Do Mills resistors REALLY sound different?

[dbe]

Re: Do Mills resistors REALLY sound different?

Which of the links in the search is the one you are refering to?

*****

I just did a basic search in reply to DDF. Reread the reply to him. I read the article a long time ago. I have better things to do than read all of the unrelated references in my search.

*****
Johnson noise in an 8 ohm resistor, at room temp, over a 20kHz bandwidth (unweighted) is 52nV rms. This is 155dB down from 2.83V rms.

*****
Wiki is a great resource, isn't it?

At what input level? I misused the term Johnson noise to include shot noise. Since the two are interrelated I used the term when referring to transients. I should have used shot noise which is exclusive of the Johnson noise and is comprised of current noise. My bad: a brain fart.

*****

Is it possible that this is audible; maybe with bionic hearing?

*****

I'll have to ask my friend, Patti, with the implant. Perhaps she can tell me.

Dave

[Pete Schumacher]

Re: Do Mills resistors REALLY sound different?

Which of the links in the search is the one you are refering to?

Johnson noise in an 8 ohm resistor, at room temp, over a 20kHz bandwidth (unweighted) is 52nV rms. This is 155dB down from 2.83V rms. Is it possible that this is audible; maybe with bionic hearing?

Louis

Bingo!

[Ludo]

Re: Do Mills resistors REALLY sound different?

That didn't take long. Go from here:

http://www.google.com/search?hl=en&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=resistor+noise+in+strain+gauges&spell=1

Dave

Which of the links in the search is the one you are refering to?

Johnson noise in an 8 ohm resistor, at room temp, over a 20kHz bandwidth (unweighted) is 52nV rms. This is 155dB down from 2.83V rms. Is it possible that this is audible; maybe with bionic hearing?

Louis

[dbe]

Re: Do Mills resistors REALLY sound different?

I ran across a paper on Johnson noise in resistors with regards to strain gauge accuracy. I can't remember where. I though it was interesting in that strain gauges are usually associated with very low currents and voltages and was somewhat surprised that resistor noise was such a problem. I'll see if I can find a reference.

Dave

That didn't take long. Go from here:

http://www.google.com/search?hl=en&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=resistor+noise+in+strain+gauges&spell=1

Dave

[dbe]

Re: Do Mills resistors REALLY sound different?

Does anyone have measurements, or links, showing instantaeous temp rise in resistors?

The AES contained many a good article on short term temp rises in voice coils. The pro sound and rigourously objective scientists in their employ felt it to be a large enough issue to publish. I see no reason why resistors wouldn't suffer the same, objectively, especially when they can be consuming watts of power, all wasted as heat (as opposed to loudspeakers where only 99% is heat

These are instantaneous temp rises and not reflected in a noticed temp rise on the surface.

I ran across a paper on Johnson noise in resistors with regards to strain gauge accuracy. I can't remember where. I though it was interesting in that strain gauges are usually associated with very low currents and voltages and was somewhat surprised that resistor noise was such a problem. I'll see if I can find a reference.

Dave

[dbe]

Re: Do Mills resistors REALLY sound different?

You forgot one: http://www.duelundaudio.com/Resistors.asp

Uhm, those are a stretch, even for me ;) I am, after all, on a budget, too.

Dave

[DDF]

Re: Do Mills resistors REALLY sound different?

Does anyone have measurements, or links, showing instantaeous temp rise in resistors?

The AES contained many a good article on short term temp rises in voice coils. The pro sound and rigourously objective scientists in their employ felt it to be a large enough issue to publish. I see no reason why resistors wouldn't suffer the same, objectively, especially when they can be consuming watts of power, all wasted as heat (as opposed to loudspeakers where only 99% is heat

These are instantaneous temp rises and not reflected in a noticed temp rise on the surface.

[DDF]

Re: Do Mills resistors REALLY sound different?

MLSSA supports a curve fitting algorithm, where measured components can be tested for correlation against ideal componts. Works for resistors, capacitors, inductors, by measuring impedance across all frequencies, then regressing to a curve fit.

Its great for finding wonky caps that otherwise measure fine on a cap bridge, and for inductors than have parasitics.

It's a great tool, it helped find an issue with my Bryston amp and the speaker wire i was using, which led to a change in the amps the output inductor. It was also invaluable to show exacrtly how different speaker cables measure differently, into real loads, with real amplifers.

Using MLSSA, I've never found any issue with resistors, but I'm runing a 8 ohm 50 watt Dale RH through tonight, after the report that they're inductive. I'll let everyone know what I find.

Cheers,
Dave 3

[Face]

Re: Do Mills resistors REALLY sound different?

You forgot one: http://www.duelundaudio.com/Resistors.asp

[dbe]

Re: Do Mills resistors REALLY sound different?

IYO, this would be due to:
A) Paralleling the replacement resistors
B) The increased power capabilities of the resistors
C) A different type of resistor? (WW vs. thick film, for example)
D) ???

*****
Yes to A&B - Instantaneous transients (micro to milliseconds: hence the burst of noise) through high power compression drivers are often in the thousands of watts while operating at sustained levels of 50 to 100 watts.

NO to C - they were all Culver ceramic boats. The company that I was doing the repair for had a huge stock of Culvers - crappy resistors, BTW

D - not so much - it's just physics

*****

That leaves a lot of territory. Can you be more specific as to which precision WW’s you found useful. I’m assuming you aren’t suggesting all 10W 1% wirewounds are equal.

*****

No, I'm not. I find the Mills, Ohmite, North Creek, and Huntington Electric wirewounds to be my choices. Pretty much I stay away from bulk metals in loudspeaker applications.

*****

Dave, I’m honestly not being critical here. While your anecdotal observations are interesting, they need a bit more data to be of any useful import.

*****

I appreciate that. I wanted more info, too. It didn't exist. Fortunately for me it started a whole bunch of "why and how" experimentation and research on my part. Check out my reply to Dave Ellis above. It is a good place to start.

Also, keep in mind that if the system being tweaked is a $100.00 DVD player used to play CDs through a low end consumer audio receiver, money is better spent on beer.

When all else fails when it comes to listening to music critically, trust your ears. What do you wish to satisfy, your brain or a screen display? Nobody, barring those with cochlear implants (they are very good at hearing incremental changes, BTW), listen to music with a measurement mic.

Dave, the audio sleuth

[dbe]

Re: Do Mills resistors REALLY sound different?

This is a good comment - I agree. I was worried when I first used the Mills MRA-5 resitors because they were very small and I was concerned they would get hot. They don't. They run very cool.

Another Dave,

Here are a few references for you:

http://www.prpinc.com/pdf/Audio_PR9372_Series.pdf

http://www.planetanalog.com/features/multimedia/showArticle.jhtml?articleID=177105460

http://www.ohmite.com/cgi-bin/showpage.cgi?product=audiogold

http://www.vishay.com/docs/49414/vse-an00.pdf

http://www.charcroft.com/site/pdf/data/Charcroft%20SCARAudio%20Resistor.pdf

http://www.millsresistor.com/pdf/pg16prn.pdf

http://www.sasaudiolabs.com/resistor.htm

http://www.freepatentsonline.com/6317024.html

and the resulting resistor

http://www.hificollective.co.uk/pdf/takamn_pdf.pdf

Let me know if you need more references. I'm sure the "Superiors" will dismiss all of this as "marketing hype".

:D

Dave, too

[curt_c]

Re: Do Mills resistors REALLY sound different?

I had just been through a road situation where I had changed the attenuating resistors on a JBL compression driver in a sound reinforcement system. I had to parallel some 50W resistors to replace a 25W that had cooked. The resulting combination sounded cleaner that the original. I then duplicated the change for the other side with the same results.

IYO, this would be due to:
A) Paralleling the replacement resistors
B) The increased power capabilities of the resistors
C) A different type of resistor? (WW vs. thick film, for example)
D) ???

It was the combined experience of these two unrelated circumstances that made me stop and try every resistor that I could find for the best sonics. My experience is that 10W (or better) 1% precision wirewounds sound the best to me. Of course I must be delusional, but it is a delusion that many people share and we are very happy in our bliss.

That leaves a lot of territory. Can you be more specific as to which precision WW’s you found useful. I’m assuming you aren’t suggesting all 10W 1% wirewounds are equal.

Dave, I’m honestly not being critical here. While your anecdotal observations are interesting, they need a bit more data to be of any useful import.

C

[dbe]

Re: Do Mills resistors REALLY sound different?

After all these years you still make me chuckle. ;)

Bro',

My pleasure :D

Dave

[dbe]

Re: Do Mills resistors REALLY sound different?

From the other perspective, and getting back to the original post, differences in resistor types from a construction standpoint increase the likelihood that a perceived difference is a possibility. But could any difference in sound lead you to readjust crossover part values due to a change in neutrality?

Anyway, it is good to see some old familiar names around here and I hope everybody is doing well.

Roman, Life is good. Thanks for the wishes.

Different resistors do sound different. Nowhere is this more evident in audio nowdays than in the musical instrument amplifier realm. You could go onto any of the discussion forums and see the comments about resistor sounds, particularly in reference to the old carbon comp resistors compared to carbon film or metal film. Resistor noise is something that we seem to have forgotten about. It was accepted as the norm, yes even in EE classes: carbon comps hiss. This is due, primarily, to their TCR and granular construction. They also drift over time. As such they are not the finite critters that some people would lead others to believe.

If my memory serves me I have never had to change the value of a crossover component due to a resistor change. Like I said in another post: we're not talking huge differences. These are incremental differences that may or may not serve every system.

The moment of truth for me was years ago when I was working with a vifa D25AG-35 tweeter. The rest of the system was comprised of a Krell amp, a passive volume control and a very good vinyl front end. I was in the final level setting of the speakers and was rummaging around in my junk box to get matching resistor values and found a ceramic boat for one side and a Dale wirewound for the other. When I played the system, the side with the ceramic sound a little bit harsher. I asked my wife to come in and listen to the system to get her opinion. She listened for a little while and said that it didn't sound balanced in the highs. I swapped the resistors and the imbalance followed the components. I called her back in and she said it sounded different, but still not right.

I had just been through a road situation where I had changed the attenuating resistors on a JBL compression driver in a sound reinforcement system. I had to parallel some 50W resistors to replace a 25W that had cooked. The resulting combination sounded cleaner that the original. I then duplicated the change for the other side with the same results.

It was the combined experience of these two unrelated circumstances that made me stop and try every resistor that I could find for the best sonics. My experience is that 10W (or better) 1% precision wirewounds sound the best to me. Of course I must be delusional, but it is a delusion that many people share and we are very happy in our bliss.

I lurk here occasionally between projects and when someone asks a question that looks like they might actually want to TRY something and wants an opinion based on experience I'll chime in. My experience is simply that and opinions are like... well, you know. Besides, I do enjoy stirring up the "superior twins". I enjoy listening to crickets.

Good to talk to you.



Dave

[davidellis]

Re: Do Mills resistors REALLY sound different?

Daryl,

I have measured all of the resistors I have on hand out to my systems 100khz limit and all of them exhibit a flat impedance vs. frequency so non-inductive is not a feature so far as I've measured.

Hmmm, I have experienced different results from 20hz to 20khz with at least 1 resistor.

About 8 years ago I managed to measure a few different resistors using LspLab before the setup imploded. For a brief period of time it produced very good results. The setup was arranged to calibrate using a specific value of resistor and then measure other components (including loudspeaker impedance) using the calibration resistor as a baseline. I had a few scattered resistors availalbe. I had Mills (MRA-12), North Creek, Eagle, and the square Sand-Cast "flavor".

Using the Mills resistor as the calibration resistor, I actually did find a rising impedance curve present in the square Madisound Sand-Cast resistors when measuring from 20hz to 20khz. I don't recall the specific value of measured inductance, but it was small. I suppose the impedance of the Sand-Cast resistor went from 8ohms (nominal & stated) to perhaps 9.5ohms at 20khz.

I cannot recreate these graphs or the test using my current software setup. As mentioned above, LspLab imploded several months later. Nonetheless, the test seemed reliable at the time. I would also like to note that at this time the Sand-Cast resistors were NOT non-inductive resistor or sold as such. Madisound sold two flavors of cheap resistors - Eagle and Sand-Cast. The eagle resistors were clearly marketed as non-inductive and their price was higher because of this. Perhaps the current genre of Sand-Cast resistors are different? I recall trying to re-create this test a few years later using a "non - inductive" version of the square sand-cast resistor, but was unsuccessful. I couldn't generate the rising impedance. It could be that the internal design of the new square sand-cast resistors has changed.

The temperature coefficient of your crossover resistors is meaningless.

This is a good comment - I agree. I was worried when I first used the Mills MRA-5 resitors because they were very small and I was concerned they would get hot. They don't. They run very cool.

Hi, Dave. I hope your elbow is doing better. Sucks to have your sanding arm incapacitated.

My arm is back to about 60%. With a shot of cortisone and no exercise/strain on the elbow the pain is very minimal – only a few twangs per week. Unfortunately, after my elbow got better, I was carrying a heavy garbage can full of Oak trimmings (straight arms) and sprained my right knee. It wasn’t getting better, so I visited the doc. They prescribed vitamin “M” and Physical Therapy (PT). The PT caused fairly significant internal swelling in my right knee and I have been limping for the last month. I can’t fully extent my right leg. I have an MRI on Wednesday and a follow-up with Orthopedics on the 11th. Dave, I am getting old. I have to start treating my body very differently.

Another Dave