Audio i2e

AG2.1  Buffer / Booster with galvanic isolation
Cable buffer, amplification adjustable between 1/4-times (-12dB, decrease) and 4-times (+12dB, increase)
Output is galvanically isolated by transformer
True bypass when switched off
Phase switchable

Manual (PDF)

Quickstart (PDF)


Buffer / Booster

 Made in Germany


"True bypass" in effect pedals has the undeniable advantage that with the pedal off, there is not the slightest influence on the looped signal. This applies only to the eventual influence of the electronics of the pedal itself, but not to influences caused by cables connected to the pedal.
Each cable has a certain capacitance, so it is a (albeit small) capacitor. This capacitance is of little importance if the cable is driven by an active electronics (activated effect pedal). But if an effect pedal is turned off and "true bypass" makes it practically transparent to the signal passing through, the capacitances of the cables in the input and output of the pedal add up. The total capacitance gets bigger. Capacitances in conjunction with resistors (internal resistance of the pickup of the connected guitar, volume pot !) dampen the high frequencies and shift the resonance of the pickup down. The more effects are connected in series, and the longer the individual cables are (not to forget the possibly very long cable from the last effect device to the amplifier ...), the more pronounced the sound influence becomes.
The easiest remedy, however, is the use of a buffer at the beginning of the effect chain. Even if all subsequent effect devices are switched to "true bypass" and the resulting overall cable length is relatively large up to the amplifier input, it can prevent the sound from influencing because it drives the cables with low impedance and thus prevents the influence of the cable capacitance.
Of course, the buffer itself should make no negative sound change to the guitar signal ...
The output of single coil guitars is sometimes too weak to fully control or overdrive certain amplifiers. Therefore, it can be advantageous if the buffer also has a boost function, ie the signal can raise in level.
On the other hand, some humbucker pickups deliver such a high output level that certain amplifiers can not be played "clean" at all, or undesirable overdriving occurs in some effects units. It would be ideal if the buffer in addition to the possibility of raising the signal (for single coils ...) would also offer a reduction (for humbuckers ...).
With the
AG2.1 at the beginning of the signal chain (as the first device behind the guitar / bass), the length of all subsequently connected cables no longer matters. The level of the guitar signal can be regulated between 1/4 and 4 times.
The output signal of the
AG2.1 passes through a transformer, which ensures separation of any ground loops.
In addition, the phase angle of the signal can be changed by means of a switch on the underside of the pedal (0 / 180 ).
The signal can be tapped symmetrically and floating with a stereo jack plug. When using a mono jack, a signal receives ground reference (ground of the following device).
As a power supply is a power supply with 9-12 volts output voltage in question, the polarity at the plug does not matter.

Frequently asked questions about the AG2.1

Technical data
  • Power supply:
    External power supply, 9 - 12V
    Current consumption: app. 30mA
  • Dimensions:
    Case: 110 x 60  x 30 mm (L x W x H)
    Weight: app. 200g
  • Parts in package:
    Power supply
  • Este 

    - robust metal case
    - high quality parts

    - developed and manufactured in Germany

    - adjustable gain of +/-12dB

    - true bypass (relay) when switched off

    - output can drive long cables without loss
    - transformer coupling against ground loops
    - phase switchable


    Videos / sound files

    Videos und sound files about
    AG2.1 are here