Jump to content

Vincent PHO preamp transformer hum?


Recommended Posts

Hi All, bit of a noob here. Just took my nice shiny Vincent PHO-300 out of the box and hooked it up. Looks and feels great quality, and a massive upgrade for my Behringer.

After hooking it up, I have noticed the power supply unit has a small but slightly audable 'hum' when you put your ear next to it. I'm not talking about hearing it through the stereo, I mean you can hear it with your ear up to the unit itself. Only subtle but that slightly annoying electric hum nonetheless. 

Is this completely normal? If so I will ignore and enjoy the records. Thanks

Link to comment
Share on other sites



7 minutes ago, aussievintage said:

Seriously I don't see it as a problem.  

Thanks, I tend to agree.

I only ask because Vincent make a big deal out of the whole separate power supply box thing to reduce noise and interference etc.  Cheers

Link to comment
Share on other sites



53 minutes ago, horatiojb said:

I have noticed the power supply unit has a small but slightly audable 'hum' when you put your ear next to it. I'm not talking about hearing it through the stereo, I mean you can hear it with your ear up to the unit itself.  

 

Is this completely normal? If so I will ignore and enjoy the records. Thanks

 

It's not desirable - but it may be DC on your mains which is causing the power transformer in the PHO-300 power supply to vibrate?

 

If so - you might need a 'DC blocker' between the PHO-300 PS and the wall socket (to stop the DC which is on your mains from passing into the PHO-300).

 

2 minutes ago, thathifiguy said:

Is it placed nearby to other power supplies or products that have large transformers?

 

That's a good question - although as the hum is not coming through the spkrs ... there's no 'induced hum' happening.  It's a mechanical thing.

 

42 minutes ago, rantan said:

I would return it for exchange if it were me. Regardless of audibility in the music, this sort of thing shouldn't happen.

 

Agreed, rantan - but it's possible that every PHO-300 the OP installs will have the same problem (if DC on the mains is the culprit!)  :(

 

51 minutes ago, horatiojb said:

Thanks, I tend to agree.

I only ask because Vincent make a big deal out of the whole separate power supply box thing to reduce noise and interference etc.  Cheers

 

Vincent's 'selling point' of having the power transformer in a separate box is good practice and will tend to stop noise coming through the spkrs!  But DC will annoy some (many?) mains transformers - whichever box they are in.

 

1 hour ago, aussievintage said:

Let's hear from someone who has one and can try the same trick.

 

So Queensland's electricity supply is so good there is no such thing as 'DC on the mains'?  :lol:

 

 @horatiojb, as you are in Melbourne, it would be simple (now we're out of lockdown!) for me to bring over one of my DC blockers and test it out on your PHO-300.  PM me if you are interested.

 

Andy

 

  • Like 1
Link to comment
Share on other sites

1 minute ago, aussievintage said:

Where the heck did you see me ever say that??  Huh???

 

You said "Let's hear from someone who has one and can try the same trick ".  My point was basically that "someone who has one " will be in a different location and might not experience the same hum because they have no (or less) DC on their mains.  Even in Qld!  :)

 

Andy

 

Link to comment
Share on other sites

55 minutes ago, andyr said:

 

You said "Let's hear from someone who has one and can try the same trick ".  My point was basically that "someone who has one " will be in a different location and might not experience the same hum because they have no (or less) DC on their mains.  Even in Qld!  :)

 

Andy

 

Wow.  You certainly didn't communicate any of those steps you took in between.  L0L! 

Just FYI, I have never needed to employ a DC blocker in all my years in hifi. Lucky me?

Link to comment
Share on other sites

1 minute ago, aussievintage said:

Wow.  You certainly didn't communicate any of those steps you took in between.  L0L! 

 

No I didn't - sorry.  :(
 

1 minute ago, aussievintage said:

Just FYI, I have never needed to employ a DC blocker in all my years in hifi. Lucky me?

 

Well, you live in Qld, right!  :lol:

 

Andy

 

  • Haha 1
Link to comment
Share on other sites



1 minute ago, Wimbo said:

Seriously you lot. A guy puts his ear next to a power supply, hears a VERY minor hum (which has nothing to do with the sound)and you are having a debate. Donald, Help me!!

Such is the nature of first world pursuits and their attendant problems.:lol:

  • Like 2
Link to comment
Share on other sites

1 hour ago, andyr said:

So Queensland's electricity supply is so good there is no such thing as 'DC on the mains'?

Definitely no different in Queensland, I had a buzzing double C core transformer in my old phono stage and a DC Blocker silenced it stone cold :D

 

Edit: I should put that in my CD Player just because I have it still.

Edited by muon*
Link to comment
Share on other sites

Thanks for all your responses. I will try plugging it in other parts of the house and see if the hum continues. Not aware of any nearby electrical transformers that might be interferring...

 

I agree it's a first world 'problem', but at the same time it did cost a bit so you'd expect it to work well. My el cheapo Behringer phono preamp doesn't hum lol

 

 

Link to comment
Share on other sites



26 minutes ago, horatiojb said:

Thanks for all your responses. I will try plugging it in other parts of the house and see if the hum continues. Not aware of any nearby electrical transformers that might be interferring...

 

I agree it's a first world 'problem', but at the same time it did cost a bit so you'd expect it to work well. My el cheapo Behringer phono preamp doesn't hum lol

 

 

Doesnt have the same size tranni most prob and this should not be recognized as an undesirable fault IMO. 

Link to comment
Share on other sites

6 minutes ago, Wimbo said:

Doesnt have the same size tranni most prob and this should not be recognized as an undesirable fault IMO. 

Okay interesting, would you mind expanding on this- as a noob I would like to learn. Are you suggesting the hum actually indicates a desirable trait? Thanks

Link to comment
Share on other sites

45 minutes ago, horatiojb said:

Okay interesting, would you mind expanding on this- as a noob I would like to learn. Are you suggesting the hum actually indicates a desirable trait? Thanks

 

"There are more things, Horatio ..."!  :)

 

Small power transformers tend not to be as affected by DC on the mains as larger power traffos.  But, in my experience, small power traffos - say 60 VA - whilst they might theoretically be perfectly suitable for a phono stage (when you just consider the current draw) ... do not give as good a bass as a larger power traffo - say 160VA.  But the larger power traffo will be affected to a greater degree by DC.  :(

 

So whilst the hum is not desirable ... the fact that Vincent would seem to have used a larger traffo - which unfortunately is susceptible to hum from DC on the mains - is a good thing!  :thumb:

 

Andy

 

  • Like 1
Link to comment
Share on other sites



12 hours ago, horatiojb said:

Okay interesting, would you mind expanding on this- as a noob I would like to learn. Are you suggesting the hum actually indicates a desirable trait? Thanks

Do you have the phono pre sitting on the power supply? If so, move it away from the power cord input side.

Some trannys are bigger and (depending on design) can make a little noise ,Laminations for a start. As I said before, I think its a mountain out of a mole hill.

Phono preamp placement is more important because of noise floor problems.

Link to comment
Share on other sites

  • 2 weeks later...

As a follow up on this thread, I took the power supply back to the good folk at Selby and we compared it with another unit in the store... guess what, they both have a hum lol! So not much to be done with this model it would seem.

 

Next step was to compare the next model up- PHO-500, and this was noticeably quieter, although did have some very minor hum too. 

 

And then the PHO-701 was totally quiet.

 

I'm planning to return the 300 and upgrade to the 701

Link to comment
Share on other sites



  • Recently Browsing   0 members

    • No registered users viewing this page.




×
×
  • Create New...
To Top