Since around 1978, Ritchie Blackmore has been running a small passive circuit inside his Stratocasters that nobody could fully explain. It wasn't a pedal. It wasn't a pickup swap. It was something he called his Master Tone Circuit — a filter box, hand-wired, tucked under the pickguard where nobody would find it. It shaped the low end tighter when he rolled back his volume, and added a mid-filter that made his tone go sweet and chiming instead of muddy at lower volume settings. Deep Purple sounds like that partly because of this thing.

In 2013, a German engineer named Bernd Meiser from BSM finally cracked it. He studied four original 1970s MTC units and reverse-engineered the circuit. In 2017, he released what he called the BSM "Spice Box" — a faithful replica, point-to-point wired, no PCBs, sized at 2¼" × 1½" × ½" so it fits under the tone pots of a standard Stratocaster. He built every unit himself, by hand, made to order.

Bernd Meiser died in July 2024 after a yearlong battle with cancer. When he died, there were no units in stock. The Spice Box died with him.

Now It's Back

Singlecoil Guitars — the company that worked with Meiser on the original analysis and research of the MTC back in 2013 — has relaunched production. The announcement came in March 2026, confirmed by Premier Guitar.

The circuit inside is identical. Same point-to-point construction, no PCBs, using parts from Meiser's own legacy stock wherever possible. Singlecoil went one step further on tolerances: 1% capacitors and 0.1% resistors, which means every unit now performs identically — something Meiser's made-to-order approach couldn't fully guarantee. They've also kept his original instruction paper, including his hand-drawn wiring diagram. The thing is renamed the "Singlecoil Spice Box … à la Bernd." The pricing comes in slightly below the original: $172 USD / €149 plus shipping.

It's passive, not active. There's no battery. No signal chain intrusion in the conventional sense. It replaces your existing tone circuit and does its work inside the guitar, before the signal ever leaves the pickup cavity. If you've ever wondered why Blackmore's live tone has that particular clarity even at rolled-back volume — that's this. Or a very close relative of it.

Who This Actually Matters To

If you're chasing sparkly strat tones and you find that rolling back your volume kills the high end in a way you hate, a treble bleed might solve your problem. The Spice Box is a treble bleed with a mid-filter bolted on — more sophisticated, more expensive, more boutique. It's a very specific product for a very specific player. But Ritchie Blackmore is a very specific player, and if you've ever sat with a Strat and wondered why your tone goes foggy where his stays focused, now you know where to look.

For everything else that shapes how your Strat sounds before you even touch the amp, your pick has more to do with your tone than most players realize. And if you want to understand how a small gear change can have an outsized effect on a legendary sound, the story of Mike Bloomfield's Telecaster and what it meant at Newport 1965 is worth your time.

The Spice Box is available from Singlecoil Guitars at treblebooster.net. Handcrafted. Limited only by how fast they can build them.