ATI AT3000 amps

[AcuDefTechGuy]

Thanks for checking.

Frig.

- Rich

Call them and let us know.

The only speakers I own that have any hiss sound are the Orion, but I am confident the hiss is from that ~ $1000 analog crossover, not the AT6012.

 

[RichB]

I spend some time talking to tech support.

They only ship 15 amp cables upon request from their legal councel. You want 20, go buy you own. No biggie.

They are going to stage an ATI3005 to see if power usage and heat production matches their expectations.
That amp may be high class-a bias causing the extra heat.

Hum is usually due to DC in the line but and the larger amps may be suspetible to it due to the large windings on the transformer.
That will not due for me of course.

They hear hiss in some of their high-efficiency speakers, but that does not explain why other Revel owners have no hiss.
I also hear some hum from the Midrange driver.
I have tried every combination of my two circuits and had just the Pream and amp plugged in. There is no difference.

They will be back to me in a couple of days.

- Rich

 

[RichB]

I got a call back from ATI.
Apparently, there was some confusion about the power cord.
At one point, they had 20 amp cords with the wrong gauge.

They do have the proper 20 amp cord and are sending me one.

Excellent support.

- Rich

 

[RichB]

I am getting frustrated with the transformer and speaker hum.

Transformer Hum
Transformer hum is separate. I have disconnected everything and plugged the amp into three different circuits.
There is no change, it still hums. I hear it in quiet passages when watching movies.

Speaker Hum
Speaker hum is coming from the midrange. Tweeter his is presant but it does not bother me as it is too low to hear unless your ear is pressed to the tweeter.
I have tried disconnected everything from the preamp except the amp.
No change. I have tried the XLR and RCA connections. No change.
Three different circuits, no change.
If I turn the volume to 0 on the Marantz AV8801, there is speaker hum.
If I Mute the Marantz , there is NO speaker hum.
I tried many different configurations of the video processing in the Marantz, no change.

I had no speaker hum and no transformer hum with the exact same configuration using the Outlaw 7500.
I suppose it could just be larger transformer size and something about my environment.
I am not sure what to do about that, I am not changing out the preamp and I am not move.

Damn it, I love the sound and the power of this AMP. ARGHHH!

- Rich

 

[adk highlander]

Rich,

I have many of the same issues that you have and it all started with I went from my Onkyo prepro to the Marantz 7005. I actually got another 7005 from my dealer and it exhibited the same symptoms. I tried everything from changing power cords, rerouting wires to various grounding techniques suggested by TLS.

There are many others that have not had any issues with this combination so I have never claimed this issue to be anything but my system. Just for giggles recently I connected a receiver to my system and used the pre outs via RCA to my amps. It was a cheap onkyo that I use in my garage. Guess what, no hum hiss or any noise from my speakers. Just like it used to be, dead quiet.

I don't know if it is poor grounding in the Marantz or what but all I can say is that I can repeat your issue and I do not think it is the amp.

 

[fuzz092888]

Something definitely doesn't sound right. I had an Outlaw 755 and couldn't get the clipping lights to come on up to +8. It got hot, but never hotter than my other high bias amps. No transformer hum, no noise thorugh the tweeters. It definitely sounds like something it wrong with the 3005, since the 755 is an older design and built for Outlaw.

I am getting frustrated with the transformer and speaker hum.

Transformer Hum
Transformer hum is separate. I have disconnected everything and plugged the amp into three different circuits.
There is no change, it still hums. I hear it in quiet passages when watching movies.

Speaker Hum
Speaker hum is coming from the midrange. Tweeter his is presant but it does not bother me as it is too low to hear unless your ear is pressed to the tweeter.
I have tried disconnected everything from the preamp except the amp.
No change. I have tried the XLR and RCA connections. No change.
Three different circuits, no change.
If I turn the volume to 0 on the Marantz AV8801, there is speaker hum.
If I Mute the Marantz , there is NO speaker hum.
I tried many different configurations of the video processing in the Marantz, no change.

I had no speaker hum and no transformer hum with the exact same configuration using the Outlaw 7500.
I suppose it could just be larger transformer size and something about my environment.
I am not sure what to do about that, I am not changing out the preamp and I am not move.

Damn it, I love the sound and the power of this AMP. ARGHHH!

- Rich

 

[RichB]

Rich,

I have many of the same issues that you have and it all started with I went from my Onkyo prepro to the Marantz 7005. I actually got another 7005 from my dealer and it exhibited the same symptoms. I tried everything from changing power cords, rerouting wires to various grounding techniques suggested by TLS.

There are many others that have not had any issues with this combination so I have never claimed this issue to be anything but my system. Just for giggles recently I connected a receiver to my system and used the pre outs via RCA to my amps. It was a cheap onkyo that I use in my garage. Guess what, no hum hiss or any noise from my speakers. Just like it used to be, dead quiet.

I don't know if it is poor grounding in the Marantz or what but all I can say is that I can repeat your issue and I do not think it is the amp.

To be clear, you had speaker hum with the Marantz, not transormer hum ?

- Rich

 

[adk highlander]

I have a hiss in the tweeters and a hum in the woofers. The amp itself makes no noise. If I mute the pre or pull the XLR's there is no noise.

Let me be clear though. This noise is not very loud and I really have to concentrate to hear it when there is no sound. When I first got the pre I was very sensitive to it and it drove me nuts for the first few months. Now I have gotten used to it and do not hear it unless I am less than 1ft from the speaker.

 

[Irvrobinson]

I had no speaker hum and no transformer hum with the exact same configuration using the Outlaw 7500.

This sounds very suspicious. It sounds like the ATI has a defect in the power supply. If you ask nicely, the local power company might be willing to send out a technician to put a scope on your AC power and make sure nothing is amiss.

Have you tried lifting the ground and seeing if the hum goes away?

 

[RichB]

This sounds very suspicious. It sounds like the ATI has a defect in the power supply. If you ask nicely, the local power company might be willing to send out a technician to put a scope on your AC power and make sure nothing is amiss.

Have you tried lifting the ground and seeing if the hum goes away?

I cut off the ground from a heavy duty extension cord that I was going to throw away.
No change when using it on three circuits that I could reach.

- Rich

 

[Irvrobinson]

I cut off the ground from a heavy duty extension cord that I was going to throw away.
No change when using it on three circuits that I could reach.

- Rich

Hmmm... do you have a different component to drive the ATI, even in stereo mode, than the one you're using? Have you already tried that?

 

[RichB]

Hmmm... do you have a different component to drive the ATI, even in stereo mode, than the one you're using? Have you already tried that?

I connected my Oppo BDP-105 directly to the AMP and disconnected everything else.</SPAN>
There was no appreciable hum or tweeter hiss.</SPAN>
So speaker hum appears to be an interaction with the AV8801.</SPAN>

However, the real problem is transformer hum which occurs with no connection, on 3 different circuits, and with a ground lifted plug.

- Rich</SPAN>

 

[Adam]

Rich, I can sympathize. My amps also have transformer hum. I hate it. I had contemplated getting an ATI amp to replace them, and I'm watching how this works out for you. Best of luck!

 

[Steve81]

Rich, I can sympathize. My amps also have transformer hum. I hate it. I had contemplated getting an ATI amp to replace them, and I'm watching how this works out for you. Best of luck!

And just think, with the $50 I'll give you for your IPS-1, you'll be that much closer to getting the ATI of your dreams. AND I'll toss in some lentil chips. Talk about a deal you can't refuse

 

[Irvrobinson]

I connected my Oppo BDP-105 directly to the AMP and disconnected everything else.
There was no appreciable hum or tweeter hiss.
So speaker hum appears to be an interaction with the AV8801.

However, the real problem is transformer hum which occurs with no connection, on 3 different circuits, and with a ground lifted plug.

- Rich

Oh my, what a good guess! What's my prize?

You need someone to 'scope your power. Call the power company.

 

[RichB]

Oh my, what a good guess! What's my prize?

You need someone to 'scope your power. Call the power company.

Hmmm.

Is this something I can do with a Multimeter?

Next Saturday, I leave on vacation.
So on Monday, I will have a plan of action.

- Rich

 

[Irvrobinson]

Hmmm.

Is this something I can do with a Multimeter?

Next Saturday, I leave on vacation.
So on Monday, I will have a plan of action.

- Rich

No, you need to look at the waveform so you can see if there's any DC offset on your outlet. That could cause the transformer hum, and it could also be indicative of a grounding problem somewhere in the house.

One thing you can measure is any voltage on the ground pin. There shouldn't be any. If there is, you need to call an electrician.

 

[RichB]

Rich, I can sympathize. My amps also have transformer hum. I hate it. I had contemplated getting an ATI amp to replace them, and I'm watching how this works out for you. Best of luck!

Others do not seem to have this issue.
Maybe it that East Coast power we get from Canada

- Rich

 

[AcuDefTechGuy]

I'm lying on my lounger now. I have my AT3005, 3002, & 6012 amps all on at the same time right now. No hum. No hiss.

 

[RichB]

I'm lying on my lounger now. I have my AT3005, 3002, & 6012 amps all on at the same time right now. No hum. No hiss.

Go ahead, rub it in.

To Summarize:

1) Speaker hum and hiss appear to be an interaction with the AV8801 because it does not happen with the Oppo BDP-105 directly connected to the amp.
Attaching a ground wire between the ATI and the AV8801 makes no difference.
Using a cheater plug makes no difference.
Disconnecting all HDMI inputs, including the TiVo that is connected to FIOS makes no difference.
I do not think FIOS is a ground-loop source since it is optical until it reaches the ONT box in my house.
One weird thing, is the there is hum when the AV8801 volume is at 0 but not when it is muted.
Still, this is a problem I could live with.

2) Transformer hum is a mystery. The cheater plug made no difference.
It occurs with no inputs attached to the AMP.
I have tried multiple circuits and that makes no difference.
I even turned the breaker off on my 20 amp circuit and ran just the 15 with all other devices disconnected. No change.

This problem directly attacks the OCD centers of my mind.
Perhaps, there is a medication you can recommend

Neither of these problems occurred with the Outlaw, 7500 which is a similar design.
It was dead quiet.

- Rich