DV247 Forums - A Global Community for Music Makers Lowest Price Guaranteed, Free Delivery, Free 3 Year Warranty
Go Back   DV247 Forums - A Global Community for Music Makers > Music Equipment Discussion > Computer Hardware
Forgot Password? Join Us!
Home Register Groups FAQ Members List Calendar Search Today's Posts Mark Forums Read Go to DV247.com
New to Forums or just joined? Why not start your journey here?

Computer Hardware Audio interfaces, MIDI interfaces, control surfaces, MIDI controllers & USB MIDI keyboards (not motherboards or system components)

Reply
 
LinkBack Thread Tools Display Modes
  #31 (permalink)  
Old 9th December 2008 , 10:22 PM
Super Member
 
Join Date: Jul 2008
Posts: 613
Default

Hi Tyrone,

Well, the few minutes I had on an audio test rig with them showed frequency response to be amazingly extended and flat and the waveform was pure but 'scopes do not give a very good indication of distortion, still, used at "domestic" levels, especially at virtually zero power (10kload) I think they are fine. My only concern is the HF peak at 60kHz but I am sure I can tame that. While we are having this happy little chat about hum, earths, isolators and suchwhich can I get very serious for a moment?

There is it seems to me to be a certain amount of confusion concerning earth loops and "isolating" transformers ( often sloppily called DI boxes).

It is IMPERATIVE to realize that NO audio transformer is usually tested for or meant as a MAINS VOLTAGE ISOLATOR. That is to say, just because a box, like the one I am making, breaks an earth path between two bits of kit FOR AUDIO signals it does NOT mean that if one piece of gear became live the box would protect you. Good quality trannies, like OEP's probably would but THEY don't say so! (except for special products). The £3 a piece or so jobs I would not trust in America let alone in 240volt land!

So chaps(&ess's) Cardinal rule, everything must have its own mains earth and boxes just keep things quiet. That's ALL they do.

Dave.
ecc83 is offline Offline
Reply With Quote
  #32 (permalink)  
Old 9th December 2008 , 10:37 PM
Forum Idol
 
sureno's Avatar
          
           
Join Date: Jul 2008
Location: west london depot
Posts: 7,873
Default

i just want to see if any hum can be removed i dont want my mains volted to a tranny isolator
______________________________
Im a Mac and Windows 7 was not my idea
WWW.SURENO.CO.UK
www.myspace.com/djsureno
http://twitter.com/djsureno
sureno is offline Offline
Reply With Quote
  #33 (permalink)  
Old 9th December 2008 , 10:50 PM
Super Member
 
Join Date: Jul 2008
Posts: 613
Default

Don't worry S!

The warning was mainly aimed at folks who use tranny boxes on live shows and a few posts at other sites have given me the impression that sometimes peeps think they can do more than they are designed to do.

Your app' is typical and non lethal I assure you!

Dave.
ecc83 is offline Offline
Reply With Quote
  #34 (permalink)  
Old 9th December 2008 , 11:04 PM
Forum Idol
 
sureno's Avatar
          
           
Join Date: Jul 2008
Location: west london depot
Posts: 7,873
Default

Quote:
Originally Posted by ecc83 View Post
Don't worry S!

The warning was mainly aimed at folks who use tranny boxes on live shows and a few posts at other sites have given me the impression that sometimes peeps think they can do more than they are designed to do.

Your app' is typical and non lethal I assure you!

Dave.
cool looking forward to the box of tricks
______________________________
Im a Mac and Windows 7 was not my idea
WWW.SURENO.CO.UK
www.myspace.com/djsureno
http://twitter.com/djsureno
sureno is offline Offline
Reply With Quote
  #35 (permalink)  
Old 9th December 2008 , 11:36 PM
Super Member
 
tyronehowe's Avatar
          
           
Join Date: Jul 2008
Location: Cirencester, UK
Posts: 444
Default

Quote:
Originally Posted by ecc83 View Post
There is it seems to me to be a certain amount of confusion concerning earth loops and "isolating" transformers ( often sloppily called DI boxes).

It is IMPERATIVE to realize that NO audio transformer is usually tested for or meant as a MAINS VOLTAGE ISOLATOR. That is to say, just because a box, like the one I am making, breaks an earth path between two bits of kit FOR AUDIO signals it does NOT mean that if one piece of gear became live the box would protect you. Good quality trannies, like OEP's probably would but THEY don't say so! (except for special products). The £3 a piece or so jobs I would not trust in America let alone in 240volt land!

So chaps(&ess's) Cardinal rule, everything must have its own mains earth and boxes just keep things quiet. That's ALL they do.

Dave.
Thank you very much for explaining that Dave – appreciated.

I was oblivious to the entire “earth loop” problem UNTIL I purchased a Mac (a white MacBook to be precise). I plugged it into my normal amplifier and there were all sorts of horrible sounds (and that was BEFORE I pressed play in Logic ).

After looking at forums and asking questions someone mentioned about an “earth loop” or “ground loop” so I looked up that gadget in Maplin and thought for a tenner it was worth a try. Bingo – instant success.

I was worried that it might affect the HF, so I A/B tested a number of times (by ear) and I couldn’t tell any difference (apart from the cleaner signal with the unit in place).

Oddly enough when I later bought a MacPro I had the same problem. So my unit is now hidden away behind the audio interface (Edirol UA-25) and everything is clean.
______________________________
Tyrone Howe
Apple Certified Pro, Logic Pro 8, Level 1
Logic Pro 9.1.2, Access Virus TI2 Desktop
tyronehowe is offline Offline
Reply With Quote
  #36 (permalink)  
Old 16th December 2008 , 08:48 PM
Super Member
 
Join Date: Jul 2008
Posts: 613
Default

Sorry chaps, been away, blood in pee sat night.

All sorted now but no lifting.

Sureno, I have all the bits for your box and will fabricate a soon as I can.

Dave.
ecc83 is offline Offline
Reply With Quote
  #37 (permalink)  
Old 16th December 2008 , 09:16 PM
Forum Idol
 
sureno's Avatar
          
           
Join Date: Jul 2008
Location: west london depot
Posts: 7,873
Default

Quote:
Originally Posted by ecc83 View Post
Sorry chaps, been away, blood in pee sat night.

All sorted now but no lifting.

Sureno, I have all the bits for your box and will fabricate a soon as I can.

Dave.
oooh that doesn't sound too good, least it wasn't burning when you pee'd
seriously hope all's well and no rush
______________________________
Im a Mac and Windows 7 was not my idea
WWW.SURENO.CO.UK
www.myspace.com/djsureno
http://twitter.com/djsureno
sureno is offline Offline
Reply With Quote
  #38 (permalink)  
Old 16th December 2008 , 09:36 PM
Round The Horn
 
Join Date: Jul 2008
Location: Morden, Surrey
Posts: 1,135
Default

Quote:
Originally Posted by sureno View Post
oooh that doesn't sound too good, least it wasn't burning when you pee'd
seriously hope all's well
True. True.
http://www.youtube.com/watch?v=3Cb7inx4BLA
saxman is offline Offline
Reply With Quote
  #39 (permalink)  
Old 17th December 2008 , 10:53 AM
Forum Scribe
 
Monarch's Avatar
          
           
Join Date: Sep 2008
Location: UK
Posts: 1,446
Default

[quote=ecc83;21719]
Quote:
Sorry chaps, been away, blood in pee sat night.

All sorted now but no lifting.
Best wishes for your health. Thankfully you got it sorted.
______________________________
Need categorised help in a hurry? Try the DV Forum Start Page.

Website: http://www.soundcloud.com/dmncwide
Monarch is offline Offline
Reply With Quote
  #40 (permalink)  
Old 18th December 2008 , 07:52 AM
Super Member
 
Join Date: Jul 2008
Posts: 613
Default

Number one channel blocked again! Waiting for taxi to A&E.

Maybe in the New Year Sur'!

Dave.
ecc83 is offline Offline
Reply With Quote
  #41 (permalink)  
Old 18th December 2008 , 10:05 AM
Administrator
 
modz1's Avatar
          
           
Join Date: May 2008
Location: London
Posts: 1,848
Default

Speedy recovery Dave..
______________________________
"The light that burns twice as bright burns half as long.."
modz1 is offline Offline
Reply With Quote
  #42 (permalink)  
Old 18th December 2008 , 11:37 AM
Forum Idol
 
sureno's Avatar
          
           
Join Date: Jul 2008
Location: west london depot
Posts: 7,873
Default

Quote:
Originally Posted by ecc83 View Post
Number one channel blocked again! Waiting for taxi to A&E.

Maybe in the New Year Sur'!

Dave.
good luck Dave, stop putting it in iffy places
______________________________
Im a Mac and Windows 7 was not my idea
WWW.SURENO.CO.UK
www.myspace.com/djsureno
http://twitter.com/djsureno
sureno is offline Offline
Reply With Quote
  #43 (permalink)  
Old 18th December 2008 , 05:00 PM
Forum Scribe
 
Monarch's Avatar
          
           
Join Date: Sep 2008
Location: UK
Posts: 1,446
Default

Quote:
Originally Posted by modz1 View Post
Speedy recovery Dave..
Yes. I hope and pray your health improves.
______________________________
Need categorised help in a hurry? Try the DV Forum Start Page.

Website: http://www.soundcloud.com/dmncwide
Monarch is offline Offline
Reply With Quote
  #44 (permalink)  
Old 31st December 2008 , 09:35 AM
Super Member
 
Join Date: Jul 2008
Posts: 613
Default

In case any of you want to know,

I'm out of H again, had an op', they said they removed a "rather large" tumour in the bladder. I won't know if it is a good or bad guy for a week or so.

Still sore but much, much better.

Dave.
ecc83 is offline Offline
Reply With Quote
  #45 (permalink)  
Old 31st December 2008 , 12:25 PM
Forum Idol
 
sureno's Avatar
          
           
Join Date: Jul 2008
Location: west london depot
Posts: 7,873
Default

Damn!!!
i really hope it all works out for you Dave!!!
______________________________
Im a Mac and Windows 7 was not my idea
WWW.SURENO.CO.UK
www.myspace.com/djsureno
http://twitter.com/djsureno
sureno is offline Offline
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
researchers create speaker from carbon nanotubes sureno Pro Audio Product News/Updates 7 23rd November 2008 09:30 AM
Speaker resistance taf_taf PA Systems & Live sound 5 6th August 2008 10:59 PM


All times are GMT. The time now is 01:12 AM.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.3.0
1999-2017 DV247 Ltd. All rights reserved.