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Any Allnic users out there? Hum problem.

I brought this up previously but was not very specific.

I bought an H3000 phono stage which I liked very much and was perfectly silent. I then bought an HA Head Amp which had a slight hum. Shortly after I got it one of the transistors blew(I believe,) it went dead and I had to return it to Korea for repair.

Since I've gotten it back the hum is worse. When I play a record the sound covers the hum but when it stops the hum can be heard and felt from the speakers where I am sitting about 8 feet away. I asked the maker about this and he told me he sent it back to me in perfect condition so that's a dead end.

Is a hum to be expected? Do you live with it? Is it a grounding problem? I asked the maker about this as well and he did not respond to the query.

I would greatly appreciate any advice from Allnic users and especially those with the HA3000. Do you get a hum? Is it noticeable when an lp isn't playing? Any grounding suggestions?

My amp is a VTL S200 with an Ayre pre K5 xe mp.

VTL super scoutmaster with 3D tonearm.

Conditioner is an Isotek Sigma.

As I said everything is perfectly quiet until I turn on the HA.

I want to fix this because I like the Allnic sound enormously and don't want to be without the HA. It really is wonderful.

Thanks for any thoughts you may have on my situation.

vindanpar

Showing 6 responses by lewm

lewm
12,453 posts
 
Dear Nandric, I left Connecticut nearly 40 years ago in order to move to Washington, DC, and I consider Connecticut to be my native language.  Moreover, I still tell people I am from New England.
lewm
12,453 posts
 
You are known to me as a polyglot. This is why I did not mention any specific language.  I would not know which language you consider to be "native", the language spoken by your parents, perhaps.  Serbo-Croatian?  If ever there were two peoples divided by a common language, those are them. 
lewm
12,453 posts
 
Nandric, There must be an equivalent in your language of "the devil is in the details".
lewm
12,453 posts
 
The question, Nandric, is why you think the Lord gives a darn.  For me, it's is there a Lord at all.
lewm
12,453 posts
 
Vindanpar, I don't think that you should conclude the situation is hopeless.  Are the two units plugged into the same electrical output or into different outlets?  Make sure they are plugged into the same outlet.  Also, try using a cheater plug to remove the HA3000 from AC ground, if the H3000 is correctly grounded itself using a 3-prong plug.  The HA3000 will still see AC ground but only via the IC that goes to the H3000, and this is safe.  Finally, try flipping the polarity of the cheater plug. All of these tricks will affect ground loops, if that is the problem.

If the tonearm is grounded to either unit, try grounding it to both and then try un-grounding it entirely from either unit.  Same goes for the turntable.

Somewhere, somehow, there is a specific combination of grounding and un-grounding that will be the cure.  But I say this on the assumption that you are hearing typical hum that arises from grounding problems, not white noise or hash or buzz, and that the problem is audible in both channels.
lewm
12,453 posts
 
I have long wondered about the philosophy behind marketing the HA3000 as an add-on to the H3000.  The latter unit is revered for its very high quality built-in amorphous core SUTs that also offer quite a bit of adjustability.   Why create the idea that a "head amplifier" is a viable alternative to using those SUTs?  Anyway, it is odd that the OP has a hum problem. I would consult the US or Canadian importer(s).  They're both very good and responsible.
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