New Poweramp Day (ISP Stealth Ultra Lite)

Discussion in 'Gear & Equipment' started by kindsage, Sep 16, 2017.

  1. kindsage

    kindsage SS.org Regular

    Messages:
    2,218
    Likes Received:
    115
    Joined:
    Feb 20, 2013
    Location:
    Los Angeles, CA
    Pictures first :)

    [​IMG]

    [​IMG]

    Sounds great for its size but the EQ kind of sucks in my opinion. I was expecting controls that behaved more like Presence and Resonance controls but, they don't. If I were to describe it, I would say the Bass and Treble knobs behave more like an 2 band graphic EQ. Which I guess I probably should have expected.

    The Mosvalve sounds much closer to a full size tube poweramp and to me the presence control behaves exactly like the presence control on my old 6505.

    I would keep this little guy if I really needed a portable setup but, I'd rather just return it and put the money into repairing channel B of the Mosvlave.
     
    exo and takotakumi like this.
  2. Kyle Jordan

    Kyle Jordan Ace of Knaves

    Messages:
    25
    Likes Received:
    8
    Joined:
    May 25, 2008
    Location:
    Karakura Town
    Beyond your Mosvalve, can you compare the Stealth to any other power amps?

    I'm looking heavily at nabbing a Theta pedal and want some type of power amp for it that's relatively inexpensive, but the few Stealth demoes I can find weren't really floating my boat. I'd like to stick to solid state for this little rig too both for the feel off SS and ease of owning.
     
  3. kindsage

    kindsage SS.org Regular

    Messages:
    2,218
    Likes Received:
    115
    Joined:
    Feb 20, 2013
    Location:
    Los Angeles, CA
    Other than the Mosvalve I've only ever owned tube heads. I would just use the poweramp of the head via the effects return.

    I recommend the Mosvalve honestly. For the price I don't think you can beat it. They're stereo, sound GREAT, and can be found used for $300.

    Warning though, the mosvalve is heavy as fu**. Heavier than some tube heads I've owned.

    There's also the quilter mini heads like the Problock 200. Many users on here swear by their quilter heads. Those go for $500 brand new and can fit on a pedalboard.
     
  4. lewis

    lewis SS.org Regular

    Messages:
    3,283
    Likes Received:
    450
    Joined:
    Aug 16, 2011
    Location:
    Norfolk, UK
    i thought this would be the case which is why I decided to add the Duncan powerstage 170 to my "to buy" list over this.
     
  5. kindsage

    kindsage SS.org Regular

    Messages:
    2,218
    Likes Received:
    115
    Joined:
    Feb 20, 2013
    Location:
    Los Angeles, CA
    Do the bass and treble knobs act like presence and resonance in the Powerstage 170?

    That's really what I'm looking for in an SS poweramp. The Mosvalve NAILS presence but, it's missing a resonance control
     
  6. HeHasTheJazzHands

    HeHasTheJazzHands greg rulz ok

    Messages:
    20,702
    Likes Received:
    1,965
    Joined:
    Jun 18, 2011
    Location:
    Louisiana
    I had the MV942. Sounded good, but I preferred the power section of my 5150II. If you like mids, the MV is good choice. It's like... nothing but mids. :lol: Not much low end thump. Probably because of the lack of a resonance control. The power amp's biggest flaw.

    And yes, it IS heavy as fuck. Around 40LB.
     
    kindsage likes this.
  7. lewis

    lewis SS.org Regular

    Messages:
    3,283
    Likes Received:
    450
    Joined:
    Aug 16, 2011
    Location:
    Norfolk, UK
    it uses the same EQ as its bigger brother.
    This vid may help. Not sure

    Mark is great so -
     
  8. kindsage

    kindsage SS.org Regular

    Messages:
    2,218
    Likes Received:
    115
    Joined:
    Feb 20, 2013
    Location:
    Los Angeles, CA
    Have you ever tried it in a live band mix? I'm curious as to how it performs in that environment (I'm more of a home jammer). I figure the lack of low end thump along with the mid-rangey character help it cut through without stepping on the bassist's toes.
     
  9. kindsage

    kindsage SS.org Regular

    Messages:
    2,218
    Likes Received:
    115
    Joined:
    Feb 20, 2013
    Location:
    Los Angeles, CA

    That video helps actually. I think I'll steer clear of the Power Stage 170. Again it just sounds like there's a 3 band eq placed before the power section. It doesn't sound like Presence or Resonance Controls
     
    lewis likes this.
  10. lewis

    lewis SS.org Regular

    Messages:
    3,283
    Likes Received:
    450
    Joined:
    Aug 16, 2011
    Location:
    Norfolk, UK
    glad I could help bud.

    Tbh I dont think anything ever really gets close to presence/resonance controls other than a tube amp with those knobs.
     
  11. kindsage

    kindsage SS.org Regular

    Messages:
    2,218
    Likes Received:
    115
    Joined:
    Feb 20, 2013
    Location:
    Los Angeles, CA
    True. I'm sure a kick-ass SS poweramp that sounds equivalent to a Fryette will come out some day but, probably not for another decade lol.
     
    lewis likes this.
  12. lewis

    lewis SS.org Regular

    Messages:
    3,283
    Likes Received:
    450
    Joined:
    Aug 16, 2011
    Location:
    Norfolk, UK
    for sure!. The fryette is godly from demos Ive heard.

    We need some sort of Kemper tech that perfectly perfectly replicates JUST tube poweramps. Kemper gets close to a recorded sound of an entire signal, but I want something that can give me the Fryette or any other unique tube poweramp, sound and Feel with real working presence/resonance controls.

    Im sure it cant be THAT far off!?!? :(
    Would buy one right now if it was announced.
     
    takotakumi likes this.
  13. Spaced Out Ace

    Spaced Out Ace 0 0 1 0 0 6 5 0 3\

    Messages:
    3,041
    Likes Received:
    433
    Joined:
    Jan 27, 2010
    Location:
    Washington
    Nice. How's the Mosvalve?
     
  14. kindsage

    kindsage SS.org Regular

    Messages:
    2,218
    Likes Received:
    115
    Joined:
    Feb 20, 2013
    Location:
    Los Angeles, CA
    Its been great. Channel B is busted but I can still drive two cabs with just channel A so that works out.

    I haven't been able to compare it to other solid-state Poweramps other than the ISP but, I almost like it as much as my old 6505 poweramp.
    It actually sounded a little bit cleared than the 6505 to me but, it just lacks a resonance circuit to give it that thump. The presence knob is a godsend though. It adds the perfect amount of cut and clarity. It's just like the 6505 presence knob.

    Really its perfect to me except for the lack of a resonance circuit.

    If you're considering it I say give it a shot. I run my AMT R2 preamp into it and together they make a GREAT tube-like solidstate rig.
    I liked them together so much I sold my 6505. This was about 2 years ago.
     
    mnemonic and Spaced Out Ace like this.
  15. Spaced Out Ace

    Spaced Out Ace 0 0 1 0 0 6 5 0 3\

    Messages:
    3,041
    Likes Received:
    433
    Joined:
    Jan 27, 2010
    Location:
    Washington
    I don't think I have the room or funds for a Mosvalve at the moment. Was just curious what you thought of it.
     
  16. Zoobiedood

    Zoobiedood SS.org Regular

    Messages:
    77
    Likes Received:
    15
    Joined:
    Sep 1, 2015
    Location:
    Tampa Bay
    The EQ on the PowerStage is active and centered here:
    • TREBLE CONTROL:+/- 13 dB @6.61 kHz
    • MID CONTROL:+/- 13 dB @712 Hz
    • BASS CONTROL:+/- 13 dB @87 Hz
    I am not sure how this relates to presence & resonance.
     
  17. Shask

    Shask SS.org Regular

    Messages:
    2,982
    Likes Received:
    163
    Joined:
    Nov 27, 2011
    Location:
    Indianapolis
    I highly doubt any solid state EQ is ever going to work exactly like a resonance/presence control on a tube power amp.

    Tube amps are current devices, and solid state are voltage devices. That means solid state amps never have that same feedback interaction with the speaker that the tube amps do through the output transformer.

    The resonance/presence controls are basically just altering the amount of feedback through the output tubes, output transformer, and speakers. Presence can get close because it is such high frequencies, but the resonance is close to the resonant frequency of the speakers, so there is extra interaction which is what causes the thump, and chug. Same reason why my Matrix GT1000FX and Axe-FX II don't have the same kind of chug and thump as a tube amp. They are good, but never the same.

    So, basically, since solid state amps have no feedback from the speakers, you cant alter the feedback, which is what the resonance control does. Best we can really do is approximate it with an EQ.
     
    takotakumi, kindsage and mnemonic like this.
  18. mnemonic

    mnemonic Custom User Title

    Messages:
    4,091
    Likes Received:
    386
    Joined:
    Sep 22, 2006
    Location:
    Chester, UK
    Good post. Goes a ways to describing why modeling by itself will never directly be the 'same' as a tube amp through a cab, no matter how accurate the modeling or how flat the poweramp. It's gonna require a different way of building a solidstate poweramp, rather than more modeling advances.

    Steven Fryette goes into this kind of stuff on his 'modelling workshop' videos on YouTube where he demonstrates various modelers through different tube and solidstate poweramps.
     
  19. kindsage

    kindsage SS.org Regular

    Messages:
    2,218
    Likes Received:
    115
    Joined:
    Feb 20, 2013
    Location:
    Los Angeles, CA

    Finally an answer! I've asked why solidstate can't have a resonance control on other forums and all I got was a bunch of smart asses trolling me.
    Thank you
     
    Shask likes this.
  20. Shask

    Shask SS.org Regular

    Messages:
    2,982
    Likes Received:
    163
    Joined:
    Nov 27, 2011
    Location:
    Indianapolis
    Yeah, with tubes, there is an impedance interaction curve that the power tubes and output transformer gets from the speaker. It dynamically interacts with the power amp to change the frequency response, and dynamics constantly. Resonance and Presence controls dial in this amount of interaction. Solid state amps dont have this same sort of interaction, which is why older solid state amps have that razor-tight response. (Marshall 8100, Ampeg VH, etc....)

    Companies are finding ways to approximate this, but it is never exactly the same. The Axe-FX II has the speaker page where you can tweak the parameters of the impedance curve simulation. The reason why the Boss Katana has been so popular lately is because it has great dynamics. It has some sort of DSP that interacts in the power amp section somehow to approximate the tube sag. I think that is the key to that whole amp, because the preamp models are not much different than their GT floorboards.

    For companies to improve it in the future, they really need to figure out a way to get the same impedance interaction with solid state components.
     
    Last edited: Sep 18, 2017
    takotakumi likes this.

Share This Page