# Victory Sonics VK-TP4 mk1 Tube Pre-amplifier Review



## Velozity (Jul 6, 2007)

I don't take the time to do reviews often, simply because of the time involved to do it properly. But every now and then I come across a piece of equipment that I just feel compelled to share.

Most of you know or have hear of Victor_Inox here on the forum. He has just started a new company "Victory Sonics" that manufactures vacuum tube based audio equipment. His first product that was conceived and born right here on DIYMA is the VK-TP4 mk1 Preamp. (I'm proud he picked the name I suggested ). Here are the preamp specs, taken from Victor's own words:

*First will be 4 ch version built by the same principals Panny did it in (the) Bottlehead. 1 double triode tube for both channels. Circuit is simple and stable. Power consumption is less than 1A fused at 1.5. 

Case is extruded aluminum 5.75"x7.75"x2.75", all connectors on one side.
Unlike some (other products,) (the) tubes (are) user replaceable; any 12AX7 or equivalent can be used to experiment with sound difference. By default I supply Russian military grade 12AX7. Tubes in this design (are) good for 10000 hours. I chose military grade for vibration resistance purpose. If it was good for planes it will be Ok for car too. 

Each channel specs:

2 gain potentiometers for each pair 

Input sensitivity: 0.1-6V 

FR: [email protected] +_1 db 

THD: 0.05%

S/N: 95dB
*



I stumbled upon a thread he started a couple months ago and was instantly intrigued by the idea of a tube preamp for car audio. Having owned a couple Panasonic CQ-TX5500 "Bottleheads" in the past, I already had a taste of a tube preamp in car audio, but that unit is going on 11 years old now and it has a severely outdated feature set. With the VK-TP4 mk1 you can potentially have the same sonic signature with any of the latest headunits and processors. Yes I was hooked and immediately overwhelmed by all the tube upgrade options available in the 12AX7 (or equivalent) size.


One of the best features of the preamp is the ability to run it in a home system off a 12VDC wall adapter. This is perfect because I'm not ready to put it in my truck, but I wanted to be able to enjoy it right away in my recreation room. So here is the review setup:

Source: Pioneer BDP-150 Blu-Ray Player
Amplifier: Pioneer VSX-1122 7.2ch Receiver
Speakers: Polk Audio T15 Bookshelf and PSW10 Subwoofer 
Sound Measuring: M-Audio MobilePre USB interface and Behringer ECM8000 Microphone connected to laptop running TrueRTA


----------



## Velozity (Jul 6, 2007)

I let the unit break in for about 10 hours before actually listening to it. It does get warm (understandable) so if you use it in a car or hot environment be sure to provide adequate cooling for the tubes. I plan to modify my case to make the tubes visible and add ventilation. Victor has other case options he's working on that will dissipate heat better also.

I used a variety of my go-to discs for the evaluation: _Foreplay_- The Best Of Foreplay, _Michael Jackson_- Thriller, _Rodrigo Y Gabriela_- Rodrigo Y Gabriela, _Snoop Doggy Dogg_- Doggystyle (remaster)

First of all let me say that listening to CDs through the HDMI connection absolutely sucks. I didn't realize it before, but now that I have the Blu-Ray player connected via analog to the receiver's CD RCA inputs it makes a big difference, even without the tube preamp in the chain. I don't know if the DAC in the receiver is that bad or if the one in the player is so much better, but I won't go back to listening to stereo music via HDMI. Sorry, back on topic...

I'm already very familiar with each of the discs listed, but I listened to each of them again via analog without the preamp in the chain to establish a baseline. While my equipment is nowhere near top of the line nor on par with my car stereo, it was enjoyable to listen to and is relatively smooth across the spectrum. The listening room is about 400 sq. ft. with carpet, rectangular shape, and sparse furniture. The seating position is about 10 feet from the speakers and the speakers are spaced about 7 feet apart.

Now, insert the Victory Sonics VK-TP4 mk1....


My one word reaction is WOW. My one word description of the sound is HOLOGRAPHIC. Why is always easier to describe sounds with visual cues? Anyway to say I was impressed is an understatement (there ya go Vic ). Is the difference in sound noticeable? Absolutely. Is the difference in sound significant? Without a doubt, you can appreciate the "tubeness" with this preamp in the chain. If you're not impressed by it then maybe finer audio isn't for you. On the flipside people with more trained ears will appreciate it quicker than a newcomer to the audio hobby because the upgrade will not sound "night-and-day" to everybody. But for the introductory price it's a no brainer IMO.

So without sounding like a music snob which I most certainly am not, I will say that this preamp seems to add a new dimension to the music. Everything sounds more spacious and natural (no surprise there). It's most evident to me in the lower midrange and lower high frequencies. The definition on bass guitars on the Thriller and Foreplay albums was very apparent. I could hear the decay of the floor toms and ride cymbals on Foreplay and the snares / high hats on Doggystyle were crisp and had great attack. Plus the bass lines on that album had my cheap subwoofer performing way better than it should. The acoustic work of Rodrigo Y Gabriela seemed more "in the room" if that makes sense. I felt like the whole staging and presentation improved. I also recall hearing sonic cues with the intro to Thriller where Victor Price comes out of the casket and limps across the stage from right to left with the werewolves howling and I was impressed by the apparent separation and depth that the tubes added.

In fact I was so impressed with what the tubes did to the music that I decided to try and see if I could quantify the difference via RTA measurement. I've never used my RTA at home before so I was excited to try this. I had already set the preamp gains by ear to make sure that my listening levels between the baseline and the VK-4T listening sessions would be similar. The RTA measurement confirmed that they were about the same loudness (~91-92dB). The frequency response playing stereo pink noise was extremely close in profile between the two. But the session with the tube preamp seemed to add a few dB here and there across the board. What is really telling however was the measurement I took with a 1kHz sine wave. Looking at my notes on the picture below you can see that while the fundamental frequency (1kHz) is exactly the same level for both sessions, the tube session showed much higher levels for the 2nd-5th harmonics (2kHz-5kHz). VK-4T preamp measurement on the top, baseline measurement on the bottom. 













So there is that harmonic distortion (particularly in the 2nd harmonic where the difference is 14dBu higher than baseline) that gives this preamp a signature tube sound. Maybe that's why it's hard to describe why tube audio equipment sounds so good. Because it's seems to be the sound around the sound that gives it a unique flavor. You hear it in the echos, reverbs, decays, sibilance, etc. that accompanies live instruments and vocalists.


I'm very happy I made this purchase, and I'll probably get another one for the car since I'd like to leave this one where it is. My request to Victor is for a 6ch version for my car so that all channels will benefit from the tubeness, not just the mids and highs.


Congrats to Victory Sonics on their first foray into tube car audio. Thank you for helping to keep high-end car audio alive!

http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/161717-tube-preamps-mobile-installations.html


----------



## Victor_inox (Apr 27, 2012)

Thank you Michael for you time effort and kind words. I promise to keep up good work. 6ch version can be done very soon. Are you sure about 6ch and not 8?

Sent from my SAMSUNG-SGH-I527 using Tapatalk


----------



## Victor_inox (Apr 27, 2012)

Now invest in a pair of nos amperex bugle boy tubes and your perception of holographic sound will be deeper. Rca cleat top if you need more sparkle on top or telefunken for better dynamics. 

Sent from my SAMSUNG-SGH-I527 using Tapatalk


----------



## deeppinkdiver (Feb 4, 2011)

Awesome! 

Id be down for an 8ch version Victor


----------



## Velozity (Jul 6, 2007)

Victor_inox said:


> Thank you Michael for you time effort and kind words. I promise to keep up good work. 6ch version can be done very soon. Are you sure about 6ch and not 8?
> 
> Sent from my SAMSUNG-SGH-I527 using Tapatalk




Sure thing. You're right I suppose 8ch would be more future-proof. I only run a 5ch system in my truck right now though.


----------



## Victor_inox (Apr 27, 2012)

Velozity said:


> Sure thing. You're right I suppose 8ch would be more future-proof. I only run a 5ch system in my truck right now though.


You can use second 4ch section in dual stage mode and get 6ch total or do a true 7.1


----------



## Victor_inox (Apr 27, 2012)

BTW original thread located here
just in case someone missed it.


----------



## casey (Dec 4, 2006)

i think im going to have to get one of these at some point once my setup is done. I dont want to throw it in before getting some seat time so that I can experience the difference.


----------



## Velozity (Jul 6, 2007)

casey said:


> i think im going to have to get one of these at some point once my setup is done. I dont want to throw it in before getting some seat time so that I can experience the difference.




You won't regret it Casey. Especially in your car with all that nice equipment and Mark's nice install.


----------



## deltasaurus (Apr 9, 2014)

I am a long time tube lover and am excited about the possibilities with Victor's new products. This thread inspired me to contact hime and I look forward to putting at least 6 channels of tube goodness to work in one of my three current builds. Thank you for taking the time to post this thoriugh review!


----------



## Victor_inox (Apr 27, 2012)

HIt me up, let`s see what you might need.


----------



## WestCo (Aug 19, 2012)

Velozity said:


> I'm very happy I made this purchase, and I'll probably get another one for the car since I'd like to leave this one where it is. My request to Victor is for a 6ch version for my car so that all channels will benefit from the *tubeness*, not just the mids and highs.
> 
> 
> Congrats to Victory Sonics on their first foray into tube car audio. Thank you for helping to keep high-end car audio alive!
> ...


Dat tubeness! 

Really awesome


----------

