Amp Build: Ceriatone Kraken 50

[FourT6and2]

Nothing wrong in trying, maybe you will like the change.

I think it is actually preference, cause metal amps, like Fortin, Engl.. use higher value slope resistor,
Diezel uses 39k, Marshall usually 33k like superlead, 56k superbass.

Also, amp will become little louder in general.

Yeah, I'll give it a try!

One thing though, I did use 470pF caps for the tone stack and treble circuit because I didn't have any 500pF or 560pF on hand. Upping those might be a good idea too.

Sounds great from what I could tell on that clip. I usually like the upper mids that 500 or 560pF add but it's all so dependant on everything else.

I'm definitely gonna use higher values going forward. I just didn't have any on hand at the time and some people on other forums were saying you can't hear a difference between 470 and 500 and 560. But I'm willing to bet there's a difference.

 

[scottosan]

Sounds fantastic. Doesn't sound like it needs much tweaking. Also it sounds dead quiet.

 

[FourT6and2]

Sounds fantastic. Doesn't sound like it needs much tweaking. Also it sounds dead quiet.

Yeah, not much noise at all.

Things I think I need to do:

1. Decide on a dropping resistor (probably 10K).
2. Replace 470pF caps in tone stack and treble peaking circuit with 500pF or even 560pF
3. I might try a 39K slope resistor. I don't have any 33K. But 39K seems to be about half way from the stock 47K
4. I might also try going back to the stock 820R cathode bypass resistor on V2a

Other than that, I think it's pretty good. I'll put some more playing time on the amp because I think it's actually breaking in a bit. Either that or it's my imagination lol.

I'll upload the other clips soon. Then I'll try the amp through another cab with G12M-75 Creambacks. Those might be punchier than the G12M-25s.

 

[psychodave]

Nothing wrong in trying, maybe you will like the change.

I think it is actually preference, cause metal amps, like Fortin, Engl.. use higher value slope resistor,
Diezel uses 39k, Marshall usually 33k like superlead, 56k superbass.

Also, amp will become little louder in general.

Yeah, I'll give it a try!

One thing though, I did use 470pF caps for the tone stack and treble circuit because I didn't have any 500pF or 560pF on hand. Upping those might be a good idea too.

Sounds great from what I could tell on that clip. I usually like the upper mids that 500 or 560pF add but it's all so dependant on everything else.

Me too. I like 560.

Nice build!!!

 

[FourT6and2]

Seems to get a bit looser, browner, gainier, and bassier as I go up in value.

10K dropper:

12K dropper:

15K dropper:

18K dropper:

 

[FourT6and2]

Nothing wrong in trying, maybe you will like the change.

I think it is actually preference, cause metal amps, like Fortin, Engl.. use higher value slope resistor,
Diezel uses 39k, Marshall usually 33k like superlead, 56k superbass.

Also, amp will become little louder in general.

Yeah, I'll give it a try!

One thing though, I did use 470pF caps for the tone stack and treble circuit because I didn't have any 500pF or 560pF on hand. Upping those might be a good idea too.

Sounds great from what I could tell on that clip. I usually like the upper mids that 500 or 560pF add but it's all so dependant on everything else.

Me too. I like 560.

Nice build!!!

You're talking about the tone stack cap, right? Not the treble peaking circuit? Or both?

 

[DragonCrestPC]

Congrats on the build man!

 

[Alex_S]

Sounds awesome!

 

[marcus262]

One thing though, I did use 470pF caps for the tone stack and treble circuit because I didn't have any 500pF or 560pF on hand. Upping those might be a good idea too.

470pf vs 500pf - there is a difference, but it is small so I don't think you would be able to perceive it, maybe i'm wrong.
on the other hand 470 vs 560, difference is around 1 db on certain freqencies, around 1k and you would hear it for sure.

Frequencies affected are the same for peaking and tone stack,
in the first picture the louder value is 560pf.

In the second one is the diff. between 39k slope and 47k slope,
louder being 39k :


also, the Kraken sounds great and mean as it is, these are just personal preference tweaks.

 

[Beyond Black]

Sounds awesome, great job!

 

[FourT6and2]

One thing though, I did use 470pF caps for the tone stack and treble circuit because I didn't have any 500pF or 560pF on hand. Upping those might be a good idea too.

470pf vs 500pf - there is a difference, but it is small so I don't think you would be able to perceive it, maybe i'm wrong.
on the other hand 470 vs 560, difference is around 1 db on certain freqencies, around 1k and you would hear it for sure.

Frequencies affected are the same for peaking and tone stack,
in the first picture the louder value is 560pf.

In the second one is the diff. between 39k slope and 47k slope,
louder being 39k :


also, the Kraken sounds great and mean as it is, these are just personal preference tweaks.

Awesome, thanks!

I wish I could use the Duncan calculators, but they don't run on a Mac

I can see the difference is subtle. But I will try it anyway because the tweaks I think I want to make are subtle anyway and I want to get this thing juuuuust perfect lol. I'm gonna change slope resistor to 39K, cap to 500pF. Treble peaking circuit cap to 560pF. And I'll lower V1a plate resistor to 330K. That should be good. And I think I'll go with the 10K dropping resistor and then I'll button the amp up and start on the next one

 

[CrazyNutz]

Sounds rad. I think I'm digging the 15k dropping resister. The 10k does sound good though. I find when tweaking the preamp voltage don't forget to check the amp at High volume too, sometimes higher voltage sounds real harsh at high volumes. You may also find the lower voltage sounds a little weak, and flubby until you crank it.

 

[FourT6and2]

Sounds rad. I think I'm digging the 15k dropping resister. The 10k does sound good though. I find when tweaking the preamp voltage don't forget to check the amp at High volume too, sometimes higher voltage sounds real harsh at high volumes. You may also find the lower voltage sounds a little weak, and flubby until you crank it.

Yeah, that's true. I really like the 15K dropper for leads. It makes the amp a little squishy and single notes are very fluid and buttery. But rhythm tightness is lacking. I will try cranking the amp though. I live in an apartment, so it's kinda hard to really crank it to 10. But hell... why not

Maybe I'll put the 15K and the 10K on a switch or something.

 

[marcus262]

Awesome, thanks!

I wish I could use the Duncan calculators, but they don't run on a Mac

I can see the difference is subtle. But I will try it anyway because the tweaks I think I want to make are subtle anyway and I want to get this thing juuuuust perfect lol. I'm gonna change slope resistor to 39K, cap to 500pF. Treble peaking circuit cap to 560pF. And I'll lower V1a plate resistor to 330K. That should be good. And I think I'll go with the 10K dropping resistor and then I'll button the amp up and start on the next one

no problem, if you need something calculated, just tell me the values you want.
There are more handy calculators here, under "amplifier calculators":
https://www.ampbooks.com/mobile/amplifi ... capacitor/

I know the higher plate resistor on v1a adds gain, but in your experience how does it change tone or freq.response, between 470k, 390k, 330k?

Yeah, that's true. I really like the 15K dropper for leads. It makes the amp a little squishy and single notes are very fluid and buttery. But rhythm tightness is lacking. I will try cranking the amp though. I live in an apartment, so it's kinda hard to really crank it to 10. But hell... why not

Do these different values only affect preamp voltages?
How far does the plate voltage vary on 12ax7 with those different values?

 

[FourT6and2]

no problem, if you need something calculated, just tell me the values you want.
There are more handy calculators here, under "amplifier calculators":
https://www.ampbooks.com/mobile/amplifi ... capacitor/

I'd love to see a few combos plotted on the same graph if possible? Or can you only do two at a time?

For tone stack:

47K/470pF
47K/500pF
47K/560pF

47K/500pF
39K/500pF
33K/500pF

For treble peaker if available:

470K/470pF
470K/500pF
470K/560pF

I know the higher plate resistor on v1a adds gain, but in your experience how does it change tone or freq. response, between 470k, 390k, 330k?

All other things staying the same (cathode bypass, etc.), it seems like the higher the V1a plate resistor, the gainer the amp, but also the more snarl and grind. If you go over 330K-390K, you will start to put DC on your guitar's volume pot and it will be scratchy. So you have to add a blocking cap to the input grid. The higher the value of that resistor, the lower the plate voltage. The Chupa's stock value is 470K. The Yeti is 390K. A lot of other builders use lower values like 330K, 220K, etc. And will boost gain later on in the preamp, which is cool too.

I just tried lowering the 390K in this amp to 330K and it reduced a bit of the hair on the gain and cleaned the amp up a bit, which made it a tiny bit punchier. But the amp lost a little bit of the overtones and snarl. I think I'll go back to 390K and use the "pussy trimmer" control to compensate by reducing a bit of the gain later on in the circuit.

Yeah, that's true. I really like the 15K dropper for leads. It makes the amp a little squishy and single notes are very fluid and buttery. But rhythm tightness is lacking. I will try cranking the amp though. I live in an apartment, so it's kinda hard to really crank it to 10. But hell... why not

Do these different values only affect preamp voltages?
How far does the plate voltage vary on 12ax7 with those different values?[/quote]

Yeah, the dropping resistor goes on one of the filter caps and sets the initial B+ voltage for the preamp. The initial B+ stays the same at whatever it is (in this case about 490v). The dropper brings that down for the phase inverter plates, which then goes to V2 plates (and the large filter cap on the board, which has its own dropping resistor), and then that goes to V1's plates. I think of each stage in the B+ line as a dam feeding a reservoir. You can alter how much water the dam allows through. In this case, I'm only changing the value of that first dam.

Here are the different plate voltages for each preamp stage:

10K Dropper:
V3-1: 270v
V3-6: 258v
V2-1: 321v
V2-6: 406v
V1-1: 176v
V1-6: 297v

12K Dropper:
V3-1: 258v
V3-6: 247v
V2-1: 222v
V2-6: 388v
V1-1: 170v
V1-6: 287v

15K Dropper:
V3-1: 248v
V3-6: 237v
V2-1: 211v
V2-6: 371v
V1-1: 162v
V1-6: 274v

18K Dropper:
V3-1: 237v
V3-6: 227v
V2-1: 201v
V2-6: 353v
V1-1: 155v
V1-6: 262v

 

[FourT6and2]

Ok I swapped out the 470pF cap in the tone stack for a 560pF and the 470pF in the treble peaker for 500pF. Definitely more mid-range growl and thicker. Amp has more grunt. But it lost some of what was going on in that first clip I posted. I might split the difference in the tone stack and go with 500pF.

Can't decide if I should stick with 330K or 390K for V1a plate. But I think it's about done once I do those things.

 

[scottosan]

The C45 mod on the Friedman used 560k/680pf

 

[FourT6and2]

The C45 mod on the Friedman used 560k/680pf

I assume this is for the treble peaker circuit and not the tone stack?

 

[CrazyNutz]

Maybe I'll put the 15K and the 10K on a switch or something.

I was thinking that too. Could put a 5k in series with a 10k, and use a switch to bypass the 5k. I've done it like this a few times.

 

[scottosan]

The C45 mod on the Friedman used 560k/680pf

I assume this is for the treble peaker circuit and not the tone stack?

right its switheable with 68k voltage divider. (560k/680pf)/220k divider vs 68k/68k divider. More gain and low mids. Realistically I'm about 2 more days out on my build. My head is spinning and the IPA's aren't helping my productivity