Take note that you can get caught out with the Transistor, 3 different part numbers!:
Celsius Preamp (Boss CE-1 Preamp) -Update Noise issue FIX!
- Thread starter MichaelW
- Start date
MichaelW
Well-known member
@music6000 I used a can 2N222A, are you suggesting this might be the source of the noise? I wonder if it is........hmmmmmm
Yes, it should be 2N2222A, your a 2 too short Ha Ha!
Just the Pinout needs to be correct!
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MichaelW
Well-known member
MichaelW
Well-known member
Crap, I just counted my "2's" one isn't accounted for.........DANG IT, did I use the wrong part?
Edit: My bad, the errant "2" was hiding behind the electrolytic cap. I DID use a 2N2222A.
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Mentaltossflycoon
Well-known member
"Why was that other transistor confusing?" "It came down to too many twos too."
Elijah-Baley
Active member
As I said early to see the schematic would be great, but I think that should be just the same schematic we can see in the CE-1 Chorus Ensemble, with one exception.
Looking the PCB here https://www.pedalpcb.com/product/pcb481/ in the MichaelW's PCB C2 is missing, but it seems to me that the ceramic disc moved upper, and is the 470nF cap is taken off, it's the one in front the pin 3 of the IC. It could look weird, but I see other redrawn schematics like that.
Then the TC1044 is for a +9v/-9v.
Maybe I'll attempt to breadboard it if I have all the parts.
Looking the PCB here https://www.pedalpcb.com/product/pcb481/ in the MichaelW's PCB C2 is missing, but it seems to me that the ceramic disc moved upper, and is the 470nF cap is taken off, it's the one in front the pin 3 of the IC. It could look weird, but I see other redrawn schematics like that.
Then the TC1044 is for a +9v/-9v.
Maybe I'll attempt to breadboard it if I have all the parts.
MichaelW
Well-known member
Let us know if you figure out what's causing the hiss, this discussion made me take mine out and play it yesterday.
The hiss actually not too bad in clean mode. but once you hit a drive with it, it gets pretty bad. As I said it's a shame since it does lovely things to another overdrive.
Elijah-Baley
Active member
Did you place your pedal before or after the drive pedal? Being a chorus the CE-1 should be after eventually fuzz, drive, etc.
Anyway, I'm working on it.
Anyway, I'm working on it.
MichaelW
Well-known member
No, I'm using the Celsius as a "boost/tone conditioner", so before drive pedals.
So here's an interesting tidbit. If you're familiar with Universal Audio product, I use an Apollo Twin X as my recording interface.
UAD makes a LOT of very accurate recording and mixing plugins of classic consoles and studio gear (Neve, etc).
They have less when it comes to specific guitar and bass effect plugins but the ones they have are very very good.
Which brings me to the point....I've been demo'ing the Roland CE-1 Chorus plug in and it sounds fabulous. When they model an amp or pedal they will model it down to the very details of the original, including it's idiosyncrasies (for instance they model the noise of the inherently noisy Friedman DS40 amp)
I was playing around with the CE-1 plug in, and if I defeat the modulation and just use it for the boost part.......guess what?....it makes the same noise....heh. I would bet if you got your hands on a vintage CE-1 it would probably have the same hiss.
Not to say it can't be improved, just sayin in my opinion, it's an inherent quality of the CE-1.
Elijah-Baley
Active member
I redrawn the CE-1 preamp from the original CE-1 chorus (voltage part is simplified, just to work around on my software).
I try it on breadboard, starting from same basic, I don't know if there's something wrong, because it doesn't work, though the schematic is that.
First of all I excluded for now the transistor stage. Voltage at the pin 7 is 9v, pin 4 to the ground. The Celsius version, I guess, doesn't have C4, so tried with and without it.
Without C4 the circuit is mute. I got over 8v at pin 2, at 9v at pin 6... it seems weird to me.
I tried with a 47nF as C4 (I don't have other 470nF, that was the first I found). Voltage changes, and it sounds very weak, muddy and I got loud crack farting sound at the peak of the strumming. With a 100uF (I know it's big, but without is the same thing). I tried it twice. It doesn't work.
I try it on breadboard, starting from same basic, I don't know if there's something wrong, because it doesn't work, though the schematic is that.
First of all I excluded for now the transistor stage. Voltage at the pin 7 is 9v, pin 4 to the ground. The Celsius version, I guess, doesn't have C4, so tried with and without it.
Without C4 the circuit is mute. I got over 8v at pin 2, at 9v at pin 6... it seems weird to me.
I tried with a 47nF as C4 (I don't have other 470nF, that was the first I found). Voltage changes, and it sounds very weak, muddy and I got loud crack farting sound at the peak of the strumming. With a 100uF (I know it's big, but without is the same thing). I tried it twice. It doesn't work.
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MichaelW
Well-known member
OMG, you've invented the much anticipated FART PEDAL!!!I redrawn the CE-1 preamp from the original CE-1 chorus (voltage part is simplified, just to work around on my software).
I try it on breadboard, starting from same basic, I don't know if there's something wrong, because it doesn't work, though the schematic is that.
First of all I excluded for now the transistor stage. Voltage at the pin 7 is 9v, pin 4 to the ground. The Celsius version, I guess, doesn't have C4, so tried with and without it.
Without C4 the circuit is mute. I got over 8v at pin 2, at 9v at pin 6... it seems weird to me.
I tried with a 47nF as C4 (I don't have other 470nF, that was the first I found). Voltage changes, and it sounds very weak, muddy and I got loud crack farting sound at the peak of the strumming. With a 100uF (I know it's big, but without is the same thing). I tried it twice. It doesn't work.
Robert
Reverse Engineer
The circuit runs on a split polarity power supply.
If you're powering it from a single polarity supply you need a VREF bias voltage on the input of the opamp.
I'm working on a solution to the noise issue and also have a couple of the other clones incoming for comparison purposes.
The fix, I believe, will be simple... There's a minor part of the circuit that is commonly overlooked (I am guilty of it).
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Elijah-Baley
Active member
I know it was something like that. Well, I have no reason to include the +9v/-9v power supply. I'm sure it will work fine.
No, really.OMG, you've invented the much anticipated FART PEDAL!!!
Elijah-Baley
Active member
On my breadboard I included the +9v/-9v supply and of course it worked (I was testing just the op-amp section).
I got a lot of volume, and close at highest volume setting I got op-amp clipping (TL071), honestly it's not so nice. My emulator software says it's over 25db, after all.
Even if it changed some circuit characteristic I added a 100k master volume to hear it well ad high gain setting.
Later I included the transistor stage: more volume, it's a a bit dull, it distorts sooner and more, of course. Again, bad distortion, to my hear it sounds fizzy and broken. This circuit seems even very sensible to the pickup position: bridge pickup (in both the guitar I tried) sounds quieter, so less aggressive. (Is it because the breadboard?)
The circuit adds some hiss. It seems to me like a boost at higher gain setting: not so good, but not so bad.
Hearing this circuit like that I don't like it. It's still worth just as clean volume boost, but when it get distortion it's nothing have to do with the mild break up of John Frusciante's sound.
And now I have a question: that bad distortion is it normal? I got something like that in other circuit experiment, and I know op-amp clipping is never so musical. But that nice break up I hear in some demo with this kind of preamp (the various pedals) is due to the tube amp? My amp is a solid state 120w.
I'm not sure because I had no experience with tube amp, unfortunately, but I have the idea that tube amp will go in overdrive at high volume boost of a pedal before the pedal's circuit start to clip. That causes that sweet break up. Instead, solid state amp "accept" all that volume boost keeping the sound cleaner, but then we can hear the pedal start to clip.
I got a lot of volume, and close at highest volume setting I got op-amp clipping (TL071), honestly it's not so nice. My emulator software says it's over 25db, after all.
Even if it changed some circuit characteristic I added a 100k master volume to hear it well ad high gain setting.
Later I included the transistor stage: more volume, it's a a bit dull, it distorts sooner and more, of course. Again, bad distortion, to my hear it sounds fizzy and broken. This circuit seems even very sensible to the pickup position: bridge pickup (in both the guitar I tried) sounds quieter, so less aggressive. (Is it because the breadboard?)
The circuit adds some hiss. It seems to me like a boost at higher gain setting: not so good, but not so bad.
Hearing this circuit like that I don't like it. It's still worth just as clean volume boost, but when it get distortion it's nothing have to do with the mild break up of John Frusciante's sound.
And now I have a question: that bad distortion is it normal? I got something like that in other circuit experiment, and I know op-amp clipping is never so musical. But that nice break up I hear in some demo with this kind of preamp (the various pedals) is due to the tube amp? My amp is a solid state 120w.
I'm not sure because I had no experience with tube amp, unfortunately, but I have the idea that tube amp will go in overdrive at high volume boost of a pedal before the pedal's circuit start to clip. That causes that sweet break up. Instead, solid state amp "accept" all that volume boost keeping the sound cleaner, but then we can hear the pedal start to clip.
Bricksnbeatles
Member known well
I’ll probably just order a new board at some point to put in the enclosure I designed for this one, but I may as well give this mod a try too instead of scrapping the board I have rn! Thanks for the heads up
Robert
Reverse Engineer
Just shoot me a message next time you place an order and I'll send you the new revision.
