jeffwhitfield
Well-known member
So I built an AionFX Stratus a few months or so ago. Basically wanted to get a solid clone of a TS-808 Tube Screamer. Decided to revisit it to see if I could get one that's closer to the original spec. Plus, with the extra sets of diodes via the Clip switch, I figured I'd play around with it and see if there are any interesting combinations. These are just personal builds so no fancy enclosures...just a bunch of Sharpies and some clear coat.
First thing I wanted to do was stick with what I thought was stock components. Basically, RC4558 op-amp, 2SC1815 transistors, and MA150 diodes. The RC4558 and MA150 components weren't a problem...but the 2SC1815 transistors were. Those didn't work at all. I ordered some 2N5088's, which were used in my first Stratus. But on a whim, I looked in my spare parts box and found a set of BC108C's which I understand are compatible with the 2N5088. They work like a charm! More on that later.
Next, I wanted to try out some different diode combinations. Specifically, I wanted to try a Nanolog N2 device...which I couldn't get to work at all. Will mess with that later. In the meantime, I tried a few other things. D9E Germaniums didn't work very well...like no clipping at all. A BAT41 works too well...way too compressed.
The weird one was a set of NTE555A diodes I had sitting around. These are actually VHF band switch diode. Seems that they're very, very close to the same specs as the MA150. Switching between the two I honestly can't tell much of a difference. Very, very subtle difference. MA150 might be slightly smoother with less attack. Upside of this is that if I decided to build more of these I could Duse the NTE555A as a cheaper replacement to the NOS MA150 diodes.
For now, I'm sticking with both the MA150 and NTE555A diodes so I can continue evaluating them.
Now, how does the new one sound? Compared to all the other Tube Screamer clones I've built, this one is perhaps the most different of all of them. Along with the original Stratus I built, I also built an Actual Overdrive Jr. (KHDK Ghoul Jr) and a Bootleg Overdrive (JHS Moonshine v2). The main common component among all of them is the 2N3904 transistors used for the input and output stages, which is similar to the 2N5088 I used on the original Stratus. By comparison to the Stratus I build using the BC108C's, these all sound more on the fizzy side with a slight bit of fuzz. Not bad per se...but not quite as good as the new Stratus. Something about the BC108C's adds a bit of sparkle to the sound. With lower bits of drive, the sound is smoother. Crank up the drive and you get a more crunchier sound. The difference is quite stark. I'm almost tempted to get an authentic Tube Screamer so I can do an A/B test.
Now, I won't be able to confirm this till I get a set of 2N5088's to test with. All the main components are socketed so no problem there. Will report more later.
First thing I wanted to do was stick with what I thought was stock components. Basically, RC4558 op-amp, 2SC1815 transistors, and MA150 diodes. The RC4558 and MA150 components weren't a problem...but the 2SC1815 transistors were. Those didn't work at all. I ordered some 2N5088's, which were used in my first Stratus. But on a whim, I looked in my spare parts box and found a set of BC108C's which I understand are compatible with the 2N5088. They work like a charm! More on that later.
Next, I wanted to try out some different diode combinations. Specifically, I wanted to try a Nanolog N2 device...which I couldn't get to work at all. Will mess with that later. In the meantime, I tried a few other things. D9E Germaniums didn't work very well...like no clipping at all. A BAT41 works too well...way too compressed.
The weird one was a set of NTE555A diodes I had sitting around. These are actually VHF band switch diode. Seems that they're very, very close to the same specs as the MA150. Switching between the two I honestly can't tell much of a difference. Very, very subtle difference. MA150 might be slightly smoother with less attack. Upside of this is that if I decided to build more of these I could Duse the NTE555A as a cheaper replacement to the NOS MA150 diodes.
For now, I'm sticking with both the MA150 and NTE555A diodes so I can continue evaluating them.
Now, how does the new one sound? Compared to all the other Tube Screamer clones I've built, this one is perhaps the most different of all of them. Along with the original Stratus I built, I also built an Actual Overdrive Jr. (KHDK Ghoul Jr) and a Bootleg Overdrive (JHS Moonshine v2). The main common component among all of them is the 2N3904 transistors used for the input and output stages, which is similar to the 2N5088 I used on the original Stratus. By comparison to the Stratus I build using the BC108C's, these all sound more on the fizzy side with a slight bit of fuzz. Not bad per se...but not quite as good as the new Stratus. Something about the BC108C's adds a bit of sparkle to the sound. With lower bits of drive, the sound is smoother. Crank up the drive and you get a more crunchier sound. The difference is quite stark. I'm almost tempted to get an authentic Tube Screamer so I can do an A/B test.
Now, I won't be able to confirm this till I get a set of 2N5088's to test with. All the main components are socketed so no problem there. Will report more later.