doctorcilantro Posted April 7, 2004 Share Posted April 7, 2004 Can changing pre-amp tubes make a big difference in tube rush/hiss? Right now I am using 5 RCA 12AX7's but I have three black plate RCA's and 2 Tele's sitting around that I might try tonight. DC Quote Link to comment Share on other sites More sharing options...
NOSValves Posted April 7, 2004 Share Posted April 7, 2004 Yes it can ! Preamp tubes can be noisy little buggers. Quote Link to comment Share on other sites More sharing options...
doctorcilantro Posted April 7, 2004 Author Share Posted April 7, 2004 Thanks. Ryan Inman did an amzing job on this integrated and it sounds incredible. I just picked up some RF-35's and they are sounding better every time I sit down for a listen. They are just so sensitive, that hiss is really overwhelming. The S-5000 is about 20-25 watts...I can't remember exactly. At noon, the hiss isn't present, but I find I am listenning at a louder level like 2:30 which is 0db on the dial; at this point when listening to classical the hiss is overwhelming the quiet passages. I have some other tubes I 'd like to try, my uncle has two more RCA black plates that would give me the 5 I would need for the preamp. I attribute the hiss to the fact that is a tube unit and just want to see if I can do anything else to help. Are those O rings for elimating microphonics? Can anyone recommend some new or NOS 12AX7's I could try. How are the new EI or Sovtek 12AX7's. thanks JOn Quote Link to comment Share on other sites More sharing options...
Brap Posted April 7, 2004 Share Posted April 7, 2004 I went from a standard Chinese 12AT7 to a NOS Mullard .... HUGE difference in sound quality and depth Quote Link to comment Share on other sites More sharing options...
Parrot Posted April 7, 2004 Share Posted April 7, 2004 ---------------- On 4/7/2004 9:20:16 AM doctorcilantro wrote: At noon, the hiss isn't present, but I find I am listenning at a louder level like 2:30 which is 0db on the dial; at this point when listening to classical the hiss is overwhelming the quiet passages. ---------------- Jon, There is something wrong somewhere. You should not have so much hiss that you can't hear the music. Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted April 7, 2004 Share Posted April 7, 2004 That hiss might be coming the recordings. Some of them were issued from the original master tapes. Try to pause your CDP and see if it disappears. Quote Link to comment Share on other sites More sharing options...
doctorcilantro Posted April 7, 2004 Author Share Posted April 7, 2004 Well I can hear the music, it just seems the hiss is quite loud, so...in a way I guess your right actually. Assuming the amp is okay...how beneficial is a pair of NOS Mullard, Mazda, RCA 12AX7's in the phono or entire pre going to be? Compared to getting a set of EI elites. I would like to find an X7 that is most importantly quiet but sounds great. I will try something tonight that I have been pondering to relieve the hiss. Jon Quote Link to comment Share on other sites More sharing options...
garymd Posted April 7, 2004 Share Posted April 7, 2004 I get a very small hiss from my pre but it does not increase with volume. I can only hear it when no music is playing and my ear is right up against the horn. If you are getting that much hiss and it increases with volume, I think there has to be more to it. I don't know enough to comment on possible correction via tube replacement though. Quote Link to comment Share on other sites More sharing options...
doctorcilantro Posted April 7, 2004 Author Share Posted April 7, 2004 This hiss increases with the volume control and is independent of any hiss on recordings or created by components (TT). It's really more than I'd like but I don't know how much to expect to have since it's a vintage rebuilt integrated (my first). Even at a reasonable listening level the hiss really "confuses" the music, especially classical. JOn Quote Link to comment Share on other sites More sharing options...
Parrot Posted April 7, 2004 Share Posted April 7, 2004 Being vintage is no reason that it should sound bad. If it's bothering you this much already, it'll drive you crazy eventually. You should have no more hiss than what Gary says, not noticeable unless you have your ear inches away from the speaker. Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted April 7, 2004 Share Posted April 7, 2004 Nearly all tube phono stages have some degree of hiss. Try to find the quietest tubes and run them in your phono stage. Quote Link to comment Share on other sites More sharing options...
garymd Posted April 7, 2004 Share Posted April 7, 2004 My scott 299b (NOSValves) vintage integrated has NO hiss whatsoever. Zero. My brand new pre has the very slight buzz I was telling you about but I believe it's due to the electrical outlet I'm using. Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted April 7, 2004 Share Posted April 7, 2004 ---------------- On 4/7/2004 1:56:07 PM garymd wrote: My scott 299b (NOSValves) vintage integrated has NO hiss whatsoever. Zero. My brand new pre has the very slight buzz I was telling you about but I believe it's due to the electrical outlet I'm using. ---------------- No hiss in the phono input? Quote Link to comment Share on other sites More sharing options...
garymd Posted April 7, 2004 Share Posted April 7, 2004 ---------------- On 4/7/2004 1:57:22 PM Guy Landau wrote: ---------------- On 4/7/2004 1:56:07 PM garymd wrote: My scott 299b (NOSValves) vintage integrated has NO hiss whatsoever. Zero. My brand new pre has the very slight buzz I was telling you about but I believe it's due to the electrical outlet I'm using. ---------------- No hiss in the phono input? ---------------- I guess zero is a slight exaggeration with the phono section. It is very quiet though and not noticable from the listening position and certainly not with music playing. Aux IS dead quiet though. Quote Link to comment Share on other sites More sharing options...
doctorcilantro Posted April 7, 2004 Author Share Posted April 7, 2004 Well I am getting this hiss on AUX and Phono. I don't use the tape input. The AM and FM sections when I switch past them going between phono and aux have a hum on them; nothing is plugged into them. I have a Ferrite core on the power cord for the heck of it. Tonight I will re-check how loud this hiss is. This amp has had some weird experiences...it blew two tubes in the pre-amp section somehow. I had to send it back to Ryan to be checked out. As I said earlier, the amp sounds great, just too much hiss, and I am starting to think it's more than I should expect. Ryan has been amazing supporting this amp and me with my questions and I am in no way saying anything bad about him and his work here; he has truly impeccable integrity. Just trying to get to the bottom of this hiss. Hopefully I will hear from him via email tonight. If I get some tubes that are renowned for being exceptionally quiet, I wonder what kind of change I can expect. This is all assuming the tubes are at fault so.... who knows? I am probably overreacting but last night that classical music just bugged me the way the hiss hung over it and blocked the quiet passages like a cloud. Jon Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted April 7, 2004 Share Posted April 7, 2004 Tungsram 12AX7's are very quiet. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted April 7, 2004 Share Posted April 7, 2004 Doc, I think I have the same 299 unit as you and Gary. Mine is a NOSValves rebuild. The only hiss I get is when a source is playing. If I put the CD on pause, and turn up the volume all the way as far as it goes, and put my ear to the speaker, you can just barely tell the amp is on. You can hear a barely detectable hiss, no hum at all. You have to get right up to the speaker with your ear (I.E. Las and Corns). Now when a CD is playing there is hiss, period. My 222 operates about the same. Good clean sound from the amp. Are you saying you have hiss in the same situation as I describe above? Quote Link to comment Share on other sites More sharing options...
mark1101 Posted April 7, 2004 Share Posted April 7, 2004 Check that Doc. I see you do not have the same amp as we do. I hope you get yours straightened out. Alternately, Smilin and others look to have some finely tuned Scotts up for sale. Smilin's 272 sounds very tempting. Quote Link to comment Share on other sites More sharing options...
Brap Posted April 7, 2004 Share Posted April 7, 2004 Ditto on the hiss with my ear up against the squakers of my Khorns. It does not increase with volume with my DIY PP amp. I note that with my Forte's the hiss is quite less, but still present. Probably to do with the sensitivity levels between the two........ Quote Link to comment Share on other sites More sharing options...
Piranha Posted April 7, 2004 Share Posted April 7, 2004 Rolling in Telefunken and Mullard 12AX7's made a world of difference in my Scott 272. Quote Link to comment Share on other sites More sharing options...
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