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How much tube hiss is normal?

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Hello friends!

I've recently acquired a Consonance Cyber 222 mkII tube preamplifier and I'm hearing a pretty consistent "hiss" at all volume levels. The volume of the hiss doesn't seem to be dependent on the volume of the preamplifier. I'm pretty new to tubes so I have no idea how to troubleshoot.

The preamp is using 4 Electro-Harmonix 6SN7's and 1 Sovtek 5AR4 tube (rectifier I believe).

Here's a current picture of my setup. It's coming together quite nicely =) Thanks for your help!

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Does the amp have level controls? The hiss can be minimized by turning the amp's level down a little and increasing the preamp volume.A sensitive amp can pick up low level hiss from a preamp sometimes.
Sometimes a tube will have excessive hiss, you could try moving the tubes to different locations to isolate the noisy tube if there is one.
 
The amp does not have level controls, unfortunately. The hiss seems to be coming from both channels equally, so I don't know if it's a single tube that's the culprit. I believe the preamp uses 2 6SN7 tubes per channel.
 
According to the specs for the amp, 125 milivolt produces 1 watt,so it seems pretty sensitive.If all of the tubes in the preamp are the same,you may want to swap one pair left to right,"just to see"if it makes any difference.
Does the combo (amp and pre) seem overly sensitive?If so,you may want to look into a passive attenuator.
Tubes in general don't usually have a hiss,many of my pre's are completly quiet.
Do you have other components to swap in to figure out the source of the problem?
 
s-petersen said:
According to the specs for the amp, 125 milivolt produces 1 watt,so it seems pretty sensitive.If all of the tubes in the preamp are the same,you may want to swap one pair left to right,"just to see"if it makes any difference.
Does the combo (amp and pre) seem overly sensitive?If so,you may want to look into a passive attenuator.
Tubes in general don't usually have a hiss,many of my pre's are completly quiet.
Do you have other components to swap in to figure out the source of the problem?
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It doesn't seem too sensitive, hmm...

I don't have another power amp or preamp laying around haha, I can't find any gain measurements on this Consonance preamp anywhere on the internet :(
 
The manual
https://shop.grantfidelity.com/files/cyber-222 MKII_manual.pdf
The manual doesn't say anything about overall gain,just signal to noise ratio.

What I was saying is if your system gets pretty loud before the volume is less the than 1/4 volume,then there is enough gain in the system to try a passive attenuator between the pre and the amp.assuming there is nothing wrong with th pre or the amp
 
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Phono sections definitely have some hiss. Some preamps when not using the phono section are quiet. It depends upon the circuit gain, type of tubes and the speaker dB rating. I just tried my rebuilt Fisher 400 and with nothing plugged into the aux input, I hear a very light hiss with volume turned up full and ear about 3 feet from 98dB Klipsch speakers. I do not hear it 5-6 feet away.
 
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I have had more noise from solid state equipment than tube equipment for sure. The one exception was some slight hum in the phono section of a homemade tube preamp I picked up years ago. Never had any hiss at all.
 
sony6060 said:
Phono sections definitely have some hiss. Some preamps when not using the phono section are quiet. It depends upon the circuit gain, type of tubes and the speaker dB rating.
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The Consonance is a line-stage preamp, so I'm using a separate phono pre. The hiss is on all inputs at equal volumes :(
 
s-petersen said:
If you turn the pre off,leaving the amp on,does the hiss go away?
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No WONDER I had a hard time describing the sound!

When it's just the power amp on, the speakers make BARELY audible "hum", that doesn't really bother me. When the preamp is on though, it makes that "hiss" I was mentioning before haha.
 
Unplug it and reverse the plug in the wall. Just a suggestion. Works for some people with a hum problem. Never tried it and never really understood it.

Hiss would almost suggest a noisy circuit/crosstalk. Anything in the area like a light or motor? Again, usually shows as hum....?
 
Without a schematic, it's dificult to tell you where to look,I don't know if there is a soild state volume control chip,or a motorized pot.
I'll have to look around some more.It does sound like the pre is the source of the hiss.
 
Looking at the pictures online it looks like a stepped attenuator using relays,so no chips in the signal path it seems
 
If you want to take a drive I have lots of 6sn7 tubes not being used. I can loan you a few for testing if that would help.
 
I'm usually down around Cherryhill Marlton area of Jersey on Sundays (next weekend being the exception). Same offer as Gadget if you want to experiment (i'll loan you some 6sn7s) if you want to meet me.
 
nj pheonix said:
I'm usually down around Cherryhill Marlton area of Jersey on Sundays (next weekend being the exception). Same offer as Gadget if you want to experiment (i'll loan you some 6sn7s) if you want to meet me.
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That's crazy, I go to church in Cherry Hill on Sundays haha. Is it more probably that the preamp tubes are the culprits or the rectifier tube?
 
If I have to go to church the deal is off. Seriously, Probably not the rectifier (might just be nature of the beast and no amount of tube swapping will affect it, but the offer is open.
 
Not likely the rectifier. I'd guess noisy 6SN7's. I'm like 45 minutes south of Cherry Hill, so not as convenient for a drop-in a nj_phoenix. I've got probably 15 or 20 of the things, but I own absolutely nothing that uses them so I don't know how quiet mine may or may not be. If you did drop by, I'd most likely hand you a box of the things and let you tell me whether they're horrible or not :)
 
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