Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Quickie => Topic started by: aragorn723 on March 25, 2015, 01:45:52 PM

Title: 3s4 hum [solved]
Post by: aragorn723 on March 25, 2015, 01:45:52 PM

Hi,

Do some tubes hum more than others?  (i.e. phillips more than westinghouse, etc).  I have 2 different tubes in my system (a french tube and a westinghouse) and one seems to hum louder than the other.  When the tubes are switched, the louder hum goes to the other side.  Is it time to clean the pins?  Or maybe switch tubes?

Dave

Title: Re: 3s4 hum
Post by: Paul Joppa on March 25, 2015, 02:42:45 PM

Since teh Quickie is battery powered, it does not generate hum on its own. The solution thus depends on what the source is. Since it is sensitive to tube replacement, it seems likely to be coming from electric or magnetic fields generated by other equipment nearby; some tubes will be more sensitive to such external fields than others.

You can start the hunt by trying different locations and different orientations of the Quickie. For example, if it is close to a power transformer, move it further away and see if the hum decreased. The second good experiment is to shut off any light dimmers, cell phones, computers, etc. that are nearby to see if they may be a source of interference. I suggest these two experiments because they are easy and lead to answers most often. If they don't lead to an answer then we can try other things.

Title: Re: 3s4 hum
Post by: aragorn723 on March 27, 2015, 11:19:04 AM

Paul,

I'll have to post a pic of the setup.  There is a wall switch on both sides of the TV stand!  (Plus a wifi router that is in the cabinet too, and probably not helping).  Thanks,

Dave

Title: Re: 3s4 hum
Post by: aragorn723 on April 01, 2015, 03:06:58 PM

Here's a pic of the system:

The Quickie is on top of the left speaker, notice the light switch next to it.  It used to be on the other speaker, which also has a light switch next to it.  The amp is on the floor on the left (R500), and the box in the middle that says "the best is yet to come" has a wifi router in it.  Any ideas where to put the Quickie?

Dave

Title: Re: 3s4 hum
Post by: Paul Birkeland on April 01, 2015, 05:01:11 PM

Quote from: aragorn723 on April 01, 2015, 03:06:58 PM

Any ideas where to put the Quickie?

On top of the speaker is, without a doubt, the worst choice. 

Go to your closest hardware store and pick up an inexpensive wall mounted shelf, then give that try.  (Or stick it on top of your TV as an experiment)

Title: Re: 3s4 hum
Post by: aragorn723 on April 02, 2015, 04:01:08 PM

What is the advantage of putting the Quickie on a shelf?

Title: Re: 3s4 hum
Post by: kgoss on April 03, 2015, 02:21:31 AM

The biggest advantage of a wall shelf is vibration control.  That is why they are popular for turntables.
You are getting a lot of vibration from the speaker with the quickie sitting on top of it.

Title: Re: 3s4 hum
Post by: mkane on April 03, 2015, 03:40:13 AM

   Heck, for that matter none of your source components should be between your speakers.

Title: Re: 3s4 hum
Post by: Paul Birkeland on April 03, 2015, 09:29:59 AM

Quote from: aragorn723 on April 02, 2015, 04:01:08 PM

What is the advantage of putting the Quickie on a shelf?

I would suggest reading up on microphonics. 

Title: Re: 3s4 hum
Post by: aragorn723 on April 04, 2015, 01:42:02 AM

Sometimes the obvious things aren't so obvious lol.  I was thinking more about the RF interaction with the Quickie but not thinking about vibrations from the speaker.  My space is kind of cramped so maybe the shelf will make it look a little better too. 

Dave

Title: Re: 3s4 hum
Post by: aragorn723 on April 07, 2015, 04:12:06 PM

Hi everyone,

I moved the Quickie to the spot where the tuner was (in the lower left by the tv) and hope to get a chance to listen to it tomorrow (the wife and son are asleep).  I'll probably try moving the cable modem and wifi to the opposite end of the room too and see what this does to the sound.  Hopefully it will be worth the effort of disconnecting and moving all this stuff!

Dave

Title: Re: 3s4 hum
Post by: Grainger49 on April 08, 2015, 01:14:27 AM

Dave,

Without knowledge of each of your components it is hard to give solid advice.  A wall shelf away from all the other components sounds good for not being there.

If you have a Radio Shack near I would suggest buying flexible 10' cables to and from the Quickie so you can move it around and see which components induce noise and which don't.  I would think a TV would be a noise inducer, but the pragmatic approach is conclusive. 

Title: Re: 3s4 hum
Post by: aragorn723 on April 08, 2015, 09:50:30 AM

Grainger,

I might have some cables like those around (think they are around 10 or 20 feet).  Interestingly enough, the Quickie picked up more noise next to the TV than on the speaker.  Might have to go with the shelf option, but i'm trying to find a way to try the Quickie behind the speaker where the shelf would go without installing a shelf at first to see how well it does.

Dave

Title: Re: 3s4 hum
Post by: aragorn723 on April 10, 2015, 07:06:25 AM

Hi,

I just moved the Quickie to the top of the entertainment center, and it is almost dead quiet now!  Thanks,

Dave