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Old 8th March 2010, 08:19 AM   #3861
PHEONIX is offline PHEONIX  Australia
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Quote:
Originally Posted by simon7000 View Post
John,

I am still measuring resistors and an interesting artifact has shown up in measuring the Vishay bulk metal film resistors. From my preliminary measurements I would characterize these as being a "Warm" sounding resistor.

Have you or any one else have experience with them?
Hello Simon

Does "warm" mean that they have a non neutral sound , and measured higher distortion.

Regards
Arthur

PS John Curl
Did you know DM68 Halcro amps that I have seen use Roderstein feedback resistors.
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Old 8th March 2010, 02:18 PM   #3862
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Originally Posted by john curl View Post
Simon, we will probably use naked Vishays for our project. I don't mind using original Roderstein resistors or Corning Grey resistors, either.
John,

I have managed samples of the naked Vishays, and the old stock Roderstein, where do I get 4 1K corning greys? I haven't seen any Corning's for 30 years.

A few more weeks and I hope to be finished with the tests.

Oh by the way, the resolution difference between a 100 ohm ten turn pot does show up between the classic wirewound and the gap filled hybrid!

So if any one else is reading this;

Have they used the Vishays and is there a warm sound to them?

Any other guesses as to what the most manufactured and widely copied sound equipment ever was?
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Old 8th March 2010, 03:31 PM   #3863
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For the record, I insisted on original Holco resistors for the Parasound HCA-2200 MK2, feedback resistors, back in 1992. All Vendetta Research products since 1984, or so, uses Roderstein resistors, as well as the CTC Blowtorch. The original Holco DID sound 'soft', that is why I chose it for the Parasound.
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Old 8th March 2010, 07:26 PM   #3864
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Originally Posted by PHEONIX View Post
Hello Simon

Does "warm" mean that they have a non neutral sound , and measured higher distortion.

Regards
Arthur
Everything so far has measurable distortion. Warm to me is one descriptive term that I associate with even order harmonics as the very dominant distortion. As to the relative level of distortion compared to other resistors I have not yet compiled enough data. Noise floor however seems quite low.

Soft I would associate with decreasing even higher order harmonics and very little odd ones.
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Old 9th March 2010, 02:52 PM   #3865
1audio is online now 1audio  United States
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Simon:
How much and what kind of distortion are you seeing? Do you have a way to quantify the systems base level of distortion? The old rule was that the residual distortion needed to be 5X lower than the measured distortion to be useful. The phase relationships between the distortion products can add or remove signals to a substantial degree. Also, when measuring at this level connections and nonlinear things nearby will affect it. RE points out that holding a pencil lead next to a resistor can increase its distortion at these levels.

I have used Vishay, Holco, Corning and Caddock resistors in different locations. I have never been able to identify a character to Vishay resistors (or measure distortion). Bob Crump felt that below 1K Vishays were the first choice and Caddock above 1K.

If you are seeing different noise floors between different resistors you need to be sure of all of the external effects. Without DC on the resistor the noise should be only a function of the resistance itself and its temperature.

If you would like I'll measure a few resistors from my collection for added noise and distortion and send them to you as a comparison to see if there is correlation in the methods.
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Last edited by 1audio; 9th March 2010 at 02:58 PM.
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Old 9th March 2010, 05:20 PM   #3866
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i have so far tried Charcroft and Texas components naked Z foil.
I find them neutral sounding but without spit in the treble.
If that is warm then i want that.
What i found special with that type of resistor is a gain in micro dynamics. I hear a lot of new tiny details and somehow the sound is faster but you have more time to analise it.
It feels like time has expanded in both directions. It is a really strange phenomenon.
Even after the music is turned off i feel i have more time to spend. I hope this statement will not push me over to the subjectivist department too much.
There must be a measurable effect at work here. This has nothing to do with parapsychology.
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Old 9th March 2010, 08:03 PM   #3867
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Quote:
Originally Posted by 1audio View Post
Simon:
How much and what kind of distortion are you seeing? Do you have a way to quantify the systems base level of distortion? The old rule was that the residual distortion needed to be 5X lower than the measured distortion to be useful. The phase relationships between the distortion products can add or remove signals to a substantial degree. Also, when measuring at this level connections and nonlinear things nearby will affect it. RE points out that holding a pencil lead next to a resistor can increase its distortion at these levels.

I have used Vishay, Holco, Corning and Caddock resistors in different locations. I have never been able to identify a character to Vishay resistors (or measure distortion). Bob Crump felt that below 1K Vishays were the first choice and Caddock above 1K.

If you are seeing different noise floors between different resistors you need to be sure of all of the external effects. Without DC on the resistor the noise should be only a function of the resistance itself and its temperature.

If you would like I'll measure a few resistors from my collection for added noise and distortion and send them to you as a comparison to see if there is correlation in the methods.
I am using a Wheatstone bridge configuration. I use ten resistors. Four are series parallel to 1K in series with a single 1K, the same upside down for the other side. At the bottom is a 100 ohm WW 10T pot paralleled with a 25 ohm resistor to give me 20 ohms of balance adjustment. I do 4096 averages of a 32K FFT. Fundamental still shows a bit (-120) and third harmonic (-150) is the dominant distortion in this mode. Clean and clear above the noise floor which is -178 db, all re my test signal of 15.81 volts. (62.5 mw vs 250 mw rating.)

When I do the unbridged test which is 1 side matched and the other side is 2k in series with 1K I see lots of nice even harmonics which were nulled by the balanced bridge. I am still playing with the second test to see if it is a valid or useful measurement. These can be as high as -120 or even more, but these results are not yet solid, still playing.

All is housed inside an aluminum case built for the project. I do see some 180 hertz dirt at -170 but that is it.

As to instrument errors or distortion, I get different enough results from the different resistors to feel it is not an issue. When I run the signal down by 6 db the distortion drops by 12.

As to comparisons when I finish I will be glad to send you my test samples. I now have better that 20 sets of different types to play with.
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Old 9th March 2010, 08:12 PM   #3868
PHEONIX is offline PHEONIX  Australia
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Hello Simon
At what frequency are you measuring at 1KHz?

Regards
Arthur
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Old 9th March 2010, 08:15 PM   #3869
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Quote:
Originally Posted by Joachim Gerhard View Post
i have so far tried Charcroft and Texas components naked Z foil.
I find them neutral sounding but without spit in the treble.
If that is warm then i want that.
What i found special with that type of resistor is a gain in micro dynamics. I hear a lot of new tiny details and somehow the sound is faster but you have more time to analise it.
It feels like time has expanded in both directions. It is a really strange phenomenon.
Even after the music is turned off i feel i have more time to spend. I hope this statement will not push me over to the subjectivist department too much.
There must be a measurable effect at work here. This has nothing to do with parapsychology.
That is what I would have expected based on the measurements. It is low noise, and the distortions I see are very musical and at a nice low level, but then I still have lots more samples to run. I do expect these resistors to be used at very low power levels below 25 mw for critical use.
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Old 9th March 2010, 08:16 PM   #3870
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Originally Posted by PHEONIX View Post
Hello Simon
At what frequency are you measuring at 1KHz?

Regards
Arthur
I test at 250 and 1000 hertz and look at 100 to 10,000 hertz. Levels are 15.81 volts and 7.59 into the complete bridge.
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