1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  

Ampeg PF-20T to (power) amp

Discussion in 'Amps and Cabs [BG]' started by Zbysek, Nov 21, 2018.


  1. Zbysek

    Zbysek

    Mar 23, 2017
    Czech Republic
    There is a black friday deal on Ampeg PF-20T in my home town. I am thinking about it... My plan is to send the signal from Ampeg's XLR output to XLR input on my MB Little Mark III to achieve gigworthy sound levels... Does anybody do this?
     
    ficelles and Wisebass like this.
  2. lowendrv

    lowendrv

    Dec 12, 2007
    SoCal
    Have done in past with a PF-50T . Worked great . Sounded better into effects return . Takes the Mark Bass pre-amp out of signal chain .
     
    Leo Smith, Aqualung60, Zbysek and 2 others like this.
  3. johnpbass

    johnpbass

    Feb 18, 2008
    Glen Mills, PA
    I'd like to give that a try with my 20T. You would need one of those Low to Hi Impedance converter thingies though to run into an effects return, right?
     
  4. Wisebass

    Wisebass

    Jan 12, 2017
    Lost in Space
    Getting Saturated Tube Amp Sound at Low Volume

    Hi Zbysek :)

    Funny! Two threads about the same thing.

    One guy wants low volume the other one wants louder! :D

    Like I posted on the other thread: Use your effect return. It works just fine! (did it with a PF50t)

    It works without thingies! :D :hyper:


    may the bass be with you

    Wise(b)ass
     
    Aqualung60 and johnpbass like this.
  5. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    The effects return on Markbass amps doesn't bypass the Markbass preamp.
     
    ahc, Wisebass, spvmhc and 2 others like this.
  6. If the effects loop is parallel & there's no input to the LM3, using the Effects Return would be equivalent of bypassing the preamp.
     
    Zbysek likes this.
  7. Zbysek

    Zbysek

    Mar 23, 2017
    Czech Republic
    What makes you think so?
     
  8. Zbysek

    Zbysek

    Mar 23, 2017
    Czech Republic
    Hi Wisebass,

    yeah, it's no concidence-the other thread inspired this thread...

    What are the advantages of going into effects return? In other words: why to by-pass the preamp? THX
     
  9. Why would you want to pipe a TUBE pre through a SS pre?

    That would be kind of like having a nice tube amp & then using a SS overdrive pedal.
     
    Ric Vice and wizard65 like this.
  10. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Because I used to own a Little Mark II and it didn't bypass the preamp, and the only difference between the two is an improved DI.
     
    Zbysek likes this.
  11. lowendrv

    lowendrv

    Dec 12, 2007
    SoCal
    Yeah Jimmy , I forgot about that . I got rid of that head . Ampeg and GK only now .
     
    Wisebass and JimmyM like this.
  12. Matthijs

    Matthijs

    Jul 3, 2006
    Amsterdam
    Just bought a pf 20 t last week to use it with my eden wt300. The idea is to use it on its own at home and with the wt for louder stuff. I’m hoping the extensive wt eq and the ampeg tubes work really well together.

    Using the effects send and return did work well. No need for impedance thingy’s. The tricky part is to dial in all the different gain levels on top of each other to get something I like at the level I want.
     
  13. lowendrv

    lowendrv

    Dec 12, 2007
    SoCal
    Zbysek , Just get one of your effects pedals and run it into the effects return . You will still be able to use the preamp eq . That's how I found out .
     
    Zbysek likes this.
  14. Wasnex

    Wasnex

    Dec 25, 2011
    For this to work, you need to be concerned with level matching and converting from balanced to unbalanced. Per the PF20T manual, the Transformer Balanced Out is Line Level.

    Using a line matching transformer would convert from balanced to unbalanced, but also shift the signal, so not the right tool.

    For example, the Shure A85U matching transformer specifically says it is not useable with line level, and the Shure A95UF matching transformer user guide indicates the voltage ratio from low (XLR plug) to high impedance (1/4" plug) is either +22 or +28dB depending on which taps are used. Line matching transformers are generally used for microphone level signals.

    If your Effects Return is line level you will need a properly wired adapter to convert from balanced XLR to unbalanced 1/4" TR plug. If your Effects Return is instrument level, you will also need an inline pad such as a Shure A15AS to knock the level down.
     
    johnpbass likes this.
  15. ficelles

    ficelles

    Feb 28, 2010
    Devon, England
    Surely using the LM XLR input and setting the LM eq flat and filters off is the way to go?
     
    Zbysek and Wasnex like this.
  16. Wasnex

    Wasnex

    Dec 25, 2011
    Specs from the Little Mark III webpage suggest you are correct:
    "BALANCED INPUT (XLR): impedance 100 Kohm, max. voltage 25 Vpp"

    Ref : MARKBASS | Products | Little Mark III
     
    Wisebass and Zbysek like this.
  17. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    That's what I'd do.
     
    Zbysek likes this.
  18. hennessybass

    hennessybass Supporting Member

    Oct 11, 2008
    Houston, TX
    I’d keep the gain on the MB way down. Use the pad switch if it has one.
     
    Zbysek likes this.
  19. Isn't the pad for input from the instrument cable jack?
    There won't be anything plugged into that jack in the MB.
     
  20. What is 25Vpp?
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.