12 replies to this topic

[craig]

Hi recently had my dynaco A25's rehabbed he double the negative on the woofer and used some weird thin exotic tweeter wire for the tweeters as well as replacing the cap with a clarity brand cap. I'm just wondering what gauge wire they came with stock, I think i want to change it back to original wire set up. Would that be hard ? thanks guys

[dynaco_dan]

Hi recently had my dynaco A25's rehabbed he double the negative on the woofer and used some weird thin exotic tweeter wire for the tweeters as well as replacing the cap with a clarity brand cap. I'm just wondering what gauge wire they came with stock, I think i want to change it back to original wire set up. Would that be hard ? thanks guys

Hi Craig

After all of your writings, I would suggest that you swallow what you've had done for the moment and ask if someone here who is knowledgable

and trustworthy would look at them and try to reconstruct them to as close as possible to original.

You need a true hifi friend now.

[Carlspeak]

Craig, what makes you want to change the wire back to original or equiv.?
How do the speakers sound?

Tweeters don't draw nearly as much power as the woofer's. That may be the reason the tech changed the wire in favor of (I'm guessing) a silver wire which some audiophiles favor over copper. Check back with the tech and let us know exactly what material and gauge wire was used for the tweeters.

[craig]

I wanted to change it back to see if it would sound more like they did before the rehab. They sound fantastic in some ways, other times they sound a little bright like they need the subwoofers help when they never did before. other times i get the feeling the bass is ok just super tight. The gain was effected more then anythingelse. I've called him a number of times i could call again but i hate to bother him, he does good work im just a little weird about it because iv gone through a lot of speakers i didn't like at all. I took a look inside to see i forget if tweeter wire was silver but it was super thin wire with a cotton outside instead of plastic. He compared it to working on a car he said the tweeters don't need the thicker wire and he doubled the negative on the woofer, i assume that means double gauge on one side of the woofer im not sure but, kinda want it back to original to hear for myself. Do you think what i said would have a dramatic effect ? or is it more the capacitor ? And yes i need an audiophile friend tech

[Carlspeak]

Things may be a bit brighter and more revealing with the changes the tech made. The most significant, I suspect, is replacing a NPE cap with a film cap. That would be my suggestion for you to change back to a NPE in the same uF as original (8 uF?). Parts express and Madisound sell very low D.F. NPE's for speaker xo use.

[craig]

I think your right, in some ways they sound very nice they get loud a little fast for me but they are catching more tones. it's hard to make a overall judgement on them sometimes they blow my mind other times they just sound too bright . I'm also curious i guess.
Now they are brighter and they have more range. Before the rehab they sounded like they could be turned up a lot more little less clean but very good high to low relationship almost as if a tiny amount of mids were making it to the highs.
Before the rehab the highs sounded more broad spectrum and less piercing allowing you to turn them up a lot more.
The bass seems tight after the rehab at times so tight i wonder if its too much for the box, but usually its very refined in bass not as draw sounding more punchy sounding.
The cap before was the original cap dynaco put in it , he had told me it was out of tolerance and read around 7 uf due to wear. he replaced it with a 5uf clarity cap. Not sure the difference between NPE and Film Caps.
I like your suggestion of trying a different capacitor because it would be a lot easier to change back.
Whats the difference in in sound between film and NPE ? and whats the difference in sound between 5 uf and 7 uf ? Would a 7uf be brighter or duller then a 5 uf ? Thanks so much for all the advice

[Carlspeak]

The bright and dull difference is related mostly to the cap type with the NPE type a bit 'duller' due to 1/4 to 1/2 ohm ESR. The 5 & 7 uF difference would relate to the crossover point. 5 uF = lower xo point and 7 a bit higher. With a 5 uF cap, The woofer will be carrying more of the frequency load and the tweeter, less. With the 7 uF cap the reverse is true.

[craig]

someone recommended dyton of solen mdf are they also duller then the clarity cap ?

[Carlspeak]

The Dayton's and Solen's are both film types. I suggest you get a non-polar electrolytic cap. Check Parts Express or Madisound.

[Transmaster]

I was just looking at Parts Connexion and they have a full line of non-polarized EL's., Because of the EURO going down the drain the price of the Mundorf Electrolytic Cap's has gone down by 13%


http://www.partsconnexion.com/

[dynaco_dan]

I was just looking at Parts Connexion and they have a full line of non-polarized EL's., Because of the EURO going down the drain the price of the Mundorf Electrolytic Cap's has gone down by 13%

It looks well worth living in the USA for buying these caps.

[craig]

I think after evaluating these rehabbed dynaco's i would like to open them up and reverse the double the negative wiring he did on the woofer.  Perhaps swap out different capacitors as well,   I've noticed some improvements and some things i don't like as well. Does anyone know the gauge for the original wires inside the dynaco A25's. ?   Also if i redo them what capacitor would you recommend ?     i found another pair of A25s at a resale shop the caps are bulging need replacing wondering what cap you recommend ?      

[dynaco_dan]

I think after evaluating these rehabbed dynaco's i would like to open them up and reverse the double the negative wiring he did on the woofer.  Perhaps swap out different capacitors as well,   I've noticed some improvements and some things i don't like as well. Does anyone know the gauge for the original wires inside the dynaco A25's. ?   Also if i redo them what capacitor would you recommend ?     i found another pair of A25s at a resale shop the caps are bulging need replacing wondering what cap you recommend ?      

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