NAD 50W Ceriatone Yeti

[BlueParfait]

I still have been going back and forth on weather to get a used Marshall 1987X and have some variation of the Jose mod done, or just go with a Yeti or Chupacabra.

I think these will be easier to mod regardless ngl

 

[PurityS.L.G]

Welcome to the club! I had the chupa a few years ago and then upgraded to the King Kong. I love that amp. It has one of the best master volumes on any amp I've ever tried. Covers all your Marshall bases you could ever want.

 

[angelspade]

Any of you owned both a Yeti and a Chupacabra? Preference? Differences?

 

[EyesOfTheSouth!]

Congrats! That is a killer amp. I would still have mine had I not discovered the Morris 67’ and 78’

 

[311boogieman]

I have half a mind to change the trannies to something lighter...

What's wrong with heavy trannys

J/K - Congrats man. Love to try one. I'd max the pussy trimmer as well. No sense getting caught in the weeds.

 

[angelspade]

S

Understood but nice that you still have the option. So basically it's a hot rodded plexi with some bright switches and additional gain on tap? I've never scoped that model out on their site.

Supposedly the Chupacabra model is "closer" to traditional modded Plexi...at least that's what's been reported by many.

 

[FourT6and2]

S
Supposedly the Chupacabra model is "closer" to traditional modded Plexi...at least that's what's been reported by many.

Neither amp is anywhere near a "Plexi". They are JCM800 clones with diode clipping. i.e. three cascaded gain stages with raised V1a plate resistors, scooped tone stacks, super hot cathode bias on each gain stage, and pre-stack master volumes with diode clipping.

The Chupa is a direct copy of a schematic (with lots of errors) drawn up and posted to the SLO Clone Forum from a one-off Fortin Jose mod that was a copy of a Cameron Jose mod. The Yeti is another variation from a schematic taken from the same forum. Both amps contain both technical errors in guitar amp circuit design as well as design errors copy/pasted directly from the incorrect schematics Ceriatone pilfered from forums.

Same with the Molecular and Gargoyle. Molecular is a copy of a Cameron Atomica (schematic posted to the same forum) and the Gargoyle is a copy of a schematic I drew as a variation to the Fortin Meshuggah, which is also just a copy of a Cameron Jose / typical DIY "Jose mod" that people have been building for 40 years. The details of that DIY circuit were all over the Metro Forum for a long time before it was shut down.

This isn't meant to shit on OP's new amp. These amps all sound good. But they're approximations of the actual amps they're attempting to copy.

 

[angelspade]

Neither amp is anywhere near a "Plexi". They are JCM800 clones with diode clipping. i.e. three cascaded gain stages with raised V1a plate resistors, scooped tone stacks, super hot cathode bias on each gain stage, and pre-stack master volumes with diode clipping.

The Chupa is a direct copy of a schematic (with lots of errors) drawn up and posted to the SLO Clone Forum from a one-off Fortin Jose mod that was a copy of a Cameron Jose mod. The Yeti is another variation from a schematic taken from the same forum. Both amps contain both technical errors in guitar amp circuit design as well as design errors copy/pasted directly from the incorrect schematics Ceriatone pilfered from forums.

Same with the Molecular and Gargoyle. Molecular is a copy of a Cameron Atomica (schematic posted to the same forum) and the Gargoyle is a copy of a schematic I drew as a variation to the Fortin Meshuggah, which is also just a copy of a Cameron Jose / typical DIY "Jose mod" that people have been building for 40 years. The details of that DIY circuit were all over the Metro Forum for a long time before it was shut down.

This isn't meant to shit on OP's new amp. These amps all sound good. But they're approximations of the actual amps they're attempting to copy.

Interesting and useful information...as you mentioned, despite the flaws and errors you mentioned...these amps seem to get pretty enthusiastic reviews from thise who own them.

 

[FourT6and2]

Interesting and useful information...as you mentioned, despite the flaws and errors you mentioned...these amps seem to get pretty enthusiastic reviews from thise who own them.

For sure. But most people have never played the real thing. I was one of those people. I bought one of the very first Chupacabras for $600 when they first came out. I thought it sounded great. Then I learned what I learned. And I played the real thing. And I built the real thing myself. When you put them side by side, the differences are apparent.

My girlfriend thought she knew how to cook a steak. Had been doing it the same way for years. Loved the results. Then I showed her to actually cook a steak. She didn't want to admit it at first, but turns out... she didn't actually know how to cook a steak.

 

[BlueParfait]

This isn't meant to shit on OP's new amp

Oh no worries. I already know all that, just not the specific original model

 

[angelspade]

For sure. But most people have never played the real thing. I was one of those people. I bought one of the very first Chupacabras for $600 when they first came out. I thought it sounded great. Then I learned what I learned. And I played the real thing. And I built the real thing myself. When you put them side by side, the differences are apparent.

My girlfriend thought she knew how to cook a steak. Had been doing it the same way for years. Loved the results. Then I showed her to actually cook a steak. She didn't want to admit it at first, but turns out... she didn't actually know how to cook a steak.

Interesting thoughts, particularly because i am trying to decide on a ceriatone...or buying a used Marshall 1987X and having a high gain Jose style mod done. I think what was drawing me towards the chupacabra or yeti was that all of the mods seem to already be performed...along with some additional options (era switch / p trimmer).

 

[Shask]

Neither amp is anywhere near a "Plexi". They are JCM800 clones with diode clipping. i.e. three cascaded gain stages with raised V1a plate resistors, scooped tone stacks, super hot cathode bias on each gain stage, and pre-stack master volumes with diode clipping.

The Chupa is a direct copy of a schematic (with lots of errors) drawn up and posted to the SLO Clone Forum from a one-off Fortin Jose mod that was a copy of a Cameron Jose mod. The Yeti is another variation from a schematic taken from the same forum. Both amps contain both technical errors in guitar amp circuit design as well as design errors copy/pasted directly from the incorrect schematics Ceriatone pilfered from forums.

Same with the Molecular and Gargoyle. Molecular is a copy of a Cameron Atomica (schematic posted to the same forum) and the Gargoyle is a copy of a schematic I drew as a variation to the Fortin Meshuggah, which is also just a copy of a Cameron Jose / typical DIY "Jose mod" that people have been building for 40 years. The details of that DIY circuit were all over the Metro Forum for a long time before it was shut down.

This isn't meant to shit on OP's new amp. These amps all sound good. But they're approximations of the actual amps they're attempting to copy.

I am curious what some of the major issues are, if it can said.

 

[FourT6and2]

I am curious what some of the major issues are, if it can said.

Mostly concerning the 50W versions:

1. Missing interstage B+ dropping resistor between PI and CF on both amps. This resistor serves a few purposes, but it mainly decouples different gain stage so they each have their own B+ filtering nodes. Without this resistor, multiple stages end up sharing the same filtering. This causes all sorts of problems like increased ghosting, decreased low-end tracking/looser low end, increased susceptibility to "motor boating", and a weaker sounding/feeling amp.

2. The Chupa's V1a plate resistor is 470K+. This increases perceived gain, but it lowers voltage at the plate of its corresponding triode. The Chupa's PT secondaries only put out 325V per side (on the low side). By the time you get to V1a, plate voltage is below 100V. That is insanely low. And it causes issues with the ratio/differential between the plate and other parts of the triode. This is why Ceriatone slightly reworked the 1M ground reference resistor, grid resistor, and a cap on the input of the first stage compared to other amps. The voltage on the plate is so low that without this oddball arrangement, you'd get DC leakage to your guitar's volume control, causing a scratchy volume pot on your guitar (which my Chupa suffered from). The solution here is to not drop the voltage to V1a so low.

3. Filtering. Just not done right. There is some major room for improvement if they had paid attention to this. Their choice in filtering (other than the missing resistor) is still how any stock Marshall would be. The filtering needs to be changed in these circuits to get real results.

4. The rest of the Chupa is technically fine for the most part. And the voicing choices here or there are personal preference, but it's just not as punchy and articulate as the circuit they're attempting to clone. The actual modded amp it's a clone of had those same values, but it was a one-off mod that I don't think was ever done again. Each gain stage is just biased super hot. And Ceriatone's version has such low voltages and low filtering, that it's just a very loose and gainy and "brown" sounding circuit. But maybe that's what Ceriatone wanted. I doubt it though, considering they just copied the error-riddled schematic from a forum. The Yeti has higher voltages and more conservative values in key places, so it doesn't suffer the same issues as the Chupa. Both amp sound fine for what they are and if you have never played the real thing, you probably wouldn't know or care.

 

[FourT6and2]

Interesting thoughts, particularly because i am trying to decide on a ceriatone...or buying a used Marshall 1987X and having a high gain Jose style mod done. I think what was drawing me towards the chupacabra or yeti was that all of the mods seem to already be performed...along with some additional options (era switch / p trimmer).

Just depends what you want. Yes, the Yeti and Chupa both have the "Jose mod" done already. But both circuits can be greatly improved by someone who knows what they're doing. Voltages and filtering are incredibly powerful tone-shaping tools that most techs and builders like Ceriatone get wrong. And there are some subtle tweaks that can be done to both in other areas that really bring them to life.

The P-Trimmer is silly. It's just a pot in place of the 470K resistor to ground in the typical treble peaking circuit. As you lower the value of that resistor (turning the trimmer down), you shunt more and more signal to ground. It's really not needed, which is why literally no other builders do it. The entire reason Ceriatone added it was they sent a Chupacabra to an "amp fest" years ago and everybody said it sounded ok but had too much gain. It does have too much gain for the reasons I stated above. The voltages are too low, the gain stages are biased too hot, and the plate resistor is too high. Ceriatone's response to the feedback they got was to let people shunt signal to ground (reducing gain) using the trimmer. Instead, they should have just addressed the voltages, filtering, and cathode bias of each stage.

 

[angelspade]

Just depends what you want. Yes, the Yeti and Chupa both have the "Jose mod" done already. But both circuits can be greatly improved by someone who knows what they're doing. Voltages and filtering are incredibly powerful tone-shaping tools that most techs and builders like Ceriatone get wrong. And there are some subtle tweaks that can be done to both in other areas that really bring them to life.

The P-Trimmer is silly. It's just a pot in place of the 470K resistor to ground in the typical treble peaking circuit. As you lower the value of that resistor (turning the trimmer down), you shunt more and more signal to ground. It's really not needed, which is why literally no other builders do it. The entire reason Ceriatone added it was they sent a Chupacabra to an "amp fest" years ago and everybody said it sounded ok but had too much gain. It does have too much gain for the reasons I stated above. The voltages are too low, the gain stages are biased too hot, and the plate resistor is too high. Ceriatone's response to the feedback they got was to let people shunt signal to ground (reducing gain) using the trimmer. Instead, they should have just addressed the voltages, filtering, and cathode bias of each stage.

Intetesting, thank you. Mmmm...sounds like you would suggest I go with the Marshall 1987X and a well done mod over a ceriatone.

 

[FourT6and2]

Intetesting, thank you. Mmmm...sounds like you would suggest I go with the Marshall 1987X and a well done mod over a ceriatone.

If cost isn't an issue, then yes. I would get a Marshall and have someone mod it. If you're main concern is value and a "one and done" solution where you just buy the amp and don't want to bother sending it off to get modded, then Ceriatone is fine. Or buy the Ceriatone in kit form, unassembled, and you can build it or have someone else build it and address the issues at the same time.

 

[BlueParfait]

The P-Trimmer is silly

Yeah I just kept it at 2 o'clock

Which appears to be where 470k would be with their log Alpha pot rofl. 2–2:20

Sounds the best there to my ears

 

[napalmdeath]

I had a 50 watt Yeti. Sounded great. I just wish Nik would figure out how to add a good loop.

 

[Shask]

Mostly concerning the 50W versions:

1. Missing interstage B+ dropping resistor between PI and CF on both amps. This resistor serves a few purposes, but it mainly decouples different gain stage so they each have their own B+ filtering nodes. Without this resistor, multiple stages end up sharing the same filtering. This causes all sorts of problems like increased ghosting, decreased low-end tracking/looser low end, increased susceptibility to "motor boating", and a weaker sounding/feeling amp.

2. The Chupa's V1a plate resistor is 470K+. This increases perceived gain, but it lowers voltage at the plate of its corresponding triode. The Chupa's PT secondaries only put out 325V per side (on the low side). By the time you get to V1a, plate voltage is below 100V. That is insanely low. And it causes issues with the ratio/differential between the plate and other parts of the triode. This is why Ceriatone slightly reworked the 1M ground reference resistor, grid resistor, and a cap on the input of the first stage compared to other amps. The voltage on the plate is so low that without this oddball arrangement, you'd get DC leakage to your guitar's volume control, causing a scratchy volume pot on your guitar (which my Chupa suffered from). The solution here is to not drop the voltage to V1a so low.

3. Filtering. Just not done right. There is some major room for improvement if they had paid attention to this. Their choice in filtering (other than the missing resistor) is still how any stock Marshall would be. The filtering needs to be changed in these circuits to get real results.

4. The rest of the Chupa is technically fine for the most part. And the voicing choices here or there are personal preference, but it's just not as punchy and articulate as the circuit they're attempting to clone. The actual modded amp it's a clone of had those same values, but it was a one-off mod that I don't think was ever done again. Each gain stage is just biased super hot. And Ceriatone's version has such low voltages and low filtering, that it's just a very loose and gainy and "brown" sounding circuit. But maybe that's what Ceriatone wanted. I doubt it though, considering they just copied the error-riddled schematic from a forum. The Yeti has higher voltages and more conservative values in key places, so it doesn't suffer the same issues as the Chupa. Both amp sound fine for what they are and if you have never played the real thing, you probably wouldn't know or care.

Interesting. Sounds like a lot of little issues that just add up.

I have considered getting a Chupa, but I also have a Fortin Killer Kali Synergy module, so I always think it would probably go for a similar thing.

 

[FourT6and2]

I always liked this clip of someone's Yeti kit build. The guy who built it did make some changes to the circuit...