Jump to content
Why become a member? ×

Noisy hissing Ashdown ABM 500 RC EVO III Head. Is this normal?


Linus27
 Share

Recommended Posts

I've just bought a brand new Ashdown ABM 500 Rack mouted EVO III Head. With the speaker connected but volume up, its as silent as a mouse. As soon as I plug my cable into the input socket, it starts to hiss. If I turn the treble dial up the hissing becomes much louder. If I turn the valve blend dial to add more valve, the hissing becomes much louder. I have tried 3 basses and its exactly the same with each bass. I have not tried a different cable yet but it is a brand new cable. I will try a new one to elimate this option.

Does anyone else have this head and notice a hissing noise when a cable is connected to the input socket?

Link to comment
Share on other sites

I reckon preamp valve. The input would have a cut off so that the valve isnt being used and there would be no output if there was no input cable connect, ehich is why it doesn't hiss without it in. I'm just guessing here, I really don't actually have a clue. Just an idea

Link to comment
Share on other sites

[quote name='peted' post='510275' date='Jun 10 2009, 03:37 PM']I would suspect the cable if the head is silent until it's plugged in.

How is the hiss with no cable, and the valve drive + volume at full?[/quote]

With the valve dial on full and the input and output on full with no cable attached it is silent.

With a cable plugged in, the valve, input and output set at 9pm, you can hear a hissing sound. If I turn the valve to full, or increase the treble dial, the hissing gets louder. I have tried different cables and there is no difference in the hissing sound :)

Link to comment
Share on other sites

  • 1 month later...

Hello Linus,
I have the same head and the same problem. I've described this problem to ashdown, and ask them for the acceptable limit for hiss, but have not recieved any answer, yet. Next week I will test this Head in our local music shop (ashdown dealer) to ask them for their opinion. I think the hiss is too loud. I wonder, if this would be covered by the warranty....

Have you got any progress on this issue ?


Regards
stephan

Link to comment
Share on other sites

Hi Stephen,

In the end, I had no problem with the head, it was something I was doing. I was testing it with the bass not connected to the cable. With the bass not plugged in, the cable then becomes an antenna and this amplifies the hum. I was testing it with the bass not connected to the cable but OBMN informed me this is not the correct thing to do. So in the end, there was no fault with the head.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...