Jump to content

Dynaco Speaker design


onplane

Recommended Posts

  • Replies 53
  • Created
  • Last Reply

Conversion:

£214.99 = US$436.86

Euro$311.74 = US$428.81

The World Designs website has the following pricing: £279/E404.55. Perhaps this kit is more 'loaded'. In any case:

£279 = US$566.93

Euro$404.55 = US$556.48

Vern, for your benefit:

US$1.00 = CA$1.052

John

>

>This particular kit, World Designs WD25A, is GBP/Euro

>E214.99/E311.74 for only the entry level parts, less

>enclosures, for a pair.

>

>Maybe someone could translate these figures to US dollars,

>please.

>

Link to comment
Share on other sites

>Conversion:

>

>£214.99 = US$436.86

>Euro$311.74 = US$428.81

>

>The World Designs website has the following pricing:

>£279/E404.55. Perhaps this kit is more 'loaded'. In any

>case:

>

>£279 = US$566.93

>Euro$404.55 = US$556.48

>

>Vern, for your benefit:

>

>US$1.00 = CA$1.052

>

>John

>

>>

>>This particular kit, World Designs WD25A, is GBP/Euro

>>E214.99/E311.74 for only the entry level parts, less

>>enclosures, for a pair.

>>

>>Maybe someone could translate these figures to US

>dollars,

>>please.

>>

>

Hi there;

Thank you for the dollar conversion.

I looked very briefly at the 2 later printouts.

The crossover certainly is a lot more complex than the original classic A-25.

Without an opportunity to hear them, I will guess that they are perhaps a little more forward sounding, or clearer, than the classic Dynaco A-25 speakers.

Certainly if it is my choice and I wanted to have a speaker that has the classic Dynaco A-25 sound, then I would buy used A-25's.

If I was wanting a similar lookalike A-25, possibly even sounding alike, newly manufactured speaker system, then here is something that may be worth considering.

If only a test drive was available to all prospective owners.

I see that the prices are not anywhere near the same as when the classics were being sold, but then again, this is 2007, over 25 years later.

Link to comment
Share on other sites

Guest denmarkdrivers

I have a pair of BW's that came with synthetic foam inserts for the ports, seems like a attempt at a dampened port. The BW 603i have a lot more range then the dynacos, but the dynacos give them a run for there money and seem to take a lot more juice. It's hard to say wich ones i like more, the 603's are very efficiant and very full sounding with a bit more range then the A25's, but the dynacos have a very natural midrange and seem to be easier to place. In the bigger room the bws seem to have an edge. Using a slightly warm amp thats not up to par in combination with the A25's almost hides some of the sharper imperfections in the highs of a warm amp. With my new better amp the BW's went from terriable to absolutely insane and the dynacos went from good to incrediable, i never realized how much the amp and pre amp can make a difference even on a vintage pair of speakers like the A25's. I've tested a lot of speakers and the dynacos will always be in the top 5 ive heard. never heard a pair of AR3A's but i know the dynacos are a lot cheaper

Link to comment
Share on other sites

>I have a pair of BW's that came with synthetic foam inserts

>for the ports, seems like a attempt at a dampened port. The

>BW 603i have a lot more range then the dynacos, but the

>dynacos give them a run for there money and seem to take a lot

>more juice. It's hard to say wich ones i like more, the 603's

>are very efficiant and very full sounding with a bit more

>range then the A25's, but the dynacos have a very natural

>midrange and seem to be easier to place. In the bigger room

>the bws seem to have an edge. Using a slightly warm amp

>thats not up to par in combination with the A25's almost hides

>some of the sharper imperfections in the highs of a warm amp.

> With my new better amp the BW's went from terriable to

>absolutely insane and the dynacos went from good to

>incrediable, i never realized how much the amp and pre amp

>can make a difference even on a vintage pair of speakers like

>the A25's. I've tested a lot of speakers and the dynacos

>will always be in the top 5 ive heard. never heard a pair of

>AR3A's but i know the dynacos are a lot cheaper

Hi there;

When the AR-3A's were selling for, $399.00 CDN list each here in Vancouver, you could buy, if you were really quick, a pair of A-25's at our Miller's Electronics for about $52.00 CDN each.

This was in limited supply but at door opening, my big bros went there and they had 2 pair for sale.

I have both speaker systems and have written a number of times about them.

I read J Gordon Holt's rave review of the Dynaco A-25, many times, over and over again.

I have not seen a copy of his follow-up review/commentary of the speaker system for many years, sadly.

He was the, "hifi god", of sorts, back then, a lot of people were waitng with baited breathe for his commentaries, so that could run out and buy the latest and greatest.

If you own A-25's and enjoy them, that is great.

If you own AR-3A's that is also great.

If you were to ask me, with you owning A-25's that is, should you go out and buy AR-3A's, will you appreciate them a lot more than the Dyna's.

In my honest opinion, if you can buy a pair of AR-3A's, in minty condition that is, for less than $400.00 - $500.00 US, I would say yes.

I've just seen a pair of A-25's go for less than $55.00 US.

The A-25's are outstanding value at their introductory price but the AR-3A is the big daddy.

Let me put it this way, A-25 is the son, AR-3A is the dad and AR-LST is the grampa.

But all in all, the A-25 is a mighty small speaker that can hold it's own with a lot of bigger amd much more expensive speakers.

This last sentance was for those with WAF problems. LOL LOL

Link to comment
Share on other sites

Guest fetzenpeter

>>Thanks a lot Vern, for coming to help me. Here in Paris

>I

>>felt pretty lost with my problem.

>>

>>I again tested in the following manner:

>>

>>- tested the good speaker on the left channel : perfect

>>- took the good speaker off its cable and hooked the bad

>>speaker on to this same cable (red-red, black-black)

>>- tested again : very bad and very w e a k sound -

>resembles

>>an old 1940ies radio with bad reception, plenty of rustles

>and

>>wissles mixed in. Sound comes out of center of speaker

>front,

>>presumably the woofer.

>>

>>There you are. And believe me, I do not burn to open the

>>cabinet !

>>

>>Best regards, Christian

>

>Hi again Christian;

>

>I wish I could come to Paris to help you. LOL LOL

>

>I read it now that you swapped the speakers, one speaker still

>works and one does not, on the same two wires?

>

>I should have suggested that you turn the switch for the

>tweeter back and forth to clean the contacts and leave it at

>the highest setting.

>

>Just to kick a dead horse, can you find another speaker of any

>kind and try the change again.

>

>This would absolutely eliminate the possibility that the bad

>speaker is the only one still bad.

>

>I am surprised that you would lose both of the woofer and

>tweeter.

>

>If you have done that, now turn the bad speakers Dynaco logo

>CCW until it is out of the grille cloth frame.

>

>Using a clean putty type knife, slide it between the cabinet

>and the grill cloth frame and pry ever so gently up.

>

>Starting near a corner is stronger.

>

>The frames are glued on with a pretty goop.

>

>Can you now take a front driver photo and rear connections

>photo as well, please, and download it for all of us to see?

>

>Then more advice to follow, Christian.

>

>After all of this is done, I would suggest a fast blow 1 amp

>fuse be installed in your speaker line.

>

Thanks Vern !

I switched the speakers again, but the result is always the same, one speaker still works fine on both of the two channels + using the 2 old connections (2xwires), and the other does not, neither on the one nor on the other.

So I will now carefully take off the grill cloth frame, and then take a photo of the back, with connecting wires attached, and the front without the cloth frame, and attach the photos to my next mail. That is what you suggested ?

Best, Christian

Link to comment
Share on other sites

Guest denmarkdrivers

I agree vern, I have seen more then one pair of AR3A's but i dident buy them because they needed serious work , drivers were missing surrounds. Thats what i love about the A 25s, almost every time they look mint with little or no rehab needed.

I think i would opt for newer speakers like B&W 630 before i would ventrue into the AR3A rehab route. (the series before the 603's.) kind of pricey but no rehab needed and they probally get the same amount of range as the AR3A's.

Link to comment
Share on other sites

Guest fetzenpeter

Hello Vern,

following your counsel as best I understood, I have proceeded to a first-ever -since factory times- uncovering of the speaker front of my bad speaker, and a photo-shooting.

I send the results in the attachment and I very much look forward to your reaction.

Best greetings from Paris, Christian

post-102618-1186939461.gif

post-20-1186939461.gif

post-102618-1186939461.jpg

post-20-1186939461.jpg

Link to comment
Share on other sites

  • 3 weeks later...
Guest fetzenpeter

Hi Vern,

coming home from a short summer vacation, I hurry to look at classic speaker pages, but do not find any reaction from you to my photos. Have I understood you correctly ? Is that what you wanted ? Or did you need something different ? I would very much love to advance in this matter. But it is true: I depend on your kind help ... .

So, a great THANK YOU for reading this, and perhaps a word from you in the coming days ??

Best regards, Christian

Link to comment
Share on other sites

Hi Christian;

Sorry, your write-up was just read this morning for the first time.

As is it appears, the woofer and tweeter in one cabinet A-25 is not working.

This is rare for all of a sudden both drivers in one speaker cabinet to just go dead.

This requires either Inspector Clouseau, or Sherlock Holmes. LOL LOL

We need to approach this in a systematic order to troubleshoot the problem.

A: You have changed the bad speaker, having also changed the tweeter level setting several times, to the good speaker wire side of the system and the same speaker is still dead.

B: You have eliminated the amp and the wire at this point as being the bad source.

C: I cannot see what may be wrong at this point, yet.

D: Is there an inline fuse, blown perhaps?

D.1: Be certain that you have left the good side wired to the speaker and amp.

E: If you are at this point you need to remove the woofer with care.

F: Lay the cabinet face up on cardboard or a blanket.

G: Remove the logo first by un-screwing CCW.

H: Gently pry up the grille cloth frame.

I: After prying up and removing the woofer from the cabinet, sit it on the cabinet away from the tweeter, with care, cone side up only.

J: Check the solder comnnections on the woofer terminals.

K: Turn on the amp and music source at real low levels.

L: Is the woofer emitting any sound, or moving back and forth at low levels?

M: Do you have another driver of any kind that you can jumper across the woofer connections, this will be in parallel?

N: What was the result of M?

O: You will not have cut any wires yet.

P: You have not heard any music, even when wiggling the woofer wires?

Q: You now need surgical gloves on to remove the insulation only from the area of the crossover panel.

R: You now need either a working driver or a pair of wires to use your good speaker and touch at the inside connections for the speaker posts.

S: By touching these two connections this will tell you if there is a continuity problem with these or not.

T: You do not want to touch the two wires together or the amp will see a short.

Let us know what has happened at this point.

Link to comment
Share on other sites

Guest fetzenpeter

>Hi Christian;

>

>Sorry, your write-up was just read this morning for the first

>time.

>

>As is it appears, the woofer and tweeter in one cabinet A-25

>is not working.

>

>This is rare for all of a sudden both drivers in one speaker

>cabinet to just go dead.

>

>This requires either Inspector Clouseau, or Sherlock Holmes.

>LOL LOL

>

>We need to approach this in a systematic order to troubleshoot

>the problem.

>

>A: You have changed the bad speaker, having also changed the

> tweeter level setting several times, to the good speaker

>wire side of the system and the same speaker is still dead.

>CD I have shifted the two speakers on each respective channel with both wires and both channels and wires function, but only with the good speaker and not with the other one.

>B: You have eliminated the amp and the wire at this point as

>being the bad source.

>CD I think so. The photos did not tell you anything, did they ??

>C: I cannot see what may be wrong at this point, yet.

>

>D: Is there an inline fuse, blown perhaps?

>CD It cannot be within the amp nor on one of the wires, might perhaps be inside the speaker cabinet ?

OK, I will now take the following steps and report back. Big THANKS !

>D.1: Be certain that you have left the good side wired to the

>speaker and amp.

>

>E: If you are at this point you need to remove the woofer

>with care.

>

>F: Lay the cabinet face up on cardboard or a blanket.

>

>G: Remove the logo first by un-screwing CCW.

>

>H: Gently pry up the grille cloth frame.

>

>I: After prying up and removing the woofer from the cabinet,

>sit it on the cabinet away from the tweeter, with care, cone

>side up only.

>

>J: Check the solder comnnections on the woofer terminals.

>

>K: Turn on the amp and music source at real low levels.

>

>L: Is the woofer emitting any sound, or moving back and

>forth at low levels?

>

>M: Do you have another driver of any kind that you can

>jumper across the woofer connections, this will be in

>parallel?

>

>N: What was the result of M?

>

>O: You will not have cut any wires yet.

>

>P: You have not heard any music, even when wiggling the

>woofer wires?

>

>Q: You now need surgical gloves on to remove the insulation

>only from the area of the crossover panel.

>

>R: You now need either a working driver or a pair of wires

>to use your good speaker and touch at the inside connections

>for the speaker posts.

>

>S: By touching these two connections this will tell you if

>there is a continuity problem with these or not.

>

>T: You do not want to touch the two wires together or the

>amp will see a short.

>

>Let us know what has happened at this point.

Link to comment
Share on other sites

Guest fetzenpeter

>Hi Christian;

>

>Sorry, your write-up was just read this morning for the first

>time.

>

>As is it appears, the woofer and tweeter in one cabinet A-25

>is not working.

>

>This is rare for all of a sudden both drivers in one speaker

>cabinet to just go dead.

>

>This requires either Inspector Clouseau, or Sherlock Holmes.

>LOL LOL

>

>We need to approach this in a systematic order to troubleshoot

>the problem.

>

>A: You have changed the bad speaker, having also changed the

> tweeter level setting several times, to the good speaker

>wire side of the system and the same speaker is still dead.

>

>B: You have eliminated the amp and the wire at this point as

>being the bad source.

>

>C: I cannot see what may be wrong at this point, yet.

>

>D: Is there an inline fuse, blown perhaps?

>

>D.1: Be certain that you have left the good side wired to the

>speaker and amp.

>

>E: If you are at this point you need to remove the woofer

>with care.

>

>F: Lay the cabinet face up on cardboard or a blanket.

>

>G: Remove the logo first by un-screwing CCW.

>

>H: Gently pry up the grille cloth frame.

>

>I: After prying up and removing the woofer from the cabinet,

>sit it on the cabinet away from the tweeter, with care, cone

>side up only.

>

>J: Check the solder comnnections on the woofer terminals.

>

>K: Turn on the amp and music source at real low levels.

>

>L: Is the woofer emitting any sound, or moving back and

>forth at low levels?

>CD: The woofer does not move in any way, it just emits a metallic sounding and weak reproduction of the source program.

>M: Do you have another driver of any kind that you can

>jumper across the woofer connections, this will be in

>parallel?

> CD: I do not know what you mean. But I have again put this speaker on the other 'good' cable and the result was the same

>N: What was the result of M?

>

>O: You will not have cut any wires yet.

>

>P: You have not heard any music, even when wiggling the

>woofer wires?

> CD No, and they do seem very well soldered and fixed

>Q: You now need surgical gloves on to remove the insulation

>only from the area of the crossover panel.

>

>R: You now need either a working driver or a pair of wires

>to use your good speaker and touch at the inside connections

>for the speaker posts.

>CD: I send you two photos of what I take to be the crossover panel. Could you indicate me w h e r e e x a c t l y I should touch here ? In making a cross on my photo and sending it back ?

Secondly, I presume that I will take a pair of live speaker wires from the amp, to do this connecting. They could be in parallel from the other speaker.

>S: By touching these two connections this will tell you if

>there is a continuity problem with these or not.

>

>T: You do not want to touch the two wires together or the

>amp will see a short.

>

>Let us know what has happened at this point.

post-102618-1189296062.jpg

Link to comment
Share on other sites

Hi again;

The two wires I was mentioning was to connect to alligator clips.

The other end to a cheap speaker of any kind almost.

At this point the amp good channel wires are still connected to the terminal posts on the rear of the bad speaker cabinet.

You would clip the one alligator clip to the more accessible machine screw thread which is the inside of the red or black speaker post fitting.

Turning your amp up to a very LOW level volume with music source on, just touch the other post end.

You should hear something from this non-descript speaker.

This confirms that the connections up to that point are ok.

Move the alligator clips to the soldered end of the clips that are under the nuts.

There should still be sound heard at this point.

You may also hear from the still connected woofer and/or tweeter if a bad connection is discovered loose.

Please confirm this.

At this point the woofer is connected and the low end only of the tweeter cap, the tweeter is still connected and should be silent still.

I would look closely at the soldered clip as this is common for both drivers and may have a bad solder connection only.

One clip has one wire (red) and cap, one has two wires (gray) or (black) and end of resistor lead.

The above information is from a Scan crossover in my hand, so the colours may be different etc.

The photo is one from ebay I kept and you will see that there is an extention piece to the left resistor at the top.

They had probably bought resistors with too short of leads.

This photo is slightly different from my sample on hand.

My point is, that you are following each connection for continuity only.

More to follow if you can confirm you are at this point.

Still no cut wires.

post-101040-1189298120.jpg

Link to comment
Share on other sites

Guest fetzenpeter

>Hi again;

>

>The two wires I was mentioning was to connect to alligator

>clips.

>

>The other end to a cheap speaker of any kind almost.

>

>At this point the amp good channel wires are still connected

>to the terminal posts on the rear of the bad speaker cabinet.

>

>You would clip the one alligator clip to the more accessible

>machine screw thread which is the inside of the red or black

>speaker post fitting.

>

>Turning your amp up to a very LOW level volume with music

>source on, just touch the other post end.

>

>You should hear something from this non-descript speaker.

>

>This confirms that the connections up to that point are ok.

>

>Move the alligator clips to the soldered end of the clips that

>are under the nuts.

>

>There should still be sound heard at this point.

>

>You may also hear from the still connected woofer and/or

>tweeter if a bad connection is discovered loose.

>

>Please confirm this.

>

Hi Dan,

as I did not exactly understand, let me tell you what I did, and illustrate this on the attached photo.

I kept the bad speaker connected to good channel, turned amp on low volume, got a small speaker and first connected its cables to the two bolts with the two red circles around it, one of the black, one of the red cable. Sound was loud and clear. Then I switched one of my ersatz-speakercables to the soldering point next to the bolt of the red speaker cable, place marked with the cross. Again sound loud and clear. Then I switched the other one of the ersatzcables to the point marked with red square. Again loud and clear.

There you are. Thanks for your help up to now. Best, Christian

>At this point the woofer is connected and the low end only of

>the tweeter cap, the tweeter is still connected and should be

>silent still.

>

>I would look closely at the soldered clip as this is common

>for both drivers and may have a bad solder connection only.

>

>One clip has one wire (red) and cap, one has two wires (gray)

>or (black) and end of resistor lead.

>

>The above information is from a Scan crossover in my hand, so

>the colours may be different etc.

>

>The photo is one from ebay I kept and you will see that there

>is an extention piece to the left resistor at the top.

>

>They had probably bought resistors with too short of leads.

>

>This photo is slightly different from my sample on hand.

>

>My point is, that you are following each connection for

>continuity only.

>

>More to follow if you can confirm you are at this point.

>

>Still no cut wires.

post-102618-1189433040.jpg

2691.txt

post-20-1189433040.jpg

Link to comment
Share on other sites

Hi again;

Sadly you have done every thing correctly and still the two main drivers are not working.

The photo is too dark and close for me to comment further.

If you could use a floodlight and move the camera back 6" or more please and re-take the photo.

You can also touch the two alligator clips to the the two woofer solder connections.

You should now hear from your smaller test speaker.

Sound?

Next time we will move to the tweeter circuit.

Link to comment
Share on other sites

Guest fetzenpeter

Hi Vern,

thanks for staying with me like that !

I had taken a photo permitting a better overview, but this site has a byte-volume-limitation for photos which did not permit it to be sent. What I succeeded in uploading for you, is already at the maximum. I will try again, but am pessimistic.

As for hitching the testspeaker to the two woofer soldering points, yes, this works and gives good clear sound -- from the test-speaker only.

Best, Christian

Link to comment
Share on other sites

The ARs have MUCH more bass extension and (I think) dynamic range, while the Dynacos have a very neutral midrange and (as others have said) are low maintenance. I've refinished the cabinets of more than 30 pair of Dynaco A-25s, A-35s and A-10s, and have RARELY encountered woofer, tweeter or crossover/switch problems. The same can NOT be said of AR (potentiometer problems) or Advent (foam woofer surrounds) speakers I've worked on.

Link to comment
Share on other sites

Hi there;

This may seem like a long way around to troubleshoot this speaker system but a person needs all the help they can receive sometimes.

Whereas if I had this bad speaker on my test bench, I would know what's wrong in about 5 - 10 minutes or less.

Those members that are following us along may have already decided that the woofer is dead.

I'm not finished with it yet, even though there is sound to the test driver and not to the woofer, on those two leads.

I have a flowchart on servicing speakers which I follow without failure.

We cannot reach to Paris and see everything, at least not just yet.

Another clear, well lit up photo should help clear things up really quick.

Link to comment
Share on other sites

Guest fetzenpeter

Hi Again, Vern,

yes, I fear the woofer speaker is completely gone. I am already asking myself what kind of replacement I could get over here.

But I suppose also that now I should check on the tweeter. Is it going to be the same kind of diagnosis ?

Best, Christian

Link to comment
Share on other sites

  • 2 weeks later...
Guest fetzenpeter

Oh dear,

my disintegrated and turned-over dynaco A25 sits in my living-room like a kind of modern art with cables sticking out. Unfortunately I do not have much other room to go or I would have to invade the rooms of my children, or my own very smallish bedroom. But then I would be away from the amp ... . It's my own dilemma.

In fact, dear Vern, if there was nothing more to do, I would rather get rid of the 2 speakers now, and pass the sponge as the French say, than in three weeks. But again, without having seen your thumb clearly turned downward, I retain a rest of inhibitions against that very destructive course.

I am really sorry for pestering you like that. But please, what do you think ? The tweeter ?

Best, and GRAND MERCI ! Christian

Link to comment
Share on other sites

Hi again;

You have done all you can to troubleshoot them, that is for sure.

Unless someone else can see where I have not suggested something, please jump in with some ideas, please do.

At this point I would suggest looking at ebay for used original Dynaco drivers.

You should also look at the possiblity of buying another pair of working speakers locally, for less money, maybe.

Another option is price a pair of speakers, working of course, off ebay for example, versus just the raw drivers.

Last ditch effort, Christian, remove the woofer and cut the wires, leaving an inch or so of coloured insulation for identification on the woofer.

Touch the test speaker to the amplifier leads to see that it is working, very low level now.

Now try the same to the disconnected woofer.

No sound?

Funeral.

Now remove and clip the leads to the tweeter, remember there is no cap, so real low level.

No sound?

Funeral.

That's all the help I can be for you at this time, Christian, sorry.

You can probably sell the enclosures, if nothing else, but I would try for the original used drivers lastly.

Link to comment
Share on other sites

Hi Christian,

I see Vern is helping you through this. Just let me mention

one of my A-25s had a loose nut on the back of the post as seen

in your picture. Did you check if those are tight?

What do you hear if you put your ear up to the woofer and tweeter?

I think you said the woofer is dead, no sound?

Does the cone move freely?

How about the tweeter any sound from it?

This is the suggested modern SEAS replacement woofer, it is very close to what was used in the A-25 XL and is more efficient so you'd want to replace both. They've gotten expensive:

http://www.madisound.com/catalog/product_i...153dd5741ab868c

Might be better to look on e-bay.

Link to comment
Share on other sites

Guest fetzenpeter

Thanks Pete and Vern !

I will go through the same procedure for the tweeter. If it does not produce any sound with direct amp connection, it will have to go as well.

Now if I have to replace woofer + tweeter, and eventually for both speakers to have an identical pair of speakers again, I will probably ditch them both (well perhaps try to sell them on ebay, even though Dynaco is a complete non-starter for example in German ebay, the biggest on the continent). Alternatively I may make a last effort to get a single used A 25 before.

Thanks a lot, Vern, for your help ! It's been a very positive experience, in spite of the hardware which does not budge.

Best regards,

Christian

Link to comment
Share on other sites

Hi again Christian;

My last write-up should have suggested disconnecting the amp from the rear connections.

With the woofer and tweeter out of the cabinet.

Cut one lead to each or both.

Separately, test with a single 1 1/2 volt, maximum, battery and see if there is a forward movement of the woofer and a click on the tweeter.

That is all I can think of, Christian.

This was the very last thing that I wanted you to do, remove both drivers and cut wires.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...