Top resistors

justubes2 or salectric, do you have any more progress to report on the Path Audio resistors. I presently have Kiwames mixed with Duelunds in the tweeter section. The top end is quite lively (bright) and using all Duelunds was too bright. Mixing Kiwames tamed things down but I would like to get better resolution but without the brightness.  Did you find the Paths mixed well will Duelunds? Also, do the Paths affect the rhythm. Any further input on the Paths will be appreciated.

@erik_squires

I think you must be referring to this type of fuse

http://www.mouser.com/ProductDetail/Littelfuse/0251002MXL/?qs=sGAEpiMZZMsNIlwy3aAdUVxIQvxhy%252bighe...

which is a fuse not a resistor, although to a layman it might look like it. That being said I find your posts enlightened and offering good advise.

I believe that this thread was questioning why one speaker manufacturer use resistors as fuses, which I consider sub par engineering at best and further evident as some report that these change value over time - which of course they will as they heat up - cool down.

Depending on their insertion in a crossover I use different resistor types, if in a zobel network for impedance correction of a woofer or midrange generally I use 25W cement resistors and almost always several in parallel as to get the power handling up where it needs to be. For attenuation of a tweeter, which I generally try to avoid, I’d use either the Caddock MP9100 which I heatsink or several 5W MOX resistors in parallel again to get the power handling up.

I agree Mills non inductance resistors are nice too and use them on occasion too.

http://pbnaudio.com/speakers/speaker-kits/scanspeak-b741

Above is a link to a kit I designed for ScanSpeak a few years back - this will give a good indication on how I propose the use of resistors in a X/O network.


Good Listening


Peter

@pbnaudio

Fusible and flame-proof resistors are quite common in the electronics industry but usually in an amplifier, not a crossover. :) The idea of the former is just like you would expect. When power is exceeded they are guaranteed to open, instead of potentially shorting or catching on fire, and save the rest of the device from a complete meltdown.

Duelund's are really weird. One of their selling points is that they have a high sensitivity to heat and power so will change values rapidly. The very last thing I want in a power resistor! :)

For speakers I stick with Mills. VERY thermally stable, very quite, very tight specs, and really small for the wattages. Also reasonably priced, all things considered.

I do want to someday work for a speaker company that will let me build with some caddock resistors and heat sink them, but so far I haven't the time / energy / funds to experiment with them.

I’m sure everyone would agree that assessing sonic characteristics of parts in a complex audio system is extremely challenging due to component interactions, but here’s my experience.

Shinkohs and Riken Ohms are nice, but just too colored, in a nice way, to use more than just a few. Have tried the old Holcos, but despite added clarity, they were a little thin sounding in the system I had back then. The Dales are natural sounding as are the old Resistas, but neither of these are as transparent as the naked Vishays.

I think the resistor of choice is the TX2575. There may be some ultimate limits even on these. After swapping in almost 80 of these in the signal path of my 2 hybrid tube amps, 60 in the crossovers, and 70 in the phono stage, I had to put 2 Resistas back in to restore a little more midbass/lower mid-range warmth (the Dales would have worked equally well). That’s all it took. Sadly, I did lose just a touch of transparency.

There are always some tradeoffs. Everyone has there own preferences. It’s really amazing (maddening?) how much changing only a couple of parts can dramatically change the sound of a decent audio system. I’m hoping to be done with all this soon!

I personally don't know the difference between old and new, my experience is recent within the past 3 years.  Also Caddock makes a very nice sounding resistor so for the prices of resistors, but several and try them for your self.  I mostly buy from Parts Connexion.  Happy Listening.

Halo All,

I am planning to buy the shinkoh resistor for my SS power amp. I have never use Shikoh before and some people mention old and new shinkoh are different.

PCX carries the shinkoh, are they the same or different one?


Thanks

Bigkidz,
Thank you for the update on Shinko resistors. I see Shinkoh Tantalum Resistors offered at Hifi collective. Are they the same as your Shinko resistors -Regards Jet

I have tried many resistors in the preamp that I build. I do like the Vishay but also the Shinko. It also comes down to the placement in the signal path. I prefer the SHinko sound because it has what I would describe as a more real sound. The Vishay is close, it has a more open sound. To describe the difference, when I listen to female vocals and the person whispers, the air coming out of the lungs and out of the mouth sound very real with the Shinko and not the same with the Vishay. You won't know the difference unless you compare them. In my preamp I can dial in 6 different pairs of resistors on the fly so I can hear the differences immediately.

Dgarretson, yes the Duelund would likely be a very good match for the esotar.

With a metal dome it can be a little distracting, very defined detailed. The other resistors are very detailed and do not obscure detail, similar to when you use silver wiring (which the leads of the duelund are.

The Mundorfs surprisingly sound very close to the Duelunds and the Paths sounding a little more laidback and softer detais(you look into the details as opposed as the details coming at you which i do find it more more relaxed sounding..

"The sound of the duelund cast were had very spotlight detailed, too much of a good thing, internet streaming showed certain tracks distortion very clearly."

I haven't tried Mundorf or Path, but Duelund R took my Merlin VSM Esotar tweeter to a level of clarity and refinement that has ended the search for resistors for crossovers. Definitely not too much of a good thing. No interest here in obscuring detail from any source.

Some developments, now came the mundorf m-resist resitor as a temporary fix till my 1 pathaudio replacement. I dont know what happened to the my pathaudio resistor which value went from 6.8ohm to 47k. It did not break but value went up so high i thought the tweeter had problems.

The sound of the duelund cast were had very spotlight detailed, too much of a good thing, internet streaming showed certain tracks distortion very clearly.

I could only try the Mundorf available the nest day, now:

M-Resist, 1 went in the right speaker first, banished the duelunds with great relief! This was much more balanced with very good detail and has a tiny hint of sharpness as compared to the Pathaudio.

This may not be sharpness, but because the Path's are darker sounding (or more neutral), not as highlighted yet detailed. The Paths were more relaxed and smooth, allowing a higher listening volume without fatique. I believe that the slight hint of brightness associated with the steel legs on the mundorf's which i feel is the minus point in the design.

Overall, these mundorfs are the best balanced out of the 3 brands tested though i will revisit the Paths after the new replacement has been burnt in on my cooker.

Update on Pathaudio and Duelund resistors.

Somehow, i blew 1 of the Path resistors and dug out my old Duelunds to replace 1 side for the tweeter network.

Same values.... now boy it was that different.

The Duelund are louder at the same volume, very clear and bright...totally unlistenable. I added another 10% increase in value Duelund i had laying around in series.

Ok, not as loud still very prominent highs. This resistor brings detail very upfront with super clarity, but uitimalely lacks the balance and depth of the Path's.

The duelunds do revealmore detail, artifact of a very upfront sound? I think they need a copper wire instead of silver leads and vice versa for the Paths stranded copper leads.

Overall

Yes, every part contributes to the sound.

In a resolving enough setup,even footers can greatly affect the sound. Every bit of wire, type of solder used etc.

I once had a bad fuse holder replaced with a different part, i noticed a difference in sound.

Each product manufacturer has a house sound, tuned based on cost of parts to achieve what the designer references presentation of music.

In the past few years, a number of very exotic equipment manufacturers now used these audiophile components, meaning -expensive parts in their design with different grades and market it accordingly. To a non tech savvy customer, at a much steeper price markup as opposed to what these parts costs, especially considering their oem costs.

Just stick to what is recommended by users based on their sonic finding and try. The more exotic parts usually always work rather well as opposed to mid tier audiophile components, which are many out there. These are a bigger effort to get them sound right in most ways than their tried popular and costlier counterparts.

" The duelund resistors do impart a "live venue" sound "

Having not followed this thread, I'm wondering if you are saying these particular or certain kinds of resistors in general will always have the certain sound signature?

Seems to me results would vary case by case design by design and I would have no clue how to pick a resistor based on how it sounds. Based on clearly specified tolerances, build/part quality, etc., but it just seems to me too much concern about the "sound" of a resistor would be a wild goose chase for most folks. Maybe not for actual product designers who have to make such choices.

Still enjoying music with the new resistors in place.

Another point, the Duelund cast resistors now seemed coloured and gives a distinct sonic flavour or same enhanced "live music atmosphere" over more songs than the pathaudio resistors. I do miss abit of the colour!

Paths are so much more neutral in this regard. By no means does the path's sound cold, thin or lean. It just sounds more linear and neutral.

For any system towards the darker side, the duelund cast resistors should work also, but cost more than the paths, so it's a hard choice. The duelund resistors do impart a "live venue" sound which is also kind of nice, maybe in a more damped or dead room will help bring the required liveliness or airiness.

I did not connect the shield, cannot imagine any improvement as the other signal path is not shielded. Could it lead to quieter/dull sound?

I feel the level of boutique parts have reached a level which one could well be happy with either of these parts with some good matching with other parts. I do have casts in the tweeter and bypass the mids in the crossover, they don't do harm but i never felt they were exception (very good as it is) comparing to teflon vcaps / jupiter copperfoil - they are all top notch. i actually felt the vcap TFTF gave more air than the duelund cast while never sounding bright, just very extended though a touch more neutral than duelunds.

The highs pricing of some of these parts , however good, just cannot maintain a decent cost/performance ratio with the competition available.

The cast caps are good in the output stage of my preamp, nothing magical. just neutral with no misgivings. I feel the Vcap TFTF and CUTF can give more noticeable difference (super linear for the TFTF and saturated tonal colour for the CUTF) which can work even better in a system correctly matched.

I have a jupiter in the output of my phono, nice and have lost the desire to find the best. Maybe sometime when i have time to listen to LP's will i swap the duelunds in - that when i have/tryout a passive preamp. The sound of the cap can be compensated elsewhere that i am lost at the number of permutations in tweaking possible. So long as the cap is of a certain level, it works for me, or should i put it as i will make it work for me.

I now focus attention to the PSU which brings about dramatic changes. Gone are the days of just swapping in "better" electrolytic caps. I now focus more on changing transformers, low noise regs etc. in the PSU circuit which i find makes more difference on a cost/improvement, but still learning in this area.

Great report Justubes2! I am glad the PathAudio resistors have worked well for you. Your description of the Duelund resistors as having "a larger unfocussed and slightly messy soundstage" is, I believe, the same thing I was trying to describe as "wispy" highs that seem to float around in space; the soundstage with the Duelund resistors is big and airy but not focused.

Have you connected the ground shield lead on the PathAudios? If so, to what? I am still using mine without the shield connected.

I want to emphasize that my misgivings about the Duelund resistors (both CAST and regular variety) do not apply in any way to the CAST capacitors. I continue to feel that the CAST caps are the single best sounding capacitor for speaker crossovers. Expensive but well worth the investment. I am not quite as enthusiastic about CAST caps in electronics. In that application I think system matching is more of an issue, and I prefer a balance of CAST and V-Caps. Right now I use a CAST cap in only one place in my electronics---the output coupler on my phono stage. All of my other couplers are either CuTF or regular V-Caps.

After a backbreaking afternoon, the paths have been installed in series the mid and tweeter.

I was broken in on the frybaby for a week and a couple of hours on a bedroom set.

I not sure if the were even close to brokem in nut has a bit strange highs which quicky vanished after half an hour.

These are good and won't hesistate to choose them on the pencil lead resistors. Duelund have good detail and did mostly good with the exception of harshness in the uppermid(midrange driver) and tweeter on 20% of recording which caused some hurt to my hearing.

All these are now banished, thanks to Salectric ;) i had always felt from changing caps etc. the duelund cast gave to the sound i would not expect more.

Details, bass, mids, highs of the path are spot on, no touch of brightness, no shortcoming that i can tell. I feel the biggest difference is the control of the individual sound and sure footedness in the music now, more balanced over the frequencies.

The cast remind me of the mundorf sio capacitors sound, beautiful but with a larger unfocussed and slightly messy soundstage. Swapping the the path resistors were akin to moving up from the mundorf sio cap to something like the duelund cast / Vcap teflon capacitors.

I initially had reservations on how the cast resistors could be bettered, and hesistant to swap in the paths as i had already bought them. I do not need to swap the duelunds back in now!

I guess they can only get better with more run in.

Yes, my resistors are all in the high-pass section of my 2-way crossover. And I am using a mix of Mills wirewound (black body) and PathAudio. I am not using any Duelund resistors these days.

As for why I have a mix rather than all PathAudio, my speakers need some emphasis in the extreme highs, and the Mills provide a sparkle or shimmer that the more neutral PathAudio does not. It is not a case of one being better than the other. You have to mix-and-match to get the particular sound that you were seeking.

Thanks Salectric,

I have just got my resistors in, 1 for the mid and 1 for the highs.

Just deciding if i should do 1 at a time or dive in with both.

The resistors you have are all in the high network? Just curious why you still have a mix of duelunds and mills.

Did you find a mix better than all pathaudios?

I have PathAudio resistors in 2 spots which are 5 and 10 ohms. Right now I am still using Mills in the other two positions. I plan to get some more PathAudios to try there as well.

You may want to break in the resistors before you put them in your speakers. I hook up new parts to the speakers in my video system first so I can run them 24/7 for a week or so without messing up the sound of the hifi.

SalectricOne more question.

did you use the same value.

I am getting some tinnitus form the highs currently s i did not mention as i like rock on a louder volume :)

I am asking as i feel that there may be seem to be a boost in the highs, could it be the bright and thinny highs.

I shall post my impressions, sadly they have a lead time as non stocked of a couple of weeks, darn!

Great,

looks like i should just ditch the duelunds.

I have always had the problem as you described thin airy and bright (adds details).

I never got a tighter solid center vocal imaging, it always sounds larger than life with the cast resistors, goes with the airy wider soundstage.

i was just thinking of changing the resistor to the midrange as i felt is has a upper midrange brightness that was a bit painful on brighter recordings.

I do however, like the overall presentation so far, guess from you description, it is worth a try (just hope its not too much of a direction change to the sound). FWIW, i am using a cast cap for the tweeter as well.

It's just quite startling just 1 resistor can contribute to the sound.

To my ears, the neutrality of the PathAudio does not make it any less exciting than the Duelund CAST. When I listen with the PathAudio, words like "direct, clear, solid" come to mind. With the CAST, I am thinking "airy, bright, thin." Individual priorities come into play here, but for me the sound with the PathAudio resistors is more satisfying and less distracting than with the CAST.

I do appreciate the work involved in replacing parts when they are inside the speaker cabinet. I moved my crossover outboard for just that reason.

Salectric, Thanks for the detailed impressions, i did just come across your other posting on the path's.

I have only tried the duelunds, both cast and non cast. Your impressions do mirror mine, although no comparing with other resistors. Having swapped the standard resistors, the detail and clarity was an overwhelming improvement.

As the lightness in the midbass, i too feel the duelunds was slightly glossed over and oversmooth, while nice, loss some weight and heft.

The high's, your definition of wispyness. I would describe a Qsound kins of effect, allowing a wide stage and sound floating midway between the speaker and listener. Its forward tendencies means the sound are not at the speaker or behind it, lessening the impression of any depth. Its like a 3d fanfare between the speaker and listener, quite pleasing i might add.

Sadly, yes the slight brightness add to the dynamics of the whole frequency range, including the bass. It this an artificial artifact of dynamics, sometime i feel its can become slightly bright and piercing.

The duelunds for sure never sound dark, alway accentuating the clarity and detail.

I will try the paths for the mids.

I do like the clarity in the highs using the duelunds, do the paths neutrality make things less exciting or more distant, i.e say cymbal stay at the plane of the tweeter and not project further out like the duelunds giving a front row seats impression. Is it more midhall presentation for the paths? Something like the presentation of a mundorf supreme cap (neutral and more distant) vs the silver oil cap(more direct and upfront with added brightness of the silver)?

Still on the fence to try the paths on the tweeters. Just too much work!

Justubes2, I am happy to provide more details regarding the Duelund CAST vs. PathAudio resistors. First let me provide some context. All of my testing has been with my DIY speakers (described on my system page) in the high-pass portion of a 1200 Hz crossover which has 4 resistors. I have tried five types of resistors: Mills 12w black body (the old Mills), Mills 12w brown body (new style), regular Duelund (brown body), Duelund CAST (black body), and PathAudio. By the way, some of my comments below relate to bass and one might question how anything in the high-pass crossover could affect the bass. All I can say is it does!

Tonal balance. The CAST resistors are slightly bright and more than slightly lean. To my ears, they are lacking in weight and foundation which gives them overall a "lightweight" sound. I think the mids may be slightly forward as well. In contrast, the PathAudio resistors are pretty much neutral as far as I'm concerned. They may be slightly dark and slightly warm. They certainly had these colorations in the first few days and even weeks, but they gradually disappeared. There may still be some trace of these colorations but if so it is quite minor.

Detail. Both the CAST and the PathAudio have excellent inner detail. I wouldn't choose one over the other in this respect.

Dynamics. Both have excellent dynamics although here I would give the nod to the PathAudio since the CAST is a bit restrained in the bass due to its lightweight tonal balance.

Transient speed. The PathAudio is faster on leading edges than the CAST which has a slight softening on sudden transients.

Overall, I would describe the CAST as having great detail and dynamics but a rather lightweight sound and wispy highs. By "wispy" I mean that the treble is airy and atmospheric, a "big" sound, but the treble is hard to pin down. It is as if the sound is in a fog floating around. I don't know if that description helps much, but it's something that I have heard consistently with the CAST resistors from day one. In contrast, the PathAudio has a solid, direct, clear sound, excellent detail and dynamics, a neutral total balance, and a neutral soundstage perspective. I have no doubt the PathAudio has faults since nothing is perfect, but I haven't identified any failings in my tests.

It might also help to provide some comments on the Mills 12w blackbody resistors, which I used routinely prior to the Duelunds. The Mills are not as detailed and not as dynamic as either the CAST or PathAudio, and they have a lean midbass and slightly crisp high frequencies with a slight edge. However, the Mills do have a solid, direct, clear sound, with none of the wispy quality of the CAST resistors. In some ways, the PathAudio has the positive qualities of the Mills resistors but with a more neutral total balance, more detail, more dynamics and no edge. (The newer Mills brown body resistors do not sound as good in my opinion.)

Of course, the above comments are simply my opinions based on my speakers and my listening priorities. There is nothing absolute here.

Salectric,

How do the PathAudio resistors sonics differ from the Duelund?

I find the Duelunds a bit bright on hasher recording, but sound sublime on well recorded.

I don't have external crossovers, so swapping is a bit of a PITA to try.

Specifically are they more neutral? (just worried they might sound detailed but too laid back or distant sounding.

Any more specifics on how is the mid bass and low bass, is it as reported above more solid and body in comparison.

I'm rather very happy with Duelunds now, except for the few recording which sound a tad sharper, could well be the silver end leads of the Duelund, but like the very lively and exceptionally clear sound.

Thanks

I need to supplement or correct my earlier post about PathAudio resistors. After a very lengthy breakin period (I wasn't keeping track but I have been using them for a couple of months), the PathAudios do sound really good. The issues I had with a recessed midrange and dark highs have faded away to insignificance. For my tastes they sound better than the Duelunds.

this is from Path Audio ,and I confirmed this from other dealers in Europe send from Path engineer below.
Yes, Duelund resistors are good. In my opinion and our customers, PathAudio resistors have some advantages:
- dynamics
- smoothness
- more „body”
- better micro details
- much better resolution in high frequencies
- much better bass when it’s parallel (with capacitor) to woofer
- neutral in midrange

If you have find it better in 5 hours… then there are a lot of new experiences to go :)
You hear probably also the new soldering now. I think 2 weeks from the begining will give you about 75% of the overall performance. The total smoothness will appear in about 1-2 months, depending on the intensity of playing hours.

I agree with you with the Cast resistors they are excellent. Email Hifi collective in the UK. 100 hrs min for runin and recommend using the ground to the Loudspeaker terminal as a RF screen.
The Path Audio resistors and Duelund resistors are both excellent
The both sound different in a given circuit. Duelund tolerance are 5% and
Path Audio a1% which will be a bit better in driver accuracy to a very
Small point.

Interesting Audioman, maybe I need to run in my PathAudio resistors some more. I was not so pleased with their sound compared to Duelund CAST resistors, but I doubt that I had anything close to 100 hours before I removed them. My main complaints about the PathAudio were a recessed distant perspective and subdued dynamics relative to the CAST. I will break them in further and try them again.

The CAST resistors are excellent in my opinion. The regular Duelunds, on the other hand, have some fairly serious colorations that make them only suitable for specific applications where the colorations are complementary. Regular Duelunds are excessively warm in the lower mids and are rolled off in the highs. But they do have very good detail and dynamics. The CAST resistors are much more neutral.

Hello I have experimented with Vishay,Caddock,
For Loudspeaker networks the Duelund was the best IMO at dissapating heat,and a Very neutral and natural presentation .
Recently I heard from friends across the pond in the U.K about the newest
Best resistor ,also incorporating a ground off the Copper chassis.
A company called Path Audio,hand made in Poland. They are a bit pricy
But the most natural resistors I have ever used.this includes others that have many years in the field. These resistors do take a solid 100 hours
Before fully settled in. Well worth the expense,$35 retail and at a 1% tolerance The best in the business for a Loudspeaker Xover.

I have bad experience with zl caps...sounds harsh -- horrible for me
I more prefer using TX2575 with better caps such as Elna cerafine or silmic or with blackgate

As for the TF020. The leads can be soldered out and replaced with some nice wire for a much improved sound.

Aa very nice balanced resistor, but felt the TX2575 to have a more incisive hifish character which can be too much of a good thing. I balanceda TX2575 with nichicon caps for my cdp output. It was perfectly balanced.

Now, with the TX2575 with rubycon zl, the sound became bright, hard and super etched. Here where the TF020 can sound nice with with the zl caps.

Thanks Rodman99999,
I haven't yet received the preamp, but as soon as I find what style of NOS Sylvania 6sn7 they use, I will be able to compare.

@ Sherod- The site wouldn't let me add this info: (http://www.ebay.com/sch/i.html?_trksid=p2055119.m570.l1313.TR0.TRC0.H0.Xsylvania+vt231+vt-231&_nkw=sylvania+vt231+vt-231&_sacat=0&_from=R40) or(http://www.ebay.com/sch/i.html?_odkw=sylvania+vt231+vt-231&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XKen-Rad++vt231+vt-231&_nkw=Ken-Rad++vt231+vt-231&_sacat=0)

@Sherod- If the NOS Sylvanias are the bottom-gettered, VT-231 type(from the 40's); they are already excellent tubes. Very natural and transparent, like the Tung-Sols. The biggest noticeable difference, would be in the sound stage depth. That would be highly dependent on how well the rest of your system performs. Regarding the price: everyone has different takes on what's important and valuations, regarding presentation. If the Sylvanias aren't the above mentioned, get a pair of those(or bottom-gettered Ken-Rad VT-231s) to compare with the ones supplied. They aren't as salty as the Tung-Sols and may satisfy any desire to further roll your tubes. Hope the OP doesn't mind us hijacking the thread!

I have a direct comparison of PRP resistors to Shinkoh Tantalums. This past weekend I replaced 8 PRP resistors (4 per channel)with Shinkoh Tants. Now my Audio Note Home brew M3 phono circuit has 6 tants per channel. 2 of those are Audio Note tants. As soon as I turned on the pre and started playing music there was an immediate and dramatic improvement in the quality of the sound. So much smoother and beautiful sounding. The increase in musicality was compelling. Of coarse the Tants are not even close to being broken in and I am noticing a bit of emphasis on the leading edge of instruments that may or may not go away. Now the circuit has a nice mix of Allen-Bradley, Tants and 2 PRP. I have the option of adding even more A-Bs if I want to totally get rid of the PRPs.

In my opinion if you are going to use PRP use very sparingly or use them to get your project up and running and plan to replace. Until this weekend, I had no idea what true potential the AN Phono pre and Rega TT was capable.

I realize this is a thread about resistors. I've ordered some PRP to try out in a vintage Marantz 2270 receiver on the preamp board I'm rebuilding to compare with the stock carbon resistors Marantz put in there. But I noticed in an earlier post by Rodman99999 raving about the sonic qualities of a vintage Tungsol CTL/6sn7GT tube. I am about to receive a preamp that uses two 6sn7( I believe the factory tubes are a NOS Sylvania 6sn7 type, but was curious how the Tungsol tube mentioned would sound like. I just did a check on Ebay and what few there are of this tube, the prices are ranging from $375.00/ pair to $675.00/pair. Are these NOS tubes really worth this much? Wow!

Yes it is strange that there is no reference to the MDN 0178 series on Caddock's website whatsoever, but it is clearly printed on the resistor itself. As far as replacement is concerned, I saw a new model on Caddock's website - the MPM 20 (with gold-plated leads). It looks like the best they have, but unfortunately it is not featured in any of the internet shops or Caddock dealers websites. Can you recommend where to buy them?

I do not see a Caddock MDN series of resistors listed anywhere so it would be hard to identify its wattage.

As far as using a resistor as a fuse, I've never heard of such thing and would consider it sub par engineering at best, probably not what one should expect form the folks at Wilson.

I would not worry too much about the fusing issue and just use the best resistor I could find, the Caddock MP9100 certainly being one of them.

Good Listening

Peter

Thanks a lot!
Actually the resistors are outside the crossover system, so it shouldn't change the crossover point. But they do act as a kind of fuse, whereby upon certain critical power load they will open saving the tweeter from injury. Thats why I was asking about its power handling capacity. I understand that if the power rating is too high, they won't do their job as fuses, right?

Look here Caddock

Depending on where in the crossover the resistor is inserted changing value is not recommended as the components values before the resistor are chosen seeing a certain load. Changing the resistor values will therefore change the filters transfer function i.e the crossover point of the tweeter.

However if the resistor is meant to be changed by the end user then on your question about power handling of the resistor in a tweeter crossover anything above 15-20W should work just fine, if you want to spend the $ go for the Caddock MP9100 they are available at Mouser MP9100 8 Ohm

Can Anyone help me identify the wattage of Caddock MDN0178 11.75ohm, 2% resistors used in the tweeter section of Wilson Audio Sophia 3?
I'd like to change it for an 8ohm resistor but don't know the required power capacity.

If you want a little warmth added to that transparency you could add a Riken Ohm in series, following the Vishay. Of course you would have to use different values to sum to the value you want.

I did something similar in my Hagerman step up. There are 2 resistors in the signal path. The first one I use the naked Vishay, but using that in both spots was just too revealing. Adding the Riken Ohm carbon to the second spot was (as the baby bear says) just right. I then used the leftover Vishay for cartridge loading, with another improvement.

As an update, I installed the naked Vishays and overall found them to be better in my preamp that the other resistors I used. Not a warm sounding resistor but open, detailed and good tone without any edge. Very good clarity. Lucky for me I can change them on the fly anytime I want. As already mentioned, mine are in a preamp and not tested in an amp or speakers, etc. I only require two resistors, one for each channel.

Bruce Hofer (founder of Audio Precision) did a recent AES Convention lecture on many topics pertaining to low-THD circuit design, including parts quality in both capacitors and resistors. He was kind enough make the PowerPoint slides available for download in his May newsletter, which can be found here: http://www.ap.com/kb/list/2

You do have to register to have access, but there's a wealth of tips available from one of the true modern masters of analog audio design.

05-26-13: Rodman99999
Testing capacitors for outer foil, has shown me how much influence a body can have regarding induced noise.

Exactly! And my suspicion is that if he were not holding the resistor in his fingers, he would not have had enough signal to make a meaningful measurement.

Note this statement in the page he links to about the corresponding measurement for capacitors (for which his methodology seems to me to make more sense):

How to do the test with Oscilloscope? Simple by testing both leads, and give some “interference” outside the capacitor (touch by hand or put some electric field interference e.g. high voltage cable, etc). The side with higher noise, means the outer foil.

Regarding

Why would the impedences of the probes, ground wire, etc not remain constant?

They would remain constant, of course, but the impedance of the path between his fingers and the probe's ground would depend on where he was grasping the resistor, and on which end of the resistor the ground clip was connected to. Likewise for the impedance of the path between his fingers and the probe's tip.

Visualize the situation taken to its extreme: He grasps the resistor at one end (without touching the lead). Regardless of the resistor's directionality or lack thereof, it would certainly seem expectable that he would see something different on the scope depending on whether the probe's ground or tip were connected to that end.

If the results were repeatable, and mostly constant, between resistors of the same value; I'd see no reason to doubt the conclusions he's made.

If the measurement were repeated for a number of resistors of the same type and value, and if he grasped each of them at approximately the same position, and if he kept his body located and positioned similarly throughout all of the measurements, I'd expect the results to be reasonably consistent. However, I don't see how those results would say anything about the directional characteristics of the resistor. They would just say something about the net result of the interplay of the five factors I listed in my previous post.

Regarding my previous post, btw, upon re-reading it I realized that the following sentence is flawed. Consider it to be deleted from the post:

That conclusion would be true even if he managed to grasp the resistor exactly at its mid-point, due to the differences in AC leakage to the probe's ground and its tip.

Regards,
-- Al

this direction matter has been debated in other forum, I read it and I tried it, so the result suprised me too..
as the link I provided he test the resistor in different method (with osciloscope and mine with ear).
so why don't you guys try it yourself and write down your opinion after...

cheers :)

Not having experimented with resistor directionality; I have no opinion regarding validity. However: I can't help but notice; in every picture the tester has his fingers on the body of the resistor and not touching either lead. no doubt; it would have been expedient, to have removed himself/his body from the test completely. Testing capacitors for outer foil, has shown me how much influence a body can have regarding induced noise. Why would the impedences of the probes, ground wire, etc not remain constant? According to the script; he was testing for voltage/mV differences. If the results were repeatable, and mostly constant, between resistors of the same value; I'd see no reason to doubt the conclusions he's made.