Crest Audio CA9 Now I understand.

[dominic54321]

I think that the point of the thread is to express an opinion, which is presented by Red Planet as a praise of a CA-9. Why dont we just leave it at that. I think every time the CA-9 is brought up in a thread someone will come in and say "It's no better an amp than... (fill in the blank.) People express their opinions on this site everyday about all types of products, non of which are disputed as must as the CA-9. I own one and it KILLS! I had a Stewart World 2.1 before it and there is an audible difference especially in the lows that is undeniable. I'll say that the CA-9 is the best power amp that I have tried in my bass rig, and if someone wants to buy it b/c I said that then let them. My guess is that they won't be disappointed.

+ 1,000,000
Once again, like so many other ca9 appreciation threads, this thread turned into a CA9 vs "insert amp here" thread, and discussions/debate about gain matching. I, for one, am an avid fan of heavy power amps as well, with the CA9 being my favorite for a bass rig. I've tried many poweramps and bass amps, and, gain matching aside, the lightweights just don't do it for me, personally and IMO. I also swapped a Stewart 2.1 in favor of a CA9, and never regretted it, the difference was astounding! I since sold the CA9 in favor of a DB750, but this thread is giving me serious gas to pick up another CA9!!! With that being said, I do keep a shuttle 6.0 in my gig bag for small gigs, practice, and as a backup.

CA9 rocks!!!

 

[Bob Lee (QSC)]

It's like a cable thread. Somebody says, "Wow, I just got a Mondo SuperBass cable, and I never sounded better!" And then some people chime in with "Yes, the Mondo SuperBass is the greatest cable ever, the bottom end is louder and tighter than ever!" And then others say, "If you know what cables do, you can get the same results with almost any other cable."

 

[blowinblue]

It's like a cable thread. Somebody says, "Wow, I just got a Mondo SuperBass cable, and I never sounded better!" And then some people chime in with "Yes, the Mondo SuperBass is the greatest cable ever, the bottom end is louder and tighter than ever!" And then others say, "If you know what cables do, you can get the same results with almost any other cable."

Great post. You made me laugh. Not so many years ago, I used to read every issue of The Absolute Sound and Stereophile. I'm not sure what happened but I just flat lost interest in those mags. Probably just a coincidence, but it was about the same time that I started playing music in a live context.

Edit: Changed playing music 'on a serious basis' to playing music 'in a live context'. Captures my intent more accurately in case there was some confusion.

M. M.

 

[Red Planet]

Well let me be the first to say you just cant have a good thread without the Soup Nazi.

Some folks would like to talk about their Gear without being called down. Is that really that big of a deal?

Anyway I'm liking this oldy road hard CA9. It certainly packs a wallop and that my friend you can not deny.

FWIW I like the QSC stuff too. I can not imagine running my PA without that Big ol Lead Sled RMX 2450 pumping those 6x15's at 2 ohms per side.

The feature set alone of the RMX's are way beyond what the CA9 can deliver so those QSC's are very versatile.

All that being said though I prefer the CA9 in my Bass Rig and the 2450 running down the low down in my PA.

I really only bought the CA9 to see what the fuss was about.

Now I see.

 

[Red Planet]

So if you use a CA9 your not a serious player?

Ha ha ha. Now that was a funny one.

 

[HugoM]

It's like a cable thread. Somebody says, "Wow, I just got a Mondo SuperBass cable, and I never sounded better!" And then some people chime in with "Yes, the Mondo SuperBass is the greatest cable ever, the bottom end is louder and tighter than ever!" . . .

Reminds me of the "join-the-bandwagon" effect...

On paper, there are sound differences betweens amps but they are too subtle for me to hear. I do confess to checking dampening specs.

Take my QSC PLX and Crown XTi. To me, they sound alike, but sometimes I wonder if the XTi has more hiss (it has elaborate sound processing configurable through USB) but that could be the placebo effect and frankly, it's not worth my time to do a blind side-by-side. I love them both.

 

[funkydanbass]

Bob, could you comment on the difference in slew rate of the CA9 and a comparable QSC product? I have always been led to beleive that slew rate is important in the reproduction of low frequencies, and that that was a strong point of the CA series...

 

[Red Planet]

Now I have an interesting question.

I notice on the Manual for the CA9 it clearly states in Bridge Mode that one should turn both Levels up both Channels up. I noticed that it does not make one bit of difference if Channel B is up or down. Is the fact that mine is an alder model it is slightly different? As a side note all the Amps I am familiar with use one level control in Bridge Mode (that I remember anyway).

I have used a bunch of em through the Years. From Macrotechs to CS800 Boat Anhcors.

I did notice if you turn the B Channel up on my RMX 2450 the Level goes down.

 

[Bob Lee (QSC)]

Slew rate is important in high frequencies, not lows. You don't get slew-induced distortion on low frequencies because the rate of change of the signal voltage is so low. Slew rate by itself is a useless spec; you have to include maximum voltage swing and maximum frequency for it to have any meaning.

I doubt that you'll find a good power amp from a reputable manufacturer that has inadequate slew rate. I have seen some amps from less reputable manufacturers that have absurdly high slew rate, and they had correspondingly high sensitivity to RF noise, which is not a good thing.

 

[Bob Lee (QSC)]

I notice on the Manual for the CA9 it clearly states in Bridge Mode that one should turn both Levels up both Channels up. I noticed that it does not make one bit of difference if Channel B is up or down. Is the fact that mine is an alder model it is slightly different?

On Crest amps, in bridged mono the two inputs are connected in parallel but the polarity of channel B's is reversed. Both channels get the same signal, except channel B is a mirror image of channel A, so both channels also must be set to the same gain. If channel B's gain control has no effect, then for some reason you're not getting signal from channel B. You should see largely the same action on the signal metering LEDs on both channels.

Make sure you have the bridged mode switch(es) set properly and the loudspeaker cable connected to the two red binding posts.

 

[Arthur U. Poon]

I think that the point of the thread is to express an opinion, which is presented by Red Planet as a praise of a CA-9. Why dont we just leave it at that. I think every time the CA-9 is brought up in a thread someone will come in and say "It's no better an amp than... (fill in the blank.) People express their opinions on this site everyday about all types of products, none of which are disputed as must as the CA-9.

+1. How can we get the CA9 the same "off limits protection" that's already been given to a few brands of basses on this forum ?

I own one (CA-9)and it KILLS! I had a Stewart World 2.1 before it and there is an audible difference especially in the lows that is undeniable. I'll say that the CA-9 is the best power amp that I have tried in my bass rig, and if someone wants to buy it b/c I said that then let them. My guess is that they won't be disappointed.

Another +1. I've bought 3 basses since I've bought my CA9. I honestly have no interest in buying a new amp. -Maybe a Bergantino NV215 & NV610, but for me, the power end is covered.

 

[funkydanbass]

Thanks Bob.

 

[Red Planet]

On Crest amps, in bridged mono the two inputs are connected in parallel but the polarity of channel B's is reversed. Both channels get the same signal, except channel B is a mirror image of channel A, so both channels also must be set to the same gain. If channel B's gain control has no effect, then for some reason you're not getting signal from channel B. You should see largely the same action on the signal metering LEDs on both channels.

Make sure you have the bridged mode switch(es) set properly and the loudspeaker cable connected to the two red binding posts.

I have not checked the Bridge Switch since I picked it up from Logical Audio.

Before I had a Problem with the Channel B Clipping and going into Protect Mode.

They told me Channel B was running Hot. They also told me it was not set in Bridge when I brought it to them.

When I got the Amp the Two Position Jumper was Clearly in the Bridge (right side) Position. This unit only has a postion for Bridge or Stereo, no Parallel Position.

The Level Indicators show a Level on both regardless of where the Channel B Level Control is but the Amp is working fine. I must say it does have twice the Power as it did before I took it to them.

They also told me only the Channel A Level should be used in Bridge. They said they called PV to verify everything they were doing to it since it is so old. They are a PV/Crest warranty service center.

Not sure of all this but the Amp works, is not overheating, and is not going into protect mode anymore. I do need to figure out the deal on the Bridge Jumper if I end up using another Cab.

They said the Bridge Switch was so confusing they had to call in but like I said it is Clearly Marked on the front side of the Circuit Board.

 

[Jim C]

I remember my dad who had a masters in EE say (back in the 60's) that audio quality was measured by the pound!

 

[Jim Carr]

It's like a cable thread. Somebody says, "Wow, I just got a Mondo SuperBass cable, and I never sounded better!" And then some people chime in with "Yes, the Mondo SuperBass is the greatest cable ever, the bottom end is louder and tighter than ever!" And then others say, "If you know what cables do, you can get the same results with almost any other cable."

Bob, I really respect your knowledge and level-headed opinion. I would just like to disagree politely here.

Much of the agreement with RP's fondness for his Crest lead-sled, seems to me to be more like "Yes, we love ours, too," rather than "Yes it is the greatest ever."

My experience is more limited that yours when it comes to power amps, to say the least. The CA6 is the only one I have ever had. Yet, I am completely satisfied with its performance. I love the sound I can get with it using any of my speaker cabinets.

I'll bet you don't really think stating that I am happy with my power amp in any way negates the quality of other products or equates to the pseudo-science of "high-end" cables.

 

[matt thompson]

As a side question for all CA-9 owners, do you guys run the gain knobs at full volume and then adjust the volume as needed on your pre? Are there advantages/ disadvantages to either way? Just noticed that in the pictures of you guys CA-9's that all of the gain knobs were to the max. I think I've asked Mr. Lee about this and there should be no difference right?

 

[Bob Lee (QSC)]

Bob, I really respect your knowledge and level-headed opinion. I would just like to disagree politely here.

Much of the agreement with RP's fondness for his Crest lead-sled, seems to me to be more like "Yes, we love ours, too," rather than "Yes it is the greatest ever."

My experience is more limited that yours when it comes to power amps, to say the least. The CA6 is the only one I have ever had. Yet, I am completely satisfied with its performance. I love the sound I can get with it using any of my speaker cabinets.

I'll bet you don't really think stating that I am happy with my power amp in any way negates the quality of other products or equates to the pseudo-science of "high-end" cables.

Hi Jim, I'm not clear where we're in disagreement.

You should be happy with your amp. A good amp is a good amp. The analogy to pseudo-science cables is that a lot of people enthusiastically think there's some inherently different sound to one or another, but that difference so often seems to vanish in double-blind tests.

 

[Bob Lee (QSC)]

As a side question for all CA-9 owners, do you guys run the gain knobs at full volume and then adjust the volume as needed on your pre? Are there advantages/ disadvantages to either way? Just noticed that in the pictures of you guys CA-9's that all of the gain knobs were to the max. I think I've asked Mr. Lee about this and there should be no difference right?

When you're not playing, do you hear buzz or hiss coming from the loudspeaker? If so, try turning the amp gain down and turning up the preamp, including the input gain, to compensate. The stronger your signal is close to the start of the signal chain (as long as you don't overdo it and cause clipping in the preamp)--instead of having a low signal level throughout and then boosting it a lot at the end--the better your signal-to-noise ratio will be.

 

[rok51]

Now I have an interesting question... Is the fact that mine is an alder model it is slightly different? ...

And I thought that I knew Crest amps! An alder model? Hang onto it...all mine were heavy gauge steel!


Kim

All seriousness aside, they are one helluva nice amp! I will stick with my PLX2 for 'old man issues', but I won't for a minute diss the CA series!

 

[Jim Carr]

Hi Jim, I'm not clear where we're in disagreement.

You should be happy with your amp. A good amp is a good amp. The analogy to pseudo-science cables is that a lot of people enthusiastically think there's some inherently different sound to one or another, but that difference so often seems to vanish in double-blind tests.

+1

I understand, and have experienced this.

At a large well-known research center where I consulted for several years, there were intense protracted (and very geeky) arguments concerning various CD players merits and sound qualities. Mind you I have a background in digital audio synthesis and software engineering--which I had pretty much concealed--and I found these arguments silly and mostly flakey. Others took great delight.

Finally, a double blind experiment was done by the company's audio club. Four CD players were compared with no one knowing which or even exactly how many devices were being played until after the many responses were tallied. Result: the preferences were statistically random.

Everyone accepted the results, even though most were a bit glum. Science can be fun until sometimes when it collapses the "geek field."