mark1101 Posted February 3, 2007 Share Posted February 3, 2007 Negative feedback......and Craig. Quote Link to comment Share on other sites More sharing options...
George Roland Posted February 3, 2007 Share Posted February 3, 2007 I agree with those who stated that preamps may add more noise than amps. That has been my experience. Using shorting plugs at the amp's inputs, my ARC VT100 is almost dead silent. My current favorite, best sounding preamp. the tube Juicy Music Blueberry Xtreme, produces a little noise, but I have found that the amount of this noise varies a lot depending on the placement of components, orientation of cables, etc. In some positions, I can nearly eliminate all hiss audible over a couple feet from the K-horns. I would strongly recommend, if you haven't done so already, carefully, systematically move your components, reorient cables, etc. You may find you can reduce noise to an acceptable level without spending a lot on electronics. George Quote Link to comment Share on other sites More sharing options...
meagain Posted February 3, 2007 Share Posted February 3, 2007 Well, if one has 3,000 cables - which cables would be the likely culprits to start with? Quote Link to comment Share on other sites More sharing options...
S2LR Posted February 4, 2007 Author Share Posted February 4, 2007 Folks, Thanks for all the input. Pardon my ignorance but I'm not sure what shorting plugs are. Are they the interconnects between the amp and pre-amp? I will try some of the things suggested to see if the hiss is the amp or pre-amp. In answer to a previous question, I don't have gain control on my amp so I'm stuck with what I've got. Quote Link to comment Share on other sites More sharing options...
markgod Posted February 4, 2007 Share Posted February 4, 2007 I am running VRD's , I have Craigs blueberry -juicy music and I get the hiss with it . Craig has my Diva M7 pre-amp ,and to me it takes out just about all the hiss, if not all the hiss. Maybe he will post his impressions of my Diva. Mark, I get about the same hiss out of your Diva as I did out of my blueberry here in fact I get something out of it I never get out of the Blueberry a small amount of hum out of my woofers (very small) but its there just the same. Now that said I can hear nothing much out of either setup when I stand up two foot away! so I guess I don't understand why this stuff is even brought up if others are getting the same noise as I am. I mean I could see if you could hear this stuff from your seated position or within say 3' of your speakers, but I can't remember the last time I listened to music with my ear up to a 104db speaker [] As far as the Adcom I suggest you do like others and try to isolate the noise by shorting the inputs of the amp and see if the amp is really the culprit making the noise. A power amp is going to do its job and amplify whatever is presented too its input. The lower the input sensitivity of the amp is the more it will amplify it. Craig Craig, I wonder why that is, at the gathering when I swapped them ,no one heard any noise at all with my system . I wonder if it is the tubes , don't really know, just thinking out loud I guess and as you said if you can't hear it from your listening position ,it does not matter to me any ways. Quote Link to comment Share on other sites More sharing options...
theplummer Posted February 4, 2007 Share Posted February 4, 2007 S2LR, I hate to say it, and I'll get yelled at for saying it, But, ADCOM and Horns do not mix very well, for this very reason. I've had, and still do have ADCOM and it is almost unusable with anything horn loaded as the hiss is rather annoying. Years ago, I thought it was my Nackamichi tape deck and Yamaha CD player. Until I purchased a Sunfire Theater Grand II and Signature amp, I did not know how quiet an amp could be, Now let me qualify that. When I used the RCA jacks (Unbalanced), I could still hear amp noise. When I connected the amp to pre with XLR cables (Balanced), the amp noise all but disappears. it's barely detectable even at 90% volume input (I've never gone higher), with no source input. I believe ADCOM makes a high quality product, but I believe there are much better products out there that work better with Horns. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 4, 2007 Share Posted February 4, 2007 I am running VRD's , I have Craigs blueberry -juicy music and I get the hiss with it . Craig has my Diva M7 pre-amp ,and to me it takes out just about all the hiss, if not all the hiss. Maybe he will post his impressions of my Diva. Mark, I get about the same hiss out of your Diva as I did out of my blueberry here in fact I get something out of it I never get out of the Blueberry a small amount of hum out of my woofers (very small) but its there just the same. Now that said I can hear nothing much out of either setup when I stand up two foot away! so I guess I don't understand why this stuff is even brought up if others are getting the same noise as I am. I mean I could see if you could hear this stuff from your seated position or within say 3' of your speakers, but I can't remember the last time I listened to music with my ear up to a 104db speaker [] As far as the Adcom I suggest you do like others and try to isolate the noise by shorting the inputs of the amp and see if the amp is really the culprit making the noise. A power amp is going to do its job and amplify whatever is presented too its input. The lower the input sensitivity of the amp is the more it will amplify it. Craig Craig, I wonder why that is, at the gathering when I swapped them ,no one heard any noise at all with my system . I wonder if it is the tubes , don't really know, just thinking out loud I guess and as you said if you can't hear it from your listening position ,it does not matter to me any ways. It could very well be partially the tubes I'm using used test good Mullard's in it. Now keep in mind my shop is an environment that is very likely too make any unshielded preamp noisier then it maybe in most anyone's normal listening room. With tubes exposed and unshielded like your preamp has I'm not at all surprised that it has noise in my room. Again this noise is only when I kneel down at get my head up to the speakers which to me is meaningless. Calling a system noisy when you have to stick your head up to the speaker to hear it is just being anal IMHO. I'm fairly sure after the rough ride the BBX was subject to on the way to you my only quiet vintage 6DJ8 has become a little noisier. My BBX is usually dead silent when I take it to shows or use it in my living room system. Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 4, 2007 Share Posted February 4, 2007 Folks, Thanks for all the input. Pardon my ignorance but I'm not sure what shorting plugs are. Are they the interconnects between the amp and pre-amp? I will try some of the things suggested to see if the hiss is the amp or pre-amp. In answer to a previous question, I don't have gain control on my amp so I'm stuck with what I've got. Take an old set of RCA inter connect (the cheapo type that come with CD players) cut the wire about 4" or so back from the RCA plugs. Strip the outer insulation off and expose the raw shielding wire. Move that wire off to the side to expose the inner conductor now strip the insulation off that inner conductor. Take these now exposed two sets of raw wire and twist them tightly together and tape them off. Do thise to both left and right RCA plugs. You now have made a pair a shorting plugs to diagnose how much noise each piece of gear and its associated inter connect is adding to your amplifier. First test the amp alone with the shorting plugs installed. then add the preamp with nothing attached to it and the shorting plugs in the inputs that the selector switch is set on. Keep adding components until the noise appears and you can start limiting it once you have pin pointed the culprit. Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 4, 2007 Share Posted February 4, 2007 Negative feedback......and Craig. Actually that is not the only reason they are quiet. Much of it can be accredited to the fact that every thing is in one well shielded and laid out box and all high gain noise sensitive tubes (12AX7) are shielded. Sure a quality rebuild helps, as does negative feedback to some degree. But a good portion of the credit belongs to the original designers of those all in one components. For instance some of the lower priced Kit integrated amps like Heathkit and EICO that have the same rebuild and negative feedback are never as quiet as a Scott or Fisher since they were real skimpy on the sheilding of the tone circuit and what not. Separates are always more susceptible to noise from various extra entry points and require great care to get them as quiet as possible. Craig Quote Link to comment Share on other sites More sharing options...
Audio Flynn Posted February 4, 2007 Share Posted February 4, 2007 My Belles only have a little hiss when I have them configured in the "headphone" orientation. My shoulders get tired before the hiss bugs me too much. Quote Link to comment Share on other sites More sharing options...
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