Zener diode changes on a Ceriatone Chupacabra/Yeti?

ledvedder

Well-known member
I'm wondering if anyone has played with different zener diodes in either of these amps. Apparently, the Chupacabra uses a 9.1v zener for 90s Era and a 20v zener for 80s Era. I love the 80s Era, but the 90s Era is too saturated. Has anyone experimented with something higher than 9.1v in the 90s mode? Or maybe even one higher than 20v? From what I understand, the higher the voltage, the less clipping occurs.
 
Not sure, but I think that type of clipping circuit is usually 2 zeners back to back. Probably 2x20's for 80's mode and 2x9v for 90's mode. And yeah, 2 x 9v zeners is a lot of clipping.
You could try 2 x 18v, 16v, or 12v for a higher clipping threshold in 90's mode. You can also mix the zeners for asymetrical clipping for a bit of a different sound. For example you could try a 20v and a 16v.
You could also try other types of diodes like MPSA06 or 2N5400.
Lot's of options.
I like 20v zeners and the MPSa06's.
 
scottosan":3pajcde3 said:
The MPSA06 or the 2N5400 will be even more saturated.
Yup, IIRC the MPSA06 are 4v and the 2N5004 are 5v. It's on the datasheet as the emitter-base breakdown voltage. You can stack them to add up the breakdown voltage but if you decide to mix them you have to note that the mpsa06 are NPN and 2n5004 are PNP, so they are connected reverse from each other. There are lots of other transistors you could use too. I read somewhere that the mpsa06 were connected BE-EB-BE-EB in at least one Cameron mod. So that would be symmetrical 8v clipping.

If you try asymmetrical, try hooking up the string both ways to ground. One way should sound better than the other. Although I'm not sure if it is because it is preserving some existing asymmetry or "making it lean the other way". It will def feel different each way.

I tried mixing them to get 8v/10v asymmetrical once but I forgot about the NPN vs PNP connection...so when I connected them BE-EB-BE-EB I essentially made an expensive 18v zener. :bash: So I just connected a 20v zener in the opposite direction to make 18v/20v asymmetrical.
 
Would something greater than 20v work? This way I'd have a mode with even less clipping than the 80s mode with the 20v zeners. That's what I'm looking for, to give an eve less gainy, more classic rock mode.
 
ledvedder":3taz25e7 said:
Would something greater than 20v work? This way I'd have a mode with even less clipping than the 80s mode with the 20v zeners. That's what I'm looking for, to give an eve less gainy, more classic rock mode.
If it where me, and I was going for more classic tones, I would get a push/pull pot and replace one of the gains. I would replace the 2nd gain stage 820/.68uf on the board with a 10k and connect a 900/.68uf the switch, so in 1 position 10k and the other stock. Kind of like a structure switch
 
scottosan":1nv41ng5 said:
ledvedder":1nv41ng5 said:
Would something greater than 20v work? This way I'd have a mode with even less clipping than the 80s mode with the 20v zeners. That's what I'm looking for, to give an eve less gainy, more classic rock mode.
If it where me, and I was going for more classic tones, I would get a push/pull pot and replace one of the gains. I would replace the 2nd gain stage 820/.68uf on the board with a 10k and connect a 900/.68uf the switch, so in 1 position 10k and the other stock. Kind of like a structure switch

Hmm, I'll have to look into that. As you know, I'm just learning about this stuff, so I'm not sure how to do this. Gain 1 already has a push/pull which seems to drop the gain a bit and add more mids. At least that's what I'm hearing.
 
I find it interesting that the mpsa06 do not clip as much as the 5 volt zeners I use.


For the question, why not use a rotary switch and use a bunch of different values? They make tons of different voltage zeners.
 
psychodave":qj8qfp2i said:
I find it interesting that the mpsa06 do not clip as much as the 5 volt zeners I use.


For the question, why not use a rotary switch and use a bunch of different values? They make tons of different voltage zeners.
didnt the old Ocean mod have that feature? You can never have enough knobs :rawk:
 
psychodave":191dv0xg said:
I find it interesting that the mpsa06 do not clip as much as the 5 volt zeners I use.


For the question, why not use a rotary switch and use a bunch of different values? They make tons of different voltage zeners.
That is interesting. A rotary is a great idea. I know I switch between 20/18 and 8/8 alot depending on my mood.
 
scottosan":2xiz91nr said:
psychodave":2xiz91nr said:
I find it interesting that the mpsa06 do not clip as much as the 5 volt zeners I use.


For the question, why not use a rotary switch and use a bunch of different values? They make tons of different voltage zeners.
didnt the old Ocean mod have that feature? You can never have enough knobs :rawk:

He did it on lots of amps. It’s really a great idea. I wish my CCV had dual rotary clipping switches on both the lead and solo masters. You could do tons of tone shaping.
 
SpiderWars":2i1cgppm said:
psychodave":2i1cgppm said:
I find it interesting that the mpsa06 do not clip as much as the 5 volt zeners I use.


For the question, why not use a rotary switch and use a bunch of different values? They make tons of different voltage zeners.
That is interesting. A rotary is a great idea. I know I switch between 20/18 and 8/8 alot depending on my mood.

Just keep in mind that you may or may not like some zener settings because of the bright caps on the gain pots. It’s the sum of all parts not just one or two. For example, when using mpsa06 transistors, I like a .002uf bright cap on the gain pot. When using 5v zeners, I like .0047uf bright caps.
 
psychodave":wqralemp said:
I find it interesting that the mpsa06 do not clip as much as the 5 volt zeners I use.


For the question, why not use a rotary switch and use a bunch of different values? They make tons of different voltage zeners.
Yeah, I was fooling around with some clipping circuits last week, and I thought that the mpsa06's were kinda' in the same ballpark as 12v zeners for saturation, but sounded way better tone-wise, so that's why I went with the 20v zener / mpsa06 dual clipper setup on a switch for an amp I'm working on. But the various clippers on a rotary switch is a cool idea. :thumbsup:
I was doing my tests with alligator clips, but now I think I'm gonna make up a rotary switch jig for testing purposes.
 
fusedbrain":2y7mayqh said:
psychodave":2y7mayqh said:
I find it interesting that the mpsa06 do not clip as much as the 5 volt zeners I use.


For the question, why not use a rotary switch and use a bunch of different values? They make tons of different voltage zeners.
Yeah, I was fooling around with some clipping circuits last week, and I thought that the mpsa06's were kinda' in the same ballpark as 12v zeners for saturation, but sounded way better tone-wise, so that's why I went with the 20v zener / mpsa06 dual clipper setup on a switch for an amp I'm working on. But the various clippers on a rotary switch is a cool idea. :thumbsup:
I was doing my tests with alligator clips, but now I think I'm gonna make up a rotary switch jig for testing purposes.

So you used 1 20v zener and 1 mpsa06 transistor back to back, instead of 2 zeners?
 
ledvedder":3cfk878c said:
fusedbrain":3cfk878c said:
psychodave":3cfk878c said:
I find it interesting that the mpsa06 do not clip as much as the 5 volt zeners I use.


For the question, why not use a rotary switch and use a bunch of different values? They make tons of different voltage zeners.
Yeah, I was fooling around with some clipping circuits last week, and I thought that the mpsa06's were kinda' in the same ballpark as 12v zeners for saturation, but sounded way better tone-wise, so that's why I went with the 20v zener / mpsa06 dual clipper setup on a switch for an amp I'm working on. But the various clippers on a rotary switch is a cool idea. :thumbsup:
I was doing my tests with alligator clips, but now I think I'm gonna make up a rotary switch jig for testing purposes.

So you used 1 20v zener and 1 mpsa06 transistor back to back, instead of 2 zeners?
No, sorry for the lousy description. I did a type of "era switch, where in one position I used 2 x 20v Zeners for moderate clipping, and in the other position, I used 2 MPSa06's for a more saturated sound. The MPSa06's are def more saturated than the 20v zeners, but it doesn't seem like it's "too much" to me, and I like the tone. It doesn't seem as over the top to me as the lower voltage zeners in my amp. Could be a different story in a Yeti for sure.
All these different diodes are cheap to buy, so you can afford to get a bunch and see what you like. For example, the little electronics place near me sells the zeners in a bag of 5 for $1.00. I think the MPSa06's are 4 for $1.00.
 
fusedbrain":ogjkdh3f said:
ledvedder":ogjkdh3f said:
fusedbrain":ogjkdh3f said:
psychodave":ogjkdh3f said:
I find it interesting that the mpsa06 do not clip as much as the 5 volt zeners I use.


For the question, why not use a rotary switch and use a bunch of different values? They make tons of different voltage zeners.
Yeah, I was fooling around with some clipping circuits last week, and I thought that the mpsa06's were kinda' in the same ballpark as 12v zeners for saturation, but sounded way better tone-wise, so that's why I went with the 20v zener / mpsa06 dual clipper setup on a switch for an amp I'm working on. But the various clippers on a rotary switch is a cool idea. :thumbsup:
I was doing my tests with alligator clips, but now I think I'm gonna make up a rotary switch jig for testing purposes.

So you used 1 20v zener and 1 mpsa06 transistor back to back, instead of 2 zeners?
No, sorry for the lousy description. I did a type of "era switch, where in one position I used 2 x 20v Zeners for moderate clipping, and in the other position, I used 2 MPSa06's for a more saturated sound. The MPSa06's are def more saturated than the 20v zeners, but it doesn't seem like it's "too much" to me, and I like the tone. It doesn't seem as over the top to me as the lower voltage zeners in my amp. Could be a different story in a Yeti for sure.
All these different diodes are cheap to buy, so you can afford to get a bunch and see what you like. For example, the little electronics place near me sells the zeners in a bag of 5 for $1.00. I think the MPSa06's are 4 for $1.00.

Yep, that's exactly what I'm trying to achieve. I like the 2 20v zeners. But, the 2 9v zeners are too much. How do you connect the mpsa06's? Don't they have 3 legs, as opposed to just the 2 ends on zeners?
 
Yes, you leave pin 3 disconnected. Connect both pin 1's together. Connect 1 of the pin 2's to the switch, the other to ground.
 

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Yeah just snip pin 3. And try stacking the mpsa06 to double the clipping threshold if 2 is too much clipping.. So 4 total.
 
Grab some 2N5400s while you are at it. I prefer these over the MPSA06 although they are very close. On these you’d wire them the exact opposite as the MPSA06, snip leg 3 as well
 
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