Hello,
With GR-Research V2 being 92db sensitive I am hearing a lot of tube rush / hissing. How do I go about reducing that?
Thanks
Hiss/rush is probably old or defective tubes. What amp is it?
92 is not so sensitive that noise should be a problem as long as the amp is healthy. All tube amps make some noise tho... hiss is usually easily ignored. But rushing means something wrong.
Quote from: richidoo on November 23, 2011, 04:06:37 PM
Hiss/rush is probably old or defective tubes. What amp is it?
92 is not so sensitive that noise should be a problem as long as the amp is healthy. But all tube amps make noise, you just have to get over it, focus on the magic - if the amp is good it's worth some noise.
The amp is Vincent SP331 (but had hiss/tube rush couple of other amps also) with Response Audio Bella LP Tube Pre. Will swap the tubes to see if the hiss is reduced.
Deepak you caught me editing! :D You are fast!!
Try removing the preamp if you have a source with a volume control, even ipod or something will be quiet for the test. I'll check out the Vincent specs.
The Vincent is a hybrid, with tube input stage. It uses extremely quiet and reliable modern tubes from the 80s. They are so reliable that they are soldered onto the PCB, and will last the life of the amp. So I doubt the noise is coming from the amp. If you have a way to short the input jack, then you can safely run the power amp with no source component, then you will be hearing only the amp, which would verify whether it is the problem.
The all tube preamp (using vintage 6sn7 or 12au7s?) is much more likely the culprit. Easy fix, buy some Sovtek/EH preamp tubes to use for testing and as a backup set. They might not sound as delicious as vintage tubes, but they are reliable and quiet. Cheap too, and probably available at your local music store.
My 104 dB sensitive horns are dead silent at idle with my all tube gear, including my CD player... my tubes date from the 1930's (Sylvania 2A3), 1940's (Tung Sol Round Plate 6SL7), 1950's (WE 417A) & 1960's (Mullard 5AR4, Siemens 6DJ8, Tung Sol 5687, etc.)... age has nothing to do with noisy tubes as long as they have no shorts and suitable mutual conductance (u-mhos)...
Check & clean your interconnects with a good contact cleaner like Caig DeOxit Gold. Also, check & see (actually hear) if your IC's are shielded. Some components really need shielded IC's. You may be picking up a 60 Hz hum from some power supply transformers or other electrical anomalies... perhaps a ground loop as well!
Finally, use a quiet power cord... yes, I have heard "noisy" power cords!
My $0.02 to help... Happy Thanksgiving --- Pete
Quote from: Triode Pete on November 23, 2011, 04:50:57 PM
age has nothing to do with noisy tubes
Agreed. I meant worn out.
Quote from: richidoo on November 23, 2011, 04:12:49 PM
Deepak you caught me editing! :D You are fast!!
Try removing the preamp if you have a source with a volume control, even ipod or something will be quiet for the test. I'll check out the Vincent specs.
I will hook up the Logitech Touch directly to the amp. I am pretty sure the hiss/rush is from the preamp. I have a stack of various tubes to try.
Quote from: Triode Pete on November 23, 2011, 04:50:57 PM
Check & clean your interconnects with a good contact cleaner like Caig DeOxit Gold. Also, check & see (actually hear) if your IC's are shielded. Some components really need shielded IC's. You may be picking up a 60 Hz hum from some power supply transformers or other electrical anomalies... perhaps a ground loop as well!
Thanks Pete. Will try your suggestions. Where would I find the deoxit stuff?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=341-200
Saw this cool little RCA cleaning tool the other day:
http://www.musicdirect.com/p-9658-signet-rca-cleaning-tool-ea.aspx
Quote from: shadowlight on November 23, 2011, 05:27:49 PM
Quote from: richidoo on November 23, 2011, 04:12:49 PM
Deepak you caught me editing! :D You are fast!!
Try removing the preamp if you have a source with a volume control, even ipod or something will be quiet for the test. I'll check out the Vincent specs.
I will hook up the Logitech Touch directly to the amp. I am pretty sure the hiss/rush is from the preamp. I have a stack of various tubes to try.
Quote from: Triode Pete on November 23, 2011, 04:50:57 PM
Check & clean your interconnects with a good contact cleaner like Caig DeOxit Gold. Also, check & see (actually hear) if your IC's are shielded. Some components really need shielded IC's. You may be picking up a 60 Hz hum from some power supply transformers or other electrical anomalies... perhaps a ground loop as well!
Thanks Pete. Will try your suggestions. Where would I find the deoxit stuff?
I prefer the "Gold Version" of deoxit... free shipping / no tax with Sweetwater...http://www.sweetwater.com/store/manufacturer/CAIG_Laboratories (http://www.sweetwater.com/store/manufacturer/CAIG_Laboratories)
Hello Deepak,
As mentioned, I would certainly try some different tubes. NOS 12AU7's can often be noisy. The circuit should be dead quiet. I ran that preamp with some very efficient speakers (above 95dB) when it came back to me for the changes and it would not have gone out the door if it was noisy.
Please keep us posted of your results. If you continue to get noise with different tubes, let me know again via email or give me a call and we can walk through it.
Have a Happy Thanksgiving.
Quote from: Response Audio on November 23, 2011, 09:13:32 PM
Hello Deepak,
As mentioned, I would certainly try some different tubes. NOS 12AU7's can often be noisy. The circuit should be dead quiet. I ran that preamp with some very efficient speakers (above 95dB) when it came back to me for the changes and it would not have gone out the door if it was noisy.
Please keep us posted of your results. If you continue to get noise with different tubes, let me know again via email or give me a call and we can walk through it.
Have a Happy Thanksgiving.
Thanks Bill. If I continue to have the issue will reach out to you.
Happy Thanksgiving.
D -
All the tubes I ran through my Purity were dead quiet, except my present faves, the ribbed plate Teles. Minor tube rush, which is excaberratted by the Reference 3s. When I had your LS6s it wasn't as noticeable, nor is it with the Vandys which I have playing Chet Baker right now, a 'quietish' album that would allow tube rush to present itself with the Ref 3s.
Try other tubes is really all you can do.
Had a similar issue with the Audio Research DR 250 Mk2 Servo [ 32 ] tubes. With the Pipedream speakers tube rush [ Hiss ] was evident. Drove me wacky.
When we replaced the output tubes it went bye bye.
Your in good hands with all the help here.
charles
SMA
Deepak,
If you like those tubes, try cleaning the pins with fine sand paper or emery cloth. Sometimes the pins just develop oxidation. Most often the tube rush will go away or become greatly reduce when the pins are clean of oxidation. It's successful about 75% of the time from my experience of cleaning thousands of tubes. The other 25% of the time nothing helps so they get tossed.
Paul
Thanks everyone for all the helpful suggestions. Will try them all over the holiday weekend. Right now it is very distracting with the hiss.
Thanks changing the tubes got rid of the rush/hiss but now I am hearing a slight hum which does not change when I increase the volume. Need to trace it down :duh
Quote from: shadowlight on November 26, 2011, 04:03:56 PM
Thanks changing the tubes got rid of the rush/hiss but now I am hearing a slight hum which does not change when I increase the volume. Need to trace it down :duh
Sounds like the ol transfomer Hum Drum. Good luck with that one.
First check your wire management, meaning to not let them touch each other. Keep them at least 6" apart. Next distance between components, keeping the transformers from being to close to each other.
Use only one outlet to avoid ground loops. If your CDP has a ground lift switch try it. Good luck
charles
SMA
Quote from: rollo on November 27, 2011, 08:02:16 AM
Quote from: shadowlight on November 26, 2011, 04:03:56 PM
Thanks changing the tubes got rid of the rush/hiss but now I am hearing a slight hum which does not change when I increase the volume. Need to trace it down :duh
Sounds like the ol transfomer Hum Drum. Good luck with that one.
First check your wire management, meaning to not let them touch each other. Keep them at least 6" apart. Next distance between components, keeping the transformers from being to close to each other.
Use only one outlet to avoid ground loops. If your CDP has a ground lift switch try it. Good luck
charles
SMA
Yep, I am going to disconnect everything and work my way in isolating the hum. Never had any ground loop hum before so that should help.
Even with the slight hum I am enjoying the sound from the GR-Research V2, Vincent amp, Bella L/P and Logitech Touch.
Found the culprit. I get hum when the receiver is connected to the preamp. If I go directly from the receiver to amp no hum. It seems that I am creating a ground loop between the preamp and receiver. The receiver has a ground post. Do I just run a regular electrical cable from that grounding post to a common ground or do I need specific size/gauge/solid core electrical wire between the two?
Thanks for all the help so far :thumb:
Deepak, by any chance do you have cable TV connected to the receiver? Cable is ground is notoriously noisy. If you do have cableTV hum or other sat/FM antenna ground loop issues, try this great little isolation tranny from jensen transformers: Model VRD-1FF
http://www.jensentransformers.com/iso_vid.html
Also make sure the cable is earthed prior to this isolator. I use these lightning protector/ground blocks for grounding my incoming coax sources:
Altelicon AL-FFFF
http://www.l-com.com/item.aspx?id=20928
Glad to hear that the tube rush is all better, and the hum is not in your stereo system. Now it's time to kick back with some tunes, eh?
Quote from: shadowlight on November 27, 2011, 11:52:05 AM
Found the culprit. I get hum when the receiver is connected to the preamp. If I go directly from the receiver to amp no hum. It seems that I am creating a ground loop between the preamp and receiver. The receiver has a ground post. Do I just run a regular electrical cable from that grounding post to a common ground or do I need specific size/gauge/solid core electrical wire between the two?
Thanks for all the help so far :thumb:
Hi. I might recommend an EVS Ground Enhancer on that ground terminal Deepak. Allthough I use many GE's in my system, I personally use an Acoustic Revive Ground Conditioner on my processor but a $25 Ground Enhancer surely beats my $450 unit. :rofl:
http://www.tweakaudio.com/EVS-2/EVS_Ground_Enhancers.html
Cheers,
Robin
I plugged in the cable tv into the APC S15 unit and from there to cable box and the hum is gone. I am in business now aa
Awesome!
Good news!
Quote from: richidoo on November 27, 2011, 04:12:50 PM
Awesome!
Thanks for all the suggestions, which helped identify the culprit. Never had any issues when I had Verizon Fios or Directv. As soon as I get Comcast I get hum. I should call them and bitch at them :duh
Now I know who to ask about TV service. Maybe I'll wait until you get Dish. :)
Quote from: TooManyToys on November 28, 2011, 07:00:29 PM
Now I know who to ask about TV service. Maybe I'll wait until you get Dish. :)
No chance. As soon as my contract with Comcast is up I am going back to Verizon Fios.