Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups darrenriley.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com

The VOX AC30S1 is a Hybrid amp if you care

Discussion in 'Amp Central Station' started by bluescube, Jan 10, 2019.

  1. bluescube

    bluescube Friend of Leo's

    Age:
    51
    Mar 9, 2004
    Greensboro NC
    Found the service manual. THe AC30S1 does use FET's in the preamp for gain stages along with a 12Ax7 and a phase inverter 12AX7.

    But you know what, it sounds freakin' incredible so it's not a big deal to me. I don;t think John Bollinger noticed any issues when he showed it off before NAMM launch. I can guess from trying to remember my electronics classes, that the FET stages are simply clean signal boosting and not part of the preamp circuit that would distort. That is pre and post tone stack.
    .

    [​IMG]

    http://dealers.korgusa.com/svcfiles/AC30s1_SManual.pdf

     
  2. VintageSG

    VintageSG Friend of Leo's Ad Free Member

    Mar 31, 2016
    Yorkshire
    There's an Aussie bloke that presents the Youtube channel EEVBlog that claims a valve is just a FET with a pilot lamp anyway. Nothing wrong with a well designed FET circuit.
    MOSFET amps underwent a vogue a few years ago. I built plenty ( bass, Hi-Fi and PA applications ) and they sounded great. I also see the ubiquitous TL072 Op-Amps sprinkled around where they can work their magic. There are a couple of discrete transistors in there too. I can almost hear the gnashing, the wailing and the renting of garments at this :)

    All that really matters is the sound coming from the speaker.

    It's certainly an interesting approach to a hybrid.
     
  3. bluescube

    bluescube Friend of Leo's

    Age:
    51
    Mar 9, 2004
    Greensboro NC
    I think it sounds better than the AC15C1. Doesn't have the blizzard of nails tone that requires clipping a bright cap. The overdrive nails the Bryan Adams tones. The EQ is really interactive
     
  4. clintj

    clintj Friend of Leo's

    Apr 4, 2015
    Idaho
    Then why in blazes are they advertising it, to use their own words, as an "all tube design" and a "full tube design" on their website, including as a Main Feature?

    I'll fully agree that solid state devices can be very useful for these applications, but don't lie to us and say it's something it's not, Vox.

    Sent from my Pixel 2 using Tapatalk
     
    Nickfl likes this.
  5. VintageSG

    VintageSG Friend of Leo's Ad Free Member

    Mar 31, 2016
    Yorkshire
    Vox aren't 100% truthful at times. One of their range of amplifiers can bend physics to their will to produce substantially more power than the power consumed. They aren't alone in this, but when your 60 Watt amplifier consumes 37 Watts, it may lead a customer to speculate they could buy a bank of them and create a power loop to light their house. An optimistic, massaged, best-case, following wind, downhill headline power figure looks more impressive. Big numbers sell!

    The truth is what people want to believe. It does have a valve in the pre-amp. It does feature a valve phase inverter and it does feature a valve power stage, so it does have valves in all stages of the design. That's what sells.

    That one valve has been omitted to drive the tone stack, and at least another + a transformer to drive and recover the reverb ( simplifying it a bit ) is merely swept under the carpet. Marketing may have a tough sell if they were honest and claimed the FET drivers, the op-amps and the discretes in the signal path.

    Various types of FET are great. The TL07x op-amps are the hidden helpers of the audio world, but they don't cause folk to emote in the same way glowing, hot glass does.

    Too much shenanigans.
     
  6. bluescube

    bluescube Friend of Leo's

    Age:
    51
    Mar 9, 2004
    Greensboro NC
    I haven't compared my AC30S1 against a regular AC30C2, and I would be curious to see a video on them. However, the S1 sounds so good, it really doesn't matter what's inside. I am going to try a 5751 soon. I just hate taking out 20 something screws to get to the tubes
     
  7. clintj

    clintj Friend of Leo's

    Apr 4, 2015
    Idaho
    A wall of amps sounds cheaper than a Tesla Powerwall. Think I'll look into that! :D

    Sent from my Pixel 2 using Tapatalk
     
  8. flyswatter

    flyswatter Friend of Leo's

    Jan 12, 2013
    Quebec

    Probably just doing what it takes to survive in a market where consumers with no technical experience treat "all tube" as the Holy Grail and "solid state" as the mark of the Devil.
     
  9. JD0x0

    JD0x0 Poster Extraordinaire

    Age:
    28
    Feb 22, 2009
    New York
    Because they're liars. Just like Supro, Mesa, (and I'm sure many others) call Class A/B cathode biased amps 'Class A amps' and advertise them as such, implying as if there was some inherent superiority compared to other operation modes.
     
  10. Mexitele Blues

    Mexitele Blues Tele-Meister

    Age:
    40
    168
    Mar 7, 2018
    Westminster, CO
    Sounds like the 'design' was all tube, just not the 'production'. ;)
     
  11. gusfinley

    gusfinley Tele-Holic

    506
    Jun 11, 2014
    SLC, UT
    This is as I suspected. This is the bigger brother of the AC10C1 with a few new features.

    I guess having at least one tube in the preamp and one tube in the power amp is good enough for Vox to call something "all tube" or "classic"
     
  12. bluescube

    bluescube Friend of Leo's

    Age:
    51
    Mar 9, 2004
    Greensboro NC
    Yeah .but it sounds really good. If it was crap, I'd raise pitchforks
     
  13. gusfinley

    gusfinley Tele-Holic

    506
    Jun 11, 2014
    SLC, UT
    Are you playing these with teles?

    I could never get excited about the tone from the AC10C1 or the AC30S1. Maybe teles are the other half of the magic recipe? Maybe it is proper speakers?
     
  14. bluescube

    bluescube Friend of Leo's

    Age:
    51
    Mar 9, 2004
    Greensboro NC
    I am using a Tele and a Guild Bluesbird. I did change the speaker to a V-type.

    I now have all Sovtek tubes as well.

    I am getting tonez I really like and to me that is the point
     
  15. Clarkj734

    Clarkj734 Tele-Meister

    285
    Nov 24, 2015
    Bloomfield Hills, MI
    I think what we need to accept is that definitions change and evolve over time. What the purists think of as being "all tube", meaning 50+ year old designs, isn't what the modern definition of a "tube amp" is today.

    I'm not arguing for or against either definition. However, it has changed.

    Personally, I could not care less. If it sounds good, it is good. If it doesn't sound good to me, that doesn't mean its "bad" or "wrong", its just not for me.
     
  16. bluescube

    bluescube Friend of Leo's

    Age:
    51
    Mar 9, 2004
    Greensboro NC
    I can't really find a bad sound in the AC30S1. The tone controls give such a wide variety of tones.
     
  17. archetype

    archetype Fiend of Leo's Silver Supporter

    Jun 4, 2005
    Williamsville NY
    To my knowledge, the definition of "all" hasn't changed.

    Vox isn't vaguely calling it a tube amp: their own description is "All tube design featuring two 12AX7 pre-amp tubes and four EL84 power-amp tubes."

    I, too, couldn't care less what's in the thing, but only if the manufacturer decides to be factual and doesn't try to manipulate me with a lie.
     
  18. Middleman

    Middleman Friend of Leo's

    Aug 29, 2007
    MV, CA
    It's an amazing sounding amp for the money.
     
  19. codamedia

    codamedia Friend of Leo's

    Apr 4, 2009
    Western Canada
    I wouldn't call this a hybrid... to me a hybrid is when either the PRE-AMP or POWER AMP is 100% SS... not when some SS technology is introduced as part of the design. (IMO of course)

    Preamp runs through a tube...
    PI is tube driven...
    Power amp is tube...

    This discussion is not unlike Marshalls use of clipping diodes in their pre-amps. Does that make the JCM 900 and later models hybrids?

    As for whether or not VOX should be marketing them as ALL TUBE or FULL TUBE... I'm not going there. I'm just addressing the "hybrid" comment in the title.
     
    3-Chord-Genius and coldengray like this.
  20. DougM

    DougM Friend of Leo's

    Jul 5, 2017
    Honolulu, HI
    Isn't it interesting how some of the same folks who complain about a tube amp having some SS components will then put a KOT, or other very expensive op-amp box, between their guitar and amp, and then gush over the "magical 3D tone" and "feel".
     
    coldengray likes this.
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.