Here's my build of the Aion Procyon, based on the BJFe Honey Bee. Kevin has a great writeup on the Honey Bee circuit, based on his extensive research and tracing this circuit. The short version is, there are several variants of the circuit, loosely based on which brand was selling it (BJFe, One Control, BearFoot FX). In the Procyon build documentation, he notes all the component value variations, including the "Blueberry", which is a variation tuned for bass.
IMO, most of the component value differences should be inconsequential (excluding the deliberate Blueberry version of course). Where the differences were non-trivial, Aion added switches so you can easily experience a few different non-trivial variations. I kept notes on the values I used where they deviated from the stock BOM:
I didn't do anything fancy for this build: normally I build with a custom bypass scheme. But I wasn't sure if I was going to like this. Even if I do like it, I'll make my own custom PCB with integrated bypass. So either way it's going to be sold, so I might as well take the easy/cheap/stock route. That thinking also allowed me to finally use my last Tayda Silver Grey Hammer. I'm not hot on this enclosure style; it looks really cool at certain angles, but at other angles, there's too much glare. Film-free decals don't transfer very well because of the texture.
As for tones: everything worked on first power-up! I actually had the wacky CA3130EZ opamp in my inventory. I'm not sure how I feel yet about the tones. It does sound and feel very natural to me. But the actual drive character is a little rougher than I usually like; and a lot of the settings are too bass-heavy for my tastes. It kind of gives "small combo amp being pushed too hard" vibes, which I can appreciate, but isn't usually what I'm going for. However, there is a lot of variability available. There's a two-way "mode" switch and a three-way "bass" switch, and the "Nature" knob is affected by the mode. So it's not something you can judge in five minutes. That said, I spent some time playing through it today, and I was really enjoying the feel, volume cleanup, and the way it really seemed to "integrate" with my amp. So there really is a lot to like here.
IMO, most of the component value differences should be inconsequential (excluding the deliberate Blueberry version of course). Where the differences were non-trivial, Aion added switches so you can easily experience a few different non-trivial variations. I kept notes on the values I used where they deviated from the stock BOM:
- R8, I used 150k instead of 147k. 147k is a weird value that I don't stock, and the the schematic says "sometimes 150k", so 150k it is!
- R15/R16, I used 33k instead of 31.6k. 31k6 is a really wacky value, and these are the resistors for the virtual ground (VREF) voltage divider. I'm really curious to know why such an oddly-specific, uncommon value was used here. The schematic notes say some versions used 47k.
- C11: the BOM calls out 4.7nF; the schematic notes say 47nF and 22nF have been used in different versions. I didn't take the time to do the math, but I suspect this value might make a difference in tone, particularly bass. I went with the "Goldilocks" middle-of-the-road 22nF value.
I didn't do anything fancy for this build: normally I build with a custom bypass scheme. But I wasn't sure if I was going to like this. Even if I do like it, I'll make my own custom PCB with integrated bypass. So either way it's going to be sold, so I might as well take the easy/cheap/stock route. That thinking also allowed me to finally use my last Tayda Silver Grey Hammer. I'm not hot on this enclosure style; it looks really cool at certain angles, but at other angles, there's too much glare. Film-free decals don't transfer very well because of the texture.
As for tones: everything worked on first power-up! I actually had the wacky CA3130EZ opamp in my inventory. I'm not sure how I feel yet about the tones. It does sound and feel very natural to me. But the actual drive character is a little rougher than I usually like; and a lot of the settings are too bass-heavy for my tastes. It kind of gives "small combo amp being pushed too hard" vibes, which I can appreciate, but isn't usually what I'm going for. However, there is a lot of variability available. There's a two-way "mode" switch and a three-way "bass" switch, and the "Nature" knob is affected by the mode. So it's not something you can judge in five minutes. That said, I spent some time playing through it today, and I was really enjoying the feel, volume cleanup, and the way it really seemed to "integrate" with my amp. So there really is a lot to like here.
