1U Power Amp For Bass

[agedhorse]

I have a Genz-Benz ShuttleMax 9.2 (which is my favorite amp of all time) and can't help but wonder why there is so much empty space. Seems to me that it could have easily been 1/3 smaller.

Because the same amp was available as the 12.2 that used a dual power amp set-up with an auto-back-up power supply for the preamp.

 

[BassmanPaul]

I've toyed with the idea of picking up a class D mono block car amp as an experiment.

But how would you power it? A 12V wall wart would not do the job.

 

[Spent]

But how would you power it? A 12V wall wart would not do the job.

Find one or build my own (finally put my EE degree to some good use).

 

[BassmanPaul]

Find one or build my own (finally put my EE degree to some good use).

Whatever way you go still adds size and reducing size is what the experiment was for I think.

 

[Spent]

Whatever way you go still adds size and reducing size is what the experiment was for I think.

That's why I was considering experimenting. I also don't trust the stats; 1,500 watts (that's 125 amps at 12v!).

 

[Josh Kneisel]

1U powe amp, ok, but where's the pre-amp? In a whole other rack space? Seems to me you could get both in 1U these days. There was, of course, the Ampeg B1R but we'd be looking for more than 150 watts these days.

Use a Sansamp or something similar or use a rack pre. I would love to have a 1U poweramp to run my Sans amp into that was designed for bass.

 

[agedhorse]

That's why I was considering experimenting. I also don't trust the stats; 1,500 watts (that's 125 amps at 12v!).

Then you need to learn what the power consumption figures are based upon and how they are calculated.

Assuming that the 1500 watts is an RMS derived figure (though in the car sound market it usually is not), the power consumption is based on 1/8 AVERAGE power which factors in the dynamics of the signal. Now it can be argued that under some applications, the averaging coefficient may be closer to 1/4 or under severe overdrive conditions even 1/3, this averaging brings the power supply's AVERAGE current down to (0.125 x 125 amps) = ~16 amps, which is what battery capacity would be calculated from. For voltage drop calculations, you would need to use the actual short term power, which would be in this case ~125 amps. Different numbers describe different aspects of operation.

In actuality, many auto-stereo components are based on peak power (1/2 the RMS based power) or even peak-peak power (1/4 the RMS based power), the devil is most certainly in the details.

 

[Aidenn7]

take a look at the quilter stuff.. not a rack but small.

 

[DigitalMan]

1U powe amp, ok, but where's the pre-amp? In a whole other rack space? Seems to me you could get both in 1U these days. There was, of course, the Ampeg B1R but we'd be looking for more than 150 watts these days.

One option could be the player who uses the Mesa Subway DI half of the time with FOH only, and the other half of the time brings a rig. Other options would be players who use one or more SansAmp rack units, but not want to commit to an entirely integrated solution.

I guess your premise is why use a rack? It seems there are numerous rack preamps available in the $300 range that people choose to mix, match, and swap around on a frequent basis. A 1U power amp could be the constant element for that use case.

 

[lomo]

GK MB head + ears and done. I don't see leaving out the preamp as saving vast amounts of $$, and it carries no weight penalty. In terms of a 1 space integrated bass amp, Demeter really has it nicely covered.

 

[blubass]

I guess your premise is why use a rack?

I can answer that from a lot of first hand touring experience. My old touring rig was a GK 700RB II, Shure wireless, rackmount power conditioner in a 6-space rack, weighing in around 40-45 lbs and really bulky! I would have "liked" to have had some kind of HPF and a compressor on-board the rack as well.

It was very streamlined as far as connectivity, and allowed me to get on and off stage in under 3 minutes. It was also very robust, taking hits and bangs, and one time coming loose in the trailer and falling 3 feet. No damage at all, fired up that night and worked flawlessly.

Now, bassists have all kinds of needs for gear. A 1U power amp would allow me to run an Ampeg SVP, GK 2001 RBP, Sansamp, BBE BMax, or any other 1u preamp. I could also mount several DI boxes to a 1U shelf, and ideally get a power amp/pre amp inside a 2U footprint. That allows me room to add that HPF, Compressor and whatnot into a 4 or 6 space rack, coming in at least half the weight or more of my previous rack.

I'll never knock or criticize these class D heads with their respective "gig" bags and all that. They are really compact and provide tremendous benefit to the average bassist. However, I've found myself becoming the bad guy already, having to hurry along bassists who go on before me, that spend way over the allotted tear-down time between sets because they have too much unorganized gear, 10 cables to wind up, and all that.

 

[DonaldR]

Anyone used Matrix 1U amps for bass?

 

[tallboybass]

Very lightweight, very versatile. Insert pre of choice. The power section of this MB800 outgunned a bridged Crown XLS1500....no kidding.

A power-amp-only would cost more since they won't sell nearly as many.

 

[DigitalMan]

GK MB head + ears and done. I don't see leaving out the preamp as saving vast amounts of $$, and it carries no weight penalty. In terms of a 1 space integrated bass amp, Demeter really has it nicely covered.

I see leaving the preamp in as nearly doubling the cost. $665 for a power amp where the preamp is a throwaway compared to around $350 for a simple power amp I think is a fair compare.

Many people who use modular systems prefer a purpose-built solution.

 

[DigitalMan]

Use a Sansamp or something similar or use a rack pre. I would love to have a 1U poweramp to run my Sans amp into that was designed for bass.

This is exactly the use case I am interested in.

 

[JRA]

just asking: why 1U? thanks. (there are tons of 2U class D power amps)

 

[lomo]

I see leaving the preamp in as nearly doubling the cost. $665 for a power amp where the preamp is a throwaway compared to around $350 for a simple power amp I think is a fair compare.

Many people who use modular systems prefer a purpose-built solution.

I see your point...depends on budget tightness as well, but a new MB500 can be had for $500, not $665. At the 500 watts into 4 Ohms price point, I'd elect to splurge the extra 150 ish for the pre. YMMV. On a related not, I just swapped a bass for a Demeter and am itching to lay ears on it!

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[Thundar]

here is a new Samson 1U that I have been looking at...seems like a sweet deal and perfect solution, and its on sale now at Sam Ash! I havent even seen it available at any other online retailer, but I think Im fixin to order one!

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• Single rack space, ultra-lightweight Class D power amplifier
• 850 watts per side at 4 ohms, 3,400 watts bridged mono at 4 ohms
• 450 watts per side at 8 ohms, 1,700 watts bridged mono at 8 ohms
• Built-in limiter provides peak power delivery while minimizing distortion
• Extensive 4-point protection circuitry (Short Circuit, DC Output, Over Current, Thermal)
• Front Panel LED indicators (Signal, 10dB, Peak)
• 2-position Mode (Stereo, Bridged Mono) selector switch
• XLR and RCA inputs
• Speakon® outputs
• Onboard cooling fans

 

[agedhorse]

I see leaving the preamp in as nearly doubling the cost. $665 for a power amp where the preamp is a throwaway compared to around $350 for a simple power amp I think is a fair compare.

Many people who use modular systems prefer a purpose-built solution.

Then you have never been in a manufacturing environment. You might want to search the internet on the topic of "economies of scale" and you will see why the manufacturers have delivered the product that the marketplace is willing and able to pay for.

As a direct example, if I could design and sell a product (any electronic product) with and without a set of features like a preamp, and I could sell 1000 with the feature and 100 without the feature, the fixed costs are about the same for each product. Fixed costs include engineering, tooling, agency certifications, production set-up, documentation, marketing, overhead. Now, when it comes building this item in 1000 piece quantities versus 100 pieces, for many items the cost difference may be 30% lower buying by the thousand. Spread ALL of these costs out over 100 pieces and 1000 pieces and the fixed cost component of the 100 piece item is 10 times as high, and there has to be 30% less (cost of) parts in the lower quantity item in order for the variable costs to be the same. Since the cost of the preamp is pretty small compared with the costs of the power and and sheet metal, generally the higher manufacturing quantity item actually costs less to build and thus sell.

 

[stevenA800]

Hello,

It seems to me there is a tremendous opportunity to build a 1U power amp designed specifically for bass players. Here is

The Demeter items don't do it for you?