Doctor's Orders-Part Two-The New Listening Room Of Steve Williams

[Bruce B]

Bruce,

Can you define "my gain"?

In my system, when I inserted all the Transparent Opus MM2 cables, I noticed I had to turn up the volume a couple more clicks to reach the same volume as before I inserted the Transparent. This was especially clear to me, because when I'm mastering, level matching is key to a good understanding of what you are changing as far as EQ/Comp and such.
I then measured the output and using the exact same voltage, I was getting a 2.9 - 3.1dB drop in output level using a signal generator.

 

[microstrip]

In my system, when I inserted all the Transparent Opus MM2 cables, I noticed I had to turn up the volume a couple more clicks to reach the same volume as before I inserted the Transparent. This was especially clear to me, because when I'm mastering, level matching is key to a good understanding of what you are changing as far as EQ/Comp and such.
I then measured the output and using the exact same voltage, I was getting a 2.9 - 3.1dB drop in output level using a signal generator.

And you have no explanation for it? In what exact line were you loosing signal? I hope you were not using them with 600 ohm impedance professional type terminated input lines, as some Jeff Rowland systems. My ARC system has 600 ohm output impedance, but input impedance are around 100 kohm.

 

[Bruce B]

And you have no explanation for it? In what exact line were you loosing signal? I hope you were not using them with 600 ohm impedance professional type terminated input lines, as some Jeff Rowland systems. My ARC system has 600 ohm output impedance, but input impedance are around 100 kohm.

Pyramix -> Horus -> Pass XP-30 -> Pass XA-100.5 -> Alexia

There were balanced IC's, PC's and Speaker cables used. I was measuring the output of the speakers using a calibrated Earthworks M50

 

[rbbert]

Sorry, but IMHO this is physically impossible in any decent power amplifier. If the amplifier gain would depend significantly on the supply voltage you would be listening to your mains, not to music! It is why power supply rejection ratio should be very high in power amplifiers.

It is also explainable if in some way the input sensitivity of the amp is lowered

 

[Frank750]

I have a similar set up to Steve's utilizing 3 Typhons and a Triton. My SPL readings correspond to Steve's after removing and then reinserting the Typhons. I knew there was a difference from the time I put the Typhons in, I just never measured it.

 

[MadFloyd]

In my system, when I inserted all the Transparent Opus MM2 cables, I noticed I had to turn up the volume a couple more clicks to reach the same volume as before I inserted the Transparent. This was especially clear to me, because when I'm mastering, level matching is key to a good understanding of what you are changing as far as EQ/Comp and such.
I then measured the output and using the exact same voltage, I was getting a 2.9 - 3.1dB drop in output level using a signal generator.

Same deal for me. I was quite surprised.

 

[ack]

Peter

can you expound upon this as I am unsure of what you mean

So with the same preamp again, using an SPL meter:

1) Test with tones (warble?) of varying frequency: can you consistently measure ~+4dB gain when the Typhon is connected, than without? I would be surprised if you do.
2) To test dynamic headroom, play music and measure peak amplitude. I suspect you will hit higher SPLs this way.

 

[jap]

JL Audio has a free app for iPhone/iPad with a SPL meter and RTA.

I'd also try measuring AC line voltage with and without the Typhon.7

 

[microstrip]

Pyramix -> Horus -> Pass XP-30 -> Pass XA-100.5 -> Alexia

There were balanced IC's, PC's and Speaker cables used. I was measuring the output of the speakers using a calibrated Earthworks M50

Although I can not find an explanation for the signal attenuation other than a faulty cable, I see one reason why the Opus should not be used with the XP-30 in balanced mode. The Pass specification states 120 ohm output impedance, but the measurements section at the Stereophile review states : The balanced output impedance was close to the specification at 20 and 1kHz, at 117 ohms, but rose to 1127 ohms at 20Hz. But The single-ended output impedance was 65 ohms across the band. This type of behavior in balanced mode would make a network cable very difficult to dimensionate. Perhaps TA just used the Pass specification - 120 ohm. As in a solid state preamplifier output impedance is constant they did not care about this strange behavior. BTW, as far as I know David Wilson used Opus MM2 in his system, although I do not have details about the power cables.

 

[rbbert]

JL Audio has a free app for iPhone/iPad with a SPL meter and RTA.

IME not as flexible or accurate as Steve's Radio Shack SPL.

 

[jap]

IME not as flexible or accurate as Steve's Radio Shack SPL.

I have both, along with another app called Octave which has more SPL features.

 

[steve williams]

I ran the experiment again. First off every line in my room is a true dedicated line each with a home run to the room's sub panel. Each AC outlet is a Furutech Rhodium Gold.

With all 3 Typhons plugged in and running pink noise with my preamp (both channels) set to the 10th detente position and using my Radio Shack SPL meter it measured 71 Db

With all 3 Typhons disconnected and running the same pink noise at the same volume the SPL reading was 72 Db

What I find interesting is that when Marty and I first did this experiment we were not using an SPL to measure. We used our ears and recollection to place the preamp volume at the chosenn level of 12 before we felt we could notice the difference ( 2 positions up on the dial is a rise of 2 db) yet the SPL meter read a difference of only 1 Db.

Long and the short of it however is that the difference in SPL was again noted tonight but only with a true difference of 1 Db- a difference nonetheless. I still don't understand why the Typhons do this to the SPL.

As to the change in Db from one day to the next perhaps this is related to my grid

 

[rbbert]

Did you mistype? You have the volume with the Typhons less than without?

 

[steve williams]

That's the whole point. Without the Typhons the volume needed to be louder to achieve the same spl. So doing true measurements (we used our ears last time) the SPL was 72 with all Typhons unplugged

So all Typhons plugged in measured 71 db
All 3 Typhons unplugged or the two at the amp unplugged measured 72 Db,

My whole premise and the first thing I noticed when I installed the 2 Typhons at my amp side was that I had to turn down the volume. The measurements seem to confirm this

 

[rbbert]

No Steve, you are now saying that the volume is one dB (measured) more with no Typhons, so you would need to turn the volume up when you insert the Typhons

 

[microstrip]

I ran the experiment again. First off every line in my room is a true dedicated line each with a home run to the room's sub panel. Each AC outlet is a Furutech Rhodium Gold.

With all 3 Typhons plugged in and running pink noise with my preamp (both channels) set to the 10th detente position and using my Radio Shack SPL meter it measured 71 Db

With all 3 Typhons disconnected and running the same pink noise at the same volume the SPL reading was 72 Db

What I find interesting is that when Marty and I first did this experiment we were not using an SPL to measure. We used our ears and recollection to place the preamp volume at the chosenn level of 12 before we felt we could notice the difference ( 2 positions up on the dial is a rise of 2 db) yet the SPL meter read a difference of only 1 Db.

Long and the short of it however is that the difference in SPL was again noted tonight but only with a true difference of 1 Db- a difference nonetheless. I still don't understand why the Typhons do this to the SPL.

As to the change in Db from one day to the next perhaps this is related to my grid

Steve,

Thanks for repeating the experience. This is what can be expected. Unless you are using a very precise sound meter (not the RS) with a tripod a 1dB difference is not significant - IMHO it is within the typical error of the experience . We can not expect a measurable sound difference using pink noise in these conditions. The important aspect of the experiment is your finding about the sound level your years perceived. Remember that sound reproduction must be debated under the perspective of psychoacoustics. In order to confirm you experience you have to ask more users to repeat it and make a statistical analysis of the results. But you will need many trials ...

 

[steve williams]

No Steve, you are now saying that the volume is one dB (measured) more with no Typhons, so you would need to turn the volume up when you insert the Typhons

no,with the Typhons, I would have to turn down the volume but you are however correct that I did have my readings reversed as you point out. IOW in post 452 I should have said all 3 plugged in was 72 Db All 3 unplugged the spl was 71

To say it backwards as we did that without an SPL meter we used our ears. Initial listening was with preamp set at 10 with all 3 typhons in.

Once Typhons were pulled our aural retention told us we had to increase the volume on my preamp by ~3-4 db to make things sound the same spl in the room. The reality however when I measured today was only a 1 db change not 3-4

 

[ack]

So $15K worth of Typhons to give you maybe 1dB gain - statistically inconclusive, I'd say. Look for dynamic headroom gain.

 

[steve williams]

Peter

I never bought them for any db gain. This was merely an observation on my part. As to your conclusions, perhaps. but I suggest you have a listen to someone who has them and listen on and off

 

[ack]

Yeah I didn't mean you bought them for the purported gain, only that the improvements can be explained otherwise.