Ashdown Rootmaster 420

5/5, 5 from 1 review
Class D Bass 420w amp

Recent Reviews

  1. GMC
    Ashdown 420 love!
    5/5, 5 out of 5, reviewed Jan 6, 2016
    Build Quality:
    • + Small, light, powerful, really well spec'd and has the sound I was after
    • - The EQ is great, but I miss the 7 band graphic from my older amp
    I bought this amp to urgently replace a damaged Trace Elliot AH 400SM head which I've been using for 20 years! I wanted to get as close to the old TE sound that I was used to...and this Ashdown is pretty close. I have a variety of basses, fretless, fretted, 4/5/6/7 strings, some with flats, some with rounds. I use a pair of custom 15" cab is in the pictures, but I also have a 12" cab too.

    Spec wise, it's very well featured: It has a 5 band EQ (and a pre shape). It's got all the usual Ashdown toys; a great VU meter, DI, send and return loops, plus an aux line in. It's also got a built in compressor, a drive and octaver analogue effects. I pop my effects inline, so I go bass > pedal board > amp, so these on-amp effects are post signal chain. It's really nice to have another compressor, grit and octaver at the end of the chain as well as in the usual spots.


    The preamp on this amp seems to like driving a lot, 3/4 is quite normal for this amp. Fully maxxed out and it breaks up to a really nice sounding overdrive. Combined with the drive knob...the overdrive grit is really nice. Nicer than a lot of my dedicated OD and Fuzz pedals, and I have a few! Who would have thought about cascading grit on an amp! Inspired!

    The amp is a newer Class D design. It's interesting how similar these amps can sound, I do miss the Graphic i might invest in an MXR 10 band graphic for my pedal board. Initially, I thought the Ashdown was more darker and boomy sounding, which is true in my front room at low power levels. But open her up in a bigger venue and that familiar old sound was's a mid honk which is specific to Mark Gooday's designs. Ashdown is the spiritual offspring to Trace and after 20's a part of my tone. After so long...any other amp just sounds wrong to my ears. This amp needs the preamp pushed quite a bit. About 70% is about where the preamp really starts to sing and it gives me the tones I'm after. So I tend to keep the preamp gain high and adjust the output gain low. If the preamp is pushed past 75-80% then it breaks up really well into a glorious overdrive. Add a little compression and turn up the drive knob to 70% and the grit is very very nice. The two cascade really well. Top marks for that design!

    The octaver is analogue and is pre blended, so if the knob is fully on, it's about a 50:50 mix. Which is what most guys need in a 'taver. It's a pity it can be dialled fully on but it's the sound most people dial in anyway...but you won't get a trigger synth sound out of it...but it's perfect for those mid 80's Pino fretless slides. It tracks ok...but not as well as my MXR BOD.
    The compressor is good, a nice simple one knob comp...but curiously the manual says that it's designed specifically to not increase the gain as the compression increases...well with my copy of this amp it certainly does increase grain a LOT.


    The 5 band EQ is great, really easy to use and good choices of frequency spots. I do miss my 7 band graphic...after 20's hard to change. So I might look up a MXR 10 band and pop it in the send and retun loop. What more can I's small and very light. It looks great and I love the VU meter. It's easy to get some great tones out of it...although it's easier to get heavy rock out of it than the trad pop / funk TE 80's tones. The mid shape EQ button does help a lot in that regard. I think there's a little bit of a baked in EQ which has been dialled at the factory. It's quite nice, but I think the 10 band graphic and a signal generator will help me dial in a truly flat EQ tone. The the way is appalling...filled with copy and paste errors.
    If money was no object, I probably would have gone for the new Ashdown Retroglide 800 or the slightly harder to find ABM 1000 class D. But I'm confined to a limited budget at the moment and hence my current choice. It's a great amp, I paid only £220 UKP for it...which quite frankly is a steal. I'm hoping that it'll service my bass playing needs for a long time to come.

    After having my old TE repaired and comparing them both..the TE seems to require a lot less input gain. The Ashdown wants a hot input and the input gain up really high. As it gets higher, the old TE tone is more apparent, at lower gain it's quite dark and woolly sounding. The bottom end of the Ashdown is tighter but it's more than capable kicking bass butt. Is it a true 400w amp? I would say easily keeps up with my TE and seems to be able to drive my two cabs to similar sound levels. I would say it's loud and as powerful as Trace 400 watts.
    Price Paid:
    UKP £220
    One member found this helpful.
    J709, Bigoo7e and bassestkkm like this.

Head Details

  1. Power:
    78mm x 313mm x 225mm
    Single jack, plus line in and send / return loops
    Combined Speakon / jack connector
    EQ / Controls:
    5 band eq, rotary. 100hz / 220hz / 660hz / 1.6khz / 7Khz
    £600 UKP
    GMC · Jan 6, 2016 · Updated Aug 13, 2016

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