Seymour Duncan Unleashes 70's/80's Half-Stack Inspired Chewy Harmonics High Gain Diamondhead Multistage Distortion + Boost

By all accounts a rather fabulous and timely pedal, in a great form factor, yet a couple of things have me a touch peeved from the outset. One fairly minor, while the other is likely a lot more significant. On the minor side - I always get somewhat annoyed when builders are overly opaque about the mechanics of their pedals. Seymour Duncan does not mention what manner of technology generates the tone, while one would guesstimate OpAmp as the likeliest source - I am one of those who likes to know the nature of what I work with. The pedal is also billed as ’Multistage’ but we’re not given any details on how many cascaded stages there are here, nor exactly how the 3 obvious gain stages - Saturation, Distortion and Boost interact. I can only infer that the 805-circuit-based ’SAT’ (Saturation) switch would be a pre-gain boost in the usual Tube-Screamer style role, meaning the BOOST footswitch would likely be post - although when the BOOST is cranked you very much get a degree of gain boost too - so it would have been nice to have had some further details on the general circuit flow/mechanics here and the degree of gain-staging. More significantly though and from what I can see - the pedal is being introduced into the American market at a very reasonable opening offer discount of $229 (c£180), while it’s on sale in the UK at Andertons for £300 - or nearly twice what the Americans will pay. I’m not disputing the quality of the pedal - but obviously price does play a key factor in acquisition strategies and £120 is a very significant margin of difference! UPDATE! UK Pricing has now been adjusted to £249 which is an improvement, but there’s still £70 difference between countries.

As for the output of said pedal, it’s exactly the sort of thing I gravitate towards - nay love even. Very obviously based on the late 70’s / early 80’s Marshall JMP/JCM 4x12 Half-Stacks - and with those unmistakable Chewy Harmonic Mids which have made the Marshall sound so well loved for so long. The +/- 13dB 3-Band Active EQ and +15dB Boost give you an enormous range as it is, but then you have the additional ’SAT’ switch which engages a Tube-Screamer style boost circuit based on Seymour Duncan’s own 805 pedal. For some metal-heads this may not be as modern and tight a pedal as they like - it’s obviously engineered more for those saturated 80’s style sounds. I would says there was a degree of equivalency here to the Bogner Ecstasy Red - but each pedal has its own pros and cons - and the Diamondhead certainly wins on the ease of use stakes - it also has that interesting triple gain-staging which obviously the Bogner does not.