Taken from Guitarist, in the Vox VBM-1 Deacy amp review (July 2003) :
Speaking exclusively to Guitarist for the purposes of this review, Brian illustrates a few tonal examples of the Deacy amp.
"I'm pretty sure I used it for making a demo of the multitracked Procession at home, probably because it wouldn't piss off the neighbours like a fully cranked-up AC30! I loved the sound it made so much that I eventually made the 'proper' version in the studio the exact same way."
So Procession has my vote too. The first version of Procession was recorded with AC30s, before being recorded again using the Deacy I think (from memory Deacy+AC30 together... i should listen to it again). But we will probably never know... could be any other song on Queen II.
I don't think Brian used the Deacy on the first album, John probably found it a bit later. But if you have spotted any guitar sounds from the first album that you think is the Deacy, I'd love to stand corrected !
From the first album Doing All Right, My Fairy King, The Night Comes Down and Jesus all sound like they have the Deacy in the guitar multitracks at different points, along with an AC30 and acoustic guitar too.
I see what you mean. But... the original Deacy does sound close to an AC30 in some occasions, and telling them apart is not always easy.
This, plus the fact that Brian probably often used them together in harmonized recordings.
The kind of tones the Deacy can produce is something Brian has always tried to achieve, even with AC30s.
One good example of this can be heard different Great King Rat recordings.
Listen to the original first Queen album recording, starting at 4:21, left channel : link
and now, listen to Great King Rat on Queen at the Beeb, starting at 4:29,left channel. link
Sounds like the Deacy, doesn't it ?
Technically, the Live at The Beeb recording was done after the Queen II sessions, so it *could* be the Deacy here.
Or not. Brian used different recording techniques, like mic'ing the AC30 from the back of the amp for instance, to achieve this kind of tone.
So I would say... Deacy first recordings in the Queen II album for sure, anything else is just "could be", but I'm not convinced !