Soundgas Type 636 Preamp Series Update: Complete Guide to Design, Build, and Availability

The Evolution of the Grampian Type 636 Circuit

What began as our enhanced and improved Type 636 Spring Reverb has grown into the complete Soundgas Type 636 germanium preamp family. The range delivers the warmth, texture and character of this unusual vintage germanium circuit combined with reliability and performance for today’s studio users.

The original Grampian Type 636, famously used and abused by Lee 'Scratch' Perry and Pete Townshend (who used the mic preamp to create his signature guitar fuzz/distortion with The Who), was the original basis for our circuits. Our design offers a significantly lower noise floor, improved bass response and greater overall reliability compared to the vintage 636 while still maintaining its distinctive sonic character.

Ever since Dr Huw designed the first Soundgas Type 636 Spring Reverbs in 2018/19, we’ve built our units in short runs, evolving and finessing the design and build processes with each new iteration - and of course always listening to our customers’ feedback to make incremental improvements wherever possible. Always learning is our mantra. I have been using the 636 circuit for decades - I still own two original (and very different) Grampian 636s - and can say without any doubt that today’s units are the very best we have produced. They represent the pinnacle of our collective knowledge and experience and our deep understanding of and love for this incredible and idiosyncratic circuit..

Three Preamp Formats: Type 636P, 636P2, and 636P-500

Soundgas Type 636P2 Twin Germanium Mic Preamp - The Studio Flagship

£2,450 ex.VAT (instalment options available)

The Type 636P2 represents the ultimate incarnation of our celebrated germanium preamp circuit. This twin-channel rackmount analogue preamp features Carnhill transformer balanced outputs, transforming the original's raw character into something that can handle everything from subtle mix sweetening to maximum sonic annihilation. 

The P2 was born of an early Type 636P customer attempting to parallel mix with his, but as the output is out of phase (as on the original Grampians) he was not having much joy! I asked Dr Huw how we could rectify this and he suggested we use an output transformer - and the rest is history. We (and our customers) soon found the nuances brought via the extra iron to be utterly beguiling and wonderful, elevating 636 preamp into new territory far beyond its original MO. Today I almost always employ my P2s for subtle enhancement and colouration rather than all-out distortion/drive. The 636 preamp has grown up (though can still behave like an unruly toddler when pushed). 

"This modern take on a vintage germanium preamp offers bucketloads of character," notes Sound on Sound editor Sam Inglis in his recent review. The addition of those big red Carnhill transformers doesn't just add versatility - it opens up an entirely new sonic palette. At higher gain settings, they smooth out some of the wildness while maintaining the enhanced harmonically rich character that’s causing producers and mix engineers to want to use theirs on everything from string sections to drums, synths, guitars and even whole mixes.

View the Type 636P2 specifications and order →

What Our Customers Say:

"This thing is incredible. Bravo Soundgas" - Ben Baptie (Little Simz, Sault, Moses Sumney, The Strokes)

"Just had to let you know - I put it in the rack immediately, ran some drums through it, VERY BIG smile straight away!" - Leo Abrahams (Brian Eno, Katie Melua, Paolo Nutini, Karl Hyde)

"...what I can't live without any more is the 636P2! Recording almost every synth through it these days...your 636s are a big part of my sound now." - Frank Wiedeman (Innervisions/Âme)

Current lead time: 1-2 weeks due to high demand

Soundgas Type 636P Guitar Preamp Pedal - The Original Desktop Format

£1,295 Preorder (deposit option of £500 available)

The original desktop/pedal preamp version of the Type 636 Spring Reverb. No corners cut, all the ragged, filthy glory of the original Grampian preamp in a portable format. Whether you're a guitarist looking for the ultimate in tone and drive or a producer wanting portable germanium preamp magic, the 636P delivers. 

We had intended to mothball the 636P after the first half of 2025 in favour of a new pedal, but the latest iteration of the 636P is proving so popular we’ve extended production for another run. Whether we will continue to build these into 2026 will depend on a range of factors (we are a small team with limited resources and new designs are in development), however, for the moment you can preorder for the autumn build which are selling out fast.

See the Type 636P preorder options →

Artist Testimonials:

"The 636 is a beast used it all over the new FDC album. My favourite overdrive ever!" - Carlos O'Connell (Fontaines D.C.)

"I think you've really got something special with the 636s… going to be all over my recordings!! Many thanks" - Ed O'Brien (EOB/Radiohead)

"Still the best // purest distortion I've ever heard" - Mason Stoops

"This is the sound I have been looking for my whole life. Thank you." - Andrew Bennett

Currently only available as preorder for Autumn 2025 build - limited numbers remaining.

Soundgas Type 636P-500 Series Germanium Preamp - The Compact Studio Solution

Starting from £830 

We've brought the 636P2's transformer-balanced germanium magic to the popular 500 series preamp format to put within wider reach for today’s engineers and musicians. While the lunchbox format is more budget-friendly, we’ve not cut any corners and you can use the 636P-500 exactly like a 636P guitar pedal (by using the front panel sockets) - the circuit is identical to the 636P guitar preamp when used in this way. 

While we couldn't squeeze those big red Carnhill transformers into this format, the ones we use are sonically very close; you get transformer balanced inputs/outputs and phantom power for recording with condenser microphones.

The vintage germanium components used mean each analogue preamp unit has its own character and response, making every 636P slightly unique. For stereo applications, we match pairs as closely as possible to ensure more cohesive performance - a time consuming process (and even then with so many variables users will still have to adjust by ear/meter). 

Learn more about the 636P-500 series preamp →

Current shipping estimate: June*-July 2025 (*limited June units remaining)

Soundgas Type 636 Taking Over Studios Worldwide

Recent coverage has only added to the legend of the Soundgas 636 series which has played a vital role in modern music production. Carlos O'Connell told Premier Guitar that the Type 636P is his "secret weapon" for his guitar and studio recordings and has become essential to his sound for Fontaines D.C.

Users consistently comment about its versatility across different sources and how even the most subtle use can add excitement and texture to your recordings.

As recent customer Andrew White noted in his review: 

"This isn't the most flexible preamp you'll ever use... But, there will be a myriad of occasions where this plain looking little box will add so much magic and sparkle to your recordings that you'll be unable to stop smiling for a week."

Design Philosophy: No Compromise

Every 636 series product is designed and built in our Derbyshire workshop with an unwavering commitment to the original's spirit. There’s no DSP or tone sucking at play here and we only use the best vintage components where it counts to deliver pure analogue germanium-driven character. 

The circuit builds on years of research into the original vintage units and our collective obsession with the sound of germanium saturation. We've addressed the noise and reliability issues that plagued originals while maintaining - and improving on - every ounce of character with increased bass response as demanded by today’s users. All our 636 preamps are carefully manufactured and calibrated in limited runs by our dedicated team of techs, ensuring consistent quality and optimal performance. Yet because of the vintage transistors, each unit has a subtly different character just waiting to be unleashed on your music!

Media Coverage and Industry Recognition

The 636 series has garnered some notable attention across the industry:

• Sound on Sound: Comprehensive 636P2 review praising the "bucketloads of character"

• That Pedal Show: Dan and Mick's enthusiastic reaction to the 636P

• Premier Guitar: Featured in Fontaines D.C. Rig Rundown

• Ed O’Brien: Radiohead Pedalboard Build 2023 With Gigrig’s Daniel Steinhardt

• Guitar World: Recent coverage of Carlos O'Connell's endorsement

Recent Customer Feedback

"Game changer - Like a Pultec EQP1A, this is a real game changer unit like you wanna run every tracks into it. The sound becomes way much warmer and present so easily." - Remi Sauzedde (June 2025)

"The missing link - couldn't be happier with it, it sounds incredible and adds enormous flexibility to my recording chain. Absolutely love it." - Christoph Bauschinger

Availability and Ordering

Due to the handcrafted nature and vintage component sourcing, availability varies by model:

• 636P2: 1-2 week lead time, available now

• 636P-500: Shipping June-July 2025

• 636P: Preorder open for Autumn 2025 build

All exports are ex-VAT worldwide, with VAT included at checkout for UK customers.

Which 636 Should You Choose?

For Studios and Mix Processing: The 636P2 offers maximum versatility with its transformer-balanced outputs and twin-channel operation.

For Guitarists and Live Use: The 636P pedal provides the pure, unfiltered 636 experience in a convenient and compact grab-and-go format.

For budget/space conscious musicians: The 636P-500 delivers the same character in a space-efficient format.

See Tony’s quick video comparison

The Final Word

The Type 636 series builds on the original Grampian circuit design while addressing the noise and reliability issues of vintage units. Each product is designed and built in our Derbyshire workshop using this legendary germanium-based circuit across all three formats.

We are, as always, indebted to the brilliant senior techs responsible for the design and build of the Soundgas Type 636 series: ‘Dr’ Huw Williams, Max Dawson, and Ryan Hingley with special mention to Steve Lenham for refining our original circuits for greater consistency and clarity.  

Visit our collections page to explore the full range and secure your piece of this legendary lineage.

Follow us on Instagram @soundgasltd for gear demos videos, studio features, and behind-the-scenes content from our Derbyshire workshop.