anybody use a Groove Tubes Soul-o 45?

Discussion in 'Amps and Cabs' started by zzzzzzz, Feb 11, 2008.


  1. zzzzzzz

    zzzzzzz Supporting Member

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    i just bought a GT Soul-O 45 1x12 combo for $420 on the bay. i've heard alot of good stuff about it but i would like to get all the opinions here about it (good and bad impressions). i'm using lots of pedals and dig super-clean guitar tones up to plenty of overdrive going. i'm not into metal though.

    any thoughts are appreciated. thanks.

    andrew
     
  2. scottlaned

    scottlaned Member

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    You got an amazing deal.

    I used to own one when I used pedals. It is still my favorite clean amp. Tons of headroom, and great great great tone.
     
  3. DanD

    DanD Member

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    I think they are a good clean amp. Mercury Magnetics output transformer with multiple taps is a great feature. Decent tone control although a bright switch would help some.
    They sound really good through 4-10's.
    Takes pedals well.
    Quiet.
    Does yours have a blue LED.
    The reverb is poor.
    Note - Watch out! The top screw nuts can break off of the inner lip of the chassis and fall into the amp and cause catastrophic failure.

    Good luck,

    DanD
     
  4. dave s

    dave s Member

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    I played one of those beauties when the model was relatively new. Soul-O 45 112 combo. Impressions of the amp were:
    • Fantastic clean tones. Lots of different tones in there given the contols and features.
    • Amp could be compressed very easily with the right settings.
    • Took pedals extremely well. At the time, I only had junky pedals because there weren't a lot of boutique and high-quality pedals out there.
    • VERY powerful for a small package, but not overly loud.
    • The only downside to the amp that I remember is that it was almost too powerful for the build quality of the box. I got the impression it was just about ready to bust out of the cabinet when the amp was cooking.
    Enjoy that new amp and let us know via a review after a good test-drive.

    dave
     
  5. TheGrooveking

    TheGrooveking Member

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    To me the Groove Tubes is one of the best made amps out there. As stated in the companies info, it is designed to take pedals extremely well and it does!

    As to Dave S's comment about the cabinet, I have never had any problems with them, the are built very stought. One of mine is my go to amp for playing out and in that combo I changed the factory speaker out for a Celestion Alnico Gold, made the amp much warmer sounding.

    I suggest you put some good tubes into it, install some good Mullard 12AX7/ECC83's into it. Presently I am running Groove Tubes 6L6GE's in mine and loving them. Another real cool feature is the biasing capabilties, by wiring a stereo T/R/S plug to the leads of a digital multimeter and plugging it into the #2 speaker output and selecting either 4 ohm or 16 ohm on the impedance selector you can measure the bias of eaither output tube. They provided a little hole in the bottom of the chassis to allow you to adjust the bias without removing the chassis from the cabinet.

    You scored a great deal on that amp!

    TheGrooveking

    [​IMG]
     
  6. theinteriorleag

    theinteriorleag Member

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    great deal!

    is that the one that was listed for $650?
     
  7. bosstone

    bosstone Member

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    They make a great base for distortion and effects. On their own they are way too clean for me. They are a bit like having half of a Twin Reverb.
     
  8. WahmBoomAh

    WahmBoomAh World Crass Guitarist Silver Supporting Member

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    great deal ... I had one and fought like hell to make it work for me but I couldn`t find the right speaker or tube combonation or something ...I found the treble to be oddly spikey when rolled up and too muffled when rolled down ...True , the reverb is not very usable .Oh , did i mention the day i turned it on and smoke came out ... Rick over there at GT is a sweetheart and they`ll back you up if you need anything.... they fixed mine for free . Don`t get me wrong it`s a quality machine and you got a steal on it ...just be wary and run it hard when you get it .. if you like the way it sounds for you ,,,, you win
     
  9. myles111

    myles111 Member

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    These amps have a cathode follower tone stack ala Marshall and are capable of being a much more agressive amp if desired via a fast and easy mod.

    The mod disables an feedback circuit (which is one aspect of the design that made it an amp specifically designed for pedal use). Some folks put a switch in to disable the feedback curcuit or flip it back to stock.

    What the mod does in brief is this: Imagine the gain control knob has a range of 1-10. With the feedback circuit removed it sort of goes from 1-30.

    How to do the mod:
    When you look at the board facing the board from the rear and looking toward the front where the pots are, look to the right. At the front right there is a pot labelled VR1. The next pot is VR2. Find the next, VR3. Behind VR3 there are to capacitors. Behind those two caps is a resistor. Behind that resistor is the V1 tube socket.

    Bwtween the tube socket and those caps the resistor that you found runs from right to left. Clip the left side of the resistor and lift the left side from the board. Under the resistor you will see the board screened Rfb (resistor feed back) You do not have to worry much about working on these boards as they are very stout with very heavy etch work. GT used PCB where it fit and PTP where it fit.

    Once you have clipped and lifted one side of the resistor you are done! No soldering iron is necessary but to out the amp back to stock just bend the lifted side of the resistor and tack solder it back to it's original position OR put a small switch where it would work for you and you can have it either way.

    These amps use Mercury Magnetics custom designed transformers for both the power and output transformer. The plate voltage is about 500+ which puts them into Bogner Shiva territory. I don't know why the amps were called "45" in the name as I have rarely seen one with even 6L6 tubes that will not put out in excess of 60 watts. They are a killer jazz amp with KT88SVs in a #7 rating (biased at 48-50mA). For 6L6's I like 32mA and for EL34's I like 36-38mA.

    On the combos ... the cabs were built lightly for sonic reasons with a light and resonant baffle board.

    As far as the chassis falling out of the cab, the post above was the first I ever heard of this. My own amp has been around most of the planet and is still as solid as the day it was made.
     
  10. TheGrooveking

    TheGrooveking Member

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    Myles, thanks for the mod info, I'll have to try that! I'll be installing a switch so I can flip between them, matter of fact could I wire it to a small relay and use a footswitch to toggle between the two circuits? Kind of like adding a 2nd higher gain channel?

    TheGrooveking
     
  11. zzzzzzz

    zzzzzzz Supporting Member

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    no, this one was a different one on ebay. the auction stated that it was pickup only but i figured i would ask about shipping anyway and he said ok.
     
  12. zzzzzzz

    zzzzzzz Supporting Member

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    hey all, thanks so much for the replies and helpful info. i'm definitely anxious to get it and try it out.

    i had a GT soul-o 150 head a long time ago and it was really cool. waaayyyy too much power capability but it was pretty sweet. i started getting into pedals alot and the amp didn't really like some of my pedals very much so i decided to try a dr z and never looked back.

    anyway, it looks like the soul-o 45 might be a very sweet amp for me.

    :AOK
     
  13. myles111

    myles111 Member

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    I guess you could do that. Might be sort of a cool idea.
     
  14. myles111

    myles111 Member

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    The S45 and S75/150 are so different they really can't be compared in any way. But ... in the end tone is in the ears of the player and all of these things are personal taste and preference.
     
  15. Gtrman100

    Gtrman100 Member

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    I've had a Soul-O 45 head and 2 1-12 cabs for several years now. I love it- totally spanky clean that sounds great with pedals. Because of the preamp design, it has tremendous definition with overdrive and distortion pedal, and chorus and flangers sound very articulate and 3-D.

    Since it's a single channel, low gain preamp, you have to use pedal to get distortion because even with the gain pot maxed, it's only slightly dirty. Not great sounding dirt, either. So, I have the input gain at about 1-2 O'clock so that it fattens up the pedal distortion and warms up the clean tones with no pedals. But the power amp \ has so much headroom that even when it's really loud, it's very dynamic. It feels like the strings are directly connected to the speakers!

    My only gripes is that it's voiced very bright and the small pan reverb isn't very good. I've tried different preamp tubes, and the Mullard clone I've got in there now has tamed it a bit, but it's still really bright. Maybe Myles has a mod to tone it down a bit.
     
  16. TheGrooveking

    TheGrooveking Member

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    Another rmighty cool feature that you hopefully never try is they designed it so that if no speaker is plugged into the amp, it automatically shuts down, therefore saving you transformers and tubes.

    I found a very cool setup and that is I run a Maxon CP101 Compressor into a Fulltone Fat Boost, when ran into the Soul-O 45 it sounds like the notes just bloom in a very musical way, like they are alive!

    Another idea about the reverb I need to look at is running tandem reverb reverb boxes. I have a Tube Works Real Tube Reverb unit, which to me is the ultimate, it has twelve springs that are about 15" long. They are set up in two groups of six, one set for each channel. But the cool thing is you can run them in series and I will tell you there is nothing else that gets that sound.

    I have noticed the reverb knob is not linear on the Soul-O 45, and until it is turned up to about 11 o'clock there really isn't much reverb going on at all. So I wonder if I installed a second reverb unit along the side wall of the cabinet and ran the output of the original lower reverb pan into that side one and then back into the amp if it would work, giving me a broader more deeper range of reverb. I'll have to contact Accutronics and GT about this but since I am going to open the amp up for the gain mod it may the perfect time.

    Eventually I'll have to add a few bolts to stick out of the side of this thing, so it's a better respresentative of being a Frankenstein....LOL.

    TheGrooveking
     
  17. myles111

    myles111 Member

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    The tone controls are very interactive. Have you tried really rolling back on the treble and presence?

    If this did not work, call Jimmy over at GT toll free at 1-800-459-5687 as he has a lot of tricks on the S-45 for things such as this.
     
  18. PSaulino

    PSaulino Silver Supporting Member

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    Try this:

    * Turn up the Preamp gain AND the Master volume to about 1:00 or a little more
    * Adjust the volume using the effects return on the back... you'll no doubt have to turn it down (!)
    * The amp will still be clean ,but very much fatter. Makes a huge difference and you will LOVE the amp even more.
    * The reverb becomes VERY wet in this mode and you have to turn it down to rebalance it.

    The RFB mod Myles describes works... I did it to mine but preferred it without it.

    Jim W. at GT recomended clipping the negative feedback loop in the output section as another mod. I believe this is more and different than what the RFB mod accomplishes.

    Paul
     
  19. myles111

    myles111 Member

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    Paul,

    As a bit of a side note, removing the NFB loop as per Jimmy makes the amp agressive and you loose the cleans. If you want something like that then go the route of a Marshall JCM800 type of amp.

    Jimmy's tastes and his own playing style tend to be on the agressive side:

    [​IMG]

    [​IMG]

    [​IMG]

    Above ... Jimmy's amps that he uses when he plays

    [​IMG]

    [​IMG]

    His own designed and built pedal:

    [​IMG]

    [​IMG]

    Jimmy with Zakk's Marshalls after we re-did them over here.

    [​IMG]

    and lastly above ... Jimmy's own amp that he makes ... skull and all.

    My question here is .... do you think he is the guy to talk to about clean tone?
     
  20. gkelm

    gkelm Supporting Member

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    Hey guys...I've been offered one of these in trade. Any idea what a Soul-O 45 combo is worth these days?
     

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