Ember Boost (TC Spark) w/C-Buffer

[MichaelW]

I'm not sure how I missed this PCB when I was building all my boost pedals a few months ago. Ironically, all the different PPCB boosts I built was to replace the last COTS pedal in my rig, which was the TC Electronic Spark. I stumbled on the Ember board in one of my late night half asleep shopping spree's and of course had to order it!

As I've said elsewhere, I think the TC Spark is one of the most under-rated boost pedals out there. It doesn't get a lot of attention but those people that do use it seem to absolutely love it (like me). It does everything an Xotic RC Booster is "supposed" to do (but doesn't imo) all for a pittance in todays pedal economy.
Sweetwater has this pedal for $69.

I would categorize it more as a low gain overdrive that also does a really clean boost. When I looked at the BOM for the pedal I got a bit of sticker shock seeing that it called for 3 OPA2134's . Not exactly sure why the original uses these pricey chips as I can't really see it making a huge difference in a pedal like this. Especially when the original pedal costs less than many AliExpress clones.....

Nevertheless, I hoarded my last 3 OPA2134's for this build although I suspect it would sound just as good with NE5532's or TL072's.

I did a search on the forum and read some posts about some suggested mods and I usually will try anything @Chuck D. Bones suggests, so I omitted C19 and dropped C10 to 100p. I wish I could say I understood what this actually is doing, but I don't, I'm just a lemming that listens to the advice of his betters

Couple of other mods I did, I socketed the clipping diodes and have BAS33's in there right now instead of the 1N914's that the BOM calls for. This was just for giggles to see what it would sound like. (And mostly because I have a boatload of BAS33 diodes.....filed under the "Why did I buy these again" category)

I also had a PPCB C-Buffer board that I bought a while ago looking for a pedal to stick it in. This was as good as any since it will probably live on my board forever.

I've been noticing some high end loss when I run my Dark Rift and Spatialist pedals into the front end of my interface. Putting a buffered bypass pedal in front of it seems to help it quite a bit. I've got two other pedals with Cornish style buffers and they seem to work well for me. Another recent build that seems to like a buffered pedal in front of it is my Tone Vendor MkII.

My primary use for my Spark is not so much boosting as much as a unity gain tone shaper. The active tone stack is very useful to dial in (or dial out) certain frequencies especially in front of an overdrive. The "Fat and Mid" switches are very useful to dial in a sweet light overdrive sound or fatten up another overdrive pedal.

Comparing side by side my Ember and my COTS Spark, it's really very close. The Ember sounds slightly fuller and maybe a wee bit warmer. The Spark sounds a bit thinner, maybe cleaner but it's really splitting hairs and probably a healthy does of placebo affect. One thing for sure though TOP MOUNTED JACKS RUUUUUULZ!!!
(Can you tell I detest side mounted jacks?

I was trying to record a demo of this pedal into my Dumbloid with some David Gilmour licks just to piss off @thewintersoldier )) but my recording set up has been fritzy since I updated the firmware.....(sigh, it's always something......). I might give it another shot or just post the truncated version of what I was able to record.

Anyway, highly recommended, flexible boost pedal, eq pedal.

(PS, not sure why the C-buffer board looks so rough in the picture. I cleaned the snot out of it with IPA last night.)

 

[fig]

Gilmour licks sure are exciting!

Great write-up sir, and some low-noise HP under the hood.

 

[MichaelW]

Well, I guess you'd have to had lived through that period when "Dark Side of the Moon" was the best record cover to use to clean the seeds out of your....uhm....Humboldt County leafy organics......so there's some nostalgia as well as "mood associations" involved. But I'm with you, I love some of the classic Gilmour riffs but I can only listen to so much before getting bored.....

My artistic capabilities would look more like "Mr. Bill" than "Dr. Strange".......I think I'll enjoy yours vicariously....hah!

 

[MattG]

That looks great! Nice clean work. Also thanks for calling my attention to the PPCB C-Buffer.

Do you play in a band at all? Since you've had the commercial Spark Booster for a while, obviously you like it, just curious about your set up. I built an Ember recently as well, but I haven't had my real Spark or the Ember long enough to see how it fares in a band context. My main goal for the Spark/Ember was to be a "glue"/swiss army knife type pedal, to help normalize tones across multiple guitars, amps, and even bands. Just something to fill in the cracks as needed.

So far I've only used it at home, and what I've found is that it seems to demand a tube amp. It sounds great as a boost/tone shaper/mild overdrive into my Trinity Triwatt. But a lot of my practice is through headphones, and for that I use a Humboldt Simplifier, and the Ember (and Spark too) sounds pretty harsh through that: I suspect the Simplifier doesn't have enough headroom, and is likely built around opamps, so the Ember is likely too much. (And to be fair, a boost is kind of silly in a headphone practice scenario anyway; but I do like to play with my pedals, even when my family doesn't want to hear it!)

I wonder if this could be run at 18v? That and a clipping switch might take the versality up another notch. Likewise, I wonder if the fat and mid filters from the Spark/Ember could be adapted for use in the Timmy and/or Colorsound Power Booster...

 

[giovanni]

I was wondering if your audio interface has an input impedance that’s too low? Does it have an instrument input mode?

About Gilmour and Pink Floyd: they used to be my absolute favorite band for a long time, starting from high school. I still love all the guitar solos and tones from Animals and Dark Side of the Moon and the solos on Comfortably Numb, but I have to admit I don’t really listen to them a lot anymore. Even when I take, uhm, organic foods with dinner. Or after dinner usually.

 

[giovanni]

Oh and I had to add the Ember to my wishlist after such a nice introduction!

 

[MichaelW]

That looks great! Nice clean work. Also thanks for calling my attention to the PPCB C-Buffer.

Do you play in a band at all? Since you've had the commercial Spark Booster for a while, obviously you like it, just curious about your set up. I built an Ember recently as well, but I haven't had my real Spark or the Ember long enough to see how it fares in a band context. My main goal for the Spark/Ember was to be a "glue"/swiss army knife type pedal, to help normalize tones across multiple guitars, amps, and even bands. Just something to fill in the cracks as needed.

So far I've only used it at home, and what I've found is that it seems to demand a tube amp. It sounds great as a boost/tone shaper/mild overdrive into my Trinity Triwatt. But a lot of my practice is through headphones, and for that I use a Humboldt Simplifier, and the Ember (and Spark too) sounds pretty harsh through that: I suspect the Simplifier doesn't have enough headroom, and is likely built around opamps, so the Ember is likely too much. (And to be fair, a boost is kind of silly in a headphone practice scenario anyway; but I do like to play with my pedals, even when my family doesn't want to hear it!)

I wonder if this could be run at 18v? That and a clipping switch might take the versality up another notch. Likewise, I wonder if the fat and mid filters from the Spark/Ember could be adapted for use in the Timmy and/or Colorsound Power Booster...

I don't play live or in a band, all my playing is really just noodling and typically at pretty low volumes. The Spark/Ember is pretty versatile in the sense that it CAN just be a "normalizer" as you put it for eq purposes and I think it does that really well. Having said that, I think a more useful pedal in a band situation might be something more along the lines of a BB-Preamp. The AionFX version has the Custom Shop mods for additional clipping and compression and it also has a mid-boost control which I find to be the most useful eq band for giving your single coils a bit of a kick in the pants or dialing out muddiness in humbuckers. 80% of the time I am playing through my UAD Apollo Twin X into a clean amp model. The UAD Unison DSP based preamps are pretty amazing in how they can react like a tube amp. But there's something about the mechanics of vacuum tubes pushing a speaker cone that can't be reproduced whether through studio monitors or headphones. I would bet that what sounds harsh to you through the headphones is probably just that you're hearing "too much information" and picking up the nuances and transients that would normally get absorbed by your room, curtains, walls, etc.

 

[MichaelW]

I was wondering if your audio interface has an input impedance that’s too low? Does it have an instrument input mode?

About Gilmour and Pink Floyd: they used to be my absolute favorite band for a long time, starting from high school. I still love all the guitar solos and tones from Animals and Dark Side of the Moon and the solos on Comfortably Numb, but I have to admit I don’t really listen to them a lot anymore. Even when I take, uhm, organic foods with dinner. Or after dinner usually.

My Apollo interface has instrument, line and mic level inputs. When I'm running my pedals it's straight into the instrument input. The way the Unison Preamps work on the Apollo is that there's a tight coupling between the onboard DSP and whatever software amp model you're running. Each amp model actually models the preamp response of that amp which is loaded into the onboard DSP's to do heavy lifting processing. One of the reasons that UAD doesn't have a bazillion amp models like the "all software" systems (Neural, Helix, etc) is that it takes a lot of work to build the actual amp model. There's a pretty noticeable difference between the amp models they offer that use the DSP Unison preamps and the software only models that don't. It's not necessarily the sound that comes out of my monitors, they can be pretty convincing, but rather how the amp model 'feels'. Some of the models are crap...but there are couple that really sound and "feel" like I'm playing through a tube amp. Most notably the Friedman and Fuchs models that I tend to use the most frequently. Sadly, I think the Plexi model is total crap as is the 5E3 Tweed model. (Although a lot of people rave about both)

I have never been a fan of running reverb and delay into the the front of an amp (even though some folks prefer it). I've always preferred having them in an effects loop. That's one thing I can't do with my version of the Apollo interface. There is no insert loop feature. (That I know of). When I use my real tube amp, I'm taking the balanced line out of the Two Notes Torpedo and going into balanced line input on my Apollo. In that setup, I'm running my delay and reverb through the amp's buffered efx loop and they sound really pristine and lovely. All of which is a long winded way of saying, there's something I don't like about how the delay and reverb sound whether running into the front of a real amp or a virtual amp. A buffered pedal close in the chain seems to help in both cases