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[billybob]

7 minutes ago, Limberpine said:

I did and still got the latest noise that I posted just a bit ago. 

Listen to one of us at a time now.

Bowing out here...

[Limberpine]

4 minutes ago, jimjimbo said:

 

Thank you. 

 

Unplug everything from that power strip other than what is absolutely needed and test.

Okay, so I will unplug EVERYTHING from the power strip and then plug JUST the power amp into the power strip with the normal 3 prong plug and see what that does. THEN I  will try in the power strip with the 2 prong end to see if anything changes. Is that what you would like me to do? 

[Dave1290]

Good man!  These guys here are the bestest just don't get cornfused!  It'll sort man!

[Limberpine]

1 hour ago, babadono said:

All the equipment has 3 prong cords? And un balanced connections? Where does the third wire go on all the equipment? To the chassis and then to the shields of all the un balanced connections?

DAC is 2 prong cord. Unbalanced connection? I don't understand your last few questions. 

[jimjimbo]

1 hour ago, Limberpine said:

Okay, so I will unplug EVERYTHING from the power strip and then plug JUST the power amp into the power strip with the normal 3 prong plug and see what that does. THEN I  will try in the power strip with the 2 prong end to see if anything changes. Is that what you would like me to do? 

Well, sort of....would prefer that you not use the power strip at all and test.

[jimjimbo]

Unbalanced connections are RCA connections if that's what you are confused about.

[Limberpine]

1 hour ago, jimjimbo said:

Well, sort of....would prefer that you not use the power strip at all and test.

Very good. I will do that right now. 

[Limberpine]

3 hours ago, jimjimbo said:

Unbalanced connections are RCA connections if that's what you are confused about.

Okay, I did the amp, direct to the wall outlet, hooked to the speakers, with nothing running into the amp. I used both the 3 prong and the 2 prong. The sound got louder with the 2 prong. 

 

Video attached. 

[henry4841]

One quick question. The sound from the post 10 hours ago, is the sound noticeable from a few feet away or just when you are close to the speaker? Definitely a change in sound from the first sound test you posted. The big Klipsch speaker you have, as I do, will show a hum a 90db speaker would not. The above sound hum is not acceptable. 

[tube fanatic]

5 hours ago, Limberpine said:

Okay, I did the amp, direct to the wall outlet, hooked to the speakers, with nothing running into the amp. I used both the 3 prong and the 2 prong. The sound got louder with the 2 prong. 

 

Video attached. 

Two things to try- 1) use an extension cord to plug the amp in someplace else to hear if anything changes.  2) if you have a multimeter, set it to the lowest AC range and clip the leads across the terminals of either speaker and report your reading.

 

 

Maynard

[billybob]

After you answer the last 2 posts above, using the same extension cord from another location, plug into it with the 2 prong DAC only.

What happens?

Now plug the amp in by itself.

What happens?

If all good after the 2 tests, plug both into extension.

Thanks!

[Limberpine]

4 hours ago, henry4841 said:

One quick question. The sound from the post 10 hours ago, is the sound noticeable from a few feet away or just when you are close to the speaker? Definitely a change in sound from the first sound test you posted. The big Klipsch speaker you have, as I do, will show a hum a 90db speaker would not. The above sound hum is not acceptable. 

I can certainly hear that same sound that I posted sitting across the room where my chairs are at about 8ft away.

[henry4841]

2 minutes ago, Limberpine said:

I can certainly hear that same sound that I posted sitting across the room where my chairs are at about 8ft away.

Then the hum is not acceptable. 

[jimjimbo]

That's not a "hum", that's a "buzz" that sounds more like a component failure than anything else.  Both speakers?  Both channels?  All inputs/outputs?

[babadono]

I am not able to play any of your demos of the hum but be that as it may....

I want to make sure I understand ,the ST70 is just a power amp, correct? Line level unbalanced (RCA) inputs to speaker outputs? When you did the 2 prong/3 prong tests were the inputs open or shorted?

And do you have any other amp you can plug into the same outlet and same speakers?

[Limberpine]

48 minutes ago, jimjimbo said:

That's not a "hum", that's a "buzz" that sounds more like a component failure than anything else.  Both speakers?  Both channels?  All inputs/outputs?

Yes, both speakers even when its just the power amp hooked to the speakers. Nothing running into it. 

[Limberpine]

22 minutes ago, babadono said:

I am not able to play any of your demos of the hum but be that as it may....

I want to make sure I understand ,the ST70 is just a power amp, correct? Line level unbalanced (RCA) inputs to speaker outputs? When you did the 2 prong/3 prong tests were the inputs open or shorted?

And do you have any other amp you can plug into the same outlet and same speakers?

Yes, just a power amp. It has one set of RCA inputs and 5 ways for the speaker connection. 

 

When I did both tests, it was merely amp to speakers connected and amp plugged in. Nothing plugged into the rca inputs of the amp. 

 

I do have another SS amp I could plug I to the speakers and outlet. Tube wise, I only have another Pre and Phono.  

[babadono]

I am trying to help you pinpoint the problem. Trying another amp in the same outlet with the same speakers will determine if its an amp problem or a house wiring problem. But to make things equal you need to short the inputs of each amp when you test. I'm sure your tube amp has a relatively high input impedance, don't know about the SS amp. But shorting the inputs will make the amp under test amplify ground, this is the quietest an amp can be. In this way it equalizes the test of different amps.

[Limberpine]

7 hours ago, tube fanatic said:

Two things to try- 1) use an extension cord to plug the amp in someplace else to hear if anything changes.  2) if you have a multimeter, set it to the lowest AC range and clip the leads across the terminals of either speaker and report your reading.

 

 

Maynard

I used an extension cord and an outlet across the room. No change in noise. 

 

I put my multimeter on the ACV 200 setting and the put the red on red and black on black terminals on the speaker and it just read 00.0

[Limberpine]

2 hours ago, babadono said:

I am trying to help you pinpoint the problem. Trying another amp in the same outlet with the same speakers will determine if its an amp problem or a house wiring problem. But to make things equal you need to short the inputs of each amp when you test. I'm sure your tube amp has a relatively high input impedance, don't know about the SS amp. But shorting the inputs will make the amp under test amplify ground, this is the quietest an amp can be. In this way it equalizes the test of different amps.

Totally appreciate your help! I just don't know ow what you mean by shorting the inputs. Would that mean, I connect either amp to the speakers with and RCA running out of said amp and then use a screw driver to connect the male end to the shield of the the White RCA plug?