michael hurd Posted September 22, 2004 Share Posted September 22, 2004 What I made of the manual of the rotel processor : Different modes have different voltage gains In stereo mode, to output 1v at the output jacks, it requires 420mv input from source (cd player) 1v output from your processor (rotel) will not produce full output in an amplifier that requires 1.55v for full output. If 1.55v input gives 115w/8r, then 1v will give 47 watts/8r. No wonder you don't think it is as loud as it should be! 32 watts = 15 db, therefore (sensitivity)96db + 15db = 111 db @ 1 m Quote Link to comment Share on other sites More sharing options...
michael hurd Posted September 22, 2004 Share Posted September 22, 2004 A little more... add 3 db for the second speaker. If you sit 2 m from the speakers, then subtract 3db, 4 m away, 6 db. Depending on the size of the room and how far away you sit, you might be getting peaks of only 105 db. Quote Link to comment Share on other sites More sharing options...
doudou Posted September 22, 2004 Share Posted September 22, 2004 111 db is very loud! if he says that it is not loud, it means that there is less then than. so here is a question:are you sure the amp is good? here is a simple test if you haven t tested your amp yet: if you have a mp3 player or a walkman or something like that, on wich you can set the volum, hooj up this device directly on the amp. if it become very loud when turning up the volume you will be sure that the amp is right. Quote Link to comment Share on other sites More sharing options...
doudou Posted September 22, 2004 Share Posted September 22, 2004 once you ll be sure the amp is good, i m sure michael knows a method to test the cd player,to be sure it feed the preamp with enough power. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted September 22, 2004 Share Posted September 22, 2004 That 111 db at 1m would be developed on peaks, when the cd player has it's highest output. Factor in possible poor connections, seating distance from the speakers, and like I say, you might get peaks of 105 db at the listening position. If we say that the peak spls were 6 db higher, then an average of 99 db would be a given. Quote Link to comment Share on other sites More sharing options...
doudou Posted September 22, 2004 Share Posted September 22, 2004 i agree with you. so does everything work well? if i remember well, an orchestra produce a sound level from 0 to about 103dB so natgun s system should be enough to listen music in good conditions. Quote Link to comment Share on other sites More sharing options...
doudou Posted September 22, 2004 Share Posted September 22, 2004 i was thinking about something: it may can be a placement issue. so from 99db to 105 we can fall to 90 and almost 100 quite easily. or even less. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted September 22, 2004 Share Posted September 22, 2004 Well, his promedia ultra system produces 108 db @ 1 m, at full whack, so I can see his point that the heresies don't seem to be as loud as they should. http://home.new.rr.com/trumpetb/audio/dBexamp.html Quote Link to comment Share on other sites More sharing options...
doudou Posted September 22, 2004 Share Posted September 22, 2004 i agree again. thanks for the document michael if the premedia ultra sat were exactly at the same place there are only few chance that the problem come from a placement issue. Quote Link to comment Share on other sites More sharing options...
radiob Posted September 22, 2004 Share Posted September 22, 2004 ---------------- On 9/21/2004 11:58:02 PM michael hurd wrote: Sounds like the preamp is not producing a large enough voltage to properly drive the input stage of the amplifier. ---------------- Ditto. Quote Link to comment Share on other sites More sharing options...
marksdad Posted September 22, 2004 Share Posted September 22, 2004 you have something wierd going on there, i am running an nad 2 channel receiver 2* 35 watts, and at about 1/4 or maybe 7 watts in an 10*10 room i cant hear other people talk Quote Link to comment Share on other sites More sharing options...
KungFuNat Posted September 22, 2004 Author Share Posted September 22, 2004 so i plugged the cd player directly into the hafler and ran it. same result as if the volume was at 100%. its just not that damn loud, i actually sat there and listened to a whole song, it wasnt anywhere near the ear-blowing SPLs im used to with my buddies heresy setup. i also tried to hook up my portable MP3 player to the preamp and result was also the same. im at a loss here guys. Quote Link to comment Share on other sites More sharing options...
ricktate Posted September 22, 2004 Share Posted September 22, 2004 Borrow another reciever or amp,,,i think your amp is broke....when our power was out one winter i hooked a battery powered boom box to my Heresys and they were very loud,,,my sons friends could not believe that good sound was comming out of such a little boom box..lolRick Quote Link to comment Share on other sites More sharing options...
KungFuNat Posted September 22, 2004 Author Share Posted September 22, 2004 well i took in the amp to get service, well see what the guy sayes about it. Quote Link to comment Share on other sites More sharing options...
doudou Posted September 23, 2004 Share Posted September 23, 2004 unfortunatly,it seems that the amp don t do his job very well Quote Link to comment Share on other sites More sharing options...
D-MAN Posted September 23, 2004 Share Posted September 23, 2004 ---------------- On 9/22/2004 11:34:36 AM NatGun wrote: so i plugged the cd player directly into the hafler and ran it. same result as if the volume was at 100%. its just not that damn loud, i actually sat there and listened to a whole song, it wasnt anywhere near the ear-blowing SPLs im used to with my buddies heresy setup. i also tried to hook up my portable MP3 player to the preamp and result was also the same. im at a loss here guys. ---------------- That amp should have ROCKED MIGHTLY; it is therefore not upto snuff. Bummer, dude. DM Quote Link to comment Share on other sites More sharing options...
AceDeuce Posted September 23, 2004 Share Posted September 23, 2004 Just a wild guess here. . . Does the Halfler have an input voltage switch for mains voltage either 220/110? If it's set in the 220 position and you run it from a 110 source, you'll be running everything inside the amp at half voltage. Depending on the design of the amp, this could result in no sound at all, really distorted sound or, just maybe, the very low output you're experiencing. Quote Link to comment Share on other sites More sharing options...
KungFuNat Posted September 24, 2004 Author Share Posted September 24, 2004 well i took it to the shop yesterday and the guy called me today and left a message on my cell. he said that the amp had been modified and one of the circuit boards was not stock, he had to replace it. good news was that all the rest of the components had been recently updated, so the amp was in pretty good condition once he replaced the funky circuit board. oh well, tomorrow ill go pick it up and rock out when i get home. ill post an update tomorrow. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted September 24, 2004 Share Posted September 24, 2004 "well i took it to the shop yesterday and the guy called me today and left a message on my cell. he said that the amp had been modified and one of the circuit boards was not stock, he had to replace it." Sounds pretty fishy if you ask me, having THE cicuit board you need on hand? I would ask for the old one back, and if he refuses, do not pay, yell fraud at the top of your lungs. I can see a repair facility having a huge assortment of transitors, resistors and capacitors on hand. Not a circuit board. Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted September 24, 2004 Share Posted September 24, 2004 He just happened to have a circuit board for an amp that is no longer manufactured!!! Right! It is more likely a fuse was replaced or something less expensive than a board. Bill Quote Link to comment Share on other sites More sharing options...
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