*Soundgas Type 636P 2 - Twin Grampian 636 Preamp

Ten entirely handbuilt examples of our latest transformer balanced twin channel 636 design. 

Select Currency

PRICE: £2,450.00 EX VAT (£2,940.00 INC VAT)



Entirely hand built ‘prototype’ of the latest incarnation of our Grampian 636 circuit: twin channel Type 636 mic preamp with Carnhill transformer balanced output option for greater versatility and extended sonic palette.

Preorders now open for the second run of ten hand built units. Build commencing Sept 2022 with delivery late October.


*Update – new transformer balanced output now incorporated into the design/pricing – twin Carnhill transformers give a different flavour (original unbalanced output still available for maximum filth). Brings the 636P2 into contention for more subtle bus or mix sweetening in addition to more full on gnarl. The unit pictured is our latest prototype – we are building a limited run to this specification.

What is it? The 636P2 has evolved from the Soundgas Type 636 and desktop Type 636P which both feature our evolution of same hairy mic preamp circuit as the original Grampian Type 636. However, with the 636P2 you get far more than just two 636Ps in a rack. The addition of Carnhill transformer balanced outputs massively increases versatility and offers a wider sonic palette: we’ve noticed a subtle sweetening and widening of audio signals passing through with very little gain applied.

At higher gain settings the transformers smooth out some of the wildness of the 636 to deliver a classy – yet still harmonically rich – sound. We have been blown away by how different these sound with the balanced outputs, and by how much we want to use it on everything. And if you want the full original 636 preamp magic, untamed by those beautiful red transformers? Simple – just plug into the 1/4″ jack ‘punch out’ socket – this bypasses the transformer circuit and gives you that hairy (out of phase) direct output as found on the 636 and 636P.

Based on the Grampian Type 636 – famously used and abused by Lee ‘Scratch’ Perry and Pete Townshend – and many others since. This circuit is designed and built absolutely in the spirit of the original vintage units – no surface mount components or tone sapping DSP. Everything entirely handbuilt from scratch in our workshops in Crich, England. Even the circuitboards are hand etched. In an era of mass production, these builds are a throwback to a bygone era when small manufacturers made everything themselves.

This is a labour of love and represents the culmination of our collective experience of – and love for – the 636 circuit. It is not the modern way: the expense of working like this means these particular units are not for everyone, but this does mean we are able to control every aspect of the process and build something of which we are all justifiably very proud. The time and outlay just to source and test NOS transistors that perform to our specification is slightly terrifying: the vast majority of OC45s we have found do not meet our criteria.

Can I hear it? Very soon! We have literally just finished building the production prototypes and testing is underway. There will be demos coming very soon. Currently there are only demos of the original 636P2 build (which was literally two 636Ps in a rack case – no transformer balanced outputs). Take it from us: if you like the 636 circuit, this gives you two channels plus something very special indeed with the transformer output option. Scroll down for many links to the desktop version in action. What you are hearing is the rawness of the mic preamp circuit without the transformer balanced option.

What is this “Prototype”? The photos are our production prototype: two boards from our Type 636P inside a 1U rack case with added Carnhill transformer balanced outputs. The two sides are independent circuits using a common power supply (on a standard IEC socket, internally switchable voltage). Each channel has a 1/4″ jack input, input level control pot (gain), Grampian specification mic transformer, overload lamp and input impedance switch (select between guitar/line use, or adjust to taste).

Staying true to the original Grampian 636 design, the mic preamp ‘punch out’ output is unbalanced on a ¼” jack socket and is out of phase – plugging into this output will disable the XLR outputs on the rear.

What you receive will may differ from the photos in the following ways:

  1. There will be a face plate that matches the 636 family design.
  2. The knobs may be different.
  3. It will have a serial plate.

As with our original 636s, we have put tonal considerations ahead of all else. I was originally skeptical that we’d see a real benefit in using germanium transistors in the buffer section: all our original prototypes had used silicon and sounded great. However Ben and Dr Huw insisted that we build an all germanium version for comparison which blew all the earlier versions out of the water; this became the 636P which has now evolved into the 636P2.

More info on the build of the original Type 636P including photos and demos.

To anyone reading this who has seen much cheaper versions for sale claiming they feature the Grampian ‘preamp circuit taken note for note’ we can categorically confirm that, while these units may be interesting in their own right, the circuit is certainly not an accurate recreation of the Type 636, nor do they sound at all close to either an original Grampian, or the Soundgas units. You do get what you pay for. The mic transformer (one element of our design process that took a considerable amount of R&D to perfect) is not the correct value, and the circuit design means the Russian germanium transistors utilised in this design are not actually being driven in any meaningful way. The overdrive/distortion these units produce is not the harmonically rich germanium distortion that is the signature sound of a Grampian Type 636. We have already spent a good deal of time researching whether we could build a modern unit at a much lower price point by redesigning the original circuitry but so far sonically it simply does not stack up.

And if you have seen a certain guitar pedal that claims to recreate the sound of the Grampian Type 636 aux circuit as used by Pete Townshend of The Who, we can confirm that what this digital processor actually does is create a slightly boosted signal with none of the harmonic richness of the mic preamp circuitry (which is what Pete actually used)…


Brand new item. See notes above on how the prototypes will differ from the unit pictured.


For sales in UK the price will include 20% VAT. Buyers elsewhere may incur VAT or other local taxes on import.

Voltage Information

Will be set up for either 120 or 240v operation before shipping.

Prototype 636P2 in action - early version without Carnhills!


*Soundgas Type 636P 2 – Twin Grampian 636 Preamp

Gear Info

Soundgas News

Soundgas Type 636 & 636P Update

We plan to build a short run of pre-production 636Ps to ship in early 2022 and then take a break while we build the final Soundgas...

PUBLISHED: 21st Dec 2021

*Soundgas Type 636P 2 – Twin Grampian 636 Preamp

Gear Info

Soundgas News

Incoming! The Soundgas Type 636P (it’s not a pedal…)

Say hello to the prototype Type 636P: all the heft and magic of the our 636 mic preamp in a compact desktop box.

PUBLISHED: 10th Aug 2021

*Soundgas Type 636P 2 – Twin Grampian 636 Preamp

Gear feature

Gear History

Grampian Type 636 – Believe the hype…

Grampians: some history and technical information about these superb, legendary machines. If you are looking to buy a Grampian or have one to sell in any...

PUBLISHED: 30th Jun 2016

*Soundgas Type 636P 2 – Twin Grampian 636 Preamp

Gear Info

Soundgas News

Grampian & Soundgas Type 636 Q & A Session

Video from the Q&A session we did on the Grampian and Soundgas Type 636 units, plus an update on the Soundgas 636 build. Also Jane Weaver!

PUBLISHED: 29th Oct 2019

*Soundgas Type 636P 2 – Twin Grampian 636 Preamp

Gear feature

(Re)Building the Ark – Grampian Type 636 News…

We now have the first working prototype of what will be known as the Soundgas Type 636. A faithful recreation/re-imagining of the original Grampian Type 636,...

PUBLISHED: 24th Apr 2019

*Soundgas Type 636P 2 – Twin Grampian 636 Preamp


Gear Info

Soundgas News

Soundgas (Grampian) Type 636 Update

Some news on progress with preorders for the Soundgas Type 636. It's an updated, studio-ready clone of the original Grampian Type 636 reverb unit.

PUBLISHED: 26th Jun 2019



"Just received my Roland RS 505 Paraphonic! Thanks so much - arrived very promptly, well packaged, in great condition and sounds amazing! Best seller."

Koko Hiras

Grabbed a Roland RE-201 (early edition killer pre-amp) and Roland DC-50. Absolutely STUNNING. These guys truly live up to the hype. They are meticulous in caring for the gear. Also, I have a few guitar pedal and plug-in emulations of tape-echo sounds and after plugging in the real unit I can't tell you how insane the difference is. It is incredible. Especially that tone from the early pre-amp! I am totally amazed. I am in heaven :) They made it safely to Nashville from the UK and were packed really really well! Thank you so much!! Worth every penny.

Chance Allen

"808 is up and running. It’s hard to stop playing it. Like even to eat. Extending testing is quality control and the quality of your stuff combined with customer service is one of the reasons Soundgas is so successful in my opinion."

Brett R

"When you are spending big money of vintage gear it's nice to have the confidence of impeccable service, sales and support... some of the best in the industry! Impeccable people, incredible equipment… my poor poor fiancé"

James DLR - Sofa Sound/Metalheadz

“I’ve bought a number of items from Soundgas recently, and have been really impressed with their service. It takes the stress out of buying vintage gear to know it’s been properly (and faithfully) serviced or restored. Their after-sales service has also been exemplary. Highly recommended.”

David Wrench

“Imagine the perfect eBay.... with everything you never knew you wanted… and you can rest assured that your vintage and rare wobbly sound device will turn up on time and in one piece and possibly in even better condition that when it left the workshop. Soundgas - literally amazing."

Josh Lloyd-Watson & Tom McFarland - Jungle

“If not a new language, then at least a very challenging, old dialect that will take me some time to assimilate. I’ve been waiting a long time for the challenge. Thank you @soundgasltd, she’s a beaut...and nobody prepares and packs like you fine folks.”

Justin Meldal-Johnsen

"Still in shock! Can not believe how good the seller is. This product was inspected, and shipped from the UK to the USA quicker than orders from my home state. Highly recommend these guys."

Thomas Tedesco

“The Space Echo made its way to me - it looks and sounds beyond dreams, thanks guys for your great service and communication.”

Julius Bonson

“The perfect place to hear, learn about and then buy your most wanted piece of vintage music gear! I've not only managed to buy a rare piece of equipment I really wanted, but I have the guarantee it's been serviced, and I got it from people who are clearly passionate and knowledgeable about what they do, as well as super friendly and responsive by email. Thoroughly recommended!”

Colleen / Cécile Schott

"Excellent equipment, wonderful service. I fully recommend Soundgas to anyone in the vintage gear market and I will definitely be a return customer. The gear itself was exactly as advertised and in great condition."

Hallam Kite

"Packed with love and care. A stampede couldn't have crushed this thing. Works great and sounds like a dream. I love you Soundgas."

Ben Van Vlissingen

“If you are a vintage audio gear head then this is the place you have been looking for all your life. Pretty much any piece of classic or obscure kit that you are after is available here... But the clincher for me is that the gear they sell has been restored by their top techs (unless otherwise noted) which is really very important when dealing with, for example, synths from 30 years ago.”

Lincoln Barrett / High Contrast

"Finally, a company that tracks down all those brilliant curiosities that bring so much character and personality to a studio."

Matthew Herbert

"Engaging with old gear can sometimes be filled with a lot of uncertainty, and I can't imagine what more could be done to reduce this aspect of it on top of the service you provide. Really phenomenal and I couldn't be happier."

Stephen Voinea

"Yes, sure, you can find a Space Echo on eBay, but you won’t find one like this — that’s certain. I am so pleased with my decision to buy from Soundgas, and suggest you stop your search now and just send them a message. You will undoubtedly find yourself writing an ecstatic review about yours in short time."

Ben Evolo

“I have bought two Moog synths from Soundgas over the past year, and I cannot say enough wonderful things about their selection of vintage products, the level of service, diligent responses to email, and expedient shipping with copious protective packaging. Soundgas is an impressive operation. My synths also sound amazing! These folks have made my vintage keyboard dreams come true in short order!”

J Yates

Purchased a Juno-60 and it works beautifully. Having gotten one teched before, I knew it was worth paying a premium to get it future proofed and Soundgas does just that. Shipped professionally from the UK to USA. Appreciate their expertise and professional demeanor!

Eric Cullen

As good as it gets. Tony, Dec and team have been incredible, prompt communication, great advice and outstanding service. It really felt like my Polysix came from a loving home.

Ben Parm

"Soundgas provided the absolutely top service in terms of item quality as well as service and communication. Shipping was fast, packing was top notch. These people deserve the best reputation they already have. Many many thanks, guys."

Dupille Luc

"The packing job to get it over to the US was superb, and the sound and performance of my Space Echo exceeds all of my expectations. I hope to do business with Soundgas again in the future. Many thanks!”

Rhett Daily

Fantastic. From initial contact to the product landing at my door the service provided was outstanding. Safe and secure shipping, quality serviced product.

Tom Johnston

Just wanted to say thank you so much for your pinch roller and echo tape. I've had a space echo for years, been sent to a shop in NYC and it never worked quite right. After installing the roller and tape, my echo works like a dream. Really incredible expertise you all have! Thank you.

Andrew Potter

"DREAM. COME. TRUE. My music has taken me around the world a few times...and if you are like me and absolutely adore vintage gear...Soundgas is the stuff of LEGENDS. It's the shop that people like us search for our whole lives- fantastic and rare selections, and the technical know-how to repair and or mod these vintage items to get them into shape to flow with your modern setup."

Tom Gossin

“I purchased a completely overhauled vintage valve Binson Echorec 2 T7E modified with varispeed, wet-only output, and a new paint job from Soundgas in early 2018. Tony and his team did an amazing job during every step of the purchase”

Matt Morton

"Soundgas offer a great service, sourcing esoteric gear that works great."

Tom Rowlands - Chemical Brothers

I have been buying vintage stuff for a long time from resellers/stores/techs. I've never been so surprised and pleased after opening! Just received a Roland RE-201 and VX55 mixer, they look and sound amazing! Thanks to Tony/Declan for the service and the Soundgas team will be back!

Dong Yun Seok

"Soundgas has an unbelievable selection of the cool, old stuff that’s hard to find. Tony knows his stuff and goes out of his way to make sure the transaction is a smooth one. Thanks guys!"

Tucker Martine - Flora Recording


Introducing the Soundgas B Channel

Soundgas News

Introducing the Soundgas B Channel

We aim to help more musicians access great vintage gear by providing an alternative that is both affordable and trustworthy, and hope to be part of...

PUBLISHED: 12th Jul 2022

Colleen using an Elka Drummer One, Live in London

Artist Feature

Electronic Music

Colleen using an Elka Drummer One, Live in London

In March 2022 we delivered an Elka Drummer One and Roland Space Echo to London in order for Colleen to recreate her entire album live...

PUBLISHED: 4th May 2022



We stand behind our gear with a guarantee of your satisfaction - see the FAQ section above for full details and buy with complete confidence.


When buying more than one item you only pay the shipping on the item with the highest shipping cost. Calculated automatically at checkout.


Get in touch via the contact page. We know & love our gear and we want to ensure you get something that matches your needs (that, and we just like talking gear).

Select your currency
GBP Pound sterling
EUR Euro