Is it possible with an "Y adaptor" like this one to create 2 outputs for "stereo reverb"?
The Hall Of Fame Mini is a Mono reverb. One Input and one Output. If you want connect the Hall Of Fame Mini to two amplifiers, you can connect the amplifiers with this Y adaptor. But you will never obtain a Stereo signal, only a double mono.
Here is a little trick: if you want a "Stereo like" reverb sound, connect the Hall Of Fame Mini to a Corona Chorus or a Vortex Flanger after the HOF Mini. You can use also a Flashback Delay in chorus mode. The Corona Chorus (or the Vortex Flanger) will give you a "chorused" reverb in stereo on its two outputs. This will transform your Hall Of Fame Mini Mono reverb into a beautiful chorused Stereo reverb. For the Corona Chorus, set the "SPEED" & "DEPTH" knobs on a gentle setting, about 10 o'clock and "FX LEVEL" all the way up. Set the three positions toggle switch to "TRI CHO" for better stereo results.
Do not forget to use always TonePrints with the software kill dry engaged and "reverb" knob all the way up. Use the TonePrint editor for engage the kill dry. it is located here.
This Stereo configuration is guaranteed to impress!