Caline CP-18 Orange Burst Overdrive  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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Brink
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Post by Brink »

TL;DR: Xotic BB Preamp
Differences from BB: 2x Tl072 instead of 1x 4558 + 1x Tl072. 2x C1815 instead of 2n5088. Larger power caps.

I bought one of these to see what it was.
2x TL072, 2 transistors (C1815). Pots are B100K volume, A1M gain, B50K treble, B50K bass.
Input cap is 22n. One IC has 2 Si diodes and a 51pf cap in the in the loop. One IC outputs to a 10uF cap into the volume control, which then goes to a 100n cap.

Cap markings:

2 ceramic caps
151
510

11 film caps
223
???, big, right by the footswitch. Probably 1u.
104
54?
472
472
104
333
can't read, but looks the same as the 333, both are by the Bass pot.
224
Some I can't read due to their placement.

4 electros
10u
10u
47u
100u (this and the 47 are at the top right of the board by a couple resistors and a zener diode)

I was going to desolder the pots and post pics, but it seems pointless now.

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AAntonio
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Post by AAntonio »

hello
I bought this pedal, the clone of the BB Preamp
disassembled, and I saw that as a transistor uses 2 C1815 :shock:

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lolbou
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Post by lolbou »

2SC1815? What's wrong with it?
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.

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aanz
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Post by aanz »

1SC1815s is used for buffer?
heres a gut-shot:
Attachments
Caline Orange Burst outside
Caline Orange Burst outside
calineburst.png (550.99 KiB) Viewed 7224 times
Caline Orange Burst gut shot
Caline Orange Burst gut shot

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lolbou
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Post by lolbou »

Seems like the BB Preamp has one 2N5088 for input buffer and one other for output buffer. 2SC1815 can achieve the same results as buffers...
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.

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AAntonio
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Post by AAntonio »

ok I understand, therefore have no effect on the sound

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Duckman
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Post by Duckman »

Well... as much, the same effect that you can hear in every TS

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Post by mictester »

AAntonio wrote:ok I understand, therefore have no effect on the sound
No. A buffer will not alter the sound at all.

However, buffers can be used to advantage (as in the Toobscreamer) to protect the op-amps from the outside world, and to do useful impedance conversions - usually high impedance in, low impedance out. They do not affect the sound at all. However, a lower impedance output from a pedal will suffer less treble loss down long cables so may sound "brighter".
"Why is it humming?" "Because it doesn't know the words!"

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Andy2No
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Post by Andy2No »

Was there a schematic here, once? The thread title indicates that there was, but if so, it's gone now.

I bought one on ebay, which I like, but it has a tendency to screech / squeal / shriek like a banshee if I plug the power supply in while the foot switch is left in the On position - I have to turn it off and back on again, with the foot switch, not the power supply.

I thought maybe it was a design fault, but I haven't seen any discussion of the problem, so maybe it's not a common one. A schematic would be useful in helping me fix it.

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Post by Andy2No »

aanz wrote:1SC1815s is used for buffer?
heres a gut-shot:
I've only seen the back of the PCB in mine, but they've changed it. The PCB fills most of the space, just leaving room for a battery.

The 1/4" jack sockets are mounted on the PCB but the power socket isn't. There are three fairly thin trailing wires from there to the PCB, which were passing under the input socket (i.e. on top, from my point of view, looking at the back of the PCB). I tried moving them, in case that helped, but I'm not sure it did.

It's currently not squealing if I unplug the power lead, give it a moment, then plug it back in, but it's louder, noisier and kind of distorted, until I turn it off and back on again with the foot switch. It does that consistently.

I've found a couple of BB preamp schematics, to look at, but there are differences, of course. I can't really picture how it could do what it's doing.

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Post by wjbguitar »

Hey guys, I'm new here. I live in Brazil and I bought a new Caline Orange Burst pedal on Aliexpress. I received the pedal today. The package was fine.

When I tested the pedal, I immediately noticed that something is wrong with it. When I engage the pedal, the led turns on and the sound is fine with the GAIN control up to 10 or 11 o'clock. If I increase the GAIN above that, the volume itself decreases and the sound gets excessively distorted, compressed and "squashed" (a horroble sound!).

I have a Caline Pure Sky and a Caline Crazy Cacti, and both work fine. I opened the bottom cover just to check things. Everything seems to be fine. The only thing I found strange is a black wire that comes from the led, connects to a small resistor and then is soldered to one contact of the footswitch. I disconnected this wire and the only change was that the led stopped working, but the horroble sound remained the same.

Have anybody had a bad experience like that with this pedal?

Regards from Brazil!

William

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Andy2No
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Post by Andy2No »

Hi William,

Did you read my post, immediately before yours?

My problem was a little different, but also related to the Gain pot. All I did to fix it was remove some stray splashes of solder, and retouch some solder joints that looked badly soldered.

A "dry" solder joint tends to look different to the others. You can often fix them by just reheating the joint with a soldering iron, for just a few seconds. Adding a dab more solder may help, but your solder might not mix well with theirs, so not always the best idea.

I recently bought a second Orange Burst, and it's identical to the one I fixed (i.e. after I fixed it, not before :) ) so my bodging worked.

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Post by wjbguitar »

Hi Andy,

Thanks for the hints. Yes, I did see your previous post. My unit is built as yours.

I checked all solder joints one more time and everything seems to be fine. The PCB is quite clean, the electronic parts are placed and soldered properly. The only "strange" thing I saw is, as I said, that black wire that comes from the led, connects to a small resistor and then is soldered to one contact of the footswitch.

I checked the voltage in the pins of both TL072 and everything seems OK too. In fact, the pedal works very well until the GAIN reaches 11 o'clock (VOLUME, BASS and TREBLE act as expected). If I increase the GAIN above that, the volume level decreases almost to zero and just an awful distorted sound can be heard.

Well, I wrote to Caline's customer support asking for help. Honestly, I will be surprised if they send any helpful feedback. Even if I cannot manage to fix the pedal, I will buy another one (from another seller). I like my Caline Pure Sky a lot and, from what I could hear about the Orange Burst, I think it is a great pedal too.

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Post by Andy2No »

I'd be surprised if they were of much help too. Still, worth a try.

The Caline Orange Burst is a truly great pedal. Using it with the Gain at zero is one of my favourite settings anyway, and they sound wonderful with two stacked together, so all is not lost. I own the Pure Sky too, but I much prefer the Orange Burst.

As you may have gathered, it's meant to be a clone of the Xotic Effects BB Pre-amp, so the schematic here may be of help:

http://revolutiondeux.blogspot.co.uk/20 ... reamp.html - the main link there is :

http://madbeanpedals.com/projects/Glitt ... rattii.pdf

One thing you could consider is replacing the clipping diodes with strings of three or four diodes in each direction. That may let you turn the Gain knob more before you reach the point where it all goes wrong - the clipping will be softer. I plan to do that to one of mine, at some point, plus change a couple of values in the tone controls, to make it more like the bass version.

I'd check the Gain pot at various positions with a multimeter first though. From that schematic, it should be wired as a variable resistor - only two pins in use, with maybe two wired together. You should get a fair idea of how it's behaving without having to unsolder it from the circuit, or at worst, unsolder one pin, to disconnect it.

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Post by wjbguitar »

Hey, Andy. Thanks for the hints!

I have tested the pedal a lot in the mean time and found out some strange behaviour. I removed one specific clipping diode and the sound cleaned up immediately. When I put it back in the circuit (same position and polarity) and removed the other one, the sound got horroble again. Initially, I thought it could be a damaged diode. So, I remove both diodes, wired the circuit to a breadboard and tested it again with new diodes and leds. The result was the same. If I use no diode at all, or only one diode or led in a specific direction (polarity), the sound is OK, although the overdrive effect itself gets very subtle. If I invert the polarity of this same diode (or if I use two diodes, with inverted polarities) the sound turns into a mess. Cannot understand why!

As I do not have an oscilloscope in order to go deeper into analysis of the problem, I decided to contact the seller and he gently agreed on sending another Orange Burst to me. :)

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Post by Andy2No »

No problem. That's good. Do you get to keep the old one?

The Orange Burst makes a great almost clean boost, so I'd be tempted to leave the diodes out and just keep it at that, though you might want to look at the bias voltage, and the components that bias the op amp stages - the Glitterati schematic shows a 47nF capacitor and 4k7 resistor, biasing the inverting input of the first op amp stage.

I've been trying to modify an MXR Bass Overdrive I bought on ebay. I don't think it's faulty, they're just not an overdrive. There's so much gain on the first op amp stage that it makes it a distortion, and not one I particularly care for. I assumed it would be a nice subtle overdrive, since it's for bass. I really should have read up on it more.

I pulled the clipping diodes out (one each way) but it's very hard to avoid op amp clipping distortion, where the signal tries to exceed the voltage powering the op amp, or tries go below ground. That sort of clipping sounds really horrible, to me. Very artificial, and just nasty.

My next step will be to try to reduce the gain of that first stage, though it's all surface mount components, so a pain to work on (plus, my hands shake quite a bit). When I'm happier with that, I'll put some diodes in, so the signal can't cause op amp clipping, but more in each direction - depending on how many I can conveniently cram into the space.

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Post by aw73 »

i know this is an old thread but i have a problem that maybe someone knows the fix. i have the newer version of the orange burst with the switch on the board. the led stays on dimly with the pedal off and also with the pedal off my guitar volume control makes static noise, but not when the pedal is on, which is really odd to me. does anyone know what could cause this?

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Post by Andy2No »

aw73, The first one I bought (on ebay) had some really dodgy soldering, and a few little blobs of stray solder stuck to it.

That one had weird problems with the gain pot, but bad soldering could affect anything. All I did to fix it was pick off the blobs of solder that were sitting on the board, then re-solder a few points that looked dodgy. It was fine after that.

I didn't even remove the old solder, I just heated up what was there with my soldering iron, and added a little bit more, in places.

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aw73
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Post by aw73 »

i have resoldered every connection. it still does the same thing.

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marshmellow
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Post by marshmellow »

Broken switch.

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