Turntable Hum


Any help appreciated!

Low pitched hum coming from TT input ...even when TT is not running . Hum is noticeable at about 1/4 volume & really bad at 50%

Manley Monoblock Snappers

VPI Scout w Hana MC cart right next to amp on table (moved TT away from amp to floor made 0 difference)

Allnic 1202 Phonostage grounded to VPI TT (on floor below JBL speakers & main speakers right to the left Tekton Encores)

Manley Jumbo Shrimp Preamp

Klark Teknik 32 band EQ

All cables (interconnects) recently replaced - Mogami

 

I tried ground lifting the TT motor - no change

unplugged tv & nearby laptop - no change

unplugged all lights nearby - no change

 

I suppose my next troubleshooting venture is to run a ground from phonostage to everywhere & start touching things? Phonostage seems to be the culprit....

😕

 

Thanks everyone!

128x128tommypenngotti

@millercarbon thanks..when I disconnected the RCAs from TT to Allnic & inputted 1 by 1 I noticed on the right input a slightly higher pitched buzzing , nothing major , just slight...electrical , emanating from speakers for sure..I'll try moveing the allnic to anotehr system & see if its noisy....Arent these Phonostages kinda inherently noisy because they are boosting the signal so much? 

@swanny76109 The Allnic 1202 Phonostage is almost brand new...I do notice when I tap on the cylindrcal tube cases I get a fair amount of feedback through the speakers ...noisy...thanks 

 

Yes, inherently noisy, and this can vary a lot between cartridges and arms even on the same phono stage. Usually anything low level and uniform like you're talking would be within the norm. You can try and reduce if it matters to you but could spend an awful lot of time for very little to gain. Except when it is one channel like you said. In that case you should be able to get the noisy one down to the same level as the other- unless there is something wrong somewhere.

That is what we're trying to figure out. That is why you want to try the phono stage somewhere else. If you get the same noises, it's the Allnic. If not, keep looking. 

You picked up on the main idea, phono stages have a tremendous amount of gain. Things that would never be audible anywhere else can be unlivable with all the gain. Worth it in the end, even if it doesn't seem that way sometimes.

 

I have had several issues with the noise coming from a Hana cartridge. It is due to the way they are internally wired. The Hana won't work well with all phonostages.

There does seem to be a power wiring issue for the phonostage based on the descriptions I see here. It may be in the power cord or inside the phonostage. It sounds a whole lot like the neutral and the hot wires are reversed somewhere.

@millercarbon really appreciate your time on this matter , the hunt continues...I'll post soon...

 

@audio-union and of course I will go down the rabbit hole of what cart works best with my set up 😃  was investigating the AT ART-9 , have heard alot of positives . I'll try a different power cord on Phonostage...thanks 

@tommypenngotti make it easy get a wall plug tester and make sure the power at the wall is correct. Check to make sure the power cords are ALL wired correctly.

I would also consider checking to make sure there is not some noise on your neutral or ground that should not be there. I once found the neutral at the power drop coming into the house was broken at the pole. This particular case will show up as a low voltage on the 110 circuits usually around 90 volts.