I think my System is virtually finished

[steve]

I just made, maybe, my last tweak. I added two turns to an inductor on my speaker crossover.
A friend, with multiple systems, came over, who owns Harbeth, LS3/5A speakers, flat out told me never to make another tweak again.

Soooooo, I thought I would sneak in another tweak, by adding one more turn to the inductor. No go. Had to remove the one more turn.

But honestly, it looks like the journey with my system is over except for speaker wire, which is prohibitively expensive. I am not sure I need it though.

The Modi 2 has been successfully modified.
My test Phono stage is sounding superb. (It is still hay wired together though.)
The 11A has been finished for some years.
My 20 watt PPT (push pull triode) mono amp design has been finished for some time.
Interconnects have been finished for some years.
Speaker wire could be better, maybe using all 6N pure solid 18 gauge wire.
Speakers are finished for use in this room. (Except for covering/painting)
Inner tube below 11A, Test Phono Stage, Modified CD player.

40 years and finally finished. Been enjoying the music so much these past couple of weeks.

As you go thru this string, another tweak or so occurs. Here is a string I started demonstrating the lack of
artificial flavoring/absence of sonic signature.

https://www.audionervosa.com/index.php?topic=6954.0

Cheers

steve

[Guy 13]

Hi Steve,
are you 100% sure you wont tweak again your system ?
Can you resist the temptation of modifying something ?
Only time will tell.

Guy 13

[S Clark]

Seriously? You could discern a difference from 2 turns on an inductor? What is that, like 1uH? 
I'm not questioning, just jealous.  That's in the realm of perfect pitch.

[Nick B]

Congratulations, steve. I’ve always admired your attention to detail and your descriptions of your testing methodology. Wish I could hear your system. 
Nick

[Folsom]

Maybe a YouTube video?

[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]

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.

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]

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.

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.

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'. 

[rollo]

  Wishful thinking Steve. 


charles

[tmazz]

Building a stereo system is like arguing with your wife, it's never over...... unless she says it's over. 

[steve]

I just performed one more experiment, that involving my speaker "cables" that I thought could be improved upon. I installed one 6N copper wire across both the right and left speaker wires. That not only increased the wires from 12 on each leg to 13, but also added a 6N pure wire.

I had to tweak my speaker controls just slightly, but a slight improvement in believability was perceived. There was just a smidgen of confusion in the lower piano range that was corrected. Checking multiple pianos pieces, it just sounds live up and down the scale. I am right at the apex of believability.

Next, Dan, an audiophile/music lover from Mt. Pulaski, will be auditioning, hopefully next tuesday.

cheers

steve

[steve]

Dan came over the other night, he is really good at speaker placement etc. Disconnected the 6N wire; we played some of the same and new selections while he adjusted, later I tweaked the speaker positions less than a 0,5 pen's thin line. Over the past couple of days, sounds just slightly better still, mainly lower end cleaner kick drum, yet still fleshy mids. I thought I was finished, but so close; this was a swing type super minute adjustment though.

Setting the temperature to 72 degrees, as per standard from what review mags used to do. Was at 70.

cheers
steve

[steve]

An update on my personal lab stereo system.

I modified the Modi 2 some months ago, I don't even consider purchasing any other, regardless of cost. I am also
willing to upgrade another's.

The reference monoblocks were obtained by special proprietary listening tests to make sure the amps do not alter the sonics of the input. (This same procedure was performed with my 10A and perfect 11A line preamplifiers when I was still active. I am retired now.)

I am working with JJ KT-88s and JJ 6dj8/Ecc88 tubes. The sound is so natural that I don't even think of changing to
NOS tubes. I know what others say concerning newly manufactured tubes. Forget their experiences.
And forget those "comparison capacitor" articles.

I am hoping this 40+ year experiment will help others find a tube combo, reasonably priced, that can be made to sound awesome in their components, along with some tweaking. Something worth trying that will not break the bank.

cheers
steve