Marco De Virgiliis' Markbass company has established quite a reputation among bassists – and acoustic players too. This combo comes from DV Mark's new line of all-valve guitar amps, inspired by Virgiliis' friendship and collaboration with the late Hiram Bullock.
The DV40 212 contains two DV Mark Custom 12" B&C neo speakers with 300W power handling. This is plenty, because the DV40 is rated at 40W, with a pair of EL34s fed by an ECC83 splitter handling power amp duties. In the front end are two ECC83s. Since these are all double triodes, Channel 1 passes through three amplification stages and the fourth triode stage is added to the signal path post-EQ, when Ch2 is selected. Although the channels share the same passive tone controls – Bass, Middle, High and Presence – Ch1 has its own Gain and Master controls while Ch2 has Drive and Master.
The two inputs are labelled Hi Z and Low Z. Hi Z is for guitars with regular passive pickups; guitars with high output active pickups should be connected to Low Z, with its 6dB pad to maintain clean headroom. A Norm/Bright switch: boosts upper treble frequencies for added sparkle or compensates for any perceived loss of brightness at low volume levels.
The Pre Out and Amp In sockets are for the effects loop, with preset operating levels to match most line-level FX. The FSW socket connects the DV40's dual footswitch; this provides easy channel switching, and activates a 6dB boost for Solo mode along with an accompanying red LED. Unfortunately, there are no LEDs on the footswitch itself.
The amp section with all the valves and transformers is located at the bottom of the cab and the control section is connected to the power amp by a long ribbon strip of wires. This separation of the controls and amp is something you might associate with very early valve guitar amps. A panel at the rear provides three speaker connections labelled 4, 8 and 16 Ohms, and the Tube Mode switch enables the DV40 to operate in Pentode or Triode mode. Triode mode drops the power from 40W to 15W, so you can choose between maximum clean headroom and volume or quicker power amp breakup for earlier cranked up tone at gigs.
A Bias switch toggles the DV40 between High and Low Bias. For best power, fidelity and tone quality the manual recommends you use High Bias, but if you want to reduce your electricity bill and prolong the life of the valves when noodling at home, then try Low Bias.
The rear panel has a Service connection that looks like an Ethernet socket. This is DV Mark's ATCS (Advanced Tube Control System) interface, allowing users or techs to connect this port to a PC/Mac. Once the software and interface become available, bias current, anode and power supply voltages and other data may be collected for DIY diagnostics.
In addition to Master Volume controls on both channels and Pentode/Triode switching, the DV40 has another level management feature – CPC or Continuous Power Control. In Pentode mode this ramps the power down from 40W Class AB to 1W Class A, and in Triode mode it drops from 15W Class AB to 1/2W Class A. DV Mark has a patent pending on this feature, but it seems not unlike the power scaling we've seen on 65 and Lazy J amps.
Switch on, and once the red power LED has stopped flashing you can flip the Standby. There's an impressive light show inside the cabinet, with orange LEDs that make the valves look as if they're smouldering.
Calling Ch1 'clean' isn't quite accurate: it has more clean headroom than Ch2, but we've played a fair few 40W amps with more clean headroom than this. With Master maxed, things stay clean with Gain below the second marker so long as you're using vintage-spec F-type single coils.
The tone is thick and juicy with a touch of compression that greatly enhances the playing experience. The reverb integrates well, from a subtle hint to a full-blown wash. Although the EQ controls are effetive, the DV40's inherent tone is always apparent. It's a very good tone, somewhere between an old 50W Marshall and a blackface Fender... extremely clear without being edgy or bright, and the characters of all our usual test guitars shone through with lovely singing sustain.
In reality this isn't a two-channel amp – it's a one-channel amp with an extra valve gain stage that you can switch in and out. Since the EQ and the signal path remain much the same we weren't expecting a Jekyll and Hyde personality, but there's a shift in frequency response that might have something to do with the way the extra valve stage is configured. The upper mids are brought forward, giving Ch2 a more aggressive rock voice with more bite but less bass and low mids. There's no clean headroom at all, and the Gain control quickly pushes Ch2 into heavy overdrive then crunch.
The shared EQ means that compromise might be required if you like bright clean tones but dark, smooth overdrive. The tonal diffrences between the channels is less apparent when the continuous power control is used. This contains the level without changing the tone or, more importantly, the dynamic feel – so it's quite different from a master volume.
This amp has a great sound and is very enjoyable to play, but the effect of some of its features is so subtle, you might think them barely worth having. The contrast between the harder and punchier pentode setting and the browner triode setting is noticeable and useful, but the Bias switch is a bit superfluous; solo mode is a bit underwhelming; and we'll have to reserve judgment on the Service port. On balance, having the Norm/Bright switch active on Channel 1 alone might have made it easier to optimise the tone for both channels. We like the leather handle and corner protectors; time will tell if they're up to the job. The DV40 certainly sounds like the expensive amplifier that it is, but it isn't especially versatile and it somehow doesn't inspire quite the same degree of confidence as some other amplifiers in its price range.