High-Gain JCM800/2204 Build

[novosibir]

Looks great, can't wait to hear what it sounds like.

Also, wanted to ask you what do you think of the whole silver mica vs ceramic capacitors for treble peaking circuit and tone stack.
In my experience with testing these on superlead circuit it seems that ceramic (some types, they all have different response) can add some high mid frequencies but also lose low mids and definition... (mica sounds fuller)

Any thoughts would be appreciated.

It's hard to say with any certainty. But yeah, MAYBE ceramic disks sound brighter and micas a little more full/balanced. But it'd be splitting hairs. I tend to prefer silver micas as long as you use high quality ones.

First what is to say is, that Silver Mica capacitors also are ceramic capacitors, but with a special cermic, which reacts much more linear to the various frequencies than common ceramics. Hence Silver Mica's are sounding sweeter & cleaner than common ceramics.

But also among common ceramic caps are huge differences, depending on the material and the voltage range of the cap.

Usual materials for common ceramic caps are NPO, X7R & Z5U and the caps differ to the Silver Mica's by their huge irregularities.
They produce, depending on their material and voltage range, more or less odd order harmonics (K7, K9 & K11), what makes it sounding dirtier, grainier and almost always more aggressive. To obtain the 'real British Dirt' in the amp's sound, ceramics (not SM's) are essential. Impossible or at least not easy, to get the same result with SM's only.

In my British Purist first I've tried SM's in the beginning, but never have been pleased with its sound. Always too clean and a tiny bit sterile.
Then I've tried various ceramics. Some were simply too dirty and too aggressive, but then I've found ceramics from Panasonic, where the 3 kV types are sounding overwhelming convincingly (watch photo), they're sounding almost like NOS Lemco's. Unfortunately they are out of production already years.

Larry

 

[FourT6and2]

Looks great, can't wait to hear what it sounds like.

Also, wanted to ask you what do you think of the whole silver mica vs ceramic capacitors for treble peaking circuit and tone stack.
In my experience with testing these on superlead circuit it seems that ceramic (some types, they all have different response) can add some high mid frequencies but also lose low mids and definition... (mica sounds fuller)

Any thoughts would be appreciated.

It's hard to say with any certainty. But yeah, MAYBE ceramic disks sound brighter and micas a little more full/balanced. But it'd be splitting hairs. I tend to prefer silver micas as long as you use high quality ones.

First what is to say is, that Silver Mica capacitors also are ceramic capacitors, but with a special cermic, which reacts much more linear to the various frequencies than common ceramics. Hence Silver Mica's are sounding sweeter & cleaner than common ceramics.

But also among common ceramic caps are huge differences, depending on the material and the voltage range of the cap.

Usual materials for common ceramic caps are NPO, X7R & Z5U and the caps differ to the Silver Mica's by their huge irregularities.
They produce, depending on their material and voltage range, more or less odd order harmonics (K7, K9 & K11), what makes it sounding dirtier, grainier and almost always more aggressive. To obtain the 'real British Dirt' in the amp's sound, ceramics (not SM's) are essential. Impossible or at least not easy, to get the same result with SM's only.

In my British Purist first I've tried SM's in the beginning, but never have been pleased with its sound. Always too clean and a tiny bit sterile.
Then I've tried various ceramics. Some were simply too dirty and too aggressive, but then I've found ceramics from Panasonic, where the 3 kV types are sounding overwhelming convincingly (watch photo), they're sounding almost like NOS Lemco's. Unfortunately they are out of production already years.

Larry

What about Philips KP? I've used them in another build. I think I've seen you use them in some amps.

 

[FourT6and2]

Less spaghetti...

 

[novosibir]

What about Philips KP? I've used them in another build. I think I've seen you use them in some amps.

The best treble cap ever, if you generate the 'dirt' elsewhere in the circuit, because this cap isn't in any way 'nicing' the sound, but also doesn't add anything to the frequencies. Brutally direct and opens up the highs full range.

It's the treble cap in my DINO 939 for the common British & Scream tone control
and the treble cap in my DINO 962 for the British channel only, due to independent tone controls for British & Scream

 

[novosibir]

Less spaghetti...

Nice & clean build

You prefer purple wires? Why?
You presumably already know, that purple wires keep werewolves away of the amp?

 

[FourT6and2]

Less spaghetti...

Nice & clean build

You prefer purple wires? Why?
You presumably already know, that purple wires keep werewolves away of the amp?

It's true. Anti-werwolf technology. But also summons Cthulhu.

 

[technomancer]

Less spaghetti...

Nice & clean build

You prefer purple wires? Why?
You presumably already know, that purple wires keep werewolves away of the amp?

It's true. Anti-werwolf technology. But also summons Cthulhu.

You don't say...

 

[novosibir]

Usual materials for common ceramic caps are NPO, X7R & Z5U and the caps differ to the Silver Mica's by their huge irregularities.
They produce, depending on their material and voltage range, more or less odd order harmonics (K7, K9 & K11), what makes it sounding dirtier, grainier and almost always more aggressive. To obtain the 'real British Dirt' in the amp's sound, ceramics...

Forgot to mention, that ceramics are drifting excessively by temperature, the value at room temperature becomes smaller, when the ceramic becomes warm or even hot inside the circuit...

... so not only your ears have been drifted and are hearing different after 1 to 2 hours of rehearsing or live show, also your amp then is sounding different, when heated up after several hours of use.

 

[novosibir]

You don't say...

No I don't! Promised!

 

[marcus262]

It's hard to say with any certainty. But yeah, MAYBE ceramic disks sound brighter and micas a little more full/balanced. But it'd be splitting hairs. I tend to prefer silver micas as long as you use high quality ones.

thank you for your answer, didn't know that the difference in quality of the mica caps is so pronounced.

First what is to say is, that Silver Mica capacitors also are ceramic capacitors, but with a special cermic, which reacts much more linear to the various frequencies than common ceramics. Hence Silver Mica's are sounding sweeter & cleaner than common ceramics.

I have been going back and fort for 2 months testing various capacitors mainly ceramic and mica for the treble peak circuit and tone stack, in a Marshall jmp 50w build and just cannot decide. My OCD and quest for perfection.
I tend to agree that mica sounds sweeter and cleaner, but I also perceive more compression from mica... like the ceramic is more raw.

But also among common ceramic caps are huge differences, depending on the material and the voltage range of the cap.

Yes, they are very different in sound, depending on voltage, dielectric, manufacturer.

In my British Purist first I've tried SM's in the beginning, but never have been pleased with its sound. Always too clean and a tiny bit sterile.
Then I've tried various ceramics. Some were simply too dirty and too aggressive, but then I've found ceramics from Panasonic, where the 3 kV types are sounding overwhelming convincingly (watch photo), they're sounding almost like NOS Lemco's. Unfortunately they are out of production already years.

I have been trying to find the perfect ceramic for the Marshall grind, just don't have the original lemcos dogbone to compare them to.
Have you compared the Panasonic one with lemco dogbone? Are there any other that sound good?
So far I have tried RMCs single layer large ones 2.5 and 3 kv , Murata blue ones, Rmc Y5F, Dielectron 3kv...

 

[FourT6and2]

thank you for your answer, didn't know that the difference in quality of the mica caps is so pronounced/

Not in terms of "tone." But some micas leak DC. So you need to make sure you're using good ones.

As far as ceramics go, there are too many variables to test. Some say to use Class 2. Others say only use C0G/NP0 Class 1. I have no idea. If I could find NOS Lemcos or NP0 that Marshall used, I'd just use those. But they are seemingly impossible to find. Same for whatever Panasonic ones Larry is talking about.

I've been looking at modern NP0. But the only ones available in 1KV or higher are PCB mount and have really short leads and won't really work for turret boards. So I'll probably just stick with Class 2 or Silver Mica.

 

[novosibir]

Have you compared the Panasonic one with lemco dogbone?

No, I've compared it to the flat, rectangular Lemco's and the Panasonic's are coming very very close.

 

[novosibir]

But some micas leak DC.

Only the black SM's are prone for leaking.

 

[psychodave]

I bought some of those yellow Panasonic caps years ago on advice from Mike Fortin. I should have bought more.

 

[FourT6and2]

I bought some of those yellow Panasonic caps years ago on advice from Mike Fortin. I should have bought more.

Do you have any actual part numbers for these? I've been trying to find some but need some sort of identifier other than "yellow ceramic cap" haha

 

[marcus262]

Not in terms of "tone." But some micas leak DC. So you need to make sure you're using good ones.

yes, I hear all over that those small black ones that are massively used can be leaky,maybe they are chinese made, I haven't heard someone complaining about Cornell dubilier ones

As far as ceramics go, there are too many variables to test. Some say to use Class 2. Others say only use C0G/NP0 Class 1. I have no idea. If I could find NOS Lemcos or NP0 that Marshall used, I'd just use those.

too much of a difference between them (ceramics).
There are also ceramic class 1 but are not cog,npo they have written on them temperature coeficient like n1500, n2200... they are large flat discs that I was testing,
ex. RMC 3kv n2200 sounds great in mids, low, mids, has great amount of perceived distortion and sustain but misses some high mid/treble punch and when playing fast open chords becomes kinda blurry like it doesn't track well.

RMC 2.5kv n1500, sounds great in crunch, is fast "tracking" but like it has distortion that doesn't last as long.

Dielectron 3kv n3300, they have short leads, so didn't test them much.

I found some NOS S.R.C rectangular silver mica and from R.S. that I think I am going to use, they are silver mica.
I couldn't find ceramic lemcos dogbone, or lemcos silver mica rectangular.
I have a bunch of those SRC and RS silver mica, and ceramics from RMC and Dielectron so if any of you tube amp builders need them for testing or use in tube amp I would be happy to send them.

No, I've compared it to the flat, rectangular Lemco's and the Panasonic's are coming very very close.

But those are also silver mica and not ceramic, and if I understood you correctly it has to be ceramic to produce odd order harmonics and Marshall crunch.

Do you have any actual part numbers for these? I've been trying to find some but need some sort of identifier other than "yellow ceramic cap" haha

Did some search, they are probably ECKA3F471KBP which are 470pf 3Kv Panasonic

on ebay they currently have ECKA3D471KBP which is 470pf 2Kv Panasonic

also found the 3kv ones on "chinese ebay"... so if someone is intersted I can try to buy them.
You can't buy them directly because everything is in chinese and local, but through an agent website, ordered once before and everything was fine, next few times tried to order and payed, seller didn't ship and the agent returned the money to me, so everything was fine, sometimes they are old listings.

 

[novosibir]

Sorry, 12 years ago that I've compared everything to everything, also all kind of MKT's and MKP's
Just checked my notes...
... have compared the rectangular Lemco's to (among others) brown SM's
... and (among others) the Panasonic 3 kV to (among others) the red tubular Lemco's
... and finally decided for the Panasonic 3 kV, but only for my British Purist, use it in some spots in my Rock Wizard, but none for my DINO's

 

[novosibir]

But those are also silver mica and not ceramic, and if I understood you correctly it has to be ceramic to produce odd order harmonics and Marshall crunch.

Correct, but keep in mind, that SM's also produce a certain amount of odd order harmonics, just less than common ceramics and IMO not enough, to get the 'British Dirt'

 

[CrazyNutz]

Yessir, ceramics bring the grit. They can add complexity, and dimension.

You can also blend silver mica, and ceramics to get cool results (use them in parallel to get the value you need). On a few SLO clone builds I did, I used a 1000pf ceramic + a 100pf CDE silver mica on the bright cap. Very cool sound.

 

[novosibir]

Yessir, ceramics bring the grit. They can add complexity, and dimension.

You can also blend silver mica, and ceramics to get cool results...

Oh yes they bring the grit, or the grain, or the salt & pepper in the soup

But you also can blend ceramics and MKT's, to reach your wanted result.
I did it in my Wrecky 35 like Ken Fischer also did it sometimes, if required.