Humbuster II or III? Has anyone used this?

headrott

I am thinking of buying a PS Audio Humbuster III to reduce or (hopefully) get rid of the hum I have induced in to my transformers. This is NOT a ground loop hum, but the transformers themselves vibrating in my amp, pre-amp, and voltage regulator. According to what I've found doing searches, this hum is induced by DC being on the AC line. That is, my power is not very good in my house. I was talkng with my brother about this and he stated that if I were to check that all the components were hooked up with correct polarity on the IEC sockets (that is, for all components) that this would also reduce or eliminate this hum on the transformers. It will take me a long time to check/reverse all the correct/incorrect polarities of each IEC socket on each component, and was interested in a "more simple" solution.

I am wondering if anyone has used a Humbuster for the problem described above and how well did it work for you? Did it reduce or completely eliminate the hum in your components?

Greg

heiney9

I thought the Humbuster products were for ground loop issues? There is a alot of info if you Google.

Buy from a retailer that allows returns, and try it out to see if it solves your problem. Electrical gremlins aren't the easiest to trouble shoot and sometimes it takes trial and error to find out what works in your particular situation.

H9

polkatese

you may want to try Panamax AC Regenerator unit such as the 5500 (old series). It isolates the circuits.

FTGV

headrott wrote: »

According to what I've found doing searches, this hum is induced by DC being on the AC line.

Some toroidal type transformers can produce mechanical hum if a small amount of DC is riding on the AC line.I'm not familiar with the Humbuster but have had sucess with a very simple DIY able circuit that connects to the neutral side of the AC line.

heiney9

I do know the people that use these seem to be happy with the results if it busts the right kind of hum. I think you are on the right track for your situation.

H9

BlueFox

This is interesting. I wasn't aware of this issue. My amps both have what I call 'vibrating transformer noise' that I can hear when up close, and no music is playing. I just assumed it was a mechanical thing, not a power issue. I have a Shunyata Triton on order, and maybe I will get lucky and it will eliminate the vibration.

headrott

FTGV wrote: »

Some toroidal type transformers can produce mechanical hum if a small amount of DC is riding on the AC line.I'm not familiar with the Humbuster but have had sucess with a very simple DIY able circuit that connects to the neutral side of the AC line.

Fred, what does the circuit consist of? I believe I have seen some DIY schematics and circuits, but it's been a year or so since I have looked and/or found these on the web. Do you have a web link to a good place to look for a DIY circuit I could build?

Greg

headrott

heiney9 wrote: »

I do know the people that use these seem to be happy with the results if it busts the right kind of hum. I think you are on the right track for your situation.

H9

It's without a doubt mechanical hum, not a ground loop hum. I cannot hear anything through the speakers at all. Only from the transformers (toroidal) in my components. Also, there was a "clicking" sound coming from the pre-amp (BAT VK-3i) potentiometer when changing the volume. Only one time it was relatively loud when turning the volume up or down. It didn't matter whether I used the volume knob or the remote it still made the "clicking" sound. I e-mailed Victor Khomenko at BAT and he responded saying it could be DC at the source output causing it. Apparently if there is enough DC on the AC line, not only does it cause mechanical hum on the transformers but it also causes noise in the pre-amp potentiometer (it must be overloading some component(s), but not sure which one(s)).

Greg

heiney9

Next step might be an AC regenerator. Not cheap but if the Humbuster doesn't work that might be your only solution.

H9

tonyb

A Humbuster in my day ment something totally different.

ac regenerator....good idea, not so cheap. Welcome to the rabbit hole.

FTGV

headrott wrote: »

Fred, what does the circuit consist of? I believe I have seen some DIY schematics and circuits, but it's been a year or so since I have looked and/or found these on the web. Do you have a web link to a good place to look for a DIY circuit I could build?

Greg

Greg it's dirt simple consisting of a bridge rectifier and a few hi value low voltage electrolytics.It is effective at filtering DC on the neutral line ,however the mechanical hum could also be a result of the way the toroid was wound (ie.poorly).The filter won't help in that case.If interested I can PM you a sketch in the next few days.

headrott wrote: »

I e-mailed Victor Khomenko at BAT and he responded saying it could be DC at the source output causing it. Apparently if there is enough DC on the AC line, not only does it cause mechanical hum on the transformers but it also causes noise in the pre-amp potentiometer (it must be overloading some component(s), but not sure which one(s)).

Greg

He is talking about DC(offset) being output from the source component not from the AC line.When there is DC present on the pot it will become noisy.

headrott

FTGV wrote: »

Greg it's dirt simple consisting of a bridge rectifier and a few hi value low voltage electrolytics.It is effective at filtering DC on the neutral line ,however the mechanical hum could also be a result of the way the toroid was wound (ie.poorly).The filter won't help in that case.If interested I can PM you a sketch in the next few days.
He is talking about DC(offset) being output from the source component not from the AC line.When there is DC present on the pot it will become noisy.

I would appreciate the diagram please Fred, thank you very much.

DC offset, ah gotcha and that makes more sense. Would this be intermittent though? And if so, why would it be intermitent and not alway present?

Greg

Edit: Also, from what I understand it takes an isolation transformer to get rid of this DC offset correct? Is there a "best" way to do this?

FTGV

headrott wrote: »

I would appreciate the diagram please Fred, thank you very much.

OK will do in the next few days.

And if so, why would it be intermitent and not alway present?

Does it happen with one specific source?If so you could put a meter on the output of that source and see if there is an DC present.

Also, from what I understand it takes an isolation transformer to get rid of this DC offset correct? Is there a "best" way to do this?

That's the roll of input and output coupling capacitors,DC servo's etc.If DC is in fact reaching the pot would indicate that the source's output and preamp's inputs are directly coupled as in no series DC blocking capacaitor.

headrott

FTGV wrote: »

OK will do in the next few days.

Does it happen with one specific source?If so you could put a meter on the output of that source and see if there is an DC present.

That's the roll of input and output coupling capacitors,DC servo's etc.If DC is in fact reaching the pot would indicate that the source's output and preamp's inputs are directly coupled as in no series DC blocking capacaitor.

I have been using my Denon DVD-5910 universal player with the digital output connected to the DAC I built located here: http://www.polkaudio.com/forums/showthread.php?119264-Fully-balanced-Buffalo-II-DAC-with-Tube-I-zator-tube-output.&highlight=tube-i-zator

It has only had this noisy pot on the BAT a couple times and only loud once. A vast majority of the time it is quiet.

The DAC I built and Denon I have been using as my source for a while now (6 to 7 months). So, could it be that the DC blocking caps on the DAC are going bad? They are only about a year old?

Greg

FTGV

headrott wrote: »

It has only had this noisy pot on the BAT a couple times and only loud once. A vast majority of the time it is quiet..... So, could it be that the DC blocking caps on the DAC are going bad? They are only about a year old?

Greg

Highly unlikely those caps are bad and since it is extremely intermittant I would suspect something else was at fault.

headrott

FTGV wrote: »

Highly unlikely those caps are bad and since it is extremely intermittant I would suspect something else was at fault.

Any ideas on what it could be Fred? I don't think it's any solder joints. I did all of them myself and did a very good job.

Greg

FTGV

headrott wrote: »

Any ideas on what it could be Fred? I don't think it's any solder joints. I did all of them myself and did a very good job.

Greg

Somthing else as in other than the DAC,maybe the pre itself?.The thing with intermitant problems they are very hard to track down.If it starts to happen again try different sources.


btw.I'll say again nice work on that DAC.

unc2701

DC blocking circuit here:
http://www.htguide.com/forum/showthread.php4?t=3584&page=2

Starting around post #49- it really is a simple circuit. Plan B would be to just get a humbuster from someplace with a good return policy. If it works, return it and build that circuit. If it doesn't... return it and look elsewhere.

BTW, AC line DC can come & go, so the hum being intermittent doesn't mean much.