The Sushi Box FX Secret Society

[chiphaleonbass]

It's just the input and output stage, the tube isn't doing any compression.


The ratio should theoretically be fixed, but I'm having trouble finding information on what it is. I'm seeing information in some places indicating it is around 1:4, but I can't find anything in the datasheet that backs that up.

The function of the Comp control is to adjust the bias of the device that's doing the compression (OTA op-amp), so it's controlling how much that stage is amplifying the signal, which I think most accurately matches the sustain control of things like the Dynacomp.

Here's a quick rundown of the controls for the pedal, which I have added to the product page on the site:

Comp - compression; effectively controls the sustain or release time of the signal. Counterclockwise will be shorter sustain, clockwise will be longer.

Output - master volume; behaves differently from an input volume control as it does not affect the operation of the compression itself, just how loud it is coming out the end.

Sens - sensitivity; sets the sensitivity threshold level for the compression.

Attack - sets the attack time of the compression. Counterclockwise is faster, clockwise is slower.

Blend - blends the dry/unaffected signal with the compressed/affected signal. Full counterclockwise is 100% unaffected, full clockwise is 100% affected.

Seems to me that comp should be labeled “release” and sensitivity “threshold”?

 

[kojdogg]

Full clockwise is 1:1, the datasheet for the VCA I'm using doesn't have the numbers I need. But I do have the equipment to measure it, I'll get it set up tonight and get numbers posted both here and on the product page of the site.


Duly noted, that's understandable. I'll prioritize getting more technical info put together for it, I should be able to get most (if not all) of what I need tonight.

The mk numbers were for internal development use, nothing prior to mk iv was ever released. Mk i and mk ii were mostly the same design with a few tweaks in between. It was an optical compressor design with two tubes and not a lot of control over the sound. When I received mostly negative feedback on mk ii I completely scrapped the design and started over, because it seemed like I was going in the wrong direction. Mk iii was the first VCA design I played with, and it was very simple, just a compression/peak reduction/ratio (whatever you want to call it) control and volume. Mk iv added the attack and sensitivity controls. Revision A to the mk iv design added the clean blend but didn't change anything else, so I kept the same mk number and changed the revision.

Short answer: mk ii and mk iv are completely different circuits.

Your transparency and responsiveness are greatly appreciated!

It's just the input and output stage, the tube isn't doing any compression.


The ratio should theoretically be fixed, but I'm having trouble finding information on what it is. I'm seeing information in some places indicating it is around 1:4, but I can't find anything in the datasheet that backs that up.

The function of the Comp control is to adjust the bias of the device that's doing the compression (OTA op-amp), so it's controlling how much that stage is amplifying the signal, which I think most accurately matches the sustain control of things like the Dynacomp.

Here's a quick rundown of the controls for the pedal, which I have added to the product page on the site:

Comp - compression; effectively controls the sustain or release time of the signal. Counterclockwise will be shorter sustain, clockwise will be longer.

Output - master volume; behaves differently from an input volume control as it does not affect the operation of the compression itself, just how loud it is coming out the end.

Sens - sensitivity; sets the sensitivity threshold level for the compression.

Attack - sets the attack time of the compression. Counterclockwise is faster, clockwise is slower.

Blend - blends the dry/unaffected signal with the compressed/affected signal. Full counterclockwise is 100% unaffected, full clockwise is 100% affected.

Single Slice is a VCA-based compressor.

Is the Mk IV an OTA or VCA based compressor? I know you indicated VCA, but I notice you shifted to talking about OTAs (boldface/italic emphasis by me).

So the tubes are something like gain stages or buffers that bookend the compression circuit?

 

[Tassieviking]

If the Tube stages are used in a similar way as the Bath Tub Reverb over at C2CE the I would not call it bookended, it would be more like the solid state input and output stage has been replaced with tube stages.
If the tube was not there then it would need to be replaced by OpAmps or transistors or similar, when you say bookended it makes it sound like the tube has been added to the in and out stages of a fully working pedal.
But only the Sushi Chef knows the secret recipe.

 

[kojdogg]

If the Tube stages are used in a similar way as the Bath Tub Reverb over at C2CE the I would not call it bookended, it would be more like the solid state input and output stage has been replaced with tube stages.
If the tube was not there then it would need to be replaced by OpAmps or transistors or similar, when you say bookended it makes it sound like the tube has been added to the in and out stages of a fully working pedal.
But only the Sushi Chef knows the secret recipe.

I tried to be careful about my word choice here. He said “It's just the input and output stage, the tube isn't doing any compression” so I asked the tubes relative to the “compression circuit” rather than the whole pedal. Gain stages and buffers in a pedal would still be considered part of the overall pedal (see Damage Control).

“Bookended” only was meant to refer to where the tubes are relative to the part of the pedal actually “doing… compression.” Input comes first, output comes last and that’s where the tubes are.

Given his admirable transparency around some unfamiliarity with things like how the controls in the circuit work (isn’t this part of knowing the “recipe?”), it sounds like, per his own reporting, he added a clean blend to a VCA (or OTA) compression design and subbed in tube input and output stages for whatever solid state components were handling that function. BTW I have a Neptunium, a Grand Slampegg and a Venus Z. I am a big fan of his work.

 

[chiphaleonbass]

I tried to be careful about my word choice here. He said “It's just the input and output stage, the tube isn't doing any compression” so I asked the tubes relative to the “compression circuit” rather than the whole pedal. Gain stages and buffers in a pedal would still be considered part of the overall pedal (see Damage Control).

“Bookended” only was meant to refer to where the tubes are relative to the part of the pedal actually “doing… compression.” Input comes first, output comes last and that’s where the tubes are.

Given his admirable transparency around some unfamiliarity with things like how the controls in the circuit work (isn’t this part of knowing the “recipe?”), it sounds like, per his own reporting, he added a clean blend to a VCA (or OTA) compression design and subbed in tube input and output stages for whatever solid state components were handling that function. BTW I have a Neptunium, a Grand Slampegg and a Venus Z. I am a big fan of his work.

All in all I trust too that this pedal is probably awesome because Nathan made it; I'm sure the tube input and output stages add that extra "tubiness" to the sound. If I didn't love my Cali76 so much I'd spring for one of these

 

[Parzival]

All in all I trust too that this pedal is probably awesome because Nathan made it; I'm sure the tube input and output stages add that extra "tubiness" to the sound. If I didn't love my Cali76 so much I'd spring for one of these

Love my Cali too and wanted to try this one out and we'll see who ends up on top.

On another note, and I don't know if it's been mentioned here before, but I use the Pedal Playground pedalboard planner site. It is really cool and since I like to keep my boards compact, its a good way to see what will work and what will not. I just noticed last night that you can pull up Sushibox pedals on there. They were not on there before. Pretty cool. Snapshots below from Pedal Playground of how my A board is set up and some of the various pedals.

 

[Tassieviking]

“Bookended” only was meant to refer to where the tubes are relative to the part of the pedal actually “doing… compression.” Input comes first, output comes last and that’s where the tubes are.

I had a feeling you knew all that already, often when I reply I do it in a way so a larger part of the readers can understand what I am trying to say.
I guess it's sort of like I was talking to a classroom of people, I try to be informative because not that many people have a background in electronics or a clear understanding of how the pedals work.
I have a dislike of short answers that don't explain why something is wrong.
My biggest problem is I can talk in circles and I end up confusing myself in the end.

 

[kojdogg]

All in all I trust too that this pedal is probably awesome because Nathan made it; I'm sure the tube input and output stages add that extra "tubiness" to the sound. If I didn't love my Cali76 so much I'd spring for one of these

I’m strongly considering one in a future batch and I already have a DLA-2A, Cali76-TX, Cali76 BC V2, Becos Twain V2 and some nice rack and 500 series compressors. I just want to know what I am getting if I do. A Dynacomp or Keeley Bassist/Becos type compressor with full voltage (vs starved plate) tube gain stages or buffers would be awesome.

 

[NKBassman]

PSA: I have a Sushi Box King Nothing listed for sale in the Classifieds.
Happy holiday week everyone.

 

[Michael Vee]

Got my Single Slice backordered earlier today. I stayed busy all day yesterday with company, so did not see that the product became available then. It sounds like Nathan will get the backorders out before 1/1/2025 and then there's the free expedited shipping. Can't wait! Congrats to you first 12 Slicers..

 

[Sushi Box FX]

I'm awake now but still on mobile, I try to use the computer for more serious/technical supplies so I don't wear out my thumbs. I'll be on in a bit with more answers.

 

[lomo]

Logical behavior would have been to wait for initial reviews, but I have been waiting for this comp for so long that in this case the notion of logical behavior proved nothing more than a transient, discarded thought

 

[_Tay_]

Logical behavior would have been to wait for initial reviews, but I have been waiting for this comp for so lung that in this case the notion of logical behavior proved nothing more than a transient, discarded thought

As soon as this was announced i just had to have it!

 

[RobD_BritBass]

Logical behavior would have been to wait for initial reviews, but I have been waiting for this comp for so lung that in this case the notion of logical behavior proved nothing more than a transient, discarded thought

Yeah I thought about waiting to see some reviews of it, then I thought to myself "the chances of not liking it are pretty slim so get with the ordering"
I think there were four left at that point so I'm glad I did.

 

[Sushi Box FX]

Seems to me that comp should be labeled “release” and sensitivity “threshold”?

I went back and forth a bunch on what the labels should be. Threshold to sensitivity was at the request of Mike Watt, that was the last change I made.

Your transparency and responsiveness are greatly appreciated!


Is the Mk IV an OTA or VCA based compressor? I know you indicated VCA, but I notice you shifted to talking about OTAs (boldface/italic emphasis by me).

So the tubes are something like gain stages or buffers that bookend the compression circuit?

I'll admit I use those interchangeably, but to be accurate, an OTA is a type of VCA. VCA stands for Voltage Controlled Amplifier, but frankly most compressors can technically be considered voltage controlled amplification since the concept of compression is that the amount of amplification being done is adjusted based on the input of the circuit which is then converted to a control voltage. OTA, or operational transconductance amplifier, is a specific type of device that is used in compressors like the Dynacomp, Keeley, and Becos compressors.

With regards to the way the tube is used, I can clarify that a little further. The best parallel I can use is actually the Effectrode LA-1A. I'm using the tube in Single Slice in the same way they are in the LA-1A. The tube acts as an input stage to "flavor" the signal on the way in and also to feed the sidechain, which is the part that tells the compression engine (OTA in Single Slice, optical in LA-1A) how to adjust the signal output in relation to the input. There is then an additional tube stage that then further "flavors" and buffers the signal on the way out. So the tube isn't providing the compression per se, but it is very much involved in the way the output sounds as the response of the input stage can affect the reaction of the compression sidechain. We all know tubes sound different than their solid-state counterparts, but I think more important is the way they feel, and the reaction of a tube input translates through to the compression sidechain, so if I were to replace the tube stages in Single Slice with solid-state components, I would expect the compression to behave differently.

The only compressor type I'm aware of that works much differently that what I described above is a vari-mu compressor, which effectively changes the amplification factor of the tube. This is fairly complicated, uncommon, and expensive. I won't go into technical details on that right now because frankly I'm still trying to understand it myself.

it sounds like, per his own reporting, he added a clean blend to a VCA (or OTA) compression design and subbed in tube input and output stages for whatever solid state components were handling that function

A reasonably accurate summary, but as mentioned above the interaction of the tube stage and the compression sidechain behaves differently than it would a similar solid-state device, that's where the magic happens, in my opinion.

I hope this helps answer some questions, and I'm always around to answer more. I love questions because that's how you're supposed to get answers, you don't learn much without asking questions. So if there's any more out there please send them my way and if I don't have an answer already I'll do what I can to find it.

 

[chiphaleonbass]

I went back and forth a bunch on what the labels should be. Threshold to sensitivity was at the request of Mike Watt, that was the last change I made.


I'll admit I use those interchangeably, but to be accurate, an OTA is a type of VCA. VCA stands for Voltage Controlled Amplifier, but frankly most compressors can technically be considered voltage controlled amplification since the concept of compression is that the amount of amplification being done is adjusted based on the input of the circuit which is then converted to a control voltage. OTA, or operational transconductance amplifier, is a specific type of device that is used in compressors like the Dynacomp, Keeley, and Becos compressors.

With regards to the way the tube is used, I can clarify that a little further. The best parallel I can use is actually the Effectrode LA-1A. I'm using the tube in Single Slice in the same way they are in the LA-1A. The tube acts as an input stage to "flavor" the signal on the way in and also to feed the sidechain, which is the part that tells the compression engine (OTA in Single Slice, optical in LA-1A) how to adjust the signal output in relation to the input. There is then an additional tube stage that then further "flavors" and buffers the signal on the way out. So the tube isn't providing the compression per se, but it is very much involved in the way the output sounds as the response of the input stage can affect the reaction of the compression sidechain. We all know tubes sound different than their solid-state counterparts, but I think more important is the way they feel, and the reaction of a tube input translates through to the compression sidechain, so if I were to replace the tube stages in Single Slice with solid-state components, I would expect the compression to behave differently.

The only compressor type I'm aware of that works much differently that what I described above is a vari-mu compressor, which effectively changes the amplification factor of the tube. This is fairly complicated, uncommon, and expensive. I won't go into technical details on that right now because frankly I'm still trying to understand it myself.


A reasonably accurate summary, but as mentioned above the interaction of the tube stage and the compression sidechain behaves differently than it would a similar solid-state device, that's where the magic happens, in my opinion.

I hope this helps answer some questions, and I'm always around to answer more. I love questions because that's how you're supposed to get answers, you don't learn much without asking questions. So if there's any more out there please send them my way and if I don't have an answer already I'll do what I can to find it.

I won’t argue with Mike Watt, bet this compressor rips

 

[_Tay_]

I won’t argue with Mike Watt, bet this compressor rips

While i do understand compressors and how they work, i am very much in the camp that if it sounds good.. its good!

 

[EastDakota]

You aren't truly a bassist until you've argued about compressors online. Very curious to read the review and hear a demo!

 

[lomo]

While i do understand compressors and how they work, i am very much in the camp that if it sounds good.. its good!

....and based on what specs are available, this sounds like (pun intended) a tone sweetening compressor rather than a full featured utility comp. Remember that More is basically the "non-compressor" part of the D/C'ed Deep Dish comp. It was inspired by comments from deep Dish users who loved how it sounded with the comp minimized. I'd really like to know what the comp ratio is. Also, I haven't read anything indicating that it has bass-specific features, and if that's the case I wonder if lows tend to trigger it early? Kwekshins kwekshins & more kwekshins.....

 

[kojdogg]

I went back and forth a bunch on what the labels should be. Threshold to sensitivity was at the request of Mike Watt, that was the last change I made.


I'll admit I use those interchangeably, but to be accurate, an OTA is a type of VCA. VCA stands for Voltage Controlled Amplifier, but frankly most compressors can technically be considered voltage controlled amplification since the concept of compression is that the amount of amplification being done is adjusted based on the input of the circuit which is then converted to a control voltage. OTA, or operational transconductance amplifier, is a specific type of device that is used in compressors like the Dynacomp, Keeley, and Becos compressors.

With regards to the way the tube is used, I can clarify that a little further. The best parallel I can use is actually the Effectrode LA-1A. I'm using the tube in Single Slice in the same way they are in the LA-1A. The tube acts as an input stage to "flavor" the signal on the way in and also to feed the sidechain, which is the part that tells the compression engine (OTA in Single Slice, optical in LA-1A) how to adjust the signal output in relation to the input. There is then an additional tube stage that then further "flavors" and buffers the signal on the way out. So the tube isn't providing the compression per se, but it is very much involved in the way the output sounds as the response of the input stage can affect the reaction of the compression sidechain. We all know tubes sound different than their solid-state counterparts, but I think more important is the way they feel, and the reaction of a tube input translates through to the compression sidechain, so if I were to replace the tube stages in Single Slice with solid-state components, I would expect the compression to behave differently.

The only compressor type I'm aware of that works much differently that what I described above is a vari-mu compressor, which effectively changes the amplification factor of the tube. This is fairly complicated, uncommon, and expensive. I won't go into technical details on that right now because frankly I'm still trying to understand it myself.


A reasonably accurate summary, but as mentioned above the interaction of the tube stage and the compression sidechain behaves differently than it would a similar solid-state device, that's where the magic happens, in my opinion.

I hope this helps answer some questions, and I'm always around to answer more. I love questions because that's how you're supposed to get answers, you don't learn much without asking questions. So if there's any more out there please send them my way and if I don't have an answer already I'll do what I can to find it.

Awesome— and many thanks again for your accessibility, willingness to answer questions and transparency! Given that it’s one tube (albeit not a mini), is it more like a PC-2A– as per Scubaduba in his stellar review of the LA-1A? (Link):

“There are two gain stages. First is a grounded cathode tube stage. The output stage is a cathode follower circuit which also acts as a buffer. While the Effectrode PC-2A uses one tube for all of this, the LA-1A has three tubes.”

Also, I don’t know why I never thought about the inclusion of the LEDs in relation to the way the tubes were being used as I could have answered my own question.