Fuchs Bruiser

[lowend1]

I had the opportunity this past week to spend a little time with a prototype of Fuchs Audio Technology's first bass amp, the Bruiser. This is an entirely new model for Fuchs, as it is a hybrid that has its roots in a tube preamp section with a parametric EQ (sorta like an updated take on the old Ampeg V-series). Max power is 600w at 2 ohms. Fuchs designed the amp to be able to cross back and forth between vintage and modern territory, soundwise. The Bruiser was paired with a Schroeder 1210 cab. (I would REALLY like to hear this amp through an old squareback SVT cab) I used two of my own basses - a late 90s Fender Deluxe P-Bass Special (passive) and a Frankenstein P-Bass with a T-Bird pickup added at the bridge. As a bit of a purist, I was most interested in the amp's vintage voice. I was immediately struck by the its midrange response and flexibility - the overtones that I get from my '71 V4B were right there, especially with the Fender, which had newer strings. Fiddling with the parametric easily got me into some old school thump. One feature that helped in this regard was a neat "Deep" switch, which narrows the amps dynamic range, clipping off the extreme highs and lows and makes it fatter sounding. Other stuff from their spec sheet: demand-controlled fan cooling, XLR line out with pre/post tone select, ground lift, and phase reversal. 4-speaker jacks, fx patch (preamp out/main amp in) What's not to like? Not much, really - The only thing on my wish list would be that I would like to see the amps full power available at 4 ohms. IMHO, most players won't be running down to 2 ohms. Part of the appeal here is that the head is only 33lbs, and those trying to save their backs will probably not be carting a pair of 4 ohm cabs. Other than that, I think Fuchs has a winner. They graciously sent me a pic to share with y'all...

[Chef]

So this is a tube front end, and an ss power section?
What kind?
Depending how they do their power limiting, it should be able to be 600 watts at 4 ohms, and "limited" to 600 watts at 2 ohms, instead of putting out more power/heat at that ohm load.
Do you know anything about eq points and type?
Got a shot of the rear panel?

Neat! thanks

[FUCHSAUDIO]

Hey Chef: Thanks for interest. I believe Bass Player may be getting a review sample in the future.

The Bruiser pictured (and which Billy played) is actually a pre-production prototype. The amp is expected to retail for $ 2,495.00 at this point. We are still waiting on some components to come in before production starts.

It incorporates an all (3) 12AX7 tube preamp somewhat inspired by the old Ampeg V-4B designs, however it has a parametric tube midrange from 300- to 3000 hz which is fully adjustable, instead of the presets the old Ampeg's had. It runs a 300-V regulated plate supply as well as DC regulated filaments. It has a subsonic filter which eliminates cone flap and wasted amplifier power.

The DI output has a ground lift, phase switch (0 or 180 degrees) and a pre/post tone control selector and it's own output level control as well as a separate stage level control.
The Bruiser has high and low gain, a deep switch (which is more a vintage/modern switch imho) and a bright switch. It gets along well with passive and active basses.

The power stage is based on the "Purepath (c) " Technology from Texas Instruments, using a conventional rectified (not switching) power supply. It weighs in at just about 33 lbs. It's 150 in 8 ohms , 300 into 4 and 600 into 2 ohms. Through two SVT Cabinets, it's truly a moving experience. The ventilation system is demand based, and the illuminated fan runs only when needed, and only as much as the amp requires.

This has been about a 2-year design effort on my part, which was done at the request of many bass players who asked for a bass amp that reflected the same commitment to tone that our guitar amps have.

My good friend Jorg Schroeder had a chance to try the amp against a number of modern bass amps like the Aguilar 750, 751, and a number of other heads and preamp/amp combinations recently, and perhaps he will chime in with his impressions.

[Chef]

Thanks for the reply!!!

[Jeff Scott]

Originally Posted by FUCHSAUDIO

.....It's 150 in 8 ohms , 300 into 4 and 600 into 2 ohms.

This is extremely rare to see in MI amplification, even in most pro power amps. Nice to see a it has a design that can actually double it's output as the Ω is halved.

Even my Aragon 2004, which has a pretty massive power supply can only do 100 watts/channel @ 8Ω;200 watts/channel @ 4Ω;300 watts/channel @ 2Ω.

[fdeck]

This one?

Speaker Amplifier and Modulator - Mid/High-Power Amplifier - TAS5630 - TI.com

[Jeff Scott]

Originally Posted by fdeck

This one?

Speaker Amplifier and Modulator - Mid/High-Power Amplifier - TAS5630 - TI.com

Hmmmm:
"Total Output Power at 10% THD+N
600 W in Mono PBTL Configuration
300 W per Channel in Stereo BTL Configuration
145 W per Channel in Quad Single-Ended Configuration"

10%??????????

[bongomania]

Interesting! I have enjoyed some email conversation with Andy at Fuchs, talking about bass overdrive effects. He mentioned an amp was possibly in the works, so it's nice to see that come to reality.

Andy, any chance of including that OD circuit we discussed into the amp?

[FUCHSAUDIO]

Originally Posted by Jeff Scott

Hmmmm:
"Total Output Power at 10% THD+N
600 W in Mono PBTL Configuration
300 W per Channel in Stereo BTL Configuration
145 W per Channel in Quad Single-Ended Configuration"

10%??????????

Honestly, I've never been a big fan of "the numbers game". I think you'd be pretty surprised at the actual measured distortion figures of many "respected" or "legendary" MI products. I don't think everyone will be running the amp at maximum output all the time.

The old B-15's cranked well over 10% distortion in typical performance use. The SVT's power ratings never cited distortion figures, but I've measured it between 8% and over 10% distortion at maximum rated power on the bench. That comes from lots of factors, not the least is transformer saturation, a natural occurence in tube amps.

The fact this is a switch mode amp means it has an output which will contain some high frequency artifacts of the switching (it's well outside the audio bandwidth) that although are filtered, will affect the true distortion measurements. It is designed to crank power into lower loads. 2 SVT cabs are 2-ohms. A bass player who's trying to build an optimum quality rig could easily order a cabinet from Schroeder, Epiphani, or many builders in a lower impedance format.

I believe the proof is in the sound.

And "bongo" no plans for the distortion circuit in the amp. Possibly in the pedal we discussed, but not the amp. My aim was purity.

Appreciate the feedback guys.

[craig.p]

I agree that the distortion figure isn't anything to be worried about. One look at a 6L6GC data sheet will convince you.

The amount of power they're getting out of a less-than-palm-sized power chip these days is astonishing.

The linear relationship between power and impedance counts as an asset for me. Less likelihood of overpowering a single cab when that's all I've brought to a job. But, that's just for me personally, and I'm not saying it's best for everyone, 'cause I could understand someone wanting to hit a four ohm load with more than three hundred watts as long as he's going to be vigilant about overexcursion.

Nice work, guys.

[FUCHSAUDIO]

Originally Posted by craig.p

The linear relationship between power and impedance counts as an asset for me. Less likelihood of overpowering a single cab when that's all I've brought to a job. But, that's just for me personally, and I'm not saying it's best for everyone, 'cause I could understand someone wanting to hit a four ohm load with more than three hundred watts as long as he's going to be vigilant about overexcursion.

Nice work, guys.

Thanks, good points. The subsonic filter (which starts low enough to be a non-issue to tone) addresses over excursion pretty well, the amp has a decent damping factor and a large supply reserve too. The decrease in wattage at a higher impedances does provide protection against "overdoing it".

I'm currently using a Neo 12/10/horn cab from Jorg. The combination of the Bruiser and that cab produces a single trip load-in into a gig: The amp and cab (one hand lift per unit), and a bass in a bag on my back.

[bongomania]

Originally Posted by FUCHSAUDIO

The power stage is based on the "Purepath (c) " Technology from Texas Instruments, using a conventional rectified (not switching) power supply.

Originally Posted by FUCHSAUDIO

The fact this is a switch mode amp means it has an output which will contain some high frequency artifacts of the switching

I just want to be sure I understand correctly: the power supply is not switch-mode, but the power amplification is. Yes?

Oh and PS, I'm a big fan of subsonic filtering, good move there.

[FUCHSAUDIO]

Originally Posted by bongomania

I just want to be sure I understand correctly: the power supply is not switch-mode, but the power amplification is. Yes?

Oh and PS, I'm a big fan of subsonic filtering, good move there.

Yes, and thanks.

[craig.p]

Originally Posted by bongomania

Oh and PS, I'm a big fan of subsonic filtering, good move there.

Ditto on that, Bongo. I think that's a major feature that, along with its knee frequency and slope, ought to make it into the marketing collateral.

[fdeck]

Originally Posted by FUCHSAUDIO

Honestly, I've never been a big fan of "the numbers game". I think you'd be pretty surprised at the actual measured distortion figures of many "respected" or "legendary" MI products. I don't think everyone will be running the amp at maximum output all the time.

The old B-15's cranked well over 10% distortion in typical performance use. The SVT's power ratings never cited distortion figures, but I've measured it between 8% and over 10% distortion at maximum rated power on the bench. That comes from lots of factors, not the least is transformer saturation, a natural occurence in tube amps.

The fact this is a switch mode amp means it has an output which will contain some high frequency artifacts of the switching (it's well outside the audio bandwidth) that although are filtered, will affect the true distortion measurements. It is designed to crank power into lower loads. 2 SVT cabs are 2-ohms. A bass player who's trying to build an optimum quality rig could easily order a cabinet from Schroeder, Epiphani, or many builders in a lower impedance format.

I believe the proof is in the sound.

And "bongo" no plans for the distortion circuit in the amp. Possibly in the pedal we discussed, but not the amp. My aim was purity.

Appreciate the feedback guys.

Very good points. I've also measured distortion figures in the ballpark of 10% on bass amps driven to their rated output levels. So it seems like a fairly common rating method. In addition, the way that an amp distorts is almost as important as the amount of distortion.

Indeed, congratulations on the new product!

[ChrisPbass]

FUCHS - for all y'allz that don't know, Fuchs is highly regarded in the guitar amplifier market/field.

[acubass]

Jimmy Herring plays through Fuchs with Widespread panic. His guitar sounds like a freight train screaming down the tracks.

[Calaverasgrande]

I have been aware of Fuchs for a while now. There was a punk band around here that had one. The guitarist put duct tape over the name plate. I think he was embarassed to have a nice amp!
I was ready to bite until I read hybrid. For that amount of coin there are several all tube heads that are easily achievable. Verellen, Matamp, Orange, Reeves etc.
There are also quite a few half tube heads that are considerably cheaper. Even Mesa's biggest.
No OD on board?

[Jeff Scott]

I too, have read great things about Fuchs amps. My comment about the 10% distortion rating was more related to my being surprised that this was a published figure as opposed to, say, 0.5%, for example. Very brave and honest of TI to do so.

[fdeck]

Originally Posted by Jeff Scott

I too, have read great things about Fuchs amps. My comment about the 10% distortion rating was more related to my being surprised that this was a published figure as opposed to, say, 0.5%, for example. Very brave and honest of TI to do so.

It's worth looking through that entire datasheet, especially at some of the graphs.

TI has to provide that information. Chip makers live and die by the quality of test and application data that they provide on their products. We can't afford to design by trial and error any more. We need to know how a design will perform before we build the first prototype.

Note in edit: The reason for such a generous 2-Ohm rating is that integrated circuits are easier to design and manufacture for high current than for high voltage.