Ashdown ABM-600 Input and Output Knob Confusion

[Lifter Tick]

Hey guys, long time lurker first time poster. I've searched for this answer but I can't seem to find it.

I bought my first big-boy amp today: a used Ashdown ABM-600 with a 4x10 Ampeg SVT cab. I like the sounds I'm getting from it, but I'm a bit confused on the knob setup. On most amps I've looked at there are two knobs for controlling the volume: master volume and gain. It seems like the Ashdown way is to use two volume knobs: input and output. Is this just a re-branding of the tried-and-true standard knob setup, or is this completely different? What should I know about this before adjusting the knobs to get the tone I want? I've tried cranking them both and they seem to do similar things.

 

[abarson]

Ashdown "Input Control" = Gain. Sets the preamp signal gain level.
Ashdown "Output Level" = Volume. Sets the overall amp output level.

User manual
https://cdn.shopify.com/s/files/1/2397/1117/files/abm600.pdf?10890871767480766198

It has a section on suggested settings, so like "METAL" has the Gain really cranked in comparison to R&B.

 

[Lifter Tick]

Ashdown "Input Control" = Gain. Sets the preamp signal gain level.
Ashdown "Output Level" = Volume. Sets the overall amp output level.

User manual
https://cdn.shopify.com/s/files/1/2397/1117/files/abm600.pdf?10890871767480766198

It has a section on suggested settings, so like "METAL" has the Gain really cranked in comparison to R&B.

Hell yes. Thank you!

 

[basscooker]

In general, for clean headroom the master is set high, and the gain is used for volume control. For overdrive, the gain is set high and the master is for volume control.

The loudest clean signal is found by turning the master full on and leaving it there, thusly using only the gain for volume control. Amps without a master volume are essentially this.

Remember that technically speaking, ALL controls are volume knobs. Some just boost or cut certain parts of the spectrum. So in practice, boosting an eq knob is still "turning up" volume; just not the entire signal.

Enjoy your new amp, BTW.