S2LR Posted February 3, 2007 Share Posted February 3, 2007 Hello, I have a pair of Klipschorns (1989 ) that are being run by Adcom components (GFP-565 preamp and GFA-545II high current amp which is rated at 100 w rms). Speaker cable is high end Kimber. This combo sounds very good except for the idle hiss when no music is being played. I suspect that this is due to the high efficiency of the speakers.?.? My question is, is there a better match for the Klipschorns in terms of a amp/pre-amp combo that sounds good and is more quiet during idle? I love the sound with the combo that I have now but the idle hiss is getting very annoying. I would also like to know what others are using for the amp/pre-amp components with the Klipschorns with great success... Any input would be appreciated... Quote Link to comment Share on other sites More sharing options...
Guest " " Posted February 3, 2007 Share Posted February 3, 2007 Your going to get a lot of feed back on this one. I have a 30 year old stock SS amp which boosted a signal to noise ratio of 106 db that is dead quiet even today, as well as new SS gear that is also dead quiet as well as both old and new tube gear which are dead quiet as well. There are probally mods for you adcom amp to quiet it up. Another option, if you like your amp, is to use an autoformer on your amp the way Mcintosh does, to tune the impedance of the apparent load your amp sees. This will lower your noise floor, reduce distortion, and increase dampening factor. If you want more info on this...send me an email. I have some loaner autoformers you can use to test the concept. Quote Link to comment Share on other sites More sharing options...
markgod Posted February 3, 2007 Share Posted February 3, 2007 Hello, I have a pair of Klipschorns (1989 ) that are being run by Adcom components (GFP-565 preamp and GFA-545II high current amp which is rated at 100 w rms). Speaker cable is high end Kimber. This combo sounds very good except for the idle hiss when no music is being played. I suspect that this is due to the high efficiency of the speakers.?.? My question is, is there a better match for the Klipschorns in terms of a amp/pre-amp combo that sounds good and is more quiet during idle? I love the sound with the combo that I have now but the idle hiss is getting very annoying. I would also like to know what others are using for the amp/pre-amp components with the Klipschorns with great success... Any input would be appreciated... 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. Quote Link to comment Share on other sites More sharing options...
SilverSport Posted February 3, 2007 Share Posted February 3, 2007 same here...I can "hear the efficiency" of the K'Horns with VRDs and BlueBerry combo...I could hear it as well with a McIntosh MAC1900, MA-6200 and an EICO HF-81... Bill Quote Link to comment Share on other sites More sharing options...
Fish Posted February 3, 2007 Share Posted February 3, 2007 With a decent amp you really should not hear much hiss at all,I know on my 7's most good amps have been very quiet,prepros have been an issue to various degrees.Is the preamp playing a part in the hiss? Quote Link to comment Share on other sites More sharing options...
meagain Posted February 3, 2007 Share Posted February 3, 2007 I have hiss also with the tubes. Not with my SS. Never heard about this autoformer thing. I'm curious as to what it is. Quote Link to comment Share on other sites More sharing options...
LarryC Posted February 3, 2007 Share Posted February 3, 2007 Your hiss is most likely preamplifier noise, not amplifier noise. See if it doesn't fall off or disappear with your amp on if you turn off or disconnect the preamp. Yes, naturally it's the efficiency of the K-horn, but only in tandem with the amount of preamp output noise and amplifier gain. I've had to do lots of gain-matching between preamps and amps in the past. Is the gain of your 545II adjustable? Try turning it down if you can. lc Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted February 3, 2007 Share Posted February 3, 2007 Your hiss is most likely preamplifier noise, not amplifier noise. See if it doesn't fall off or disappear with your amp on if you turn off or disconnect the preamp. Yes, naturally it's the efficiency of the K-horn, but only in tandem with the amount of preamp output noise and amplifier gain. I've had to do lots of gain-matching between preamps and amps in the past. Is the gain of your 545II adjustable? Try turning it down if you can. lc The efficiency of the K-Horn is both a curse and a joy. I also supect it may be in the pre-amp, but my guess is based on experience rather than real knowledge. I have used a similar model adcom and it was quiet (a weak hiss at the driver but certainly not audible at the listening position). Just to make sure, is this a hiss or a low frequency hum (that is a different problem)? Good Luck, -Tom Quote Link to comment Share on other sites More sharing options...
Guest " " Posted February 3, 2007 Share Posted February 3, 2007 The autoformer solution has been around for decades. Mcintosh, Atlas, Crown, and others offer products or incorporate in their gear. Here is a fellow who is doing quite well selling his custom autoformer to high end audio folks. He has a nice product, and lot's of happy customers. I have exchanged emails with him numerous times and he is very responsive to questions. You can read the various links about this product to get the pro's and con's of these autoformers. Paul sells assembled versions for about 800 a pair, and bare bone units for about 450 a pair. http://www.enjoythemusic.com/magazine/equipment/0603/midmonth/zeroautoformer.htm For the DIY crowd, like with many high end audio add ons, there are DIY options at various costs. If triordial is not a requirement, Atlas, Crown and a few others have steel laminated versions for about 100 bucks a pair. If there is a lot of intrest for triordial versions, i can put in a request for a bulk buy, and we can all get a pair at cost, from various transformer/autoformer suppliers. Cost depends on the max power requiremnts, if we can get to 10 units (5 pairs) we could get something simular in triordial form for about a third of the price. Quote Link to comment Share on other sites More sharing options...
markgod Posted February 3, 2007 Share Posted February 3, 2007 Your hiss is most likely preamplifier noise, not amplifier noise. See if it doesn't fall off or disappear with your amp on if you turn off or disconnect the preamp. Yes, naturally it's the efficiency of the K-horn, but only in tandem with the amount of preamp output noise and amplifier gain. I've had to do lots of gain-matching between preamps and amps in the past. Is the gain of your 545II adjustable? Try turning it down if you can. lc On my VRDs , the noise is there if I don't turn on my Diva preamp. Once I turn on the Diva pre ,the noise is gone. Quote Link to comment Share on other sites More sharing options...
meagain Posted February 3, 2007 Share Posted February 3, 2007 My hiss comes from my pre-amp, not the VRDs. (I think). Quote Link to comment Share on other sites More sharing options...
Ki Choi Posted February 3, 2007 Share Posted February 3, 2007 I would suggest shorting the inputs of your Adcom power amp and listen for the hiss. In my experience, most modern SS power amps have high enough signal to noise ratio to avoid any hissing to be heard from your listening position if it is working within its design parameters. With some power amps you could hear some hissing when you have your ear right next to the tweeters especially with Khorn's senitivity. If no hiss is heard with shorted inputs to your power amp, try by passing the preamp with any CD players with variable outputs connected directly to your power amp for test. Listen for silent passages and while paused to be sure. You power amp may be fine and the source of the hissing is from upstream equipment. There are no hisses and I get dead quiet with my Khorns when I use most of my tube amps and tube/SS preamps. Only exceptions are HK Citation II and when I had fake NOS driver/gain tubes in my AudioPrism Debut II Silver Sig tube amp. Ki Quote Link to comment Share on other sites More sharing options...
Moderators Travis In Austin Posted February 3, 2007 Moderators Share Posted February 3, 2007 Ki, You are dead on correct to try using shoring plugs on the amp to isolate the problem. With my VRD's shorted I have to put my ear up to the Khorn squaker or tweeter to hear any hiss. With quiet tubes in my MX-110 pre-amp it is still dead quiet, i.e. you can hear it but only with your ear up to the speaker. I bet boomer's (Scott) rig is ultra quiet, Bat preamp and amp, fully balanced, I am wondering if he even hears hiss with his ear up to the speaker. Travis Quote Link to comment Share on other sites More sharing options...
Mick Bell Posted February 3, 2007 Share Posted February 3, 2007 S2LR: I'm using a McIntosh MC-240 with a Juicy Music Blueberry Extreme. When I first switched to the Blueberry I had the same problem -- hiss in the K-Horns. Turning down the gain on the amp and turning up the gain on the pre-amp solved my problem. It's dead quiet now. Mick Quote Link to comment Share on other sites More sharing options...
Speedball Posted February 3, 2007 Share Posted February 3, 2007 I have heard another members K-horns being run with Aragon and it was very quiet and sounded very nice. Quote Link to comment Share on other sites More sharing options...
psg Posted February 3, 2007 Share Posted February 3, 2007 Hiss is a major criterion for me as well, and the reason I'm afraid to gamble on a pro amp without hearing it first. My h/k receiver is quiet when using its amplifier outputs, it's quiet when using it as a pre-amp with an old Nikko Alpha 220 power amp, but a Carver m4.0 is so noisy I can't even use it for KHorns. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted February 3, 2007 Share Posted February 3, 2007 Shorting plugs proved to me that my VRDs are virtually silent. Most all hiss which is very minimal and considered normal comes from the preamp (tubes). Different tubes different noise, but minimal My Denon solid state AVR has hiss as well. The quietest amps I have are my 40+ year old rebuilt vintage HH Scott 299, and LK-72. Just about totally silent. Pretty surprising given their age. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 3, 2007 Share Posted February 3, 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 Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 3, 2007 Share Posted February 3, 2007 The quietest amps I have are my 40+ year old rebuilt vintage HH Scott 299, and LK-72. Just about totally silent. Pretty surprising given their age. Wonder why that is [] Quote Link to comment Share on other sites More sharing options...
bluesboy Posted February 3, 2007 Share Posted February 3, 2007 The quietest amps I have are my 40+ year old rebuilt vintage HH Scott 299, and LK-72. Just about totally silent. Pretty surprising given their age. Wonder why that is [] Yeah me too. My old Fisher X-100 without any modifications is also dead silent. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.