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Crest CA9 Rack Space

Discussion in 'Amps and Cabs [BG]' started by Big String, Jun 14, 2004.


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  1. Figured it was time to start a new thread instead of the hijacked Bergantino NV425 that had all the discussion on the CA9.

    Anyway, I've got a new Crest CA9 on the way and one thing I didn't notice in the specs was it is 18" deep as opposed to my current amp the PLX2402 which is 13.5" deep. Do any of you CA9 owners currently use a standard SKB rack case? I believe it will still fit but hang out the back when the rear cover is off.... Yikes, I think I'll have to change a few things around now. :rollno:
     
  2. inazone

    inazone

    Apr 20, 2003
    Colorado
    First let me kmow if your findings are the same as mine on th CA-9. I put mine in a two space gator rack. I think its about a inch longer than skb but it still hangs out the back when the cover is off. Now that I went with the crest my rig has more power than I know what to do with. Last night I played with "3" 100 watt marshall 412 cabs and heads and had NO problem filling the room with no PA. I even had the bass nob up and didnt have to run it flat. :bassist: :hyper: :bassist:
     
  3. Hi Zone, will do. Hopefully I'll get it before Friday and be able to put my rack together. I kinda figured it would be hangin' out after I read the spec sheet again. I did a test about three months ago with my QSC MX2000A and it was very impressive which lead me to go for an amp with transformers etc. My Mx's are dedicated to my PA and talk about heavy ..... and deep. I remembered those hanging out the back of some SKB's I had them in until I switched to a custom made case with heavy duty casters. The whole thing with the MX2000A and 3000A and case is close to 180lbs. Everyone complains about picking it up and moving it. The seperate cases were an even bigger pain in the A$$ so I told them :crying: too bad dudes take your turn....

    I remember you said on the other thread you mounted yours in a seperate case, which is probably a good idea. I really like having mine all in one case, plus I have a Tripp-Lite racked jobby on the back rack rails. It's a 4 space case and kinda tight with the amp, preamp, and tuner on the front rails, but it's actually balanced and works great, one plug... I gonna miss that because it sure won't work with the CA9 hanging out the back. I may have to go with two cases or get a bigger one which I don't want to do. :meh:
     
  4. DEVILMAN

    DEVILMAN

    Nov 24, 2001
    New York,NY
    ...ya think your getting that much more of a sound improvement from the QSC, considering the weight?

    I have a QSC3402 & a Crown MA2402. The MA has more lows but both are as crystal clear as each other.

    Unless your going for low "B" or sub sounds, I don't think you can go wrong with a QSC(PLX).

    The Crest is a great amp, but, unless you utilize the total maximum benefits(ie: more lows), it seems to be a waste of time & extra weight...

    Anyways, let me know how you fare against the switch, I'm always interested in opinions & hands on experiences...


    ~S~
     
  5. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    Actually, the PLX isn't deficient in lows (unless you have the low-frequency filters engaged in a way that you didn't intend).
     
  6. Brian Barrett

    Brian Barrett

    Nov 25, 2001
    Murfreesboro, TN (Nashville)
    Dealer LowEndBassShop.com, Builder LowEndBasses.com
    I don't think you all should have any problem with the Crest. I have the CA6 in an SKB rack and it fits fine. It hangs out the back when the covers off, but that’s not really a big deal to me. I have an LT2000 as well that’s of course shorter and doesn't hang out.

    The CA's are wonderful amps and you will notice quite a difference in your sound from the full switching amps to the CA's. Everyone I've ever had switch amp's comes back with amazement. Even those that went down in power to the transformer amps verse higher power switching find that the transformer’s had more fullness and seemed to have more power then the switching. I think its their smooth and fullness they have.

    Enjoy, Crest makes wonderful Amps. It's great that the high-end cabinet companies thank enoughof the Crest to even use these for testing and in their personal rigs.......
     
  7. inazone

    inazone

    Apr 20, 2003
    Colorado
    I have a plx 3402 and went down in power by 200 watts a side. I can get more out of my rig now that Im using the CA-9. I was going to post a long review on another thread but I'll just start now.

    In my main band I play rock, metal, numetal. A lot of stuff is drop D and some drop A. On two songs I have to tune down my 5 string. Some songs I play up on the neck. Im picky about my tone and ask a lot from my basses and rig. Now that I have made the switch, not only can I "feel" the low end I can hear it in all its tight, fullness with authority!

    My gig rig is two Bergantino 322s, Aguilar db680 pre and Modulus basses. For comparison sake I also used a Warrior, Pedulla, Fbass and Tobias basses, Navigator, Demeter, rpm1 EVO II and db680 preamps. All kinds of different tones, sounds and eq settings, both live and at home. In all cases there is a difference. Enough of a difference that it is worth the extra weight and hassle.

    I’ve often wondered why my practice rig, Trace Elliot head (280 watts RMS 540 watts peak at 4ohms), Crate 8ohm 410 and sonic 8ohm 410 was as loud as my gig rig with the PLX 3402. At first I thought maybe the 322s weren’t for me but I have A/B them with Accuegroove, EBS, Epifani, Eden, Acme, Glock, Aguilar, many others including the standard cabs of all sizes. The Berg 322, to my ears, is the best sounding cab I’ve heard! I then tried my other basses (listed above) and ruled that out. I tried the above named pre's as well as others and still didn’t have what I was looking for. I still couldn’t figure out why my practice rig could keep up with the gig rig. Then I thought it was speaker area and took a hard look at the Epifani 410s and Acme 410s Being that a 810 has more speaker area than two 322s. Did a lot of A/B with the 322 and I still like the 322 for both volume and tone.

    From a recommendation I tried the CA-9 and problem solved. Im still looking for a second pre that I like (I’ve sold all but the db680) but I have my sound. I now have very powerful, tight lows, cutting mids like there is no tomorrow and glassy smooth yet crisp highs. I was looking for a classic meets hi/fi tone and a have it. This is all JMO and experience and has been gig tested for my needs.
     
  8. inazone

    inazone

    Apr 20, 2003
    Colorado
    1)Yes. 2) I still think the plx is a good amp. 3)above.
     
  9. Inazone, Brian thanks for all the info. Great reviews!
    Dev, Bob, thanks for input as well. All very valuable points.
    I find my 2402 to be adequate for my rig, but when I do drop D tune on at least ten tunes the lows sound anemic and strained. I've managed to eq things but all that fiddlin' around between songs is a pain because I have to do it on the preamp, my bass is passive. All in all the 2402 is a great light weight amp that definaltly gets the job done for less money.

    As I mentioned earlier, my brief experimentation with my MX amp indicated to me that the transformer loaded unit does seem to have that "reserve" that makes the notes carry on instead of running out of breath so to speak. That analogy came from a highly respected friend of mine. Anyway, we will see. I look forward to reading everyone's opinion and will try to provide an equal review after some live jammin' which to me is the only true test of gear, unless of course your strictly a studio player.

    I guess I'll just have to deal with the amp sticking out the back. I hate being so OCD about stuff like that, but... I just did this outside benefit gig last Friday, and the disorganiztion was a total joke. No stage, inadequte power, no lights, soundman was a total amature etc. So... we moved into this tent with the impending rain and the moist grass and uneven turf made me very nervous. We played for about 45 minutes before we decided it was just unsafe. Now if I would have had my Crest CA9 sticking out the back of my case at that gig I'm sure it might have gotten wet some. I know there is no perfect senario or set up, but sometime those little things count. OK, enough whining.... I can't wait to try the CA9. :D
     
  10. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    If you match the gains of the amps you compare, you actually won't be able to tell them apart sonically unless you listen closely for the reduced noise floor and lack of hum in the PLX.
     
  11. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    Do you have the low frequency filter engaged on the amp?
     
  12. Hiya Bob,
    Yes, the 30hz filter is engaged. I tried it without, it didn't seem any different to me. Even though it's my bench mark to test things live, it's still difficult compare while on a live gig. I could only switch it between sets. There could be other factors I'm sure, but I just want to try the Crest and see if it does it for me. Expensives tests though...
     
  13. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    With the 30 Hz filter engaged, the fundamental of a low D (36.7 Hz) will be reduced almost 2 dB.

    If you want to compare a PLX and a CA on equal terms, then turn off the PLX's low frequency filter and match the gains. (If you don't want to compare them on equal terms, just make sure the one you like is set louder than the other.)
     
  14. Humerous.... Is there some friendly sarcasim there....

    I don't know if it's exactly a question of "louder" or not.
    Maybe it's like a good single malt scotch compared to a good blended scotch. Flavor. But I certainly don't want to dredge up any facts about a power amp having any affect on sound or tone. Just taste. I don't think anyone can dispute "taste" electronically or factually. Can they... As I said, we will see.

    Could you please run it by me again. Your method of making sure the gains are matched. I know how to turn the filter on and off. Thanks in advance.
     
  15. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    No, just alluding to a too-common but often unintentional sales ploy in music stores, hi-fi shops, et al. You may find that an amp that carries a nice spiff for the salesman is turned up a bit louder than another. ;)

    This is where double-blind listening tests come in handy. The scotch analogy doesn't apply to pro power amps.

    The most precise way to match gains is with a tone generator and an AC voltmeter. You put a steady tone into both amps and then adjust their gains so that their output voltages are the same. For example, with the same input signal you get 20.0 volts out of one amp, and so you adjust the gain of the other amp so that it also puts out 20.0 volts, ±0.1 volt.

    Without test gear, you would have to know what the amp's gain actually is. The gain controls on PLX amps are labeled with the actual voltage gain; the maximum is 32 dB, or 40×. The maximum gain of a standard CA9 is 38.7 dB, or 86.5×, but its gain controls are labeled only in dB of attenuation from maximum. So if you turn the PLX all the way up, you would turn the CA9 down 6.7 dB to match the gains.

    There is also a version of the CA9 that has a maximum gain of 32 dB, or 40×; for that, you would also turn it up all the way, or at least match the two amps together, so that if the CA9 is at, say, -4 dB, the PLX would be properly set at 28 dB, etc.

    Gain controls match up best in the upper half of their rotation. Below around 9 or 10 o'clock, the tolerances of the potentiometers have a greater influence on the amount of attenuation they provide. As a result, even on the same amp, two gain controls set at, say, 8:30 or 9 o'clock might be mismatched from each other by 1 dB or so.
     
  16. Thanks Bob for the detailed and understandable method.
    I believe CA9 I will soon receive is the standard. 6.7db it is.
    I'll print this up and have it handy to give it a test.

    I still like trying the Scotch test anyway.... :)
    Might have to do it a few times though. But not before the amp testing.
     
  17. Just to make it even more clear to me, would reducing the gain 6.7db be a little more than half of the CA9 gain, say somewhere around 11:00? My guessing method is by the figures you provided. 40x and 86.5x
     
  18. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    When I worked at Crest, the gain controls on most, if not all, of the amps were designed to have a generally linear taper, so that -6 dB was at 12 o'clock.

    The CA amps came out after I left there to go to QSC, but I think they are the same way. So -6.7 dB would be a little to the left of 12 o'clock.
     
  19. Pretty nice guess hey?

    So basically to match test the two amps "fairly" one would be set roughly at half the gain of the other. Fair is fair and that is fine with me, but if the CA9 has appoximatley 51 % more gain to go, no wonder we are hearing that the omph is more pronounced on the Crest. Am I confusing the bottom line hear.... I mean the amps ARE what they ARE, not saying one is better than the other, one is just more powerful when all is said and done... correct?

    I definatley appreciate what you have provided and will try it out.
     
  20. Rock City

    Rock City

    Apr 8, 2001
    Boston,Ma
    Bob Lee,
    With all due respect, and without saying which amp is best for every application, how can you say that all power amps sound the same? Have you ever listened to a Bryston or Krell in a hi-fi system, and then plugged in a PLX? Have you actually plugged a Crest, Crown, or other brand into a bass rig, and then a PLX. They all sound VERY different.
    This is not to say that any one power amp is better, just that there are differences in "character" and tone.
    Corey
     



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