Can I use the HIGH-WIRE™ DUAL BUFFER/OUTPUT BOOST as a 3-way splitter for two amps and a tuner?
You certainly can, but keep in mind that under some circumstances, the drive capabilities of the SEND and TUNER jacks might not be as robust as the OUTPUT jack. Additionally, the SEND, TUNER and OUTPUT jacks are not transformer isolated, so it would be necessary to use a CLEARLINK™ CONVERTER/ISO TRANSFORMER in front of one amplifier, to prevent the hum and noise that would occur as a result of the ground loop that’s always created when running multiple amplifiers.
Why wasn’t a transformer isolated output provided, for splitting or ground loop elimination applications?
A transformer isolated output was not included in the design for several very good reasons; (i) fact is, the noise immunity and signal integrity provided by a specially designed and shielded audio isolation transformer at the end of a long cable run is far more superior than that provided by a transformer at the beginning, worst-case is it’s just as good (ii) we know from previous buffer/splitter designs that not everyone makes use of a transformer isolated output; so instead of including a great, and very expensive transformer, and of course having to charge for it - we made it optional via our passive CLEARLINK™ CONVERTER/ISO TRANSFORMER (iii) the primary utilitarian design goal of the HIGH-WIRE™ DUAL BUFFER/OUTPUT BOOST was to provide the two constants in every guitar rig, the guitar and amplifier, with a resolute load and source, via its input buffer and output line-driver, respectively (iv) pedalboard real estate - specially designed and shielded audio isolation transformers are not small, so you won’t see (or hear them) in any sub-compact buffers (v) finally, experience has also taught us that a good number of people who start off with signal splitting, soon wish or opt for devices that provide them with the ability to split AND switch each output on and off individually.