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Tube power sections, what am I missing?

Discussion in 'Amps and Cabs [BG]' started by jazzbass_5, Jul 16, 2017.

  1. jazzbass_5


    Sep 1, 2007
    NY, Albion
    I guess I really need to invest in an SVT-VR. I always tout the awesomeness of my Ampeg preamps and the very convincing emulation my Sansamp RBI produces (pic below). Other that playing through an SVT-VR at a music store (not the same) I've never played through one in a professional stage setting. Even after 35+ years of playing. Sad...
    My SVP-PRO has a great growl, what sounds to me like the true Ampeg sound through my SVT cab, the SVPCL Is clean and sweet with crystal highs and great mids and lows, always can get the nice scooped sound if I need it from both. The Tech 21 Sansamp RBI is superb at getting all of these sounds in one package. All preamps though.
    I have a selection of cabs I use, 2x10s, 2x12s, 2 - 4x10s, and my 8x10 SVT heritage.
    Here lies my issue.
    Usually I use one of my 2 Peavey DPC 1400x power amps to power whatever setup I have. I also use a QVC PLX3002 and I have a Peavey GPS 3500 as a backup.
    So, no tube power.. I dont know tube power.
    Can someone explain what I'm missing with a tube power section? I'll take the plunge if needed at some point.

    armybass and jimmyjames77 like this.
  2. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Fairly hard to explain, but the valve amp good tone vibe comes from the power section.
  3. The warm glow of filaments. :smug:

    Likely you'll just have to experience it in real life at a gig to know what it's about.
    If you've never eaten ice cream, (or never partaken in another activity of your choosing ;)) someone could try to describe to you what it is like. But it really wouldn't be the same.

    Maybe you need to rent an amp (or whatever ;)) and try it for yourself.
    P-oddz and jazzbass_5 like this.
  4. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    It can't really be explained because it's something you hear and feel. People use all these terms like "warm", "organic", "three dimensional" that are really meaningless...you have to experience it for yourself.

    I've never owned an SVT (though I've had many other tube amps) but have played through plenty of them at gigs with provided backlines. They are a lot of fun, have their own sound and it's not just the preamp, it's also the power amp and speakers (I think the low end rolloff is key to the cabs).

    If you're really curious, just rent a head for a gig and use it with your 810.
    jazzbass_5 likes this.
  5. jazzbass_5


    Sep 1, 2007
    NY, Albion
    The low end roll off is absolutely present with that cab with any of my preamp/amp setups, but again, I'd need to hear it with an SVT head.
    My 4x10s and my 2x12s have much better low end response, and of course are ported cabinets.
  6. Power Tube overdrive.
  7. jazzbass_5


    Sep 1, 2007
    NY, Albion
    I'm guessing that's the sound I'm missing, the SVP-PRO has a great over driven sound, has 5 preamp tubes within its circuitry (the SVPCL 4). But I'm sure it's not the same.
    armybass likes this.
  8. geowis

    geowis Supporting Member

    Dec 31, 2011
    Hopewell, NJ
    I grew up with all tube power sections and it really is a thing. But, since I'm only a few years from 60, their weight is becoming an obstacle.

    I've recently added a Two Notes Torpedo CAB. It's marketed as a cab sim, but it also offers several power section sims. I have it set on the K88 power amp through an Ampeg Fridge and can barely discern the difference from the real deal. One reason it's so close is because it's effected by how much you dig in. Another plus is it's there no matter your volume.

    I've learned that the only hair I desire on my tone is a driven power section, as it also acts as a natural compressor which is a big part of that elusive tone we all chase.

    If you want more details on my rig, let me know.
  9. jazzbass_5


    Sep 1, 2007
    NY, Albion
    At 53 I know the struggle. I actually have my SVP-PRO and SVPCL in one rack and I A/B Them when I play for clean and dirty. In fact, I just sat in front of them and did it to compare.. again. It really is the Ampeg grind with the pro, and yes its nice that I can adjust the volume from at the power amp. I will at some point own an SVT-VR just because. I do also have and use a Alesis nanocompressor (in the picture single rack with my wireless). But I'm sure it's not the same as tube power section sound.
    armybass likes this.
  10. NoiseNinja

    NoiseNinja Experimental-psychedelic-ambient-noise-drone Banned

    Feb 23, 2011
    Well, tube amps tend to have a certain organic quality, like they respond more immediate and naturally to your play and dynamics.

    Hard to explain, but in a way a typical tube amp will reproduce tones with more depth, like adding another dimension to your sound or something.

    In other words you wont know what you are missing out on, and if it even really is something for you that would accommodate the tone you seek to achieve, before you try it out.

    I myself run a bi-amp rig with a SS section and a tube amp section simultaneously, even if I do actually run a tube preamp in front of the solid state section also.

    I for one love this combination.

    The majority of the time I played bass I used a pure tube amp though, an Ampeg B-15S 60W, and I started out with a hybrid with something as rare as SS preamp stage and tubes poweramp stage.

    I preferred what the all tubes B-15 did to my tone over the hybrid, but honestly what I got now tube preamp>SS preamp>SS poweramp/pure tubes amp is near optimal for the tone I desire to achieve at the moment.
    Last edited: Jul 16, 2017
    armybass likes this.
  11. jazzbass_5


    Sep 1, 2007
    NY, Albion
    Here's a question, in looking at the Ampeg SVT-VR reissue (new) and consideration in purchasing an old one in decent shape. Besides the obvious with the used one, making sure it works, having it gone through and possibly retubed by a pro.

    Are there any real differences in the sound?
    Last edited: Jul 16, 2017
  12. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    Depends on who you ask. I think the variance comes down more to individual amp/cab setups and selective memory than anything else. I've had an SVT-CL and now a 74 SVT. Haven't owned a VR. There are circuit differences, obviously, but you can get the same sounds out of all of them. And for not having to deal with the occasional headaches of vintage amp a used VR would probably be the route I went assuming similar pricing. If you decide to go vintage consider recap costs if it hasn't had that kind of work done. The early VR amps had the low voltage protection relay circuit issue but there's a workaround and it was corrected in the newer models.
    jazzbass_5 likes this.
  13. jazzbass_5


    Sep 1, 2007
    NY, Albion
    Thank you,

    As an Electronics tech by trade for years I guess I would expect, as they claim, the circuitry is the same but I'm sure they use newer style boards, and possibly different layouts. Better parts (newer caps) and weeded out the problems the unit may have had. I'm all good with that, I expect and difference in sound would be only slight.
    @JimmyM ?
  14. Ampslut

    Ampslut Supporting Member

    May 15, 2017
    I am a dedicated SS guy mostly due to bad experiences with Traynor tube bass amps. I did however play for several years a Sunn 200S 80 watt tube amp through a Sunn Sorado 2x15 EVM-B's. During that time I did switch between the 200S and a Peavey Centurion head. The tube head had a much more transparent tone. The overtones were clearer and more defined. The Peavey head however, seemed to hit harder with a less compressed sound. Fast forward to a few years back and I'm using a Alembic F1-X (arguably the best bass tube pre-amp ever made) with a QSC PLX1202 bridged into a Whappo Jr. At this time I felt this was the best rig money could buy for me. The transparency of the overtones were very similar to the old 200S but, with a much tighter punchier feel. Comparing the tube and SS power sections I think the biggest difference is with the feel, how the amp responds to your touch. I have found this to be the difference.

    PS. I sold the F1-X after I got a SVP-Pro which I liked even better.
    Last edited: Jul 16, 2017
    jazzbass_5 likes this.
  15. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    One of the bigger differences with the vintage and modern amps is the tube complement. Up to the first SLM era amps in the mid 80s they used a 6C4 which is highly prone to microphonics, 12BH7 in the driver positions, and up until the early 80s they were using 12DW7s. The new design drops these in favor of more commonly available 12AX7 and 12AU7 tubes but keeps a similar circuit path. The SVT-CL is single channel versus the two channels of the vintage and VR amps.
    jazzbass_5 likes this.
  16. jazzbass_5


    Sep 1, 2007
    NY, Albion
    This thread may be of intrest to you.
  17. ThinCrappyTone

    ThinCrappyTone Mostly harmless

    Oct 1, 2011
    Massachusetts, USA
    My very non-scientific impressions of the tube power difference, based on personal experience:

    • The ones I have played tend to sound great as you dig in and push them toward the edge of distortion, where ss power amps I have used often have the opposite response in those situations

    • There is something about the audibility/presence of tube power amps in a loud band situation. Somehow they cut through and have impact, while still being warm, even when playing with one or two overly loud guitarists with 100w half-stacks and a hard hitting drummer, for example

    • There is a response when you are playing that is different, and somehow more inspiring (to many). It's a hard to describe sag and push. Some say it's psychosomatic. Many swear by it.

    I have both ss and tube. Prefer tube in most cases.
    Jefenator, P-oddz and jazzbass_5 like this.
  18. seamonkey


    Aug 6, 2004
    You're not missing anything if you like the sound you got.
    There is nothing magical about tube power sections. Reverse is also true, nothing magical about solid-state (any class) power sections. The good tone is from the pre-amps
    jazzbass_5 likes this.
  19. jazzbass_5


    Sep 1, 2007
    NY, Albion
    I absolutely do love my tube and solid state preamps. I will someday own an SVT-VR just on principle alone, and it would go so nice with my 8x10. I'm not missing out from what I can hear.
    When the day comes that I do get the chance to play live through an SVT head I will see the difference then I guess. Can't believe I've gone this long without that.
  20. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Corey pretty much answered you...they do use more common tubes in the preamp than they did back in the day, but all those oddball tubes are just variations on the 12ax7's and 12au7's they use now, so through different wiring schemes, they can get the exact same sounds. And to me they sound the same, too, but they can change slightly depending on the brand of V1 preamp tube you use IMHO.

    This comment would have a lot more authority if he ever played a tube amp, but he has not. Instead, he continues to insist that SS and digital modelers sound exactly the same and all the sound is from the preamp only, despite zero hands-on experience with tube amps. He is wrong. Do you absolutely have to have a tube amp? No you don't. Plenty of folks use SS amps and are happy with them. But this comment from him is a flat-out lie.
    Arrow, bobyoung53, Jefenator and 9 others like this.