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1U Power Amp For Bass

Discussion in 'Amps and Cabs [BG]' started by DigitalMan, Mar 19, 2017.

  1. DigitalMan

    DigitalMan Owner of seven basses - eligible for 44 TB Clubs Supporting Member

    Nov 30, 2011

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

    - single channel
    - reasonably low fan noise
    - adjustable HPF
    - class D

    That's it really. I know there are a few 1U class D amps out there, but none really suited for bass players. If a true bass amp company designed such a product they would OWN the bass rack market.

    @agedhorse, does Mesa give you 20% of your time to work on discretionary projects like Google does? :D
  2. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009

    if not 1U then in micro-head format; i suppose the quilter 800 is sort of like this, except it does have a simple "bass amp" front end and that weird XLR line in jack if you wanted to access just the power amp part.
  3. BogeyBass


    Sep 14, 2010
    can it be 2 ohm stable too or nah. not 3 not 2.6 but a whole 2 ohm stable.
    how many watts you talking here
  4. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    You know, a specialty product that applies to a very small part of the market with major PA competitors offering similar products seems like a mighty big challenge. The SWR AMPLite was verbally well received and seemed to work fine, but at the same time did not appear very successful from the sales side of things. It was 1 space in a half-rack kind of format.

    And yes, part of my job is doing "hard core" R&D work, developing and exploring new approaches, working on reliability metrics of different approaches and exploring things that seem mighty cool on the surface that might be even more cool the deeper it's examined. Every morning with my coffee I read my engineering trade magazines trying to stay on top of the new technologies coming down the way, and there's a ton of new stuff... some of it mighty interesting. On the other hand, I am also looking at some of the old, obscure technologies that might be more practical now that technology has caught up.

    For example, class D was originally developed in the 1930's using tubes, but it just wasn't practical, even with transistors it wasn't practical until the speeds and the saturation/cutoff performance evolved. It was quite possible to build class D and SMPS using (fast) bipolar transistors, but once switching MOSFETs became reliable it was worth revisiting the original class D work from the 1930's and re-think how it might better adapt. I believe Crown's adaptation in the K series amps came about it this sort of manner. Currently I am reviewing some very interesting work done by Western Electric, RCA, Ampex and Simplex in the 1950's, they were very big in the cinema market (and of course the military markets) and the reliability metrics had to be very good as the electronics operated 14-16 hours a day, 7 days a week and the amps were expected to run several thousands of hours between service calls, as well as have a life expectancy of maybe 20,000 hours or more. I suspect that there might be something interesting to learn from this. I also study circuits from test and data acquisition equipment from the same era, most was military, aerospace and industrial and many audio circuits evolved from this branch of electronics as well. Ironically, Ampex was a big player in this market too. Their big multi-track data servo driven recorders were used to store and analyze data from test flights and of course early space launches through probably the late 1960's or even well into the 1970's.

    (edit for old fart brain fart)
    Last edited: Mar 19, 2017
  5. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    I think you mean the Amplite, the Headlite was a full integrated bass amp. Acoustic Image also took a stab at a pretty similar product and by their own account managed to sell less than 60 units in the two or three years they were producing them. All of which leads me to believe that even 100% of a really tiny market probably isn't worth the hassle.
    smogg and wave rider like this.
  6. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Yes, it was the AmpLite. I never understood the naming convention they chose! Still confusing today ;)
    BassmanPaul, Stumbo and Passinwind like this.
  7. 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.
  8. JGbassman

    JGbassman Supporting Member

    May 31, 2011
    Cedar Rapids Iowa
    I'd love to find a single rack space power amp with at least 300watts @8 Ohms per side.

    That would be perfect for my rack.
    tattooSAM likes this.
  9. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    This is, I suspect, one reason they are not so popular.
  10. jsbarber


    Jun 7, 2005
    San Diego
    Demeter makes a 1U 2x800 watts bass power amp:
    H-Bass 1600D

    I started a thread on it a few months back asking if anyone had experience with it or owned it. I don't think anyone did. At $2k it's not inexpensive, but it looks like a nice unit.
    JGbassman, MVE and peterpalmieri like this.
  11. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    Maybe I’m of an older school of thought but I see no practical reason for a 1U power amp. I would not like to use a Micro amp that fits into the pocket of a guitar case either though I do admire the technology. With the poor memory I currently have I’d be terrified I’d forget it and leave it at a gig. Add to that the gradually failing vision that we old farts have to deal with it might be hard to read the control labeling on a darkish stage. I prefer the 2U form factor that fits nicely into my standardized case size of 4U. As long as it is a dream to lift up and down, I really am not concerned with size.

    Edit: Besides a 4U case allows better air flow for cooling. :)
    andrew likes this.
  12. Well, there ya go. Interesting.
  13. monsterthompson

    monsterthompson The Eighth Note Wonder Of The World Supporting Member

    Nov 25, 2008
    Lots of guys going to pedal based pre units. Noble, Darkglass, GK, the new Trace unit.
    If it was another single unit rack pre, then I could see the ease of a 2U rack being carted over a 3u as being convenient. Or, as @BassmanPaul noted, an extra space for air cooling could be had in a 3u rack instead of a 4u. Space is space when you're packing out and loading in.

    However, I tend to believe that if the market demand was there, we'd see it developed, if a profit could be had. It doesn't seem like an earth shattering secret that some demand might exist.
  14. tallboybass

    tallboybass Supporting Member

    Feb 25, 2003
    Tulsa, Oklahoma
    Honestly, find a nice used GK MB800 and use the effects return. I used one in a super lightweight 2U shallow rack, with Ampeg SVT IIP preamp. Works great!
    andrew, jmlee and Plectrum72 like this.
  15. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    With the economies of scale, it is probably no more expensive to manufacture a fully integrated amp versus a stand alone power amp given the relative demand and sales between the two. The size would not be much different either.
  16. Plectrum72

    Plectrum72 Supporting Member

    What @tallboybass said. Effects return of the 1U bass amp of your choice.
  17. Spent

    Spent Supporting Member

    May 15, 2011
    Upstate NY
    I was pondering the same thing this weekend. I'd love a small amp to power one of my pre amp pedals. It seems to me that with the acceptance of class D amps and the plethora of pedals (e.g. GK Plex, Ampeg SCR-DI, Two Note Le Bass, etc.) there may now be a viable market. I've toyed with the idea of picking up a class D mono block car amp as an experiment. A small amp on a pedal board may very well be the next big thing.
  18. Raw N Low

    Raw N Low If I can't hear it, hopefully I'll feel it Supporting Member

    Jul 16, 2009
    Denver, Colorado
    Ouch! $2K for a 1U power amp???

    I would jump on the bandwagon of 1U power amps if more companies manufactured them. I think it's a great alternative to the class D craze that's been going around. I own 7 different rack mounted preamps and 2 in pedal form. This would be a godsend to gigging musicians who have most of the front end of an amp on a pedal board.

    Would also give more companies a reason to get back in the rack pre-amp game. You could build a nasty dual amp rig with 2 preamps, a 1U amp, and 2 neo cabs. Just the thought gives me the jitters.
    tattooSAM likes this.
  19. Spent

    Spent Supporting Member

    May 15, 2011
    Upstate NY
    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.
  20. Alivefor5

    Alivefor5 Supporting Member

    Jul 17, 2006
    Stewart made the PA-1000 which later morphed into the World 1.2. Full sized 1U rack mount units. Light weight switching power supply units that did 1000w bridged into four ohms. Drawback was (is) no fan but lots of heat sink fins. Recommended to mount in a 2U case with 1/2 space above and below for ventilation.
    I have the PA-1000 mounted like this and have used it with a variety of regular rack pres and pedal pres and had great success with it. These days the form factor and sound of the Aguilar TH-500 and the Mesa 800 have retired the Stewart.
    funkinbottom likes this.