Some Discussion on Amp EQs

Discussion in 'Amps and Cabs [BG]' started by dunwichamps, Jan 21, 2013.


  1. ejsagun

    ejsagun

    Jan 20, 2003
    i have been trying to wrap my head as to how to do it with fets (SVT) style. I read your posts on the first page and it got me wondering on how to execute it. opamps would be easier but wheres the fun in that.
     
  2. dunwichamps

    dunwichamps Commercial User

    Jul 23, 2012
    Owner: Dunwich Amps
    op amps by far are easier to do that with. You can drive a passive james/bax then afterwards use an active mids control (quite a few out there) which do not even need inductors but give you a good approximation of that control.
     
  3. dunwichamps

    dunwichamps Commercial User

    Jul 23, 2012
    Owner: Dunwich Amps
    id need a schematic
     
  4. will33

    will33

    May 22, 2006
    austin,tx
    I don't know how much peaveys VB-2 & 3 have in common with my older Classic 400, but it also has the resonance control.

    Schematics here http://www.hartsafire.com/classic400/

    Turning that control up makes the lowend really big...and "looser" the higher you go. I always kept mine pretty far left as that amp sounds deep and strong as is.
     
  5. dunwichamps

    dunwichamps Commercial User

    Jul 23, 2012
    Owner: Dunwich Amps
    if its a negative feedback control, then it decouples the negative feedback in low frequency resulting in more low end or less low end in the output of the amp.
     
  6. dunwichamps

    dunwichamps Commercial User

    Jul 23, 2012
    Owner: Dunwich Amps
    necrobump!
     
  7. DethByDoom

    DethByDoom

    Sep 23, 2012
    Houston,Tx
    Did someone say necro ?!?
     
  8. eddododo

    eddododo Supporting Member

    Apr 7, 2010
    This thread never dies for me
     
  9. B-string

    B-string Supporting Member

    What do you think of combining shelving and active bandpass such as Gallien uses.
     
  10. dunwichamps

    dunwichamps Commercial User

    Jul 23, 2012
    Owner: Dunwich Amps
    bumping this back up after a bit
     
  11. eddododo

    eddododo Supporting Member

    Apr 7, 2010
    Everybody should subscribe to this, especially amplovers and diy guys
     
  12. dunwichamps

    dunwichamps Commercial User

    Jul 23, 2012
    Owner: Dunwich Amps
    Seems some of the photos may have died, I should try to find a way to make it a bit more permanent
     
    Sartori likes this.
  13. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
  14. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    No need for that anymore, you can just upload them straight to TB.
     
  15. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    With no limits based on subscriber level?
     
  16. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Last edited: Jun 10, 2014
  17. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    I should actually read those new usage links one day ;) Glad you did, though...thx Charlie!
     
    DethByDoom likes this.
  18. BbbyBld

    BbbyBld

    Oct 13, 2005
    Meridian, MS
    Here is a new one for the thread. This is a VB-2 EQ, which is a negative feedback type that is unique to Peavey. This is with one setting of the mid shift switch. The frequency seems a little off from the actual amp, but I'm going to blame the tube models in this case. This is also just the EQ, not the actual speaker output curves. VB-2 low sweep.JPG
    VB-2 mid sweep.JPG VB-2 high sweep.JPG
     
    Sartori, will33 and Passinwind like this.
  19. will33

    will33

    May 22, 2006
    austin,tx
    Again...what a nice thread. It may seem simple for you designers and techs out there, but for the rest of us simpletons it goes a long way towards explaining what's really going on. Especially with things like the losses you get in circuits, and makeup gain, NFB, and the fact that when we say things like we're adding or "boosting" something in the sound we're really not, we're just losing less of it.


    I'd like your take on B-strings question quoted here when you have time...



    I have schematics for these I could dig up if need be, tucked away in old crashed computer hard drives and old emails. A bit outside the jist of this thread as there isn't a tube to be found in the amp anywhere. :)

    But, I find the older Gallien-Kruegers, where the treble shelving is set low enough to have a nice effect on regular paper cone speakers rather than being a sort of quasi tweeter knob, to be extremely musical and useful for our instrument. Simple, intuitive 4-band but the frequency centers, slopes, Q widths, etc. are just spot on to my ear. Notable for musical sounding boosts as well as the "cut what you don't want" approach.

    If I could get that eq coupled to some big honkin' power tubes and iron, with a nice wide range between too clean and too dirty, it might well be my last amp. :)
     
  20. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Nice to see an amp designer from a big company get in on the fun. Thx for sharing, Bobby!
     
    Sartori likes this.
  21. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
    Aug 4, 2021

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.