I just received my Doge 8 Charity 2022 Special Edition. It has Brimar 6060 and TAD 7025 tubes I’m using the MC phono stage with a Rega Apheta 2. I also have a bad hiss.
This is my first tube gear Iv got a lot of good info from this forum.
Is it really just tubes that cause this ?
Mostly. In any high performance vacuum tube product, the tubes have to be hand-picked. I know a lot of NOS tubes are preferred over new tubes because of the sound. But something to keep in mind: people have been scouring the world looking for low noise NOS tubes for the last 50 years.
For that reason its highly unlikely that the NOS tubes you're using are actually quiet. If you really want quiet tubes, these days they will have to be new. And hand picked for low noise.
You might have to do the hand-picking yourself. Most 'tested' tubes really aren't screened that much IME. So buy about 20 of the tube you want, and then start at the input section of the phono circuit- replace the input tube in one channel only. Warm up the preamp and wait about a minute. Is the new tube quieter than the other channel? If no put it in the reject pile, shut off the preamp and try again.
If yes, tap on the tube. If you hear a loud noise in the speaker, reject the tube. If you hear something but its not loud, keep it and then repeat this process for the other channel.
If you run into a tube that is a lot quieter in the other channel, that means that your first pick wasn't all that quiet- return to that channel and repeat the process.
In this way its sort of like a ladder of steps you take to grade the tubes and you'll wind up with a pile of rejects. They might be good for other locations in the audio chain, just not the input of a phono section. If you don't need them though, send them back for a refund immediately.
Remember to shut the preamp off prior to removing and replacing a tube! Otherwise damage to speakers or your amps could result!
