Systemic Development > Bipolar System Disorders
I think my System is virtually, finally finished
steve:
Guy13, I think so as I have not had any inclination to make another tweak to the digital source system, since I attempted the addition of one more turn on the speaker inductor. I probably should have stated that I still need to make it look much better, but that was not my point.
I did tweak the interconnect between the TT to phono stage IC by adding a shield. Not great looking, but pretty much eliminated any 60hz hum.
Scott, with the inductor I am using, the two turns added approximately 20 micro henries to the inductance. Sonic change does not really surprise me as I have altered a resistor parallel with my full range driver (FRD) by a millionth of an ohm and music lovers notice the sonic difference. It is not the spl change, but the frequency response change that is perceived. +/- 0,1db 20 - 20khz spec is almost meaningless.
I have another resistor in series with the FRD and I also alter its resistance by a millionth of an ohm, which changes the FRD to woofer spl "matching", if I can use that term.
Thanks for the compliment Nick. I try to be as accurate as possible.
Hi Jeremy. I have no idea of how to do YouTube, nor mics, nor camera etc. I have attached a photo of my test system in the listening room. It does not look pretty at all. That is my fault. I am somewhat scared to move the speakers when putting on a covering. Last time Dan was here, he moved the speakers about 1/16".
A few comments on the photo.
The small capacitors in front of the monoblocks are switchable, for different input/output tube combinations.
Next, the speaker drivers have been modified.
The test modified Modi 2 DAC is inside the aluminum chassis on the floor, to house polypropes.
The gold colored chassis is the test phono stage with 36db of gain. I wish it was more, will tinker later, maybe.
Power conditioning has been incorporated inside each component.
Here is a selection that will test one's system.
https://www.youtube.com/watch?v=jaugLriyEbs
Cheers
steve
S Clark:
--- Quote from: steve on October 26, 2019, 06:29:47 PM ---
Scott, with the inductor I am using, the two turns added approximately 20 micro henries to the inductance. Sonic change does not really surprise me as I have altered a resistor parallel with my full range driver (FRD) by a millionth of an ohm and music lovers notice the sonic difference. It is not the spl change, but the frequency response change that is perceived. +/- 0,1db 20 - 20khz spec is almost meaningless.
I have another resistor in series with the FRD and I also alter its resistance by a millionth of an ohm, which changes the FRD to woofer spl "matching", if I can use that term.
--- End quote ---
Interesting. One year I had my physics students wind their own inductors, and we didn't see that kind of sensitivity. But I never tried it again...winding inductors from scratch is a royal PITA.
And how in the world do you vary a resister by .000 000 1 ohm? I've heard differences in 1/2 ohm, but 1/1000000? I'm always amazed by what you guys with good ears can hear.
steve:
--- Quote from: S Clark on October 26, 2019, 07:36:39 PM ---
--- Quote from: steve on October 26, 2019, 06:29:47 PM ---
Scott, with the inductor I am using, the two turns added approximately 20 micro henries to the inductance. Sonic change does not really surprise me as I have altered a resistor parallel with my full range driver (FRD) by a millionth of an ohm and music lovers notice the sonic difference. It is not the spl change, but the frequency response change that is perceived. +/- 0,1db 20 - 20khz spec is almost meaningless.
I have another resistor in series with the FRD and I also alter its resistance by a millionth of an ohm, which changes the FRD to woofer spl "matching", if I can use that term.
--- End quote ---
Interesting. One year I had my physics students wind their own inductors, and we didn't see that kind of sensitivity. But I never tried it again...winding inductors from scratch is a royal PITA.
And how in the world do you vary a resister by .000 000 1 ohm? I've heard differences in 1/2 ohm, but 1/1000000? I'm always amazed by what you guys with good ears can hear.
--- End quote ---
Hi Scott,
The inductor is iron core, rated 600 watts if memory serves me correctly, so not as many turns. (The amp only puts out 20 watts or so.)
For the second question, an example. Say we have a 20 ohm resistor "A" shown in schematic below. I used a similar circuit as shown below. Adjusting "F" pot (we measure across resistor "E"), we can then calculate the total resistance change of resistor "A". I did not actually calculate this circuit, I used different values, but it does show how it can be done.
Your third question, I think, has to do with how much masking does the system, each component create. When each component is designed/listening tested for accuracy (does the output sound like the input signal), it is my opinion that true openness occurs. It is quite easy to perceive minute changes in tonal balance, assuming no masking is occurring. However, when masking occurs, in varying degrees, tonal balance changes are not as noticeable. +/- 0,1db means a small change in frequency response correlating to ~54db down, varying over octaves. Of course venue also influences our perceptions
Another aspect is that frequency response (FR) changes, usually toward frequency extremes, the harmonic structure changes. The higher the harmonic number, the easier it is to perceive the change (RCA Radiotron Designers Handbook, 1960).
Late now, cheers
steve
steve:
I see we have an optical illusion with the right speaker appearing to be severely slanted. However, that is not the case, the speakers are straight up and down.
cheers
steve
mresseguie:
Steve,
Several of the audiophiles I know and hang out with in Taiwan are engineers (electrical, mechanical). One of the guys is the husband of a friend of my wife. His audio room looks quite a lot like yours. I call his room 'the mad scientist room'. :rofl:
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