MichaelW
Well-known member
- Build Rating
I built my first General Tso compressor a bit over a year ago and it has literally never left my signal chain in all that time.
It's been an "always on" pedal for me since the day I built it.
I know I've mentioned many times how much I love what this pedal does for my sound. But just to recap and tie all together here, it's an optical compressor designed by Dan Coggins and Adrian Thorpe based on Dan's earlier "Dinosaural OTC-201". (Which I have also built as Aion's "Convex" compressor).
I think by the time I built the Tso's I was either right in the middle of or just finished a tear of building every compressor project I could get my hands on.
I love optical compressors, they really do for my sound what I need it to do for my use case. In general opticompressors are more subtle in how they work than JFet, VCA, etc compressors. They won't get the squish that you can get from a Ross/Dyna comp or the MBP Oracle (Boss CS-3).
I've always found them to be quieter than IC based compressors. The down side is that in "general" they tend to color the tone, albeit in a good way sometimes.
Having said that, the Fat General and Dinosaural OTC-201 are the most transparent of all the optical compressors that I've built yet.
For me, one of the reasons I use a compressor as an always on pedal is that I play at very low volumes or through headphones most of the time.
Even with attenuation, I rarely get the kind of power tube compression that you get playing through a cabinet at club levels. Enter the compressor, it gives me a bit of that "tube compression feel" under my fingers in way that I absolutely love. I was chatting with @Guardians of the analog about his recent compressor build and we were discussing how it's really hard to "show" how a compressor sounds in a demo. It's probably as much about "feel" under the hands as it is about toanz.
The Tso/Fat General has a couple of neat features that are part of the reason I love it so much, first there's a dedicated treble control. This helps with the aforementioned "coloration" as most optical compressors can shave off a bit of high end at higher compression settings. It's subtle control but also very useful. It won't give you the level of obvious "jangle" like the Byrdhouse/Janglebox will but it does restore any loss of "sparkle" from the compression. Secondly, it's a "parallel" compressor in that the clean signal is always blended back in, to any degree you like, with the Blend control. Or you can opt to use the Blend in control in "volume mode" where I believe you're getting 90% compressed signal and it acts like a normal volume control. Both modes have their uses in certain scenarios.
So why am I building a second Tso? Well, I saw a post where @manfesto mentioned using Vactrols in place of the LED/LDR combo the BOM calls for. It was an "aha" moment because I had also built the Tso's predecessor the OTC-201 (AionFX Convex) and it uses VTL54C's. Being that they are both essentially the same circuit with some minor EQ differences, it was like "duh, why didn't I think of that?". Not that there's anything wrong with the LED/LDR combo but I'm always wondering what variables I've introduced by how I mounted them, how far apart from each other they are, what brand LED, etc etc. Using a pair of vactrols eliminates that variable. (as far as we can trust XVive, heh). The original OTC-201 uses vactrols, and though I'm not sure whether or not Thorpy version uses them or not, I thought I'd give it a try.
After comparing them to each other I've found that there IS a difference, although it's slight, between my new Ver2 Tso and my original. There's slightly more compression on tap, which would point to the vactrols making a difference. And there's slightly difference EQ curve, which most likely points to the variances in the potentiometers or other components. It's a little brighter at the same settings as my original one.
I've been comparing the 2 Tso's along with my OTC-201 since yesterday and they all 3 sound remarkably similar. They all have that "fullness" that they impart to the signal, like a subtle fattening that I haven't heard with any of the other compressors I've built. Especially on clean tones, it's just gorgeous. It's also one of those circuits that you don't really HEAR the compressor, it's extremely transparent. Like "helloooo....is this thing even on???". Until you turn it off that is, then you immediately hear what's missing.
The Fat General/Tso with the dedicated treble control makes it more flexible than the OTC-201. (The OTC-201 has another toggle that sets a fixed 3db gain boost or cut to match the pickups. Which was dropped in the Fat General since it's not very useful).
So with all my rambling, where's the demo? Heh, I'm still mulling over how to demo the pedals. I'll try to get something posted in the next day or so.
In the meantime, I highly recommend this build, especially if you're NOT a fan of compressors because they're noisy and squishy. If you're into the DynaComp/Ross or VCA sound then this is probably not the right compressor for you. But if you like the idea of having a mini LA-2A "tone conditioner" on your pedalboard then this thing is absolutely killer!
It's been an "always on" pedal for me since the day I built it.
I know I've mentioned many times how much I love what this pedal does for my sound. But just to recap and tie all together here, it's an optical compressor designed by Dan Coggins and Adrian Thorpe based on Dan's earlier "Dinosaural OTC-201". (Which I have also built as Aion's "Convex" compressor).
I think by the time I built the Tso's I was either right in the middle of or just finished a tear of building every compressor project I could get my hands on.
I love optical compressors, they really do for my sound what I need it to do for my use case. In general opticompressors are more subtle in how they work than JFet, VCA, etc compressors. They won't get the squish that you can get from a Ross/Dyna comp or the MBP Oracle (Boss CS-3).
I've always found them to be quieter than IC based compressors. The down side is that in "general" they tend to color the tone, albeit in a good way sometimes.
Having said that, the Fat General and Dinosaural OTC-201 are the most transparent of all the optical compressors that I've built yet.
For me, one of the reasons I use a compressor as an always on pedal is that I play at very low volumes or through headphones most of the time.
Even with attenuation, I rarely get the kind of power tube compression that you get playing through a cabinet at club levels. Enter the compressor, it gives me a bit of that "tube compression feel" under my fingers in way that I absolutely love. I was chatting with @Guardians of the analog about his recent compressor build and we were discussing how it's really hard to "show" how a compressor sounds in a demo. It's probably as much about "feel" under the hands as it is about toanz.
The Tso/Fat General has a couple of neat features that are part of the reason I love it so much, first there's a dedicated treble control. This helps with the aforementioned "coloration" as most optical compressors can shave off a bit of high end at higher compression settings. It's subtle control but also very useful. It won't give you the level of obvious "jangle" like the Byrdhouse/Janglebox will but it does restore any loss of "sparkle" from the compression. Secondly, it's a "parallel" compressor in that the clean signal is always blended back in, to any degree you like, with the Blend control. Or you can opt to use the Blend in control in "volume mode" where I believe you're getting 90% compressed signal and it acts like a normal volume control. Both modes have their uses in certain scenarios.
So why am I building a second Tso? Well, I saw a post where @manfesto mentioned using Vactrols in place of the LED/LDR combo the BOM calls for. It was an "aha" moment because I had also built the Tso's predecessor the OTC-201 (AionFX Convex) and it uses VTL54C's. Being that they are both essentially the same circuit with some minor EQ differences, it was like "duh, why didn't I think of that?". Not that there's anything wrong with the LED/LDR combo but I'm always wondering what variables I've introduced by how I mounted them, how far apart from each other they are, what brand LED, etc etc. Using a pair of vactrols eliminates that variable. (as far as we can trust XVive, heh). The original OTC-201 uses vactrols, and though I'm not sure whether or not Thorpy version uses them or not, I thought I'd give it a try.
After comparing them to each other I've found that there IS a difference, although it's slight, between my new Ver2 Tso and my original. There's slightly more compression on tap, which would point to the vactrols making a difference. And there's slightly difference EQ curve, which most likely points to the variances in the potentiometers or other components. It's a little brighter at the same settings as my original one.
I've been comparing the 2 Tso's along with my OTC-201 since yesterday and they all 3 sound remarkably similar. They all have that "fullness" that they impart to the signal, like a subtle fattening that I haven't heard with any of the other compressors I've built. Especially on clean tones, it's just gorgeous. It's also one of those circuits that you don't really HEAR the compressor, it's extremely transparent. Like "helloooo....is this thing even on???". Until you turn it off that is, then you immediately hear what's missing.
The Fat General/Tso with the dedicated treble control makes it more flexible than the OTC-201. (The OTC-201 has another toggle that sets a fixed 3db gain boost or cut to match the pickups. Which was dropped in the Fat General since it's not very useful).
So with all my rambling, where's the demo? Heh, I'm still mulling over how to demo the pedals. I'll try to get something posted in the next day or so.
In the meantime, I highly recommend this build, especially if you're NOT a fan of compressors because they're noisy and squishy. If you're into the DynaComp/Ross or VCA sound then this is probably not the right compressor for you. But if you like the idea of having a mini LA-2A "tone conditioner" on your pedalboard then this thing is absolutely killer!
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