Thunderfunk TFB550-B - All upgrades completed

[ebulakowski]

I am putting my Thunderfunk 500B up for sale.

It has recently come back from Dave in february and it received all the available upgrades for this model. That includes a modified power section, with 6 filter caps giving the amp more headroom, and opening up the lows quite a bit. This also received improved heat-sinking. Dave said this would make the amp 2 ohm capable, though as you can read in many threads, it was designed for optimal 4 ohm operation.

I should note that the original reason the amp went to dave was a broken power switch (physical break/ not electrical) and a bent volume knob. They were replaced at the time of the upgrades.

The upgrades and repair totaled $295 with return shipping. Here they are as Dave put them on the receipt...

TFB550-B Upgrade 2
=====================
Surge Protection
In-Rush Current Limiting
Improved Heatsinking
Part Value Changes providing stronger drive, lower DI-2 Output, Less DC Offset on DI-2
Six Transistor Upgrade
Automatic Fan Thermostat
Current Limiting Adjustment for 2-Ohm Drive
Service and return freight

Pics to follow

Asking $850 Shipped o.b.oSOLD for $800

[melodiaopus]

Would you be interested in a TC Electronics RH750 with Footswitch?

[Astroman]

PM sent...

[ebulakowski]

For anyone thinking local meet up. I am in Calabash, NC. My usual radius is Charleston, SC to Wilmington, NC

I'll try for photos today.

[JeffplaysBass]

Is this the upgrade from 550 watts to 630 watts 4 ohms as the 750a? or was it more for the switch and broken parts?...Thanks!

[ebulakowski]

thanks for the question on that one Jeff, The switch and pot were the main reason it was sent in. While under the knife I decided to have Dave do any upgrade he offered. The breakdown is...
$40ish shipping
$75 bench fee and component upgrades (i.e. gold chip, some voltage adjustments, etc.)
$50ish Improved heatsinking, runs cooler, helps with impedance load.
$150ish Upgraded power section. 6 caps rather than 4.
- Somewhere the math doesn't align, either Dave cut me a deal, or I am mis-remembering a quote. I know it was $295 shipped back to me

The result is a more open low end than the usual low end compression the 550's have. It is not quite like the 750 because some of that open low end comes from the transformer. But it is a great update for what I like. The other results are a little more headroom, though I don't think Dave wanted to put a number to it. Also, 2 ohm capability, though it does not gain much more wattage and like the 750 is still a better match at 4 ohms. I love the sound of this amp as it sits. I actually dial my 750 in to sound like it. I have just decided, should my tastes ever change to keep the 750 which can have a little more natural girth present in the lows. But IMHO we are splitting hairs once you are talking a stage mix.

[ebulakowski]

Pics Finally added...

[ebulakowski]

Price Drop - $850 Shipped.

[JeffplaysBass]

Mmmmmmm....

[JeffplaysBass]

No rack ears?

[ebulakowski]

SOLD to JPB...