Nail Pete Townshend’s legendary tone!
The Windmiller Preamp is a faithful recreation of the Grampian Reverberation Type Unit 636 built-in preamp.
This rare unit was used by The Who’s Pete Townshend between ’66 and ’67 to fatten his legendary tone and saturate his amps.
The Windmiller is a versatile pedal that can be used as an always on preamp, a booster for solos, or as a tool to saturate your amp.
Original Grampian units are known for their amazing tone when paired with Marshall stacks and single coils.
However, the Aclam team decided to create a device that could impart a similar character through any guitar and amp combination.
They achieved this by extending the Windmiller's frequency range and include EQ controls (all while retaining the original's unique tone).
Additionally, Aclam has eliminated the original’s ever-present “hiss,” crafting a quieter circuit with true bypass switching.
Plug into the Windmiller and attain Pete Townshend's timeless tone!
Aclam Windmiller Preamp features:
• Based on the preamp of the Grampian Reverberation Unit Type 636.
• Suitable for guitar, bass and keys.
• Improved and quieter circuit including true bypass switching.
• Hi. Cut and Lo. Cut tone shaping controls for maximum versatility.
• True Bypass.
• Power: 9V DC.
• Current Draw: 38mA.
• Dimensions: 5.4" x 3.4" x 2.2".
Specs
Type | Preamp, Overdrive |
Condition | New |
Power | 9V DC |
Current Draw | 100mA |
Power supply included | No |
Manufacturer Warranty | 2 years |
Country of Origin | Spain |

FREE SHIPPING
- Free shipping within Canada.
- Free shipping to the USA.
- Free shipping on international orders over 520$.
Visit the Shipping page for more.

Fast Delivery
- Canada : 1 - 2 business days
- USA : 1 - 2 business days
- Rest of the world: 3 - 5 business days.

Hassle-Free Returns
You have 45 days to test your new gear. If you choose to return it, we’ll send a full refund. It’s that simple: no bogus restocking fees or charges.
Visit the Returns page for more.
Frequently Asked Questions
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How can I tell if an item is in stock? +
Each product page shows an availability status.
• In stock items are ready to ship.
• Out of stock items are currently unavailable.
You can enter your email to be notified when an item is back in stock.
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Where are you located? +
We’re based in Blainville, Quebec, Canada.
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When will my order ship? +
Orders placed before 12 PM EST ship the same business day.
Tracking details are sent shortly after purchase.
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How much does shipping cost? +
Most orders ship free to Canada and the US.
International orders ship free on purchases over $520 CAD.
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Which shipping methods do you use? +
Orders ship via UPS Expedited by default.
For faster delivery, you can select UPS Express Saver at checkout.
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How long does shipping take? +
Typical delivery times are:
• Canada: 2–3 business days with UPS Expedited, 1 business day with UPS Express Saver
• USA: 2–3 business days with UPS Expedited, 1 business day with UPS Express Saver
• International: 3–5 business days with UPS Expedited, 2–3 business days with UPS Express Saver
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Which payment methods do you accept? +
We accept all major credit cards and PayPal.
Financing options are available through Klarna and RBC PayPlan.
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Do Canadian customers pay sales tax? +
Yes. Sales tax is applied based on your province of residence:
• Alberta: 5%
• British Columbia: 5%
• Manitoba: 5%
• New Brunswick: 15%
• Newfoundland and Labrador: 15%
• Northwest Territories: 5%
• Nova Scotia: 14%
• Nunavut: 5%
• Ontario: 13%
• Prince Edward Island: 15%
• Quebec: 14.975%
• Saskatchewan: 5%
• Yukon: 5%
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Do USA customers pay import fees? +
Yes. Starting August 29, 2025, all US-bound shipments will be subject to duties, taxes, and brokerage fees.
These charges are determined by US Customs and collected by UPS at delivery.
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Do international customers pay import fees? +
Yes. International shipments may be subject to duties and taxes.
These charges are set by the destination country’s customs authority and collected by UPS at delivery.