Brian May's Deacy Amp Plinth

Brian’s Deacy Plinth

A while ago now, Pete asked me if I could build a power supply for the Legendary Deacy Amplifier as PP9 batteries were starting to get scarce and the ones you could buy had been sat on the shelf for so long, if was already half discharged.

Now, we already made the KAT DABS unit (Deacy Amp Battery Simulator unit) and Pete was quite happy to just buy one of those, but, I figured the Legendary Deacy Amplifier had, due to it’s age, service given and out and out rarity, earned something a little more than just a very stable and adjustable power supply. In my mind at least, it justified having a power supply with both over-current and over voltage protection, just in case!! Let’s face it. Killing the Deacy Amp would not make me a very popular chap, so we all agreed that it should have a very protective and kind power source. This, then, would not be a small unit like the DABS, but a full-size linear power supply with its associated control circuits.

Once I’d worked out the size of the circuit boards, I started looking for suitable enclosures for them. It was going to reside full-time in the studio, so it needed to look the part, so I decided that a nice teak plinth-style cabinet would do the job. Once I’d decided to make the plinth the resting place for the Deacy Amp, I started thinking about what else we could do to make the most of the amp in the studio.

The final Deacy Plinth included the power supply, an in-built treble booster, a gooseneck for the microphone, a fully buffered and transformer isolated effects loop, a balanced line-out to the desk and a balanced line in from the desk. This allowed Brian to record the TB output directly to Pro-tools, edit it, then send it back to the Deacy Amp via the plinth to re-amp it. The plinth could also now be taken downstairs and connected to an AC30. Brian could record with the AC30 whilst the line-out was taken straight to Pro-tools. This meant that all the high-level feedback Brian was getting from standing in front of the AC30 could be recorded and then re-amped through the Deacy.

Editing the Deacy tracks in Pro-tools was also made easier as the clean signal from the TB was far easier to decipher than the highly compressed and distorted output from the Deacy Speaker..

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