TF 550 V 420

Discussion in 'Amps and Cabs [BG]' started by bsc, May 19, 2007.

  1. bsc


    May 23, 2006
    Hey everyone,

    just wondering what the main differences between these two models are? Is the 550 much of an upgrade?

  2. spiritbass

    spiritbass Supporting Member

    Jun 9, 2004
    Ashland, MO
    In the current model 550B, there is now a new, improved preamp chip. More capacitance in the power supply. There is now a mute switch. The "bat" switches are shorter. There is a Solid State/Tube emulation switch. There is a new pre-eq balanced DI out. More watts in the mix. That's all I can think of. Fairly significant upgrades IMO.

  3. Mcrelly


    Jun 16, 2003
    Minnesota, USA
    I love my 550b! must be an improvement over the 420, right? if I'm right he added "the switch" which can change the sound: from the Thunderfunk website:

    "The Switch"

    "The Switch" came about in September, 2003 when I spent some soundcheck time with LeAnn Rimes' bassist, Victor, and brought two Thunderfunk amps with me. We AB'd these two amps along with his EBS system. I had made a change to my design that I wanted to test, and the result was that the amp sounded more like the EBS... more "HiFi" and to my ears more "sterile." I decided I liked my original tone better, but then I thought, "Why not just put in a switch?"

    "The Switch changes between the original High Voltage power supply that feeds the power amp, and a separate Low Voltage power supply that gives a more hifi tone. It is subtle. It's not some dramatic tone shaping circuit. It's a change in response and texture. The more sensitive your touch, and the louder you're playing (as the effect is more pronounced when the High Voltage power supply is sagging more). the more you'll hear the difference. It's NOT a two channel amp. It's NOT intended to be changed mid-song as it's not silent. It's just another option to setup the amp for use with different instruments and styles. The Switch is not a tone shifter. In the "tube" position there's more upper mid-range honk." Dave Funk


    I tend to like the newer hifi setting, but its nice to be able to switch back to a fatter rounder sound. according to Mr Funk the switch is not capable of "noiseless" switching between modes, but there is a fairly loud "pop" if the master is up above 10 o'clock.

    I also like the "timbre" constrol. I'm not sure if its on the 420.

    and the 550 has more watts!!!
  4. svtb15

    svtb15 Inactive

    Mar 22, 2004
    Austin,TX - McKinney,TX - NY,NY, - Nashville,TN
    I play it all. Whatever works for the gig. Q+
    The 550B is one great plug and play amp.. incredible and its a top of the line amp in every way
  5. jock


    Jun 7, 2000
    Stockholm, Sweden
    The 420 has the timbre knob too. Only difference on the front is the switch. At least on my 420.
  6. Mcrelly


    Jun 16, 2003
    Minnesota, USA
    ...and power increase.

    have you heard the 550? you might be in a better position to describe the tonal differences between the two.

    I'm just assuming that David Funk would not come out with a newer model unless it was significantly different/better than its predesessor.
  7. jock


    Jun 7, 2000
    Stockholm, Sweden
    I have never heard the 550 so I cant help there.
    I was under the impression that the components changed in the 550 was to lower noise floor and raise the output power etc. But I hear no noice form my 420 at all and I have never run out of power.
    The "switch" seems to be the biggest difference IMO.
    Some of the earlier 420:s had no fan on the back, mine does. But that was a "mod" done by Mr Funk before my amp was shipped to Sweden.
  8. The 420, 550a and 550b sound quite similar. The additional wattage of the 550a and 550b is noticeable IMO, but not overwhelmingly so. The additional 100+ watts does provide a deeper, more solid low end as you push the amp, so to me, it's a meaningful and positive improvement.

    I hear no difference at all between the 550a and 550b, and also have been told that the new preamp chip in the 550b is so subtle as to be not really noticeable.

    There are significant feature differences between these amps. The later 550a and all the b's have double speakon outputs, the 'switch' as described above, which is a GREAT feature (in SS mode, the amp stays crisper and tighter all the way up the volume spectrum to my ear). In addition, the 'B' model has a mute switch and a pre DI out.
  9. Joe BassPlayer

    Joe BassPlayer Supporting Member

    Aug 18, 2002
    Others have specified the feature differences. That being said, I'll just add that having owned both, the TFB-420 and TFB-550 (A/B) both have the classic TFunk sound.

    If you've just got to have a mute switch or want all of the headroom you can get, and have the cash, go for the 550B. If not, the TFB-420 will do just fine. There's not a significant clean volume difference that I can hear. The 420 is a very loud and clean 400 watts.
  10. derrico1

    derrico1 Supporting Member

    Apr 12, 2005
    Charlottesville, VA
    +1. As I've posted elsewhere, the 420 paired with an efficient Schroeder 21012L gets Very Loud.

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