Ashdown Rootmaster-500-EVO Lightweight 500w Head


Ashdown's range of Rootmaster amplifiers are well known for being high quality, lightweight bass amps made for the gigging player. Now Ashdown are improving these amps even further with more power, lighter weight and more tone options in the Rootmaster Evo series. The RM-500-Evo is a 500w amplifier that is perfect for everything up to mid sized gigs.

Lighter Weight

While the previous generation of Rootmaster amps sounded amazing they were a little bit heavier than what some players wanted. With the EVO's new more powerful power amp section and a new lighterweight design on the cabs you can expect your rig to be 35% lighter than the previous Rootmaster rig. Same great more back pain. This model weighs only 4kg.

Dual Inputs

Changing between active and passive basses can be a bit of a pain. Mainly because the input level is so different instrument to instrument that if you forget while on stage you may have no level or all of a sudden become way too loud. The EVO now has dual inputs so you just need to change the input to be attenuated to the right level at a moment's notice.

Powerful EQ

Ashdown have always been known for their EQ circuits and the one on this little head is incredible. With 5 bands covering bass, middle and high as well as specific 240Hz and 1k5Hz controls you have a huge range of sounds at your hands. Not to mention that by flicking in the Shape switch you can transform the tone from the Rootmaster to a classic ABM style Ashdown tone.

Tone Shaping Options

If having all of those EQ options was enough this amp also has high quality, single knob compression built in. You even have built in overdrive and sub controls letting you really shape the tone to your liking. This really is the king amp for the player who wants to dive between a bunch of different sounds without having to change amps or carrying a massive pedalboard.

Here's what Ashdown say about the RM-500 Head

Now in its second evolution is the RM-500. The 500-watt power section of the RM500 EVO has been developed to maintain a deep low end, defined mids and transient highs delivering its output into a 4-ohm load. Ashdown Rootmaster heads are the perfect choice for working bassists looking for power and features without the weight.

The Rootmaster EVO series' pre amp now includes a passive and active input jack socket for use with high and low output instruments, this sets a clear signal path to the input control enabling you to fine tune your input level using the trademark Ashdown VU meter. With the signal at its optimal level, you then hit the rich features designed enhance your tone, such as the shape button, 5-band EQ and on-board compressor. The drive control, as always delivers a delectable valve emulated over-drive, whilst the sub harmonic controls add further fatness to your tone - both can be foot-switched via an FS 2 footswitch (sold separately).

Rootmaster EVO heads also feature an upgraded power section plus a handy mute button. What's even cooler is when switched to mute, the trademark Ashdown Engineering VU meter changes from orange to cool blue - creating the perfect on stage mood lighting between sets.

Simple, powerful EQ
The Rootmaster EVO series' pre amp now includes a passive and active input jack socket for use with high and low output instruments. The five- band rotary tone controls act with surgical precision to provide total control over your sound, while a shape switch instantly dials you in to a classic Ashdown tone setting, straight from the world-famous ABM.

One-knob Compression
Instantly adding warmth and body to your tone, this simple to use, great sounding compressor delivers a powerful, even sound to make sure your bass will fill out any mix.

Footswitchable variable overdrive
With footswitchable flexibility, our tube-emulated overdrive can take your core bass sound and push it into warm overdrive through to distorted filth whenever you need to add extra grind and girth to your tone.

Kick it down
Bringing extra depth and definition to your bass parts, the Sub-Harmonic Generator lets you dial in a sub-octave and kick it in via footswitch whenever you need the extra depth for those super-heavy Godzilla moments.

Totally connected
If you want to use your favourite pedals or multi-effects, you'll find send and return sockets on the back panel, along with a DI output for direct injection into the PA mixer or recording console and a Line Input (with front panel level control) so you can jam along with a backing track in rehearsal.

Create the perfect rig
A combined Jack/Speakon socket with a minimum 4 ohm load provides flexible partnering options with a dedicated range of Rootmaster EVO cabinets. Ashdown's 1 x 12", 1 x 15", 2 x 10", 4 x 10" and 6 x 10" cabs all feature Ashdown White Line speakers for a refined tone, plus a high- frequency 3-way controllable tweeter for additional top-end bite.


  • Power Output:  500 Watts
  • Power Handling:  115 - 230 Volts
  • Speaker Outputs:  2 x Speakon
  • Frequency Response:  -3dB at 17Hz and 30kHz
  • High Instrument Input:  Impedance 3.9m Ohms, input range 150mV - 20mV p-p
  • Low Instrument Input:  Impedance - 1M ohms Input range 150mv to 10v p - p
  • Line Input:  Impedance 10k Ohms, input range 300mV - 40V p-p
  • DI Output:  600 Ohm balanced / Level -20dBu nominal
  • Tuner Output:  Impedance 22k Ohms / Level 0dBu nominal
  • Impedance:  Minimum 4 Ohm
  • Signal to noise:  Better than 80dB (EQ flat)
  • EQ:  Bass +/-15dB @ 100Hz Lo Mid +/-15dB @ 220Hz Middle +/-15dB @ 660Hz Hi Mid +/-15dB @ 1.6kHz Treble +/-15dB @ 7kHz shelving Deep +
  • Effects Send:  impedance 22k Ohm / Level 0dBu nominal
  • Effects Return:  impedance 22k Ohm / Level 0dBu nominal
  • Distortion:  Less than 0.5% THD
  • H x W x D (mm):  78 x 313 x 225
  • Weight (kg):  4kg
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