Does the Celsius preamp behave like a fuzz when it comes to buffers?

[mkstewartesq]

Like probably a lot of people, I find that I build my pedals more than actually play them. I'm trying to change that so I set aside some time to play with my Celsius. Because I have it running iin a 2-in1 build with my chorus and I’m not really a fan of the overdriven sound of the “high” mode on the Celsius, I rarely use it in either "high" mode or as a standalone pedal. In addition to being more overdriven than I’d like, "high" mode is also very dark and muffled.

But today I noticed that if I flipped on a buffer in front of it while the Celsius is in "high" mode, the sound not only gets noticeably louder but much more defined with a lot more treble content (it actually sounds better to my ears than it does with without the buffer in front of it.). Flipping on a buffer while in "ow" mode doesn’t really seem to make any difference – only in the “high”mode.

Is this huge difference I’m hearing akin to what happens when you put a buffer in front of a fuzz or a treble booster (which is usually not recommended)? If so, why does it only affect “high” mode and not “low” mode? Schematic attached.

(Or..... does the dark muffled sound I get on the “high” mode without a buffer indicate something might be wrong with my build and I really should just leave a buffer on all the time or even build a small buffer board directly into the pedal?)

Thanks,
M

 

[jwin615]

Cable may be loading down the transistor stage?
See if it changes with a different cable from the guitar.

 

[Bricksnbeatles]

Sounds about right. Look up Joe Perkins’ videos on both the original boss CE-1 and the Past FX Preamp Crunch. Buffers are generally seen as a huge improvement with the CE-1’s preamp, and are included in most of the commercially available CE-1 preamp pedals I’ve seen, but the darker sound without a buffer is also nice

 

[mkstewartesq]

Sounds about right. Look up Joe Perkins’ videos on both the original boss CE-1 and the Past FX Preamp Crunch. Buffers are generally seen as a huge improvement with the CE-1’s preamp, and are included in most of the commercially available CE-1 preamp pedals I’ve seen, but the darker sound without a buffer is also nice

Thanks for this. Now I guess I’m going to need to go build a small buffer on Vero, crack open my build, and insert it on the input line just for those times when I don’t have an external buffer running in front of it. I really do quite prefer the sound of the high mode with the buffer than without.

Of course, I could’ve spent less than a buck eachand just bought a couple of buffer boards from Robert had I known about this when I placed my last order TWO DAYS AGO

 

[coltonius]

In “high mode” the input capacitor lets in a lot more bass (1uf), so placing a buffer before it will generally negate this effect due to the buffer’s smaller input cap. A typical klon-style buffer has a 100n (.1uf) input capacitor, which is why you get relief from the woofiness.

 

[mkstewartesq]

In “high mode” the input capacitor lets in a lot more bass (1uf), so placing a buffer before it will generally negate this effect due to the buffer’s smaller input cap. A typical klon-style buffer has a 100n (.1uf) input capacitor, which is why you get relief from the woofiness.

In addition to the very useful resources @Bricksnbeatles pointed me too, I also found an article by Boss, all confirming that, because this chorus and preamp was originally designed for use with low impedance instruments like keyboards, treble loss is to be expected in both high and low mode when using a guitar if a buffer is not present. The Boss article, along with some other articles I read said this could also be remedied a bit by using a pot with a larger value than the 50 K pot used in the preamp (again, which Boss says is better suited to low impedance instruments). I will say, however, that both my high and lo mode seem even darker than the samples of other preamps that I have heard on YouTube, so I’m also not ruling out that there could be something slightly up with my build as well.

So I’ll build a buffer and install it. I actually have buffers in other pedals ahead of the preamp in my chain but it seems easier just to make a self-contained solution within the pedal box itself. Maybe I’ll put it on a switch for the ultimate flexibility Although it breaks my heart to drill another hole in this case because I like the design so much.

Mike

 

[mybud]

'...both my high and lo mode seem even darker than the samples of other preamps that I have heard on YouTube, so I’m also not ruling out that there could be something slightly up with my build as well.'

For various reasons, I've been following this thread with great interest, and I've recently breadboarded the selfsame circuit. I'm not getting a change of tone colour between the two switches, nor the distortion you mention. Mine (subject to my own possible mistakes, of course) seems quite bright and doesn't get fuzzy even when fully maxed in the high setting.

I wonder if your different results stem from the recombination of the two different boards, which somehow has contributed to impedance complications, which cause the breakup and loss of tone you're experiencing? I grant that you've done much more research into the Celsius' foibles than I, so maybe just thinking aloud on my part. Someone with more knowledge and experience will no doubt contribute in time but I'm struck by our different sonic experiences here.

 

[mkstewartesq]

For various reasons, I've been following this thread with great interest, and I've recently breadboarded the selfsame circuit. I'm not getting a change of tone colour between the two switches, nor the distortion you mention. Mine (subject to my own possible mistakes, of course) seems quite bright and doesn't get fuzzy even when fully maxed in the high setting.

interesting that you’re not getting any distortion/fuzz in the high setting – my understanding is that that distortion in the high mode is basically a hallmark of this preamp (because the 2N222 is brought into the circuit when you switch to high mode).

Looking at YouTube videos demoing other clones of this circuit seem to be consistent with my experience – in low mode, unity volume is at around 3 o’clock and maxing out low mode gives a nice boost, whereas, in high mode, unity volume is about 9 o’clock and you start getting into a distorted tone as you go above that. One demo-er noted that, in low mode, any break-up he was getting seemed to be coming from the amp, whereas, in high mode, a lot of the distortion was being generated directly from the preamp circuit.

Similarly – and I should’ve looked at it before I posted this thread – in his build review and demo over in the build forum, @Guardians of the analog mentioned that one should expect a lot of loss of high-end frequencies in the absence of a buffer.

Would be interested to hear what others say about their experiences with this build.

 

[mybud]

'...interesting that you’re not getting any distortion/fuzz in the high setting – my understanding is that that distortion in the high mode is basically a hallmark of this preamp (because the 2N222 is brought into the circuit when you switch to high mode).'

Let's not rule out the possibility that I've somehow got this wrong on the breadboard, shall we? I'll double-check and get back to you on this.

 

[mkstewartesq]

'...interesting that you’re not getting any distortion/fuzz in the high setting – my understanding is that that distortion in the high mode is basically a hallmark of this preamp (because the 2N222 is brought into the circuit when you switch to high mode).'

Let's not rule out the possibility that I've somehow got this wrong on the breadboard, shall we? I'll double-check and get back to you on this.

Understood. But I’m still very interested in how things go for you. I’m never one to rule out the potential for issues in my own build caused either by my own mistakes (I once blew out four LEDs in succession before I realized that I had used a 4.7R resistor as the CLR rather than a 4.7 K) or my sometimes wacky set ups (like this 2-in-1 build).

Mike

 

[mybud]

Understood. But I’m still very interested in how things go for you. I’m never one to rule out the potential for issues in my own build caused either by my own mistakes (I once blew out four LEDs in succession before I realized that I had used a 4.7R resistor as the CLR rather than a 4.7 K) or my sometimes wacky set ups (like this 2-in-1 build).

Mike

Curiouser and curiouser. I can’t see any obvious errors on the breadboard (famous last words), but then I’m running it as a standalone preamp. Maybe there’s a gain staging difference in the 2222 I’m using? I’ll check the voltages in due course; maybe that will reveal some significant differences between our builds. I have noticed that some preamps overload the following stage, which mine doesn’t seem to. As before, never rule out operator/assembler error on my part but it does seem functional. BTW as regards 4R7 vs 4k7, I had to smile in recognition of the kind of errors I make to this day…

 

[mkstewartesq]

Curiouser and curiouser. I can’t see any obvious errors on the breadboard (famous last words), but then I’m running it as a standalone preamp. Maybe there’s a gain staging difference in the 2222 I’m using? I’ll check the voltages in due course; maybe that will reveal some significant differences between our builds. I have noticed that some preamps overload the following stage, which mine doesn’t seem to. As before, never rule out operator/assembler error on my part but it does seem functional. BTW as regards 4R7 vs 4k7, I had to smile in recognition of the kind of errors I make to this day…

1. With regard to the LED mistake I made, you may or may not be aware that, contrary to my expectations, an overloaded LED doesn’t simply burn out. It actually explodes. Into pieces.

2. As far as my Celsius – actually, all of my comments in this thread describe my experiences running it as a standalone pedal as well. Yes, it is part of a 2-in-1 build but with a dedicated foot switch so I can deactivate the chorus and the output from the Celsius will simply pass straight through the other 3PDT to the output jack without touching the chorus circuit. I wanted to maintain the flexibility to use the preamp as a standalone since my understanding is that a lot of people use it that way just to overdrive an amp.

 

[mybud]

Ok, understood I‘ve had some fairly spectacular mishaps too, usually with miswired voltage regulators. They became literally too hot to handle and then other components start complaining…

Running it standalone as you (and I both) do makes these differences even more baffling. Will get to those voltages soon.