About Tonebones and FLATLINER PRO

Radial Engineering makes the finest effects pedals in the world. To provide enough headroom in their Tonebone effects they run them on 15VDC. Since 15VDC is an uncommon voltage for guitar effects it was a challenge for us to modify our Flatliner Pro to be able to run the Tonebone pedals with the same or even higher tone quality. Our research resulted in the TBMod, a modification that runs 2 Flatliner outlets of 15VDC, parallel wired.

Tonebone Mod explained

For the Tonebone Mod we modify the two 12 VDC outlets to just over 15VDC. With a parallel Y-cable we share the two outlets to provide 400mA. An extension cable will reverse the polarity. Because the Tonebone Mod ‘sacrifices’ both 12VDC outlets we convert the adjustable 3-9 VDC to 3-12 VDC to sustain the versatility of the FLATLINER PRO.


Many guitar players use a myriad of different analog- and modern digital effects pedals. Most of these run on 9V batteries, which don’t last long and are an ongoing expense to replace. An adaptor is a common solution and a good alternative, however using several pedals together will inevitably result in a jumble of cables. Alternatively a hum-free adaptor is an expensive option and may only power a few pedals. Although most effects pedals need 9V supply, there is now an increasing number of pedals that need 12 or 18V and draw higher current. For this reason you need special adapto


Burkey noticed these problems and came up with a solution: One central power supply that can power almost every effects pedal in the world.

The Flatliner Pro is specifically designed for use with pedalboards. Its compact, rugged and virtually indestructible build quality will guarantee many years of carefree power supply. No more flat batteries or humming adaptors. No tangled mess of cables on the floor. With our Flatliner you will have a well-organised and reliable power supply setup ready for the wildest performances.

The FLATLINER features 9 completely isolated outputs, ready to power a large pedalboard. Voltages may vary from 3-24 V DC and the FLATLINER can even power 9/12 VAC pedals.


9V DC 5 Outputs 9 Volt DC, 200 mA, short-circuit protected with a current-limitation on 200 mA
12V DC 1 Output 12 Volt DC, 200 mA, short-circuit protected with a current-limitation on 200 mA
3-9V DC 1 Output variable ca. 3-9 Volt ; V = voltage, R = resistance ( 0…20 Ohm)
3-12V DC 1 Output variable ca. 3-12 Volt ; V = voltage, R = resistance ( 0…20 Ohm)
9/12V AC 1 Output 9 or 12VAC*, capacity 1000 mA This output is protected with a 1AT fuse (on the rear panel)
Polarity All outputs are centre negative
Fuses 1AT:1A-fuse (9VAC output) 230/240V:2 x 250mAT —– 115/120V: 2 x 500mAT
Mains 230VAC 50/60Hz for European power. Configurable for 120VAC/60hz for US power
Capacity 33 Watts max
Weight 1960 gr
Dimensions (LDH)233x110x72 mm
Warranty 24 months


Power Features ( chart )
Standard 9V De FLATLINER has 8 DC outputs for the use of 5.5×2.5 mm barrel connectors (Boss-type). These are standard connectors which fit most Ibanez and all Boss, Voodoo Lab and many others. Polarity The 8 DC-outputs are centre-negative , a standard for effects pedals. Some pedals have reversed polarity (Fulltone ’69 en Octafuzz). To prevent damage to your pedal it is important to check the polarity of the input jack of the pedal. A special cross-cable is provided with the FLATLINER to connect to a center positive effectpedal. If you need more cables you can order them on the BURKEY website.

12 VDC Some pedals need higher voltage supply. Examples are: Boss ACA-type pedals made before August 1997. These need 12VDC to run properly. All Boss PSA-type pedals and post-August 1997 pedals can be run from the 9VDC outlets.
18V/24VDC Because all outputs are isolated it is possible to join two 9VDC or 12 VDC outputs in a serial connection to double the voltage to 18 or 24 VDC or a parallel connection to double the current to 400mA. For this you need a special Y-cable which you can order from our on-line store.

9/12 VAC Most tube-driven pedals need AC power. FLATLINER V 2.0 can be configured to 12 VAC, instead of standard 9VAC. Other brands that require AC power are EHX (Wiggler, Tubezipper), Mesa Boogie (V-Twin), Boomerang , Hughs & Kettner, Digitech Whammy, Line 6 Pods, DL4, VoodooLab GCX Switcher a.s.o.
Note to Boomerang pedals: The Flatliner Pro works well with the new Boomerang pedals, which require at least 500mA. You needn’t worry about polarity because these pedals accept AC, DC neg tip or DC pos tip. We advise you anyway to use the AC outlet ( Boomerangs need 2.5 mm barrelconnectors (cable SC-AF25).

The Line 6 modelling pedals can be powered through the 9VDC (MM4, FM4) or 12VDC (DM4,DL4) outputs. Since these effects draw more current (150-185 mA) than average you can connect one effect with one output. The FLATLINER can power several Line 6 effects simultanously. Note: Line 6 modelling effects have reversed polarity. Use the right cable.

Dying battery This option gives creative guitarists the opportunity to simulate the special effect that an almost flattened battery causes in some fuzz and overdrive effects. The FLATLINER’s dying battery option provides variable voltages from 3-9V and 3-12V, this in combination with variable output resistances, to achieve the right mix. Learn more about the dying battery option.

Cables Your FLATLINER comes with 9 cables, 7 regular, different length, 1 for reversed polarity, 1 for AC output.