5 second buzz after turn on of amp - resolved!

0 Members and 1 Guest are viewing this topic. Read 4742 times.

charmerci

5 second buzz after turn on of amp - resolved!
« on: 2 Nov 2015, 06:02 pm »
I've doubly made sure all the connections are firm. USB DAC > Odyssey pre-amp > AVA amp > GR Research speakers.


I recently re-hooked up this system and the buzz comes out of the speakers for 5 seconds before going away. Everything is fine after that. It's been about 9 months since I hooked this system up before in another location - and this never happened before. I grounded the pre-amp to a vent on the floor.


Any other suggestions?
« Last Edit: 7 Nov 2015, 12:17 am by charmerci »

mikeeastman

Re: 5 second buzz after turn on of amp
« Reply #1 on: 2 Nov 2015, 06:15 pm »
Hi, the vent isn't a good ground.

charmerci

Re: 5 second buzz after turn on of amp
« Reply #2 on: 2 Nov 2015, 06:18 pm »
I'll be hooking it up to the outlet ground later.

avahifi

  • Industry Contributor
  • Posts: 4689
    • http://www.avahifi.com
Re: 5 second buzz after turn on of amp
« Reply #3 on: 2 Nov 2015, 06:54 pm »
Shut system down.

Disconnect the interconnect cables from the preamp to the AVA power amp at the amplifier end only.  This leaves the amplifier connected only to the speakers.

Turn amplifier back on.  Does the buzz go away?  If so the issue is ahead of the amplifier. If the buzz remains, let us know which amplifier you have.

If its not the amplifier, then repeat test with only amplifier and preamplifier connected, preamp volume all the way down.  Does the buzz now come back?  If so its a preamp issue or possibly interconnects between amp and preamp.  If buzz stays away, then DAC or cables between DAC and preamp are suspect.

I hope this helps.

Frank Van Alstine

charmerci

Re: 5 second buzz after turn on of amp
« Reply #4 on: 2 Nov 2015, 08:28 pm »
It's not the amp.


I grounded the pre-amp to the wall socket. Now, it's simply a slight buzz that fades away - only after I turn the pre-amp off. No buzzing on turn on. (Edited - see below.)


I think I can live with it?
« Last Edit: 3 Nov 2015, 12:30 am by charmerci »

RDavidson

  • Full Member
  • Posts: 2864
Re: 5 second buzz after turn on of amp
« Reply #5 on: 2 Nov 2015, 10:15 pm »
You say you recently re-hooked up this system.
Did you move?
How long has the gear sat?
Did you make any changes to the system since you last had it hooked up?
What Odyssey preamp do you have? Is it the Candela? If so, have you tried swapping tubes or even just pulling the tubes and reseating them?

Sorry for all the questions.
Just trying to get a better understanding of the circumstances and things to look at. Maybe try cleaning your connectors too. Perhaps somewhere you're not making good contact even if everything seems tight.

jea48

  • Full Member
  • Posts: 307
Re: 5 second buzz after turn on of amp
« Reply #6 on: 2 Nov 2015, 10:37 pm »
It's not the amp.


I grounded the pre-amp to the wall socket. Now, it's simply a slight buzz that fades away - only after I turn the pre-amp off. No buzzing on turn on.


I think I can live with it?

You should turn off the amp first wait about a minute or so for the caps in the power supply to bleed down and then turn off the preamp.

Turn on procedure, front end >>> preamp >>> Amp last.

Turn off procedure, Amp first >>> preamp >>> front end.

If you are wanting to leave the amp on 24/7 but turn off the preamp you might try muting the preamp first then turn it off. It depends on the muting circuit in the preamp if it will still pass a transient voltage spike out the outputs.

 

charmerci

Re: 5 second buzz after turn on of amp
« Reply #7 on: 3 Nov 2015, 12:37 am »
You should turn off the amp first wait about a minute or so for the caps in the power supply to bleed down and then turn off the preamp.

Turn on procedure, front end >>> preamp >>> Amp last.

Turn off procedure, Amp first >>> preamp >>> front end.


I do that turn on/turn off procedure normally.

The situation now is - with the amp on and the preamp off. There is a slight buzzing out of both speakers. (Yes, I changed cables - though all I have now is two sets of the same boutique brand.)

If I turn the amp off and then as I turn the preamp off, that buzz occurs until the preamp or amp stops sending the signal.

If the amp is on and then I turn the preamp on, the buzz occurs for about 5 seconds and then it quickly stops.

It's a Tempest ss pre-amp.

Speedskater

  • Full Member
  • Posts: 2680
  • Kevin
Re: 5 second buzz after turn on of amp
« Reply #8 on: 3 Nov 2015, 01:45 pm »
I would guess that a relay has something to do with it.
Try some plain-jane coax interconnects. Boutique cables are always suspect.

jea48

  • Full Member
  • Posts: 307
Re: 5 second buzz after turn on of amp
« Reply #9 on: 3 Nov 2015, 03:38 pm »
I do that turn on/turn off procedure normally.

The situation now is - with the amp on and the preamp off. There is a slight buzzing out of both speakers. (Yes, I changed cables - though all I have now is two sets of the same boutique brand.)

If I turn the amp off and then as I turn the preamp off, that buzz occurs until the preamp or amp stops sending the signal.

If the amp is on and then I turn the preamp on, the buzz occurs for about 5 seconds and then it quickly stops.

It's a Tempest ss pre-amp.

Sounds like either the preamp does not have a turn on muting circuit to protect the outputs or the circuit has a problem and is not functioning properly.

The buzz you are hearing is the preamp when first being powered up is its' circuits/components stabilizing. It could be worse. You could get a loud pop through your speakers when turning off the preamp when the power amp is still on. That can damage speakers. Why can't you just leave the SS preamp powered up when the power amp will be left powered up?

The preamp doesn't appear to have a muting function. I see the preamp does have a tape loop circuit. Is that correct?

charmerci

Re: 5 second buzz after turn on of amp
« Reply #10 on: 3 Nov 2015, 05:18 pm »
The pre-amp does have a tape loop circuit - I'm assuming that means just having tape in/out.


The cables are Soundsilver Purity interconnects. (http://soundsilver.tumblr.com/)


I'm going to leave the pre-amp on for now and see if that helps.


I live downtown (small town really) and I can faintly hear a radio station coming out through the speakers - though there is no tuner hooked up.

Speedskater

  • Full Member
  • Posts: 2680
  • Kevin
Re: 5 second buzz after turn on of amp
« Reply #11 on: 3 Nov 2015, 05:52 pm »
The cables are Soundsilver Purity interconnects. (http://soundsilver.tumblr.com/)
That could be part of both of your problems! Just try some ordinary coax interconnects.

jea48

  • Full Member
  • Posts: 307
Re: 5 second buzz after turn on of amp
« Reply #12 on: 3 Nov 2015, 06:32 pm »
The pre-amp does have a tape loop circuit - I'm assuming that means just having tape in/out.


The cables are Soundsilver Purity interconnects. (http://soundsilver.tumblr.com/)


I'm going to leave the pre-amp on for now and see if that helps.


I live downtown (small town really) and I can faintly hear a radio station coming out through the speakers - though there is no tuner hooked up.

Do you have a radio transmitting antenna tower close to your home?

From your provided Link.

Each conductor is housed in an individual Teflon tube in a braided configuration to lessen EMI (Electromagnetic interference) and to prevent crosstalk between the conductors. This configuration dramatically increases soundstage, delves into the most intricate musical passages, and offers an exceptionally silent background.


What are you using for a front end source? Turntable/ phono cartridge? CDP? Both? Please explain. If turntable disconnect the phono ICs from phono RCA inputs of preamp, set selector to another input on the preamp and check for the radio station.

Post back your findings.

 

charmerci

Re: 5 second buzz after turn on of amp
« Reply #13 on: 3 Nov 2015, 06:47 pm »
Do you have a radio transmitting antenna tower close to your home?

What are you using for a front end source? Turntable/ phono cartridge? CDP? Both? Please explain. If turntable disconnect the phono ICs from phono RCA inputs of preamp, set selector to another input on the preamp and check for the radio station.

Post back your findings.

I kind of doubt it. we have one radio station - but several relay stations from out of town radio stations - a relay station could be on top of the building - it's not a house - but I seriously doubt it.

As in my initial post - it's just a laptop>ODAC>Kabeldirekt cable into the pre.

charmerci

Re: 5 second buzz after turn on of amp
« Reply #14 on: 3 Nov 2015, 11:46 pm »
I've ordered another set of connects (again Kabeldirekt - on a budget) - so we'll see.


I do suspect it is the silver.


Also, hearing the radio is very slight - I can only hear it if I put my ear up to a speaker. Over about a foot away, I can hardly hear anything coming out.


It's not a serious problem just one that I didn't think I heard when I had this system hooked up when I lived in AZ last year....it could have been like this then too.

Speedskater

  • Full Member
  • Posts: 2680
  • Kevin
Re: 5 second buzz after turn on of amp
« Reply #15 on: 4 Nov 2015, 05:36 pm »
From your provided Link.
Each conductor is housed in an individual Teflon tube in a braided configuration to lessen EMI (Electromagnetic interference) and to prevent crosstalk between the conductors. This configuration dramatically increases soundstage, delves into the most intricate musical passages, and offers an exceptionally silent background.
A twisted pair is always good for reducing interference. But for a unbalanced RCA interconnect, it's nowhere near as good as a coax with a heavy braided shield.
Teflon tubes have nothing to do with EMI interference. But they may increase handling noise.

avahifi

  • Industry Contributor
  • Posts: 4689
    • http://www.avahifi.com
Re: 5 second buzz after turn on of amp
« Reply #16 on: 4 Nov 2015, 08:08 pm »
The slight remaining buzz is probably noise pickup from your essentially unshielded interconnect cables.

As suggested above, try a simple set of true coax shielded interconnects replacing your twisted pair boutique ones.

Buzz when turning on preamp into energized power amp strongly suggests you should follow good system saving practice:

Power amplifier on LAST.  Power amplifier off FIRST.  This prevents turn on or off  transients from line level equipment from getting through the amplifier and into your speakers.

Which AVA amplifier are you using.?

Frank Van Alstine

charmerci

Re: 5 second buzz after turn on of amp
« Reply #17 on: 5 Nov 2015, 01:54 am »
The slight remaining buzz is probably noise pickup from your essentially unshielded interconnect cables.

As suggested above, try a simple set of true coax shielded interconnects replacing your twisted pair boutique ones.

Buzz when turning on preamp into energized power amp strongly suggests you should follow good system saving practice:

Power amplifier on LAST.  Power amplifier off FIRST.  This prevents turn on or off  transients from line level equipment from getting through the amplifier and into your speakers.

Which AVA amplifier are you using?

Frank Van Alstine

I've just ordered a set of connects.

I do turn them off that way. I just did it a few times for testing purposes.


Synergy 240

charmerci

Re: 5 second buzz after turn on of amp
« Reply #18 on: 7 Nov 2015, 12:16 am »
New (inexpensive Kabeldirekt) connects came in.


Start up and amp on with pre-amp off buzz is gone. Can no longer faintly here the radio through the speakers either.


Thanks!
« Last Edit: 7 Nov 2015, 05:38 pm by charmerci »

avahifi

  • Industry Contributor
  • Posts: 4689
    • http://www.avahifi.com
Re: 5 second buzz after turn on of amp - resolved!
« Reply #19 on: 7 Nov 2015, 02:48 pm »
This shows that my thoughts that boutique interconnect cables can change the sound of your system is correct.

Unfortunately, not always in the direction intended.

Frank