Author Topic: Crell CA-20 vs. Soundstandard CA-20 (Read 42579 times)

mr. ultimate · « **Reply #75 on:** February 03, 2011, 10:36:22 AM »

D naman ko sinabi na accurate yung fomula ko plus minus 10% lang yung sakin para madaling mo mahuha kung ok yung amp o hindi , hindi naman tayong puwede magdala ng oscilliscope palagi mayron lang batayan yung bibili , walang perfect sa audio no end yan palaging may bagong lalabas Sir eirol alam ko alam mo yung paliwanag ko hindi sagot sa lahat ang gumanit ng oscilliescope hindi lahat kagaya mo na alam gumamit yan test instrument yung sa akin para sa lahat mas intindihan mas simple ika nga. Pero thanks for the replys may natutunan din ang mga mag babasa sa mga paliwanag natin.

eirol_99 · « **Reply #76 on:** February 03, 2011, 01:46:23 PM »

Quote from: mr. ultimate on February 03, 2011, 10:36:22 AM

D naman ko sinabi na accurate yung fomula ko plus minus 10% lang yung sakin para madaling mo mahuha kung ok yung amp o hindi , hindi naman tayong puwede magdala ng oscilliscope palagi mayron lang batayan yung bibili , walang perfect sa audio no end yan palaging may bagong lalabas Sir eirol alam ko alam mo yung paliwanag ko hindi sagot sa lahat ang gumanit ng oscilliescope hindi lahat kagaya mo na alam gumamit yan test instrument yung sa akin para sa lahat mas intindihan mas simple ika nga. Pero thanks for the replys may natutunan din ang mga mag babasa sa mga paliwanag natin.

di ko sinasabing accurate yang formula mo sir, mali yan!! watts times voltage eh walang formula na ganyan..

gamitin na lang (supply voltage/ 1.414)squared divided by load resistance, mataas yan lalabas, pero pag mas mataas pa kaysa nacompute mo yung sinasabing power ng amp na bibilhin mo duda ka na,

for example sa qsc rmx 850, supply voltage is 67 Vdc
67/1.414=47.38
47.38 squared=2234

at 8 ohms load. power = 2234/8=280 watts

the rmx 850 is rated at 200 watts @8 ohms. mas mataas ang computed value, pero talagang sagad na yun. then if specs ng rmx is sinabing 300 watts at 8 ohms.. duda na

lighttech · « **Reply #77 on:** February 03, 2011, 02:09:24 PM »

Quote from: mr. ultimate on February 03, 2011, 10:36:22 AM

D naman ko sinabi na accurate yung fomula ko plus minus 10% lang yung sakin para madaling mo mahuha kung ok yung amp o hindi ...

first i would like to make an apology to forumers, di na po sana ako sasagot para hindi hahaba ang discussion pero i strongly feel na i must straighten a myth being offered as technically true.

sir ultimate, with all due respects sir, your formula is waaaaaaaaaaaaaaaaaay off.. sige sabihin na nating empirical formula and disregard the unit of the result. let's examine say QSC RMX1850HD. published specs is (FTC) 350w at 8r, 550w at 4r and 900w at 2r. it uses 4 pairs of 2sc5200/2sa1943 transistors. high rail voltage is at 88V and low rail at 44V. so with your formula that is power rating of transistor times the number of transistors times voltage is 150W x 4 x 88 = 52800W.. 52.8kW, ano ito plus minus 10% ng P.M.P.O?

masyadong mataas ang result ng formula kahit pa sa lower rail voltage i-compute. partida na yung number of pairs ang nilagay ko, hindi number of transistors. kahit i-derate pa yung pd sa 10%, masyado pa ring malayo.

by the way yung 150W ay Pd ng 2sc5200 at 2sa1943.

yung formula ni sir eirol, mas malapit pa sa katotohanan. you can actually use that formula as a "ceiling" or upper limit. if the published specs is equal or higher than the results of that formula, then the published specs is "padded". (this holds for non BTL amps). to be more accurate, you could measure the voltage while the amp is operating (kung papayag na buksan) then subtract 5-10V as voltage drops across emitter resistors and transistors and use it instead. again, this is just a ballpark formula. to be able to get the ACTUAL power output, measurement with an oscilloscope, IMHO, is a must.

edit: fixed 2sa1943 datasheet url

king_james · « **Reply #78 on:** February 03, 2011, 02:21:16 PM »

I've been using QSC RMX5050 for 4 years now and we don't have failure issues for the longest time. We did however busted our DAS 18" when a group rented our subs and they were using these Chinese amps - Crell model.

There were instances when we compared the sound quality of our QSC RMX with any Chinese made/designed amps - Sound Stnadard, Music Focus, Konzert K10, BTS, Crell etc., and we all agree that not just the sound quality is obvious but also the over-all sound integrity. All attributed to QSC amp.

mr. ultimate · « **Reply #79 on:** February 03, 2011, 02:29:30 PM »

Hindi naman ganyan ang formula ko medyo malapit si sir eirol pero kay sir lighttech malayo sa akin pero am sure d ako puwedeng mag kamali sa dami ng mga amp na hawakan ko hindi lumalayo ang rating sa pag kuwenta ko . Sa factory hindi pa ginagawa ang isang amp alam na kung ilan power trasistor at volt ang gagamitin nila para maabot ang wattage na gusto nilang gawin hindi naman puwede gagawin nila muna bago malanan ang wattage may bilang talaga yan mga boys para dumating ka sa tamang wattage na gusto ni lang gawin , alangan gagawin muna nila tapos gagamitan ng oscillescope bago nila sasabihin ang wattage ng amp may pano na talagang wattage sila bago nila gawin kung ilan wattage ang gagawin nila

lighttech · « **Reply #80 on:** February 03, 2011, 02:33:59 PM »

Quote from: mr. ultimate on February 03, 2011, 02:29:30 PM

Hindi naman ganyan ang formula ko medyo malapit si sir eirol pero kay sir lighttech malayo sa akin pero am sure d ako puwedeng mag kamali sa dami ng mga amp na hawakan ko hindi lumalayo ang rating sa pag kuwenta ko . Sa factory hindi pa ginagawa ang isang amp alam na kung ilan power trasistor at volt ang gagamitin nila para maabot ang wattage na gusto nilang gawin hindi naman puwede gagawin nila muna bago malanan ang wattage may bilang talaga yan mga boys para dumating ka sa tamang wattage na gusto ni lang gawin , alangan gagawin muna nila tapos gagamitan ng oscillescope bago nila sasabihin ang wattage ng amp may pano na talagang wattage sila bago nila gawin kung ilan wattage ang gagawin nila

sir sinundan ko lang yung sinabi nyo sa post ninyo.

sir kaya nga may R&D.. magdedesign sila, tapos gagawa ng prototype then make lots of design veirfication measurements, then if it passes the tests, then the design goes to the factory for mass production. talagang gagawa muna sila ng amp, tapos susukatin using not just an oscillioscope but a lot of other audio test instruments to verify their design.

mr. ultimate · « **Reply #81 on:** February 03, 2011, 02:36:45 PM »

Am sure QSC is very good quality no question even crown macro tech malalakas at matitibay

lighttech · « **Reply #82 on:** February 03, 2011, 02:43:52 PM »

btw, all amps of some qsc models undergo thru tests using oscilloscope + dummy load to set the current limit trimmers. the procedure is stated on qsc service manuals, you can check if you have one.

lighttech · « **Reply #83 on:** February 03, 2011, 02:47:04 PM »

Quote from: mr. ultimate on February 03, 2011, 01:40:59 AM

At sa pag kilatis nang isang amp pakiusapan niyo ang dealer na buksan para makita mo anong part no ng transistor , tapos hanapin mo sa goggle makikita mo yung wattage ng parts times mo kung ilan pcs ang ginamit times mo ulit sa voltage na pumapasok sa trasistor duon malalaman mo na kung tama ba ang rating na nakasulat sa spec nila paano mo kukunan sa oscillescope kung hindi mo pa nabibili, kung branded ang bibilhin mo sigurado ko hindi mo na kaylangan nang pagtesting bilhin mo na lang pero kung kaya nang bulsa mo hehehe , spend your money wisely, hirap kitahin ngayon ang pera

sir eto po yung post ninyo regarding sa formula.. baka sabihin pa ng iba na ako ang nag-imbento niyan.

mr. ultimate · « **Reply #84 on:** February 03, 2011, 02:59:24 PM »

Sir eirol saludo ako sayo Halos paheras lang tayo na lumabas na sagot sa rmx 850 yung watts na compute ko hindi tayo nagkakalayo yan ang simple na makukuha ang tamang wattage isa isang amp ibang paraan lang ang ginamit ko sa pag compute .

eirol_99 · « **Reply #85 on:** February 03, 2011, 03:10:53 PM »

number of transistors used is just for the for the power handling sir ultimate, not for the power output. yung ibang amps minsan use same pcb ng lower at higher model. binabawasan lang nila ng power transistor at iba ang supply voltage, now if you add more transistors sa bakanteng slots, di sya tataas ng power. kahit taasan mo ng supply di rin sure na tataas power nya kasi baka iba ang gain sa design ng higher model

qsc rmx 1450, rmx 1850hd, rmx 2450 uses same numbers of output trannies, same part number, but different out put power ang mga ampli, kakataka ano?! voltage gain nila is 40x(32dB), 46x(33db) and 50x(34dB) respectively

lower powered amps have lower gain. higher has higher voltage gain.

mr. ultimate · « **Reply #86 on:** February 03, 2011, 03:11:22 PM »

Sir lightech basahin mo na lang post ni sir eirol mas madali mong makuha ang formula

eirol_99 · « **Reply #87 on:** February 03, 2011, 03:17:47 PM »

Quote from: mr. ultimate on February 03, 2011, 02:59:24 PM

Sir eirol saludo ako sayo Halos paheras lang tayo na lumabas na sagot sa rmx 850 yung watts na compute ko hindi tayo nagkakalayo yan ang simple na makukuha ang tamang wattage isa isang amp ibang paraan lang ang ginamit ko sa pag compute .

sir ultimate mag post ka na lang ng sample computation mo para maliwanagan ang lahat based on your formula,,
based on sir lighttech explanations mas waaay hightech pa sya sa akin, wala ako arguement kay sir lighttech, hats off ako sau sir lighttech. E.C.E po ba kau sir lighttech?

lighttech · « **Reply #88 on:** February 03, 2011, 03:18:40 PM »

Quote from: mr. ultimate on February 03, 2011, 03:11:22 PM

Sir lightech basahin mo na lang post ni sir eirol mas madali mong makuha ang formula

sir with all due respects, alam ko na po yung formula na yun. sa basic electronics pa lang tinuturo na yun. at wag ninyong sabihing malapit ang formula ninyo sa post ninyo sa formula na P=IIR or P=VI or P=VV/R.

lighttech · « **Reply #89 on:** February 03, 2011, 03:25:42 PM »

Quote from: eirol_99 on February 03, 2011, 03:17:47 PM

sir ultimate mag post ka na lang ng sample computation mo para maliwanagan ang lahat based on your formula,,
based on sir lighttech explanations mas waaay hightech pa sya sa akin, wala ako arguement kay sir lighttech, hats off ako sau sir lighttech. E.C.E po ba kau sir lighttech?

mr. ultimate · « **Reply #90 on:** February 03, 2011, 03:28:25 PM »

Bakit si sir eirol nakukuha niya ang ibig kong sabihinbnong una palang sory kung hindi mo makuha

mr. ultimate · « **Reply #91 on:** February 03, 2011, 03:32:21 PM »

You can get it for just simple basic math you dont have an ece degree to solve it

lighttech · « **Reply #92 on:** February 03, 2011, 03:34:36 PM »

Quote from: mr. ultimate on February 03, 2011, 02:59:24 PM

Sir eirol saludo ako sayo Halos paheras lang tayo na lumabas na sagot sa rmx 850 yung watts na compute ko hindi tayo nagkakalayo yan ang simple na makukuha ang tamang wattage isa isang amp ibang paraan lang ang ginamit ko sa pag compute .

i second the request of sir eirol. paki show kung paano ang computation.

RMX850
number of otput transistor Pairs per channel == 3pairs of 2sc5200/2sa1943
supply voltage == 67Vdc
2sc5200/2sa1943 Pd == 150W

anyway, kung mapapansin ninyo lamang lang ng isang pares ng output trannie ang rmx1850HD compared sa rmx850, pero take note na class H ang RMX1850HD.

lighttech · « **Reply #93 on:** February 03, 2011, 03:36:46 PM »

Quote from: mr. ultimate on February 03, 2011, 03:32:21 PM

You can get it for just simple basic math you dont have an ece degree to solve it

bakit sir, sino bang nagsabing kailangang maging ece para ma-solve yan?

wala ngang nagsasabi/nagyayabang na ece sila dito sa thread na ito e. hehehe

eirol_99 · « **Reply #94 on:** February 03, 2011, 04:34:16 PM »

Quote from: mr. ultimate on February 03, 2011, 03:28:25 PM

Bakit si sir eirol nakukuha niya ang ibig kong sabihinbnong una palang sory kung hindi mo makuha

sorry sir di ko kuha ang ibig mong sabihin. ako nga nagtatanong ng example computation mo based on your formula kung mag aarrive tayo sa same or near values..

eirol_99 · « **Reply #95 on:** February 03, 2011, 04:44:03 PM »

Quote from: lighttech on February 03, 2011, 03:34:36 PM

i second the request of sir eirol. paki show kung paano ang computation.

RMX850
number of otput transistor Pairs per channel == 3pairs of 2sc5200/2sa1943
supply voltage == 67Vdc
2sc5200/2sa1943 Pd == 150W

anyway, kung mapapansin ninyo lamang lang ng isang pares ng output trannie ang rmx1850HD compared sa rmx850, pero take note na class H ang RMX1850HD.

sir ultimate;
ayan sir may given data ka na. pakicompute na yung power output based on your formula/computation. para magkaliwanagan na,

mr. ultimate · « **Reply #96 on:** February 03, 2011, 04:48:22 PM »

Sir eirol ibang paraan ginawa mo ibang paraan ang sakin ang ginawa ko lang ay kinuha ko ang volt transistor at voltage nang amp kinuha ko ang percentage na ginamit nang amp times mo sa percentage na ginamit sa wattage nang trasistor times mo kung ilan transistot , hehehe sir lighttech gigi na gigil ka maku ha

constantpressure · « **Reply #97 on:** February 03, 2011, 04:51:31 PM »

Suko na ako...paano ba yun???

eirol_99 · « **Reply #98 on:** February 03, 2011, 04:53:19 PM »

Quote from: mr. ultimate on February 03, 2011, 04:48:22 PM

Sir eirol ibang paraan ginawa mo ibang paraan ang sakin ang ginawa ko lang ay kinuha ko ang volt transistor at voltage nang amp kinuha ko ang percentage na ginamit nang amp times mo sa percentage na ginamit sa wattage nang trasistor times mo kung ilan transistot , hehehe sir lighttech gigi na gigil ka maku ha

kahit ano na sir, ipakita mo na, times times lang naman yan, ipakita mo numbers, para maliwanag

lighttech · « **Reply #99 on:** February 03, 2011, 04:53:57 PM »

Quote from: mr. ultimate on February 03, 2011, 04:48:22 PM

Sir eirol ibang paraan ginawa mo ibang paraan ang sakin ang ginawa ko lang ay kinuha ko ang volt transistor at voltage nang amp kinuha ko ang percentage na ginamit nang amp times mo sa percentage na ginamit sa wattage nang trasistor times mo kung ilan transistot , hehehe sir lighttech gigi na gigil ka maku ha

hehe, hindi po ako nanggigigil.. natatawa na nga lang ako sa mga palusot ninyo. lagi ninyong dinadivert/iniiwasan ang discussion. ayan na nga may data na di nyo pa ipakita yung computation.. so to be clear, i am not asking you to show your computation so that i will know your "secret" formula.. i am not interested in that, i am just interested if there is just a bit of technical truth on or not.

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Author Topic: Crell CA-20 vs. Soundstandard CA-20 (Read 42579 times)