with some threads or you get left way behind. I read the frist 118 pages of the DC offset thead over a period of time. Haven't really been back, but let me look...it is up to 233 pages, I'm way behind but that might not be one I go through. The other one is the post ads from the past. Those are in the magazines linked in the post 117 above so I don't need an AK thread on that. Again only lasted 100 pages before I couldn't keep up. Now up to 332 pages.Guess I should have read the entire thread.
RobRoy
It's just stuff - but fun
Yeah, I have a rule of thumb that unless a thread's subject is of a particular interest to me, I'll avoid it if there are over 100 posts. I forgot to look at the post count on this one.
OutlawSun
Well-Known Member
That or the seller picked up on the surge in interest in the Dynacos and bothered to google them...
TheWolf82
Active Member
The seller didn’t know what he had. He was just all over the place and couldn’t coordinate anything...I deal with a lot of that
He seemed like the type of guy that wouldn’t even bother searching for pricing online...The way he listed them made it clear he just wanted them gone..all of them..and that’s what it came down to. That’s fine, I got what I wanted, and I’ve got back almost all my money i spent getting the speakers
I did pay someone to change the caps and that was 40 bucks though but it was worth it. Don’t have the equipment or soldering experience.
Now that they’ve been completely recapped they sound awesome!!!! They look great too. It’s crazy what a little Howard’s restor a finish along with some Howard’s Wax will do...Slapped some new speaker cloth on them and I’m golden
My new fav speaker. Oh yea, and I know that the a25’s are more suited for Jazz, Classical, Acoustics, etc. but with the bass these suckers can handle, some rap and hip-hop I listened to sounded awesome.
He seemed like the type of guy that wouldn’t even bother searching for pricing online...The way he listed them made it clear he just wanted them gone..all of them..and that’s what it came down to. That’s fine, I got what I wanted, and I’ve got back almost all my money i spent getting the speakers
I did pay someone to change the caps and that was 40 bucks though but it was worth it. Don’t have the equipment or soldering experience.
Now that they’ve been completely recapped they sound awesome!!!! They look great too. It’s crazy what a little Howard’s restor a finish along with some Howard’s Wax will do...Slapped some new speaker cloth on them and I’m golden
My new fav speaker. Oh yea, and I know that the a25’s are more suited for Jazz, Classical, Acoustics, etc. but with the bass these suckers can handle, some rap and hip-hop I listened to sounded awesome.
I agree. I like them but the KLH 6 and my Imperial 6s and now the Optimus 5s really out perform them. BUT, for their size they are unbeatable.
62vauxhall
Addicted Member
I decided to remove the drivers from the box then try and get the outsides looking presentable. If not by sanding, then some new veneer, Oh boy, my favorite - a veneer job!!
But holy cow, can these woofer magnets be any smaller? I have to say I was surprised. Makes me wonder how I never tore woofers to bits when I had a brand new pair of A25's and couldn't keep my fingers off the volume knob.
There is one electrolytic capacitor inside - a 50V 4.7uF. Because it electrolytic, I will be replacing it with a film type of some kind I have on hand. Something I think I bought when I intended to "hot rod" some Minimus 7's but never did.
They are 100V 4.7uF - and they're yellow!
Will also give those switch contacts a shot of cleaner while I'm in there.
.
But holy cow, can these woofer magnets be any smaller? I have to say I was surprised. Makes me wonder how I never tore woofers to bits when I had a brand new pair of A25's and couldn't keep my fingers off the volume knob.
There is one electrolytic capacitor inside - a 50V 4.7uF. Because it electrolytic, I will be replacing it with a film type of some kind I have on hand. Something I think I bought when I intended to "hot rod" some Minimus 7's but never did.
They are 100V 4.7uF - and they're yellow!
Will also give those switch contacts a shot of cleaner while I'm in there.
.
scoloheros
Super Member
I had a blown woofer, a couple years later I found one on CL here. Not only are the magnets small, I can't even get a tack to stick to the magnet. I wonder if the alnico mag needs to be re-magnetized? Is this a cover over a smaller magnet?
62vauxhall
Addicted Member
That's what i was wondering too, about the cover I mean. And in my case, when I had the woofers out, I placed one of them magnet down on a steel filing cabinet and there was barely a tug when I lifted it off.
EDIT: I noticed as well in my examples that the terminals fixed onto the woofer baskets were very loose to the point of being nearly detached which one was. I hot glued them in place and during that process noticed one tinsel wire noticeably shorter than the other - not much slack. Moving the cone back and forth does not seem to stretch it to the limit but if that cone ever bottomed out, it might.
EDIT: I noticed as well in my examples that the terminals fixed onto the woofer baskets were very loose to the point of being nearly detached which one was. I hot glued them in place and during that process noticed one tinsel wire noticeably shorter than the other - not much slack. Moving the cone back and forth does not seem to stretch it to the limit but if that cone ever bottomed out, it might.
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That is what is so funny about the A25s......the big woofer and small cab should mean no bass, but they have a ton of bass. And the tiny magnets, no way should they perform well.....but they do. A great reason to never judge speakers by looking at them.
OutlawSun
Well-Known Member
It's definitely a testament to the engineering.
RTally
Speaker addict
Your cap looks like an old-style film cap. And the value does not match specs. Does it look like it has been replaced?
Every Dynaco I've opened up has had an electrolytic cap that is can shaped and 5 uF. Here is a pic of one of my A25s showing the original cap.
62vauxhall
Addicted Member
I would need to take a closer look at the soldering but at a glance, it appeared unmolested. That said, I thought the electrolytic that's in there looked more modern than I was expecting. But it is 4.7uF which seemed about right and I just happened to have those two films handy.
I don't think I've got 5uF's of any type so if that's a must have value, I'd need to get some.
It was my understanding that with single cap crossovers such as these there is some wiggle room when it comes to value. A pair of old Wharfdales's or maybe Goodman's I once owned had what I thought were capacitors too far apart in value - one 5uF and it's counterpart 7uF.
I was told then that it was not unknown for this to happen when building new (using of parts on hand) and the sonic differences were minuscule enough so as to make no difference.
If that was so my thought with these A25's was that a .3uF difference one direction or another would be less than negligible.
I'm willing to be stood corrected.
I don't think I've got 5uF's of any type so if that's a must have value, I'd need to get some.
It was my understanding that with single cap crossovers such as these there is some wiggle room when it comes to value. A pair of old Wharfdales's or maybe Goodman's I once owned had what I thought were capacitors too far apart in value - one 5uF and it's counterpart 7uF.
I was told then that it was not unknown for this to happen when building new (using of parts on hand) and the sonic differences were minuscule enough so as to make no difference.
If that was so my thought with these A25's was that a .3uF difference one direction or another would be less than negligible.
I'm willing to be stood corrected.
RTally
Speaker addict
Many of the old electrolytic caps were rated with a 10% or 20% tolerance. Substituting a 4.7 uF cap for a 5 uF cap is within the typical rated tolerance, assuming that modern caps are close to the rated capacitance value, which is mostly true. The only impact with a lower cap value is that the crossover frequency will be raised a slight amount. Considering manufacturing tolerances of the woofer and original cap, I would not expect that slight difference to be audible.
I used 5.2 uf film caps in one of my Dynaco speakers. There was no audible difference and, according to my phone app, no measurable difference in sound when comparing an unchanged A25 to the one with the new cap. I can only conclude that those metal can electrolytic caps are of a better quality than most others of that vintage used by other speaker manufacturers.
I used 5.2 uf film caps in one of my Dynaco speakers. There was no audible difference and, according to my phone app, no measurable difference in sound when comparing an unchanged A25 to the one with the new cap. I can only conclude that those metal can electrolytic caps are of a better quality than most others of that vintage used by other speaker manufacturers.