At this time, I am not really inclined to do anything besides replace the tweeter capacitor, but clearly there's a lot to think about there. I think improvement there is highly likely, but I'm a little less confident about the wiring/inductor/post changes. My soldering skills are improving, but I prefer not to touch what I don't have to.
And in regards to some of the conversation, I've looked inside the speakers and indeed, the only cap is on the tweeter. The mid-range is connected directly to the binding posts, and I'm pretty confident that the only component inside the subwoofer cabinet is the large inductor coil.
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Thanks again for all the conversation... All very useful. |
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Let me know if you want to buy Jupiter caps. I have different values than I would like to unload. |
"I suspect the Duelund by=pass caps might give the accutrons a bit too much resolution. They are not lacking in air and extension even with the Solens, and he could end up with a hyper detailed presentation would be my concern."
It works opposite.
I put Duelund Cu-Sn bypass (in my Altec 604E Werner Jagusch Crossover) bypassing old vintage oil capacitor.
As result a lot of music that sounded bad before started sound good.
After that I replaced old vintage oil capacitor to Duelund RS capacitor with the same bypass Duelund Cu-Sn capacitor. It gave me big improvement in transparency and musicality.
After that I exchanged Belden internal wire to Duelund 16AVG Cu-Sn wire. I can say this wire is magical.
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Hi Bill,
As usual you've made wise and very rational decisions, binding post for example. No good reason to change the Coincident binding posts. They're pure solid copper as opposed to the typical utilized brass posts
Charles . |
@charles1dad, I did not consider replacing the internal wiring. I have used Coincident wire externally, and found it to compare well with a few other options in the same price range, so I didn't think it would be an experiment with a high probability of success. I did use a few inches of Duelund Tin/Copper here and there where I needed to make things work, as there was nothing extra to work with. I also did not consider replacing the binding posts. I spent ~ 1200 on the project, and don't feel compelled to go any further. I am more than pleased with the speakers as they now stand, so at least in my case, going further might well be diminishing returns.
The op is starting with speakers that are several levels better than my super victorys in stock form. I think replacing the solen cap in the PRE is a no brainer, and would advise he start there and proceed slowly. I suspect the Duelund by=pass caps might give the accutrons a bit too much resolution. They are not lacking in air and extension even with the Solens, and he could end up with a hyper detailed presentation would be my concern.
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Agree with advice regarding the inductors, you can easily degrade the sound quality if not sure of specific specifications. Thread carefully.
Don't agree with advice to rewire as the internal Coincident wire is very good quality.
Brownsfan (Bill) nice approach for your tweeter capacitor. Some folks don't like to use bypass capacitors but happy this solution worked for you. I went Duelund CAST copper foil capacitors at the tweeter. 5 years later I remain very pleased with the improvement. Did you consider changing the internal wiring? I sure didn't.
Charles |
I agree with Erik you only change inductors if you have the correct
inductance reading or label on the inductor. The Jantzen Copper foil waxed paper inductors are a great buy and close to the best out there .wiring cap, for sure better Gold over Copper Connectors
vs the stock Gold over Brass ,4x the conductivity ,
And rewire it with a Quality Wire ,Supra awg 13 ,and 15
is a Huge upgrade then the Coincident Wire at less then $3 a ft Madisound. |
Good article on capacitor comparison and listening tests. http://www.humblehomemadehifi.com/Cap.htmlMy speaker manufacture uses extremely tight tolerances so as Erik mentioned above just the differences in tolerances can shift the cutoff frequency substantially. One of the reasons I chose the capacitor I did was tight 1% tolerance along with excellent sound for expense ratio. I am a Mundorf Supreme Silver Oil guy myself for preamps and Supreme in speakers. Paper in oil capacitors typically have 10 to 20% tolerances. So do pay attention to attempting to get a reasonably tight tolerance match of the capacitor you are replacing. I have had good experience with Sonic Craft as a seller, large inventory, good prices, fast shipping and they do capacitor matching for a minimal fee. Warning: Do not measure capacitance value when tweeter is still in circuit. To duplicate its value precisely, I measured the capacitance value before I ordered replacement. Since the capacitance meter puts a signal out to measure capacitance value it can fry you tweeters! Don’t be a dummy like me, remove the capacitor from the circuit. My mistake cost me a few hundred bucks; however, I was able to replace the ribbons later and now have a spare set of tweeters. I am good with my mistake now, but when I looked at my tweeters and saw those shredded tweeters I was kicking myself. |
Do not willy nilly change coils!
You have to match the DCR or you can make fundamental changes to the tone, and not in a good way.
For the woofer coil DCR sets the bass level, as well as helps with baffle step. Meaning, you must measure the DCR and only replace with equivalents (within reasonable tolerances).
In parallel to the driver, changing DCR without adding R can really muck with the impedance curve and have unintended consequences.
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I wonder how the PRE would sound with some paper in oil caps? It only uses two so it wouldn’t be that hard of a mod? |
@cal3713 Another vote for the Jupiter Coppers in your application as a cap to be placed in series with the Accutron tweeter. I used the Jupiter in my Coincident Super Victory II for that application with a Duelund Silver by-pass, and could not be happier. In the end, all we can do is guess. The good news here is that it is not hard to improve on the Solens, but no one can tell you for sure what the "best" cap for your application is going to be. Just be aware that the Jupiters are painfully slow on break in. They oscillate between really good to really bad for at least 120 hours, maybe 200, and apparently it is common for them to require 400 hours to completely stabilize.
@audioman58 I am also perplexed by the crossover design in the PREs. I don't know what one might find in the woofer cabinet, but since the preferred wiring arrangement is a direct connection from the monitors to the amps, with a second set of cables running to the woofers, and since the monitor enclosure contains only one crossover in series with the tweeter, I must surmise that the midrange is being run full range. It would seem that the midrange is truly crossoverless, with no inductor or capacitor in series or even in parallel. When I rebuilt the crossovers on my Coincident Super Victory IIs, I chose to stick with the stock Solen 12 and 14 gauge inductors. I don't regret the decision, but of course it may have been possible to improve upon them. I think the big bang for the buck here is going to be in swapping out the tweeter cap. The PREs are already superb, in my humble opinion, speakers. It may not take anything more to get cal3713 where he wants to be.
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In my extensive use of capacitors in components meaning DAC, preamp and power amplifiers, but not in speakers, I find the best capacitors are V-Caps (Oil & Copper versions). I find that the Jupiter copper caps have an emphasis in the mid-range. They have a very musical sound but the mids standout at the expense of the other frequency ranges. Just more focus in the mid-range. One of the manufacturer of panel speakers that I partner with also used the Jupiter caps and when I told them to try the V-Caps, they were surprised how much the sound staged opened up with greater detail and separation of vocals and instruments. Another Audiogoner had Jupiter in his preamp and he herd the V-Caps in the components that I build where we swapped out the caps. He heard the differences and decided to try the V-Cap coppers in his preamp versus the Jupiter capacitors, he also noticed the same advantage. BUT it comes down to the sound you prefer and you also may have to try both to see the benefits in your own system. Happy Listening. |
Cal3713
for sure change the binding post which are Brass to a Furutecor WBT next gen Gold over Copper ,and put in a Quality Wire the tweeter and mid are connected to. The inductor to create
the Xover ,and you can put in a much better inductor
to a awg 12 Jantzen inductor far better especially for the Bass
i would think there is another inductor there somewhere as well as resistors, pull out the midrange and woofer you will see other things hiding in there. I have found that to be true case up grade
the resistors Path Audio, the best if parts connecxion has them in stock, Ohmite Gold, Mundorf Supreme, or Mills
resistor ohms rating on the resistor. It’s up to you.
best of luck and use a good soldering station recommend at least
80 watts and Cardas,WBT, Johnson’s, or Mundorf Silver Gold
minimum of 5-5% silver solder content Cardas has. Flux built in
which helps a lot to clear and bond surfaces. |
@audioman58 And fortunately there's nothing else really to change. The PREs only have that one 4.7uF capacitor on the tweeter. The midrange is directly wired to the binding posts and the the bass just has a single inductor coil. |
Thanks for the recommendations everyone.
@justanotherhifiguy Isreal states that they use Mundorf in current models of the PRE, but my pair (I purchased used) just have Solens. The frankenstein amps also have solens throughout... although to be honest I tried replacing with Duelund and didn't like the result.
@erik_squires Lots to think about in there... I'm very torn. |
Here is my thinking:
4.7uF :
Clarity CMR : $54
Jupiter CF: $265
0.1uF:
Jupiter CF: $63
Audyn : $20 (Parts Express)
So somewhere in there I think the OP can find a fine solution. :)
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i think isreal uses his top of the line statement cabling inside throughout for his PRE i dont think youd need to upgrade the wiring inside. dont know about the caps.
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Geta2ay from plastics like a Mundorf s ownedtheir Best Silver Gold oil supremes several times . TheJupiter Copper foil
muc more natural and meaty once you give them 300 hours,
and a Duelund. Silver foil ,oil.01 Bypass cap really opens the top up . Solen is junk, depending on budget .
go to humblehomemadehifi capacitor test. A solid A recommendation I usethem myself in my speakers .whileyou are
at it rebuild the whole Xover austral bloom uses Nothing
remotelyhigh quality .i owned several amps speakersall economy
parts .I modded them myself , a Huge difference , and for suerewire them , I just used VH Audio New AWG 21 for the tweeter, awg15 forthe other drivers a Litz ssmall diameter
OCC - 0 crystalCopper verythinned foamed Teflon dielectric
fantastic wire . He sells a awg 12 and awg 11 forLoudspeaker cables, and use Copper get rid of the junk brass ,on the terminals
not natural stall I changed every connection throughout to copper
at lesst a 10% improvement . I used the exsctwiring for my amp-preamp, Loudspeakers also. The whole system .time consuming and maybe $1500 in wire but the results are substantial. |
Another vote for Jupiter. |
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Have you thought about using paper in oil caps? |
@cal3713
Right. You could probably even go lower, but hard to find a film cap any less. :)
Of course, higher voltage = higher cost, so watch out!
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Thanks Erik. Also, just to be doubly sure. I don't need to worry about voltage rating as long as I meet or exceed the original value (100V), right? |
Hey cal,
Mundorf Supreme has a particular house sound. Scintillating to over-saturated color. Magico uses them extensively, as does the top end B&W.
Otherwise, if you want something more natural and open, Clarity CMR to Jupiter Copper foil is the range I normally recommend.
Try the Clarity CMR with a small (0.1) Audyn TruCopper or Jupiter copper film as a really great low cost compromise.
The best way to find caps right now at Parts Connexion is to type the value into the search window:
4.7uF
and you'll find everything they have.
Best,
E
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