High-Gain JCM800/2204 Build

[FourT6and2]

Had a chance to compare different types of caps in for the bright cap and tone stack treble cap. The differences are astoundingly obvious. Not at all subtle. My friend is here. He doesn't play guitar or any instruments and without me telling him what I was doing, he was able to hear and describe the tonal differences as I swapped out caps.

Treble Cap:
CDM 1% silver mica:
Flat freq. response, but kinda dark. No grain. Lets you push mids/treble high. But lackluster all around. Feel-wise, it's like you're fighting the guitar.

BC Y5P 3kV ceramic disk:
Lots of grain or crunch or "crispness" as my friend described it. I'm not a huge fain of the grain it adds. BUT... I LOVE how it changes the feel of the amp. It has a lot of bounce to it, yet remains tight somehow. It makes the guitar really easy to play. It's like you can dig in harder somehow with your attack and instead of getting harsh or brash, heavy power chord riffs kind of drip off the fretboard. Hard to really put into words.

Philips KP 630v polyprop.:
Not as grainy as the ceramic disk. But still bright. Not as much bounce either. But authoritative, clear, and gives the amp a strong, stout response. "Clarity" is a good word here. Doesn't really color the sound of the amp at all. But lets the mid-range peak through. I think I might go with this one, but hard to say. I'd like to A/B some other types of ceramics first. Like a C0G/NP0.

Bright Cap
Only had a chance to A/B a ceramic disk vs Philips KP. Philips KP is much too bright here. I prefer the ceramic. But I would like to try a Mallory 150 (which I have in my other amps).


I'm a complete skeptic when it comes to "mojo," so all in all I'm surprised by how big of a difference I can hear.

 

[novosibir]

BC Y5P 3kV ceramic disk:
Lots of grain or crunch or "crispness" as my friend described it.
(...)
I think I might go with this one, but hard to say. I'd like to A/B some other types of ceramics first. Like a C0G/NP0.

Hard words spoken out calmly: If you want to turn an aggressive wolf to a tame sheep, then swap the Y5P with a C0G or a NP0

 

[CrazyNutz]

Hard words spoken out calmly: If you want to turn an aggressive wolf to a tame sheep, then swap the Y5P with a C0G or a NP0

Thats good info. I haven't had the time to compare all the different dielectric/classes.

Do you have more info to share about the characteristics of different ceramic dielectric? It' would be much appreciated.

 

[psychodave]

Had a chance to compare different types of caps in for the bright cap and tone stack treble cap. The differences are astoundingly obvious. Not at all subtle. My friend is here. He doesn't play guitar or any instruments and without me telling him what I was doing, he was able to hear and describe the tonal differences as I swapped out caps.

Treble Cap:
CDM 1% silver mica:
Flat freq. response, but kinda dark. No grain. Lets you push mids/treble high. But lackluster all around. Feel-wise, it's like you're fighting the guitar.

BC Y5P 3kV ceramic disk:
Lots of grain or crunch or "crispness" as my friend described it. I'm not a huge fain of the grain it adds. BUT... I LOVE how it changes the feel of the amp. It has a lot of bounce to it, yet remains tight somehow. It makes the guitar really easy to play. It's like you can dig in harder somehow with your attack and instead of getting harsh or brash, heavy power chord riffs kind of drip off the fretboard. Hard to really put into words.

Philips KP 630v polyprop.:
Not as grainy as the ceramic disk. But still bright. Not as much bounce either. But authoritative, clear, and gives the amp a strong, stout response. "Clarity" is a good word here. Doesn't really color the sound of the amp at all. But lets the mid-range peak through. I think I might go with this one, but hard to say. I'd like to A/B some other types of ceramics first. Like a C0G/NP0.

Bright Cap
Only had a chance to A/B a ceramic disk vs Philips KP. Philips KP is much too bright here. I prefer the ceramic. But I would like to try a Mallory 150 (which I have in my other amps).


I'm a complete skeptic when it comes to "mojo," so all in all I'm surprised by how big of a difference I can hear.

Don't forget to try mixing caps in parallel to get different responses as well.

 

[CrazyNutz]

Had a chance to compare different types of caps in for the bright cap and tone stack treble cap. The differences are astoundingly obvious. Not at all subtle.

Yeah, it's pretty big.

And from my experience when I was into building 100w SLP's, it's damn near impossible to get that vintage tone, and feel with modern silver mica's. This is probably why people get discouraged building plexi clones, and not getting the vintage sound.

Most important spots being treble peakers, bright caps, and tone stack treble caps.

 

[FourT6and2]

Hard words spoken out calmly: If you want to turn an aggressive wolf to a tame sheep, then swap the Y5P with a C0G or a NP0

Really? Haha good to know, thanks. Some people say Class 2 are good. Others (like Aiken) say they will never use Class 2 ceramics. Hard to know without trying it!

Don't forget to try mixing caps in parallel to get different responses as well.

Ugh... that's too much work. I'm gonna keep it simple lol.

Yeah, it's pretty big.

And from my experience when I was into building 100w SLP's, it's damn near impossible to get that vintage tone, and feel with modern silver mica's. This is probably why people get discouraged building plexi clones, and not getting the vintage sound.

Meh, I'm not going for "vintage" tone lol. This amp is a fire breather. Modern metal all the way, but with a classic "sweetness" going on. Not clinical/sterile at all. Perfect for '90s hard rock through modern prog metal. I basically took a certain HG Jose amp out right now and tweaked it a tiny bit so it's less for people who drop tune 5 steps and more for standard/Drop D or maybe 1/2 to a full step down. So it isn't overly bright and tight. It has some bounce to it. But still really angry.

 

[technomancer]

Some great information in here, thanks guys. Build looks fantastic as usual.

 

[jimistheman]

I love threads like these!

 

[FourT6and2]

Some great information in here, thanks guys. Build looks fantastic as usual.

Dude, this amp sounds amazing. It's the way the "original" should have been. I will admit this specific voicing sounds a little better than my other builds. Only three real differences to be honest. But they're cool enough.

 

[technomancer]

Some great information in here, thanks guys. Build looks fantastic as usual.

Dude, this amp sounds amazing. It's the way the "original" should have been. I will admit this specific voicing sounds a little better than my other builds. Only three real differences to be honest. But they're cool enough.

Awesome, glad it turned out well. I wonder how much of a difference the NOS components make in the mix in addition to the circuit changes.

I'm going to grab some of those Vishay ceramics to compare with the Muratas I have.

 

[FourT6and2]

Some great information in here, thanks guys. Build looks fantastic as usual.

Dude, this amp sounds amazing. It's the way the "original" should have been. I will admit this specific voicing sounds a little better than my other builds. Only three real differences to be honest. But they're cool enough.

Awesome, glad it turned out well. I wonder how much of a difference the NOS components make in the mix in addition to the circuit changes.

I'm going to grab some of those Vishay ceramics to compare with the Muratas I have.

No idea how all the magical NOS parts really impart into the sound of the amp. But hey, the treble cap type makes a difference. So I'm guessing everything else does too. Maybe not worth the added price and headache of sourcing them though. I think Mallory 150s are a great cap to be honest. The IC MPW are good too.

 

[novosibir]

I think Mallory 150s are a great cap to be honest.

You now have to go the way from 'thinking' to 'knowing'.

Try to find old ERO MKT1813 - the orig. Roederstein.
The newer Vishay MKT1813 don't have the same charism, but still are better than Mallory 150's, what would be my last choice, if all & everything else is sold out.

ERO... ERO... ERO...

 

[novosibir]

Forgot to mention, search for the 630V types, not the 400V types

 

[FourT6and2]

I'm using Vishay MKT1813 in the 0.68uF cathode position and use them in other amps. Haven't been able to find original ERO ones. I've used Mallory 150s before. I like them more than Sprague or TAD or Mojo or Sozo.

 

[technomancer]

Some great information in here, thanks guys. Build looks fantastic as usual.

Dude, this amp sounds amazing. It's the way the "original" should have been. I will admit this specific voicing sounds a little better than my other builds. Only three real differences to be honest. But they're cool enough.

Awesome, glad it turned out well. I wonder how much of a difference the NOS components make in the mix in addition to the circuit changes.

I'm going to grab some of those Vishay ceramics to compare with the Muratas I have.

No idea how all the magical NOS parts really impart into the sound of the amp. But hey, the treble cap type makes a difference. So I'm guessing everything else does too. Maybe not worth the added price and headache of sourcing them though. I think Mallory 150s are a great cap to be honest. The IC MPW are good too.

Yeah I've basically got 3 builds planned out and I'll be using IC MPWs in 2 and Mallory 150s in the third. The build getting the Mallory caps is a clone of an amp that uses them, so figured might as well stick with what is in the original for the preamp. The 150s also sounded good in the amps I had that used them. I still need to finish the current build and get a headshell for it, then order transformers for the next one so it may be a bit before I make too much progress. Or I may work on the boards for them while I get the transformers etc since I have most of the parts, just need the actual boards and turrets.

I'd love to try the MKT1813s but they are just a bitch to find the originals, and the new ones aren't exactly common either though I think Mouser does have a few values.

Larry: you really do have some of the cleanest work in the business, always a pleasure looking at your amps

 

[CrazyNutz]

]

Meh, I'm not going for "vintage" tone lol. This amp is a fire breather. Modern metal all the way, but with a classic "sweetness" going on. Not clinical/sterile at all. Perfect for '90s hard rock through modern prog metal. I basically took a certain HG Jose amp out right now and tweaked it a tiny bit so it's less for people who drop tune 5 steps and more for standard/Drop D or maybe 1/2 to a full step down. So it isn't overly bright and tight. It has some bounce to it. But still really angry.

Yeah, I know, not saying you were going for vintage.

 

[novosibir]

... and the new ones aren't exactly common either though I think Mouser does have a few values.

Try your luck at Newark.
They should have the same part #'s than Farnell here in Germany, because it's the same company.
So you'd have:
1166829 MKT1813 1.5/63V
1166830 MKT1813 2.2/63V
1166832 MKT1813 4.7/63V
1166838 MKT1813 .22/250V
1166843 MKT1813 .68/250V
1166867 MKT1813 2.2n/630V
1166869 MKT1813 4.7n/630V
1166871 MKT1813 10n/630V
1166873 MKT1813 22n/630V
1166874 MKT1813 47n/630V

And if you're lucky, then sometimes you'd get 1813's with yellow ends (not white ends), which are orig. ERO's, just 'Vishay' printed.

Larry: you really do have some of the cleanest work in the business, always a pleasure looking at your amps

Thank you! Your words are very appreciated!

 

[technomancer]

Thanks for the tip... now I have to order more caps

 

[FourT6and2]

... and the new ones aren't exactly common either though I think Mouser does have a few values.

Try your luck at Newark.
They should have the same part #'s than Farnell here in Germany, because it's the same company.
So you'd have:
1166829 MKT1813 1.5/63V
1166830 MKT1813 2.2/63V
1166832 MKT1813 4.7/63V
1166838 MKT1813 .22/250V
1166843 MKT1813 .68/250V
1166867 MKT1813 2.2n/630V
1166869 MKT1813 4.7n/630V
1166871 MKT1813 10n/630V
1166873 MKT1813 22n/630V
1166874 MKT1813 47n/630V

And if you're lucky, then sometimes you'd get 1813's with yellow ends (not white ends), which are orig. ERO's, just 'Vishay' printed.

Larry: you really do have some of the cleanest work in the business, always a pleasure looking at your amps

Thank you! Your words are very appreciated!

What's up with the EROs that are wrapped in green?

 

[novosibir]

What's up with the EROs that are wrapped in green?

The former Greenies still are sounding a tad more vintage with a pronounced mid range, compared to the later Yellowies...
... but they do have sometimes a leaking problem quite like the orig. Astron's in old Fender amps