A51 buzzing?

[netarc]

Has anyone experienced buzzing on an A51 - not from the speakers, but from the amp itself? I installed one several months ago with a C2 (XLR cables from C2>A51, amp 12v trigger controlled); several months later the A51 has started emitting a buzzing sound upon being powered up.

[Vince Helm]

Sounds like a transformer. Is your dealer close by?

Vince

[Peter Nielsen]

Has anyone experienced buzzing on an A51 - not from the speakers, but from the amp itself? I installed one several months ago with a C2 (XLR cables from C2>A51, amp 12v trigger controlled); several months later the A51 has started emitting a buzzing sound upon being powered up.

That's the transformer buzzing. If the problem recently appeared, it probably means that the power in your neigborhood recently got "dirty". (Might be your power company, might be your neighbour(s) installing new appliances, or it might even be caused by a new appliance you got for yourself...)

Do you use any type of power conditioning? A PS Audio power regenerator or an EquiTech transformer should solve the problem...

Peter

[mitch57]

I had the exact same problem. The PS Audio Hum Buster solved the problem for me. Here's a link to it.

http://www.psaudio.com/products/upchb.asp

[netarc]

Do you use any type of power conditioning? A PS Audio power regenerator or an EquiTech transformer should solve the problem...

The A51 is plugged into a Panamax 5300 line conditioner

[netarc]

I had the exact same problem. The PS Audio Hum Buster solved the problem for me. Here's a link to it.

http://www.psaudio.com/products/upchb.asp

Did your A51 exhibit this issue from the first time you hooked it up, or did it occur at a later point?

[Peter Nielsen]

The A51 is plugged into a Panamax 5300 line conditioner

Does it remove DC components? (Most "line conditioners" don't do that, and thus have no effect on transformer hum).

Peter

[mitch57]

Did your A51 exhibit this issue from the first time you hooked it up, or did it occur at a later point?

It happened immediately. My Rotel RMB-1095 did the same thing. But it's worth mentioning that the issue came and went depending on how clean the power was in my neighborhood. I live in a rural area where lots of people own shops with table saws, and large welders as well as a lumber mill a mile or so down the road. Some days the amp was silent but other days it would buzz like crazy.

I'm fairly confident that your problem is power related and not the amp. You can try out the hum buster and if it doesn't solve the problem they will take it back no questions asked. They even offered to pay return shipping when I bought mine. That's how confident they are with their products.

[netarc]

Thanks for the info/feedback, folks - I'll contact Parasound re: this, but also confirm whether the 5300 I'm currently using w/it removes DC components, and contact PSAudio re: this "hum buster"

[mitch57]

Keep us posted on what the out come is.

[Peter Nielsen]

Thanks for the info/feedback, folks - I'll contact Parasound re: this, but also confirm whether the 5300 I'm currently using w/it removes DC components, and contact PSAudio re: this "hum buster"

FYI, PS Audio used to sell the Humbuster AC for $299. Unfortunately it's discontinued. Now you have to get the UPC-200HB version with Ultimate Power Cell technology and pay $499...

Either one will work. Obviously you will save $200 if you can find the older model...

Peter

[Vince Helm]

I think I saw that CI audio (channel Island) now has a humbuster type product for ~$200.

Vince

[blownrx7]

I experienced the exact same thing as you with "dirty" power only happening occassionally with the associated "mechanical" hum. This would happen even with a Richard Gray Power company 1200S OR an Exact Power EP15A in the setup.
I bought a UPC200HB with the specific purpose of cleaning up the occasional transformer hum. I was surprised - and disheartened - to find that it did not do anything. I was quite surprised because I fully expexcted it to work for my issue.
YMMV but I wanted to let you know my experience. It is still worth a shot but make sure you can return it or resell it and get your investment back.
They are going very cheaply now on the used market due to PS Audio's new product line. You might be able to pick up a B-stock unit directly from PS Audio and you can take advantage of their 30day trial period

Parasound content: The JC-1's I used to own were dead silent. But I had two A51's for a short time, one hummed (very low level) and the other was virtually silent.

[Peter Nielsen]

AFAIK, PS audio offers a 30 day in-home trial if you buy their products on-line (www.psaudio.com)

Peter

[mitch57]

They do offer a 30 day free trial and may even pay for the return shipping. I am surprised that blownrx7 bought one and it didn't work. Maybe you got a defective unit. Also it's worth noting that there are 4 outlets on UPC 200HB and two of them DO NOT provide the filtering/cleaning properties of the other two outlets. Here's a quote from the manual.

"The UPC-HB has two output choices available: “FILTER ONLY” or “FILTER AND HUMBUSTER”. Choose FILTER ONLY if you want to run equipment with the benefits of filtered AC. Examples would be analog sources and digital sources. Analog sources might be a preamplifier, phono stage or analog power amplifier. Digital sources might be a CD player or a D to A converter.

Choose FILTER AND HUMBUSTER if you want to lower or eliminate hum inside a unit, sensitive to DC on the line. Examples might be a noisy power amplifier."

Is it possible you didn't have it plugged into the "HUMBUSTER" outlet?

[blownrx7]

Mitch57,
I wish it was that simple.
I did have it plugged into the "Humbuster" outlets. Just did not work in my case. Maybe it was defective.
Also, I just remembered another very important point about the HB. Keep in mind the Humbuster version does NOT have the "bridging" capability to double the current capability of a single outlet - something that would be very desireable (necessary) for the A51.
Believe me, I fully expected and wish it worked for me. It just didn't.

[mitch57]

Mitch57,
I wish it was that simple.
I did have it plugged into the "Humbuster" outlets. Just did not work in my case. Maybe it was defective.
Also, I just remembered another very important point about the HB. Keep in mind the Humbuster version does NOT have the "bridging" capability to double the current capability of a single outlet - something that would be very desireable (necessary) for the A51.
Believe me, I fully expected and wish it worked for me. It just didn't.

That's unfortunate. It's worked absolutely flawlessly for me ever since I bought. I also have the A51 and I had it connected to two Richard Gray RGPC 400 Pros prior to the Humbuster and nothing would stop the buzz. Then I got the Humbuster and everything has been perfect since.

Why would it be necessary to double the current on a single outlet? I have two dedicated 20 amp circuits for my HT and don't see how the A51 could draw more then 20 amps even if you drove it beyond it's clipping stage. Am I missing something here?

[blownrx7]

Check the PS audio forum. There was some discussion about the which UPC to use for high power amps. Some people mentioned that dynamics were limited unless they put the UPC in the "parallel" mode so that precluded the option of using the HB. PS Audio even recommends the non-HB for high power amps. The A51 definitely qualifies for "high-power" territory.
From the UPC description: "Using the bottom mounted switch on the UPC 200, you can combine both internal 20 amp capable UPC modules into one ultra high current device."
I didn't get far enough to test that out.
I wish it worked for me BUT that does not mean it doesn't work at all and I encourage anyone who wants to try it to take advantage of the 30 day trial policy. All you'll lose is shipping charges in that case.
Your own ears can be the judge then.