The Stack amplifier

Tele shot resizedLove the sound of 100W+ valve amps driven into overdrive? That sound defined rock music back in the 60s and 70s and continues to this day. Introducing ‘The Stack’ an amazing new concept in valve amplification that faithfully reproduces the huge sound of a stack of overdriven valve amplifiers at a manageable home/apartment volume. You won’t believe the tone from this tiny powerhouse!!

Huge 100W+ amplifiers are great – however in a home environment they are just too loud!  Attempts to lower the volume of large amps while maintaining tone have had limited success – the desired tone disappears.

The all-valve Stack amplifier has been developed by Valve Heaven an established company with years of experience designing and repairing guitar amplifiers.

From the insights gained through years of analysis of many amplifiers, The Stack was expressly designed to produce that classic rock sound at neighbour friendly levels!

Even though it produces less than 1 Watt of power, The Stack delivers unbelievable rock tones from warm, harmonic cleans through to ‘wall of amplifiers’ overdrive.  An innovative design feature allows you to further customise your amplifiers tone, through plug & play valve substitution.

The Stack amplifier is precision hand-crafted – the way they used to do it back in the 50s. Great pride is taken in the handwired, point to point construction, and this is reflected in The Stack‘s amazing tone.  In spite of its tiny size – 12cm x 8cm x 9cm and weighing only 650grams“ The Stack is a complete all-valve amplifier.

Wiring The StackThe Stack has been designed for all kinds of musicians – bedroom blasters, apartment dwellers, home recording engineers and bands on tour.

It’s tiny, lightweight size is ideal for touring musicians, especially with the option of headphone use.  Because of the low 12V power requirements of The Stack, it can be used for hours at a time by buskers or in fact anyone who is off the mains grid.

Design features

A classic rock tone is the result of heavily driving the output stage of an amp into overdrive. Attempts in the past to reduce the volume of an amp while maintaining tone have had limited success – power attenuators, master volume, power scaling, etc. In contrast with these approaches, The Stack design produces the same overdriven power stage grind at a volume level that is manageable.  The Stack drives an all-valve preamp/power amp combination beyond full power, producing a rock tone in exactly the same way as an overdriven larger amplifier.

The Stack is an amplifier that does exactly what it sets out to do create great rock sounds at home levels. Its retro appearance pays homage to the golden days of rock and roll with its minimalist design just two controls for drive and tone.  The gain structure and tone of the amp have been carefully balanced to create its own distinctive sound. In addition, The Stack has the unique feature of ‘plug and play’ valve sockets that allow you to substitute a wide range of different valve types to further customize your sound.

Using an innovative power design, The Stack is powered by a 12V DC universal power pack. This also allows for 12V battery operation of the amp by buskers or touring musicians on the road.

The Stack is of rugged but lightweight construction, which combined with its compact size, allows it to be easily transported.

Valve Heaven provides a 12 month back to base warranty, including 3 month valve warranty.

The Stack closeup

Here is a testimonial from a happy Stack purchaser:

“Hi Grant, Thanks for sending The Stack. I love it, it’s definitively the best small amp I have tried running it through a 12” Blue Marvel speaker. Has a really nice valve feel at low volume….The Stack is really going to make a big difference in my enjoyment of the electric guitar at home. I no longer have to work with poor tone at low volume or get into trouble for being too loud.It’s been great trying a range of different valves. I like the option to clean up the amp a bit. All of my guitars give me different sounds and I can play with the guitar volume to clean the sound up a bit or play at various degrees of distortion. I love the fact that I can get the guitar to determine the sound rather than the amp. And all that at great low volume with nice valve dynamics.
I am really happy, thanks for making a great product.”


  • Output power: 1/3W clean power, 1W distorted.
  • Heavy duty die-cast metal case.
  • Valve complement: preamp 12AX7, power 12AT7.
  • Input: ¼” socket, 1M impedance suitable for all types of pickups.
  • Controls: volume/drive with concentric power switch, tone.
  • Output: ¼” socket optimised for 8 ohm speakers but will also drive 4 and 16 ohm speakers.
  • Headphone operation: available via the included adapter.
  • Power requirements: 12V DC from the supplied plugpack or via the optional DC power lead.
  • Power rating: 12V DC @ 450mA 5.4W power consumption.
  • Power protection: protected from reverse polarity connection.
  • Dimensions: 12cm x 8cm x 9cm.
  • Weight packed: 1kg.

Hear The Stack

Check out these clips of The Stack on YouTube below. They sound great from your computer, and even better through headphones!

Download The Stack

Purchase The Stack

Each Stack amp is hand built in the Valve Heaven lab.  Once your order has been placed, your amplifier should be shipped to you within 5 – 7 days.  In times of high demand, we’ll contact you to advise of any delays.

Product Description Price (AU$) Purchase Now
The Stack 1/3 Watt all-Valve Guitar Amplifier (+ Postage & Handling within Australia*) $399 + $15 P&P
+ Option 1: 12AU7 “Tweed” output valve For a less ‘gainy’ tone, reminiscent of old Tweed amps $30
+ Option 2: Line out cable Line out adaptor cable for recording/DI $20
+ Option 3: 12 Volt battery power lead Cigarette lighter Car/Battery power lead $20

If you have any questions about the Stack Amp please contact Grant Wills: