Crest CA18 & 9001
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Category: General
Forum Name: Amp Forum
Forum Description: The 'Stopping Jake Fielder moaning constantly' forum description...
URL: https://forum.speakerplans.com/forum_posts.asp?TID=23953
Printed Date: 18 April 2024 at 3:53pm
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: Crest CA18 & 9001
Posted By: levyte357
Subject: Crest CA18 & 9001
Date Posted: 12 February 2009 at 1:08pm
Last time I looked at schematics, I "think" the 9001 also has 12x smoothing caps, but higher values, and "maybe" higher ripple current. Does the CA18 have same number of O/P transistors as 9001 ? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
levyte357 wrote:Replies:
Posted By: demanddeepbass
Date Posted: 12 February 2009 at 1:34pm
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Yep, 18 and 9001 have same number and same type of OP devices. I did a very quick tot up of farads: 75000uF in the 18 and 76000uF in the 9001: near as makes no difference. Didn't look at ripple figures. ------------- "These amps go up to 11" |
Posted By: levyte357
Date Posted: 12 February 2009 at 2:30pm
@deepbass:I heard a rumour, that the CA18 current limiting in 2.66 ohm mode is not as restrictive as in 2 ohm mode, hence the amp can actually output over 2.5kw per channel in this mode? Does that seem possible to you? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Elliot Thompson
Date Posted: 12 February 2009 at 4:42pm
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The Crest CA 18 offers a voltage rail of 99 Volts DC +/-
The Crest Professional Series 9001 offers a voltage rail of 114 Volts DC +/- These amplifiers are not the same. Best Regards, ------------- Elliot Thompson |
Posted By: chickenfizz
Date Posted: 12 February 2009 at 5:03pm
| My knowledge of class h and class g designs isn't great but I'm guessing ripple current would not be a factor in these designs? Please someone correct me if I'm wrong. |
Posted By: demanddeepbass
Date Posted: 12 February 2009 at 5:22pm
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The schematics show them both as having +- 120V are your figures measured voltages Elliot? I'll check the schematics in detail if I get time but the output stages look mighty similar.... It's possible that you might get more power at 2.66 that at 2 if there is indeed a current limiter but id need to sit down and do maths to check - no time right now I'm afraid. ------------- "These amps go up to 11" |
Posted By: Elliot Thompson
Date Posted: 12 February 2009 at 6:11pm
Both came directly from Crest's spec sheet. It is more than likely taking the load into account. In addition to the power supply sag for, the 9001 offers 65 Amps (120 Volt) while, the CA 18 will deliver 36 Amps (120 Volt) @ 4 ohms maximum. The CA 18's power supply is weaker than the 9001, which affects the overall performance. Without doing the calculations the CA 18 will meet it's specs while the 9001 will exceed it's published specs. Best Regards, ------------- Elliot Thompson |
Posted By: csg
Date Posted: 12 February 2009 at 6:39pm
| Having owned a few 9001's in the past, and having compared them directly to ca18's i can assure you there is a considerable difference in practice. the 9001 is considerably more powerful. |
Posted By: levyte357
Date Posted: 12 February 2009 at 8:02pm
Please correct me where I'm wrong, Assuming amp is 100% Efficient, which it isn't, How can 240(V) @ 18(A) * 1 (100% Efficiency) = 5000W ???? EDIT:Suggests values are not measured, but estimated ? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: TRE4U2NV
Date Posted: 12 February 2009 at 8:15pm
ear 2 ear 9001 all day everyday ------------- IM SO SECRETIVE BUT I CANT TELL YOU WHY |
Posted By: ceharden
Date Posted: 12 February 2009 at 9:59pm
| A 9001 installed with no more than 4m of 10mm square cable back to the main 100A incomer to the building definitely brings a smile to my face every time! |
Posted By: Elliot Thompson
Date Posted: 12 February 2009 at 10:08pm
Well I did say, I did not do the calculations. 
Right! 240 Volts @ 18 Amps = 4320 watts. Bare in mind the amperage stated is under 4 ohms stereo mode not, 2 ohms. Under a 2-ohm configuration the amperage will be greater so, it should achieve 5000 watts. 4320 watts versus 5000 watts yields a 0.6 dB gain. Whether 5000 or 4320 watts you will not hear a difference. Best Regards, ------------- Elliot Thompson |
Posted By: Rog
Date Posted: 13 February 2009 at 1:31am
Are you sure 9001 has 76000uf of caps. That seems really low. In comparison the Infinite 8 V2 has just under 500000uf of caps. I wonder if you charged the caps on an inf 8 and then unpluged it from the mains, there would be enough charge left to run the bass on a small disco setup all night. Free bass. |
Posted By: Rengade Project
Date Posted: 13 February 2009 at 2:17am
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9001 is the more powerful of the two,the techs at old crest said to me (not the exact words) the CA series are the watered down version of the 00 pro. ------------- MUSIC SWEET,www.myspace.com/renegadeproject |
Posted By: levyte357
Date Posted: 13 February 2009 at 2:36am
Of course that's right. The only question is how similiar are they. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: demanddeepbass
Date Posted: 13 February 2009 at 11:15am
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Looked at the schematics a bit more carefully today: @Rog - I wasn't very clear here I've only totted up the total caps on the + rail.... and I've got it the wrong way round! The 1997 CA18 has a total storage across all rails of 152000uF 36000uF on the low rail and an additional 40000uF on the high rail. (there's a note on the drawing saying that the total was upped from 144000uF) The 1996 version of the 9001 has LESS storage @150000uF total. 42000uF on the low rail and 33000uF on the high rail. I'm afraid not everybody builds amps like you Rog....... @Elliot: I've found where you got your numbers from now. You're talking about the max output voltage specified but the DC rail voltage available to the output devices is shown as the same in both amps. Intestingly I cant out what find the low rail voltages are in either. I also can't find any info on the mains transformer which is the bit which could make quite a difference. Anybody know the specs? I was also going a bit blind yesterday - the 9001 has 2 additional output devices on the + and - low rails, over the CA18 so it will deliver a bit more power. In most other respects I would describe the output section of these amps as near identical. Even the component numbering is the same. One is very clearly a variant of the other. ------------- "These amps go up to 11" |
Posted By: Elliot Thompson
Date Posted: 13 February 2009 at 12:51pm
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demanddeepbass
The power supply is the key.
The 9001 state a 10kVA transformer and, weighs 49.94 kg. It offers the same size transformer as the Crest 10,001 (Two 5kVAs). The CA 18 weighs 34.96 kg. When you take into consideration the weight in addition to the current amongst the two, the 9001 is far superior than the CA 18. The Crest 9001 is close to 8000 watts from a current standpoint whereas the CA 18 is close to 5000 watts @ 4 ohms. levyte357 If I were in the UK, I would buy 5 of Rog's Infinite 8 Amplifiers. It is a very good amplifier. I'm not sure why the interest in the Crest CA 18 when it offers the least amount of power of the three from a current standpoint. If I remember correctly, the Infinite 8 should offer around 8200 watts when comparing amperage versus wattage. If one is looking to load eight 8-ohm woofers on one amplifier, you look for the amplifier that offers the most current. Best Regards, ------------- Elliot Thompson |
Posted By: levyte357
Date Posted: 13 February 2009 at 12:57pm
Thanks for that Elliot. I already own a CA18, and just wanted to clear up some rumours regarding the CA18 and 9001. Fully aware of Inf8 MK2 prowess, however my back has instructed me that my next sub amp will be lightweight, even though that means reduction of floorboard rattling.  ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Elliot Thompson
Date Posted: 13 February 2009 at 1:38pm
Fair enough.
If you compare the Crest 9001 to the CA 18 for Highs-Mid frequencies using an 8-4 ohm load per channel both, should give you the same output. The difference will be noticeable under 2-ohm per channel loads supplying Bass-Sub Bass frequency notes. It would imagine this is why demanddeepbass mentioned the voltage rails being identical so, the output amongst the two would be the same. I was looking at the amplifiers from a current perspective, which shows a difference amongst the two under low impedance loads. Best Regards, ------------- Elliot Thompson |
Posted By: Rog
Date Posted: 14 February 2009 at 1:35am
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Thanks for the Inf 8 big up Elliot.
An Inf 8 V2 got tested by the demon amp tester and the results were, well, unexpected.
2800 watts into 4 ohms per side. Thats a lot more than the spec sheet says.
Note to self: Don't be so economic with the ratings next time.
|
Posted By: Elliot Thompson
Date Posted: 15 February 2009 at 3:39am
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Let those who buy
amplifiers based on brand name remain baffled when their shiny new insert name here amplifier cannot deliver the
same amount of raw power as yours without current limitation although, stating more power Best Regards, ------------- Elliot Thompson |
Posted By: RC1 Sound System
Date Posted: 05 June 2015 at 10:30pm
| Just done a bench test head to head between a CA18 and a 9001. They are not the same. 9001 is a bigger amp. Pretty much regardless of load the 9001 comes out about a third more powerful in terms of actual wattage output. Interesting.... |
Posted By: nickyburnell
Date Posted: 05 June 2015 at 10:41pm
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Your roadies just ran for the hills screaming NNNnnnnnnooooooo ------------- It's everything, not everythink! |
Posted By: mini-mad
Date Posted: 05 June 2015 at 10:53pm
 ------------- If it sounds like a gorilla is trying to escape, turn it down. |
Posted By: Dub Specialist Sound
Date Posted: 06 June 2015 at 11:41am
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nah keep it alive lol, love these 2 old skool amps still yes! ------------- Musical Roots Reggae Vibration is Life! for music is sound...sound is vibration...vibration is energy... and energy begets life. Therein lies my passion!...MUSIC IS LIFE... |
Posted By: Heathrow_B_line
Date Posted: 06 June 2015 at 12:50pm
9001 is more powerful/aggressive sounding 8001 sounds more like a CA18... hate to use this term but sounds rounder/fuller lol ------------- Produce a killer sound. Take no prisoners. |