pedal for Fender Bassman sound

[gutsofgold]

I've been itching to get a Fender Bassman RI for a long time now. So much of my inspiration comes for those late 50s early 60s guys but I just can't afford one now. Is there a pedal I can build to get my close that sound? I know boss makes one but I'd rather get my hands dirty. Any ideas?

[petemoore]

  I saw a Fender Bassman pedal at GC yesterday, and a Deluxe Reverb one IIRC. 
   See Runoffgroove.
  DIY, Use Jfets @9 or more volts.
  Get a schematic of the pre-amp only, build it as described above, using Jfets to 'replace' any active tube stages...
  Not sure at all what Fender has under the hood of their Bassman Amp-pedal.
  Low voltage Amp-Pedals do 'Close' or what I'd call 'averaged'...the frequency response of the components in the output section of a tube amp changes with frequency and amplitude, to get this into a pedal means these time/frequency changes can be 'averaged'..iow treble can be rolled off, but at a constant amount [this, and other 'parameters' don't change so much with input levels that change over time like the output section of an amp would].
  These amp frequency and amplitude changes happed as fast as the frequency and amplitude changes do at the input, some of that can be emulated at 9V with Jfets, however the actual amp has a speaker which changes it's load etc. etc. during it's excursions...influencing all that other amp stuff [OT / Tubes / PS].
  My question is how well do they work when used like an amp ? You'll be getting some amp sound anyway because you'll be using one...how do the pedals respond in comparison to the way an amp responds when pedals are used to push it harder, or a clipped signal is the input.
  I'll have to check and see if there are any lucid reviews of these 'Fender Amp' pedals, I wonder if anyone has dissected one and found Jfets in it.
  I also would guess it isn't simply a 9v recreation of the pre-amp section, I should try one out and see how much they distort.
  And somehow get increasing amounts of subtle distortion as input level rises, ['numerous soft clipping stages?] plenty of boost at the output.
  Now that I've provided some blind speculation, it'd be fun to see if they put in a two-pole LP filter in the middle or at the end...lol...more BS [blind speculation]...or beneficial suggestion.

[dschwartz]

the fender bassman pedal..probably all DSP...

try the professor tweed from ROG..it gets pretty close to a bassman or princeton amp..

[bool]

ho...hum

many takes possible on this one ...

http://www.redcircuits.com/Page120.htm


look at roland cube preamp...

http://www.freeinfosociety.com/electronics/schemview.php?id=1328

[JHS]

Take the B-of-Rock schem (can be found in nearly any other FX-forum) and modify the filter at the output a bit and you're get what you want.

The B-of-Rock is IMHO one of the best JTM45 emulaters and the JTM45 is 99% identical to the old Fender Bassman. The RI is tighter, harsher sounding with more headroom and is voiced a bit different to match the blue Alnico speaker (they sound quite different compared to the real ones), but this can be implied in the output-filter too.

JHS

[SPAZ]

               Why not the bassman, the geniuses of all great amp tone ? So many amps that followed have been emulated.

[JHS]

A bassman played clean sounds really nice but overdriven totally crap, especially the Ri-Bassman. The sound at full tilt is to bassy, middy and loose and pumps due to the rectifier like hell when dimed. IMHO impossible to emulate the pumping of the rectifier, maybe with a pumping compressor in front of it.

Same with a JTM45 and furthermore the JTM RIs with this cheap Drake output transformer making the Distortion thin and harsh when dimed. When I play a BM or JTM45 I always stuck a treble booster in front of it to kill the rumble bass and for adding treble bite to cut through.

BTW: most amp-emulaters sound like crap and don't react to the guitar like the real amp.

JHS

[petemoore]

  The Cube's 1rst 220k at Q1 base looks like it has a jumper wire across it..