Auto-mute feature on Ashdown ABM?

[dudu]

Hi folks,

I have just bought an Ashdown ABM EVO IV that I love so far, there is something about it that I'm not sure whether to classify as a bug or a feature, though.

I have a couple of bass preamps that I wanted to try with the Ashdown power section. The thing is, irrespective of which line input I use (either line or fx return), the power section is mute unless I plug a cable into the instrument input on the front of the amp.

Can anyone else confirm this behaviour with their ABM? Thanks!

[Woodinblack]

I can give it a try later on (it is behind me but not connected to anything, and I dont' have a spare pre up here), but a much simpler answer would be to drop a line to ashdown and ask them if that is the correct behaviour. They have always been pretty helpful and fast at responding.

[la bam]

I think that's standard on the ABMs.

Either a headphone jack plug or cable. I think that defeats it's own pre amp?

[dudu]

10 minutes ago, la bam said:

I think that's standard on the ABMs.

Either a headphone jack plug or cable. I think that defeats it's own pre amp?

I see. Defeating the preamp makes sense, what surprised me was that it also defeats the power section (which is bypassed when plugging an external preamp into the line input on the back).

[la bam]

I'll have a look at mine this afternoon.

Have you tried the send and returns, and both at once?

[dudu]

16 minutes ago, la bam said:

I'll have a look at mine this afternoon.

Have you tried the send and returns, and both at once?

Thanks! Not both at once, but I have tried them both, it works exactly the same.

[la bam]

Mine works fine doing the following:

Bass into preamp IN.

Preamp OUT into amp RETURN.

Dummy jack lead or jack plug into input on amp.

That defeats the eq etc but volume works fine.

[dudu]

10 minutes ago, la bam said:

Mine works fine doing the following:

Bass into preamp IN.

Preamp OUT into amp RETURN.

Dummy jack lead or jack plug into input on amp.

That defeats the eq etc but volume works fine.

If you remove the dummy jack from the input does the external preamp still work?

[la bam]

No. If I take the dummy jack out nothing works. No preamp, no volume at all.

When I plug it back in everything works again.

[dudu]

6 minutes ago, la bam said:

No. If I take the dummy jack out nothing works. No preamp, no volume at all.

When I plug it back in everything works again.

Alright, then they are all the same. Thank you very much!

[funkydoug]

This is what I also found out. If there is nothing plugged into the input the whole thing is silent. It was designed for safety apparently. A dummy jack defeats it and lets you bypass the (wonderful) preamp.

[Chrisan2]

I just recently spoke with Dave Green at Ashdown on a similar subject involving my ABM Evo Iv,  I was plugging my i phone into the line in Jack on the back with a auxiliary cord and a quarter inch adapter. 
He said if nothing was plugged into the input  it meant there was a global mute by design, He also said do not plug your iPhone into the line in and as the iPhone was “reversed” and could damage the phone. not exactly sure what that means but it may be something to do with it being a stereo output and the line in  is mono perhaps. As the manual says the input can be used to plug-in tape decks or CDs ,so I’m not sure. Is it just an iPhone thing?