Latest Thread Images

Vali 2 tube rolling
Feb 2, 2016 at 11:35 AM Post #256 of 6,436
When you get the tube from Upscale audio and listen to music you know well with that tube and the stock tube, get back to us.
 
If that music sounds identical to you with tube A and B, GREAT, save your $$$, listen to whatever equipment you own  and be happy!
 
There are folks that can't tell the difference between Bud Light and a great hand crafted micro brew. They drink Bud and love it.
 
Feb 2, 2016 at 1:53 PM Post #257 of 6,436
jennifersyummie said:
Why do the spectrograms of a SS amp and a Tube amp look the same?

Hi everyone.  I love my [COLOR=800080]Vali 2[/COLOR] !  I love the way the tube glows and it just looks so regal on my desk.  I put the amp in italics and purple (as a sign of reverence) because I like it so much!  I like the idea of changing the tubes and seeing what happens.

A small problem though.  I can't tell the difference between Tubes and Solid State.  Maybe my ears are bad?  I have good HE400i headphones so I don't think that's the problem.  I keep my ears clean (thanks mom!).  I've been listening to some soundtracks (FLAC), some streaming (320 kbps), and stuff by those people with the white wigs a long time ago.  They all sound the same to me.  So I had fun and made some pretty pictures to delve into this.

What I did:

1.  I used Audacity to generate 30 seconds of White Noise.  I saved this into a FLAC file which I then transferred to my Fiio X1.
I used the Fiio X1 to play White Sound into my computer's sound card via a TRS cable.  The volume used on the Fiio X1 was ( ugh!  I forgot) with no equalizer engaged.  The recording software was Audacity.  In Audacity I turned the signal into Mono (because later it makes the visual inspection easier and the L/R signal's are identical).

2.  I then attached the Fiio X1 to the Vali 2 and the Vali 2 into my computer's sound card via a TRS cable.  The volume of the Vali 2 was low gain and max volume (because I think the tube's coloration may be more noticeable when the [COLOR=800080]Vali 2[/COLOR] is maxed out (if I'm wrong please let me know).  The volume on the Fiio X1 was reduced to compensate.  After some trial and error I found the volume level to match the initial recording via a dB or two (visual inspection of the waveform's amplitude at identical areas).  Then I recorded it using the same method as above.  Once again, the Fiio X1 did not have any equalization engaged.

3.  I opened both files into Audacity.  The pics below show the spectrograms.  The top is the Solid State recording from the Fiio X1 to my computer's sound card.  The bottom is the Tube recording from the Fiio X1 to the Vali 2 to the computer's sound card.

4.  The Tube used was the stock tube that accompanied the [COLOR=800080]Vali 2[/COLOR]. The Tube is a Sylvania 6BQ7A.  The Tube was warmed up for 30 minutes before testing.  The Fiio X1 had a full charge.  My cables are those media bridge ones.

Well, the spectrograms kind of confirmed what my ear's were thinking.  No difference.  WHY?  This was a not-so-great discovery to make since I recently ordered this cute, expensive little guy:  http://www.upscaleaudio.com/telefunken-e88cc-6922/

The first picture shows the frequency from 0 Hz to 11000 Hz.
The second picture shows the frequency from 0 Hz to 172 Hz.  I zoomed in on this frequency range because the Tube's sound in general is supposed to be warmer.

The only difference I can see is the 60 Hz noise (and a fainter 120 Hz of course) from the power supply.

Why isn't there any difference between solid state and Tubes?




The file below has a zoomed y-axis.
Click to expand...


I couldn't tell the diff either. There were some differences on the treble end with the eh6922 and the eh6cg7. Other than that I didn't hear much diff
 
Feb 2, 2016 at 2:16 PM Post #259 of 6,436
Because we all loves very much pretty pictures.....
 
Below is a White Noise profile of the Solid State Fiio X1, the Vali 2 with a National 7DJ8, and finally the Vali 2 proudly holding the expensive Telefunken E88CC within its loving socket-embrace.
 

 
 
Here's a pic (below) when I vastly increased the sensitivity of Audacity's spectrum function.  I zoomed in on the low region so I could how the 1 second of silence before the White Noise started. 
 

 
 
Was that a birdy I heard?  Hee hee hee.  Here are some Chirps from 0 to 10000 Hz.
 

Ooops.  I forgot to replace White Noise with Chirp in the two bottom ones.
 
 
Now here is the same pic (notice the bottom two don't have "Chirp")?  I once again turned up the sensitivity to a much higher amount than 4 out of 5 Audiophiles would recommend.
 

 
 
 
The upshot is that my ears can't tell any difference (I'm using excellent HE400i's, but perhaps not so excellent ears).  Playing with the spectrograms show pretty much no differences.  Remember, to generate that weird stuff at 1 Hz (and it's only that low area which makes the National harmonics) I had to vastly increase sensitivity.
 
I'm not too surprised I can't tell the difference, but I expected to see a difference in the spectrograms.
 
Feb 2, 2016 at 3:25 PM Post #260 of 6,436
So are you concluding that listening to music with the HE400i, the Vali2 with a Telefunken E88CC sounds more or less the same as a Fiio X1, and this is supported with your spectrograms?
 
Feb 2, 2016 at 4:16 PM Post #265 of 6,436
Is all the testing supposed to show the (no)-difference in sound signature between a solid state amp and the Vali 2? Or is it to scientifically prove there is no audible difference between tubes? If it is the latter, I have to wholeheartedly disagree. Had 2 weeks of listening experience with my 1st rolled tube replacing the stock tube. "Challenged" by the white noise experiment I just switched back to the stock tube, firing up "Royals" by Lorde, which btw is one of the few examples of a mainstream pop track that is really well mastered, and what a difference, especially in harshness and bass / drum control. The bassdsrum kicks are all over the place, not well controlled, not tight, and the overall sound signature is colder / harsher (not analytical). Quite fatiguing actually.
 
Stock tube: US made NOS Sylvania 6DJ8, replacement tube : NOS Tesla E88CC.
 
Maybe it lies in our ear's anatomy, quite special compared to other sensory organs. A whole apparatus of mechanically interconnected parts (you know the three tiny bones) moving, before finally getting translated into electrical signals unlike eyesight (direct nerve stimulus) and taste (also direct nerve stimulus). And hey, at the end of the whole system is our brain, where "Hearing" actually happens. Fascinating thing that brain, it INTERPRETS electrical signals from our sensoric system. So yeah our highly complex auditory system might be one of the reasons why listening is such a highly individual thing ...
 
Feb 2, 2016 at 4:52 PM Post #267 of 6,436
FWIW: When I first got the Vali 2 it seemed to sound 'different' somehow from the GO450 that I was using before with all my headphones, later on I felt it was more dynamic, smooth and three-dimensional. Then I built myself an A/B switch and calibrated the output of the Vali 2 (stock tube, both high and low gains) and low-z out of the GO450 within 0.1 dB and I couldn't reliably tell the difference with a wide selection of music. As it stands, I don't think I would pass an ABX test. I played with this for about 2 hours.
Maybe I will do it again another time to see if the results are different, if somehow I've gotten better at listening for these nuances (even though I've successfully ABX'd MP3 VBR V0 from lossless in the past). For now I will continue to enjoy the soothing tube glow and physical volume control.
 
Feb 2, 2016 at 5:52 PM Post #268 of 6,436
I'm going to listen to the Telefunken for a very long time.  It will be the only way I will listen for two months.  Then I'll abruptly switch and see if I fancy any difference.  And I'll do the test again also.  So...... see you in March!
 
Feb 2, 2016 at 6:53 PM Post #269 of 6,436
jennifersyummie said:
  Why do the spectrograms of a SS amp and a Tube amp look the same?
 
 
 
Click to expand...

 
In many cases tube amps were designed quite intentionally to sound "warmer" than regular solid-state amps. Not that you can't make a solid-state amp sound "warm" by tweaking the circuit, but it became a "thing" that tube amps sounded a certain way, especially when a raft of Chinese tube amps were popular here for a while. What really was going on, from my limited understanding, was that the designs introduced pleasant-sounding harmonic distortion. A "properly designed" tube amp shouldn't have distortion.  Nor should a solid-state amp, but all components have their own noise profiles and varying degrees of linearity and every designer has their own preferences, making components sound sometimes very subtly different. 
 
The Schiit tube amps don't have a "tube" sound to them, but since there is a greater variation amongst tubes of a certain type than there are variations of transistors, the Vali 2 makes for a cheap toy to play with in this way.  My main amp has 6 tubes and doesn't sound "tubey" either, unless I want it to. The fun is buying a bunch of tubes of the 4 different types it takes (excluding variations) and rolling them to get the most sonically pleasing results for the headphones I use. It's just one of those things that are part of the hobby that we do for fun. 
smile.gif

 
You must log in or register to reply here.

Users who are viewing this thread

Total: 4 (members: 0, guests: 4)
Back
Top