ThunderFunk TFB420, TFB550-B, or Gibson GB440. Your Choice
"Natural, focused, clear, and coherent. That's the goal."
Those who have heard me play know these amplifiers sound phenomenal - after all, it's not entirely my magic fingers ...
If you surf, here are the prices you'll typically find:
• TFB550-B (Gold Chip Version) - $760 (were about $1000 new) - Excellent condition. This one also has the handle but the rack ears are squirreled away somewhere. My intent is to auction the rack ears separately (when they are found).
• TFB420 - $600 - Very Good condition (a NAMM 2004 prototype, and one of the first of second generation models). This one has a factory-original fan, but when purchased, cash-strapped Dave just poked a hole in the standard non-fanned chassis (there are perhaps a dozen or two out there like this one). It has a handle but the rack ears are available. My intent is auction the rack ears separately - apparently they are no longer available - or we can negotiate with your best offer.
• Here's how this unusual listing works:
• You pick ONE. Make me an offer. I accept and that one is yours. The remaining amp will be inserted into my EA VL-208 Combo.
• Bottom Line: The Long Story Short: Taxes to Pay so one must go to a new home, and there is not enough difference for me to really choose - so you get to help me decide!
Be clear: you get only ONE ... but you choose which one, and we agree on a fair price. Make your best offer for the early ThunderFunk TFB440 (10" deep and with a Factory Original-if-hacked-in Fan) ... OR the ThunderFunk TFB550-B (10-1/2" deep with a bit more power, plus a mute, "the switch", and the so-called Gold Chip).
EXTRA's: I have also a custom shoulder-strap carrying case for the T'Funks - made for 2004 NAMM and with the T'Funk Logo embroidered. It is pretty cool and fits both ... and ... I have a factory original all-aluminum but not-yet powder coated TFB420 chassis (used to size this carrying case). My intent is auction this separately - or we can negotiate with your best offer. If you want more details, just ask.
Conditions range from great to near-mint.
Here is some history ... it should be mostly accurate.
Over 20 years ago, Russ Allee, who designed the 360 and 370 amps for Acoustic, left that company to start a new company called Amplified Music Products (AMP). Russ hired Steve Rabe, another ex-Acoustic guy, to come up with a new design. The preamp including an “enhance” switch (at the time an original concept, iirc), fixed frequency bass and treble knobs, plus four semi-parametric midrange bands. The design had a variable limiter and a crossover for bi-amping. AMP called the all solid-state 400-watt model the 420 and they made a lower wattage version was called the 260.
Steve Rabe left AMP and founded SWR. SWR’s Studio 220 and SM-400 were pretty similar to the old AMP design except a 12AX7 tube was used in the input gain stage, and the enhance switch was replaced with a variable “aural enhancer” knob. Since he had located his shop in the same industrial mall as Groove Tubes, Aspen had Steve design the near identical GT bass preamp which was identical to the front end of an SWR studio 220, but without a power section.
David Nordschow, after a failed partnership with Steve Rabe (perhaps it was a speaker line?), opened Eden Electronics including Russ Allee on the design team. The “world tour” series were developed, very similar to the AMP-420 and SWR studio 220 except with 3 semi-parametric bands and the compressor simplified to a simple on/off switch (a design feature which stayed with the Gibson Design, relabeled "Limiter"). Like SWR, the Eden incorporated a 12AX7 preamp tube.
AMP folded in 1988 and was apparently bought by Gibson. Some say Russ Allee was then hired by Gibson for additional design tweaks to create the GB-440. Production of the GB-440 was short lived - halted around 1992. I’m not sure why but do know they were really really expensive - as an example the 1x15" cabinet-only listed for $849. Remaining components were warehoused.
Dave Funk was a repairman for Gibson when, around 2001 (?), a Gibson manager offered him the warehouse contents. Funk paid about $2000 and found enough remnants to assemble eighty GB-440 amps. You can identify these because they are labeled "Gibson" but Dave signed each one on the back (as part of his deal and for warrantee concerns). After hearing rave comments from the players who tried them, Dave started building his own - duplicating the design in a chassis with his name on them, and then steadily “improving” the design - although he will be the first to say there was not much to improve upon. He started by swapping out for better components and making a "cleaner" circuit board to remove flying wires, then over the past decade, adding speakons, the fan (added because although the amp can run without it, digital equipment running in racks adjacent may not survive the heat), more power, a switch to select two different (albeit subtle) voicings, variations on DI taps, etc. Dave will modify or repair any of his earlier builds, but is currently only offering the 800 amp model at a cost of about $1900.
I have owned them all: The AMP 440 and AMP SL-1, The Groove Tube Preamp (mine sounded lifeless, perhaps it was just a lemon), a different Gibson 440 assembled & signed by Funk. All these have been sold. Left is this original Gibson 440 (which I bought in the Original Cabinet), this early T'Funk 420 (taken to NAMM in 2004 to demo the "new" T'Funk), and this more recent T'Funk 550-B.
The AMP was definitely far more Tubey - not muddy but leaning that direction. T'Funks have moved towards Hi-Fi as the series progressed. The Gibson is between them - and the favorite of many who have tried them all, including myself, they just seem more musical - (more airy? organic? less aggressive?) - there is not much difference but it is audible if you listen very carefully when A/B/C'ing them. Funk claims the Gibsons lack a bit of deep end and punch compared with the T'Funk. Maybe he's right but I don't hear it and I use these three pretty interchangeably. There is simply not much difference between them.
The AMP was 2.5 spaces high, perhaps 23 pounds, Gibson / ThunderFunk are 2U and about 16 pounds. The current TFB800 weighs 21 pounds.
The AMP had a clipping indicator sourced from several different places throughout the signal chain as not a "you've run out of watts" indicator but rather a "you've overloaded something" indicator. The Gibson / ThunderFunks have a single Input Overload Light and a Switch to affect a limiter.
In addition to bumping the power & chassis size, here are the other changes according to Funk:
“... increased the early preamp gain slightly to give the amp a punchier sound (The Gibson/ Early Thunderfunk preamp itself loses power (push) before the power amp does (Ed: in guitar amp speak, think 12AT7 or 5751 vs. 12AX7 in the first gain stage).
“… changed all the signal path caps polyester film and silver-mica … double-sided preamp board .. changed 5-watt power supply resistors to 10-watts … increased power supply filtering … added a copper shield to the transformer … reduces the amp's hum … black anodized the heat sink plates for better heat transfer … switched to brass screws for the power transistors … added a cap to the power switch to de-click it”. (Ed: I don't hear a "click" in any of these - that's one more cool thing: silent on, silent off.)
The enhance control boosts the high end grit and provides more definition to the amp. Funk says a normal setting to be between the 3 and 4 o'clock positions. “The timbre control is a see-saw filter that boosts the highs as it cuts the lows and vice-versa. You might say that turning the timbre control completely to the left is a Jazz bass setting while full right is a Rickenbacker setting.”
Funks suggests “The quickest way to setup the amp is to position all of the controls at their 12 o'clock detents. Turn the timbre control to the left until you are happy with the low end, and then rotate the enhance control to the right until you are happy with the high end. Usually, you are done at that point.”
“The Switch” powers the preamp circuit from a dedicated low voltage. The "Tube" position keeps the original upper midrange honk that some preferred – while slap and double bass players may preferred the cleaner, smoother upper range that the "SS" position provides. The difference “is not dramatic, but at higher volumes, the ‘Tube’ position has more interaction between the power amp and the preamp which produces a more pronounced effect.”
Funk concludes: “The Eden, SWR, and Thunderfunk power amps are all the same basic 1980’s HiFi design, when transistor power amps were perfected. There hasn’t been much improvement made since then.”
NOTE: The Gibson BH-440 is Gone.
Last edited by Blue : 03-01-2013 at 02:27 PM.