Advice on Ampeg PF-50T/PF-210/PF-115HE setup....

Discussion in 'Amps and Cabs [BG]' started by SidNitzerglobin, Jun 11, 2020.


  1. SidNitzerglobin

    SidNitzerglobin

    Feb 12, 2019
    fROMOHIO
    So I've had this setup for a few years & been generally very happy w/ it w/ either of the lower output basses (Guild B-301 & a Ric 4003S) for just about any sounds I'm shooting for but am running into challenges dialing the driven sounds w/ the pickups on the higher end of output (JMJ Mustang, Reverend Wattplower, & now a LP Jr. DC). Seems to be going overly fuzzy/grindy & a bit fart-y at pretty moderate volume levels & dialing back gain at the head or the compressor, preamp or OD just seems to take me back to saturated cleans.

    I'm sort of feeling it might be the stock speakers/cabs given the same setup into either of the Eden cabs seems to hold together better in addition to providing a bit better clarity all around (although maybe going a bit more modern sounding than I think would be ideal for me).

    I've generally got the head on the 210 fliptop & have found it to be the better option sonically if I'm going somewhere w/ just one of the cabs so my first thought was to look for a 15" that was going to work better for me, but I really don't know bass speakers very well outside what I've owned so far.

    I guess my main question is am I tilting at windmills going down the path of speaker swaps w/ these cabs? I honestly really like the flip top setup & aside from the lack of side handles (which I could fairly easily remedy if they wound up travelling in & out of my music room w/ any degree of regularity) it seems like a nice setup from a logistical PoV. Love the aesthetic too.

    What do you think?
     
  2. rickdog

    rickdog Gold Supporting Member

    Mar 27, 2010
    My thoughts: if a hotter bass is "fuzzy/grindy & a bit fart-y" and dialing back the gain gets you the sound you had before, it's probably a problem in an early gain stage in the amp, not the speaker.

    Before you start spending $$$ on speakers, try some different preamp tubes in the first gain stage. This is usually identified as V1, I don't have a schematic for the PF-50T to verify this. There might be a block diagram in the owner's manual.

    You might have luck with a different brand of the same type of tube; or you might find that a lower-gain tube in this location helps.
     
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  3. SidNitzerglobin

    SidNitzerglobin

    Feb 12, 2019
    fROMOHIO
    Thanks for the feedback & suggestion!

    That was a path I was considering for sure as I'm still all stock tubes in there as well. I'll grab one of the 5751s I've got in one of the guitar amps & give it a spin. I think they generally used Rubys in these from the factory, I wouldn't be surprised if V1 is going south from where it once was.

    The only reason I'd held off is w/ the lower output ones I've been fairly convinced the tube breakup was a key component of the good driven sounds for me & dialing the gain up at the head just took me further down the path to the (to me) glorious SVT style meltdown sounds. I kinda feel like some of the unpleasantness w/ the higher output pickups have similarity to a "cone cry" type of thing in guitar land.
     
  4. rickdog

    rickdog Gold Supporting Member

    Mar 27, 2010
    I just downloaded the PF-50T Owner's Manual (https://ampeg.com/support/manuals/pf_50t), V1 is the first tube and it's a 12AX7. The block diagram shows there's one gain stage before the gain knob, maybe you're hitting that one too hard?

    A lot of people here have said they like a 5751 for a little less gain, since you already have one it's easy (and free!) to try.

    You can also try different manufacturers' 12AX7/7025/ECC83 (read through 12AX7 / 7025 Tube Reviews - www.thetubestore.com, but take this all with a grain of salt). Try some of those from the guitar amps too, see if they make a difference.

    Nothing like a little tube drive... I have an SVT-3Pro (all tube except the MOSFET output stage), turning up the gain knob brings out the best in that amp.
     
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  5. SidNitzerglobin

    SidNitzerglobin

    Feb 12, 2019
    fROMOHIO
    Forgot that all my JAN 5751s are residing in amps that require chassis removal to get to them so took a path of least resistance & borrowed a known good GE 12AX7A from my AST Pro. Certainly sounds a bit better than the Ruby branded 12AX7WBC HG+ that was in V1, but probably the same fuzz & fart level. I also went ahead & checked bias on the power section & it seemed fairly overbiased, tweaking that to the higher current side of their guidance (right on the edge of the red LED illuminating) it seems like a happier amp generally (better definition/clarity & dimension/bloom to my ears & just a bit more authoritative & solid in general), & minor improvement to the driven sound (later onset of the raggedy fart overtones) but still not quite there when I'm thumping/fingering/popping more aggressively.

    I'm half wondering if my compressor has developed an issue, watching the meter it seems like I'm getting the onset of bad breakup once it traverses ~6db gain reduction w/ the high output basses at 4:1 w/ the output gain right around unity to my ears. I've got the blend fairly low though so it would seem weird if it was the major contributor...

    Another thing that occurred to me is that all of the problematic basses are short scale. Maybe the different transient frequency centers on them is contributing?
     
  6. What's wrong with a volume pedal for the hot basses?
     
  7. rickdog

    rickdog Gold Supporting Member

    Mar 27, 2010
    You might be onto something here. The first bass I ever owned was a medium-scale EB-3. I never got on with it, it seemed awfully woofy, which I thought was because of the shorter scale.

    A few other things I can think of to try to pin down the problem:
    • Plug the basses straight into the amp, eliminate the outboard processing.
    • Set the EQ flat. Start with the master volume up all the way and bring the gain up from the minimum - this will run the preamp as clean as possible and tend towards saturating the power amp. Then reverse this - with the master at a low setting, turn up the gain. Does one way or the other produce better or worse distortion?
    • Try rolling some different tubes through V2 (12AX7) and V3 (12AU7), does this make any difference?
    • Do you have access to a high-pass filter to try? That might tame the short-scale basses.
    In the end, you may find your short-scale basses are simply able to push the amp beyond its limits. In this case, more speaker area might turn out to be your best solution after all.
     
  8. SidNitzerglobin

    SidNitzerglobin

    Feb 12, 2019
    fROMOHIO
    With the Mustang it's a fairly effective option to roll the volume pot off ~25-33% w/o loosing too much but w/ the Wattplower or LP Jr I seem to lose too much of the definition of the edge & the drive/break up gets lost in the fundamental & lower harmonics. I've never had too good of luck w/ the volume pedals not stepping on either the tone and/or the dynamics so far when using it in front of the amp's pre section.

    I'm feeling it's a good bet the most significant source of my discontent is likely in the cabs/speakers. I can reproduce some of the same behaviour cranking the PF50-T output past noon w/ the Guild or the Ric w/ the pre & OD on (either a Tone Hammer or Jr. Barnyard > a Fairfield Circuitry Barbershop) & getting somewhat aggressive w/ my right hand. If I were experiencing the same thing w/ my guitar rigs I would be fairly certain the source was too much speaker breakup anyway.

    Thanks again man! I've been through a lot of that so far (sorry I wasn't more explicit on my troubleshooting to date in the OP), but I appreciate the advice. I've spent a few hours w/ the EQs on the boards trying to pin down my hypothesized transient frequency/ies but so far I haven't found the magic center & Q to fix it w/o loosing the edge that I need. I will try rolling all the tubes here (including the 6L6s as they've been very pingy on cooldown pretty much since I got the amp), that's been my MO w/ my guitar amps for a bit even when it probably wasn't strictly necessary.

    I'll do some more searching on the cabs & see if I can find any pre-existing guidance on if the potential weak link on them in regards to my issue is the speakers or the cabs themselves. I'm awfully tempted to just start trawling for an SVT 6x10 to try out, but I don't know where I'd put another bass cab at the moment & I don't think my back could handle moving that one in & out of the 2nd floor music room :confused:
     
  9. rickdog

    rickdog Gold Supporting Member

    Mar 27, 2010
    "There's no replacement for displacement." Equally true for engines and speakers. ;)

    Big cabs and stairs are not a good mix.
     
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  10. SidNitzerglobin

    SidNitzerglobin

    Feb 12, 2019
    fROMOHIO
    Lol, that exact same truism was running through my head earlier today (although I often find myself happier w/ a well tuned modern FI 4 banger in a car than the modern design smaller cabs I've played through).
     
    Last edited: Jun 12, 2020
  11. el jeffe bass

    el jeffe bass

    Nov 22, 2013
    New Mexico
    I have a Pf20t/Pf112hlf setup that sounds awesome with all of my long scale basses but every time that I’ve tried my jag short scale it sounds nasty. I can’t for the life of me dial out the distortion. I just assumed that it’s just a cheap bass and considered replacing the pickups. The thing is the jag sounds great through my Rumble 100.
     
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  12. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Have we established that you're turning off your tweeters yet?
     
  13. SidNitzerglobin

    SidNitzerglobin

    Feb 12, 2019
    fROMOHIO
    Thanks for that! I haven't tried that yet. I've pretty much left the tweeter alone since I dialed in what seemed like a good blend at the time back when I first got the Portaflex rig together. I would typically run my OR50 > PPC212 alongside the Portaflex stack for the driven sounds (& that's produced my best sounds to date but it's a logistical nightmare for me to take that setup anywhere).

    I'll give it a shot when I get back home.
     
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  14. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Good, because while I have run into folks who actually like the sound of dirt with tweeters, the vast majority of us hate it and experience the same problems you're experiencing. If not the problem, back to the drawing board, but I have a PF-50T and love its dirt, even with stock tubes and stock PF cab.
     
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  15. PraiseBassing

    PraiseBassing Supporting Member

    Mar 6, 2017
    California
    Have you tried plugging straight into the amp without the pedals to confirm it is the amp, not the pedals causing the distortion?
     
  16. rickdog

    rickdog Gold Supporting Member

    Mar 27, 2010
    I used to get great dirt sounds with an 18 in a folded horn... opposite of having a tweeter :laugh:. Amp was a 100W Marshall with the two preamp channels jumpered together and the treble channel cranked into serious distortion. I'm sure it would have sounded horrible with a tweeter, but that cab fixed it.
     
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  17. SidNitzerglobin

    SidNitzerglobin

    Feb 12, 2019
    fROMOHIO
    I must plead ignorance, hadn't even occurred to me to tweak the blend or turn it off all together :confused: This is why I need to spend more time on here... :)

    Wound up getting home late then needing to take care of day job stuff until past my safe/considerate window rattling hours so I didn't get to test it out yet but am looking forward to the opportunity.

    Yeah, the tonal character changes but the raggedness seems to be persistent just straight in when I get the relative gain/back up where I want it (which really isn't all that awfully high in my view), maybe more pronounced on the harder hits as there's no compressor in line.
     
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  18. SidNitzerglobin

    SidNitzerglobin

    Feb 12, 2019
    fROMOHIO
    I got in about an hour & a half switching between the Mustang & the LP Jr. & the tweeter on the -4db setting & off on the PF210 (I had apparently decided I liked the PF115 better w/ it off already so didn't bring it into the mix) & it seems to have made a really significant improvement to my issue w/ it off so far & doesn't seem to have lost anything for me w/ the cleaner sounds w/ those 2 basses either :)

    Thanks alot for the suggestion @JimmyM! Is that like a thing w/ horn tweeters in general or specific to these cabs/tweeters/crossovers? I'll have to haul up the Eden 210XLT & see if there's tweeter related gains to be had for the dirty sounds w/ it too now.
     
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  19. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Glad it worked out for you! It's a thing in general. If I run a DI that doesn't cut off all those high frequencies above 4 or 5 khz, I will stick some sort of low pass filter in front of it for the sole purpose of knocking out those higher frequencies in the PA, no matter how good the PA is. Clean or dirty, I never want those high frequencies on my bass sound. Got no use for them whatsoever. There's a lot of us. Tweeter haters, they call us. But I don't hate tweeters...they have a place...just not on my bass sound :D
     
  20. SidNitzerglobin

    SidNitzerglobin

    Feb 12, 2019
    fROMOHIO
    Makes sense, helps give guitar, cybmals, vox, etc. space in the mix too. Thanks again for the advice!
     
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