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What amps have a tube power section and solid state preamp section?

Discussion in 'Amps and Cabs [BG]' started by fireincairo, Sep 9, 2008.


  1. fireincairo

    fireincairo

    Jul 8, 2008
    I think Music Man used to make some models like this, but did they make bass versions? What other makes/models fit this mold?
     
  2. TFunkadelic

    TFunkadelic

    Apr 9, 2006
    I think you might have a tough time finding something like this. It's essentially the opposite of what is considered desirable in an amplifier these days, and I guess I'm curious what you're going for with this (purely curious, not judging/questioning you).

    Do you want the clean input stage a SS provides but the soft clipping of a tube output stage? If that's it, why not just get an all tube head but keep the gain in check so that it's running clean and not clipping? There are SS heads that have both SS/tube pres, dunno about the reverse though.

    You could buy a tube power amp (plenty of these from various manufacturers around) and get an SS preamp for it.
     
  3. Spencer!

    Spencer!

    Jun 25, 2006
    Seattle
    Owner, Pike Amplification & 3Leaf Audio
    You could always buy a tube power amp and run a SS preamp through it, but what would be the point of that?
     
  4. fireincairo

    fireincairo

    Jul 8, 2008

    Yeah, you have some good ideas here. See, I was thinking that I could user a tube poweramp with a solid state preamp in order to avoid the grind and get as much headroom as possible while still having that fat tube compression tones.
     
  5. fireincairo

    fireincairo

    Jul 8, 2008
    Again, more headroom from your preamp, but still having the fatter tube tone and compression offered by a tube power section.

    Leo Fender made guitar amps like this in the 70s with his Musicman company. I'm betting he made some bass models, too.
     
  6. TFunkadelic

    TFunkadelic

    Apr 9, 2006
    I'll be the first to say I don't know much about the details of tube compression/physics in general, but doesn't a tube preamp accomplish this? The SS power stage can only amplify the signal given to it by the preamp, which, in a tube preamp, could be compressed and grindy. It's cheaper and easier to use a tube pre/SS power hybrid than the other way around, and it seems like they'd serve the same purpose. I've actually heard that the signal is multiplied more times in the pre stage than the power, and thus more of the 'tube tone' is imparted to the signal than if you were running the system in reverse. I don't know how true that is though.
     
  7. edbass

    edbass

    Nov 8, 2004
    +1, I think that's your best bet, a big headroom, clean all tube head (Reeves, Hiwatt, etc.).
    Probably something SS rectified and as TFunkadelic said just watch your gain.
     
  8. not many, as the transformers are already adequate for the high voltages. its a good concept, as solidstate preamps can offer more control over things if they are designed right.
     
  9. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    There seems to be a misconception among solid state fans where they think that tube lovers only use them for grind. Their clean sounds are just as awesome. As long as you don't push a tube power amp past its RMS wattage rating, it will stay clean. My SVT's clean volume tops out at 11 o'clock, but it's giving me all 300w of clean volume.

    And some tube preamps specialize in grind, but almost all of them have a wide enough clean gain stage to where clean and loud shouldn't be an issue. So get what you want, but don't think you can't get great clean tones from tubes at high volumes. You just have to be willing to do some heavy lifting ;)
     
  10. fireincairo

    fireincairo

    Jul 8, 2008
    I tweaked a bit more with my rig and here's what helped:


    So, this 4x10 cab has casters on it. I decided to throw it on its side on the carpet and that eliminated a lot of the boom. I'm also finding that this cab can't really handle the lower frequencies as well as I've read 4x10 cabs can. With my P neck pickups, it's just too fat in the low frequencies. Actually, my J bridge pickups have never sounded fatter and fuller. I've been so used to simply use the P I haven't even really tried the J bridge pickups. It's pretty rad with the bass frequencies turned down a bit. Still fat and the tiniest bit growly, but not like grindy like a preamp overdriving, growly like a J bridge pickup is, you know?

    Thanks for all the thoughts!
     
  11. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    I think there were some strange Trace Elliott heads like this in the late 80s, with solidstate preamp with graphic EQ and dual band compression, driving a valve power section.

    Alex
     
  12. Guitar player friend of mine has a MM 2x10 combo amp that's like this. I gave him the eyebrow :eyebrow: when he told me it was configured that way, as I am not educated on why that config is desirable.

    I don't know of any bass heads that are configured like this.
     
  13. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
  14. JTE

    JTE Supporting Member

    Mar 12, 2008
    Central Illinois, USA
    Yes, Music Man's original amps were solid-state pres and tube power amps. They had two bass heads with the same pre-amps. One had a pair of 6CA7s and the other had four of them, rated at 65 WRMS and 130 WRMS respectivley. Great amps! I wish I still had my old HD-130. The earlier ones had 12AX7 driver between the pre and the power amp, and the later ones only had the power tubes.

    Why? MM's lit touted the advantages of clean sound and low noise in the preamp, with the reliability and power of tubes in the power section. I know I really liked how my rig sounded, and it would be nice to play that with more efficient speaker cabs. Just because it's not still popular doesn't mean it was a bad idea. I doubt that the single 12AX7 in my Eden's pre really adds much "tube-ness" to the sound. All I know is that I like that amp's sound. But that also doesn't mean that the Music Man concept is bad.

    It could be just pricing- if you make the amp with a tube pre and a SS power amp, you don't have to invest in the big honkin' output transformer, nor the expensive tubes. And I suspect that you may be able to build a good SS power section with a slightly less robust power transformer than needed to heat up a bunch of 6CA7s or 6L6s. Thing is that weight costs a lot of money at every step in the distribution chain. You gotta pay to get them shipped to the factory, to get them stocked, to ship them to the dealers, etc.

    Also, you could get a nice SS stand-alone pre-amp you like and match it up with a tube power amp. I don't know what's out there for tube power amps, but in the late '80s Peavey had series of rack-mount tube power amps. I think they were all 6L6 driven, and they had a 100 WRMS version. It's the same power section they used on the Alpha bass amp.




    jte
     
  15. bertbassplayer

    bertbassplayer Supporting Member

    Jul 7, 2000
    Dallas/Ft. Worth, TX
    I have a Peavey Guitar Amp (Deuce) that's solid pre with tube power. I wonder if they made any bass amps like that.
     
  16. danomite64

    danomite64

    Nov 16, 2004
    Tampa, Florida
    Yes, the 100-B.
     
  17. thumpbass1

    thumpbass1

    Jul 4, 2004
    Good old Hartley Peavey did the solid state preamp and tube output thing for the earlier Classic series of guitar amps in the 70's and 80's. I do not recall him ever using that formula for any bass amps. He did the right thing by making the Classic series all tube by the 90's and I wish I'd had the foresight to have bought an all tube Classic 400 bass head back then.
     
  18. +1 I think MM had two models (I think they were called the HD130 and HD150 later on). I owned one way back in the day. Pretty nice sounding at the time, but as posted above, it didn't really make any sense to me from a design standpoint. Those are the only heads I'm aware of that had that design (tube power and SS pre).
     
  19. Hawkeye

    Hawkeye Canuck Amateur

    A guitarist in our worship team at church plays an ancient Peavey Audition series guitar combo. I actually wonder whether it would work as a bass combo because it has a 15" speaker in it and weighs about 80 lbs.

    Anyway that combo has a solid state preamp and 6L6 output tubes. Sounds fantastic by the way. The nicest clean I've ever heard on a cheap amp.
     
  20. danomite64

    danomite64

    Nov 16, 2004
    Tampa, Florida
    The 100-B was the last one they made (in 1982), and it's companion was the all-solid state 120-B. The HD130 and 150 were '70's heads, and IIRC, they had both guitar and bass versions, sort of like Ampeg had the V9, which was the guitar verion of the SVT.
     

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