High-Gain JCM800/2204 Build

[FourT6and2]

Ok, updated the amp. Running the HV taps now, 2N5401 and 18v zeners for clipping and running a 68k/68K voltage divider on Gain 1. Tried all my cabs and it sounds best with G12H-75 Creambacks. Will make a new clip sometime this week.

That's pretty close to where I'm at I use 2n5400s in series with 11v zeners when switch is to the left and on the right it shorts the 11v zeners leaving just the 2n5400s. Are you using the Ceriatine depth or a Cameron depth?

Just standard 4700pF with 1M pot for depth. I have a bunch of schems for different depth circuits but it's just so much work to try all these options. NFB before or after depth, and use a switch for this or that, and then you gotta change the NFB resistor value to compensate for the different depth circuits, and blah blah blah. It's a headache.

 

[scottosan]

Ok, updated the amp. Running the HV taps now, 2N5401 and 18v zeners for clipping and running a 68k/68K voltage divider on Gain 1. Tried all my cabs and it sounds best with G12H-75 Creambacks. Will make a new clip sometime this week.

That's pretty close to where I'm at I use 2n5400s in series with 11v zeners when switch is to the left and on the right it shorts the 11v zeners leaving just the 2n5400s. Are you using the Ceriatine depth or a Cameron depth?

Just standard 4700pF with 1M pot for depth. I have a bunch of schems for different depth circuits but it's just so much work to try all these options. NFB before or after depth, and use a switch for this or that, and then you gotta change the NFB resistor value to compensate for the different depth circuits, and blah blah blah. It's a headache.

To me it's the most critical change. The NFB can stay before the depth

 

[FourT6and2]

Ok, updated the amp. Running the HV taps now, 2N5401 and 18v zeners for clipping and running a 68k/68K voltage divider on Gain 1. Tried all my cabs and it sounds best with G12H-75 Creambacks. Will make a new clip sometime this week.

That's pretty close to where I'm at I use 2n5400s in series with 11v zeners when switch is to the left and on the right it shorts the 11v zeners leaving just the 2n5400s. Are you using the Ceriatine depth or a Cameron depth?

Just standard 4700pF with 1M pot for depth. I have a bunch of schems for different depth circuits but it's just so much work to try all these options. NFB before or after depth, and use a switch for this or that, and then you gotta change the NFB resistor value to compensate for the different depth circuits, and blah blah blah. It's a headache.

To me it's the most critical change. The NFB can stay before the depth

You're talking about the CCV depth circuit, I presume?

 

[scottosan]

Ok, updated the amp. Running the HV taps now, 2N5401 and 18v zeners for clipping and running a 68k/68K voltage divider on Gain 1. Tried all my cabs and it sounds best with G12H-75 Creambacks. Will make a new clip sometime this week.

That's pretty close to where I'm at I use 2n5400s in series with 11v zeners when switch is to the left and on the right it shorts the 11v zeners leaving just the 2n5400s. Are you using the Ceriatine depth or a Cameron depth?

Just standard 4700pF with 1M pot for depth. I have a bunch of schems for different depth circuits but it's just so much work to try all these options. NFB before or after depth, and use a switch for this or that, and then you gotta change the NFB resistor value to compensate for the different depth circuits, and blah blah blah. It's a headache.

To me it's the most critical change. The NFB can stay before the depth

You're talking about the CCV depth circuit, I presume?

CCV, Jose, or Aldrich all used depth mods different than the ceriatone

 

[psychodave]

Ok, updated the amp. Running the HV taps now, 2N5401 and 18v zeners for clipping and running a 68k/68K voltage divider on Gain 1. Tried all my cabs and it sounds best with G12H-75 Creambacks. Will make a new clip sometime this week.

That's pretty close to where I'm at I use 2n5400s in series with 11v zeners when switch is to the left and on the right it shorts the 11v zeners leaving just the 2n5400s. Are you using the Ceriatine depth or a Cameron depth?

Just standard 4700pF with 1M pot for depth. I have a bunch of schems for different depth circuits but it's just so much work to try all these options. NFB before or after depth, and use a switch for this or that, and then you gotta change the NFB resistor value to compensate for the different depth circuits, and blah blah blah. It's a headache.

I find that .0047 can be too much. I really like the .003. Then you can add the resistor like the CCV to focus in on some more mids.

 

[Kapo_Polenton]

Jesus, that is a monstrous sounding amp. I like that mucho.

 

[FourT6and2]

Ok, updated the amp. Running the HV taps now, 2N5401 and 18v zeners for clipping and running a 68k/68K voltage divider on Gain 1. Tried all my cabs and it sounds best with G12H-75 Creambacks. Will make a new clip sometime this week.

That's pretty close to where I'm at I use 2n5400s in series with 11v zeners when switch is to the left and on the right it shorts the 11v zeners leaving just the 2n5400s. Are you using the Ceriatine depth or a Cameron depth?

Just standard 4700pF with 1M pot for depth. I have a bunch of schems for different depth circuits but it's just so much work to try all these options. NFB before or after depth, and use a switch for this or that, and then you gotta change the NFB resistor value to compensate for the different depth circuits, and blah blah blah. It's a headache.

I find that .0047 can be too much. I really like the .003. Then you can add the resistor like the CCV to focus in on some more mids.

These are some variations I've seen. Haven't tried either though. Seems like the easiest way is to use 2.2nF caps instead of using a bunch of 1nF wired together. I might throw a bunch on a pot and wire it in temporarily to see what all the fuss is about.

 

[FourT6and2]

Jesus, that is a monstrous sounding amp. I like that mucho.

Thank you thank you. Sounds a bit better now too.

 

[scottosan]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

 

[FourT6and2]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

Right, but why not just use a 2nF ceramic instead of two 1nF?

 

[MYLILSS]

that is a gorgeous build !!!

 

[scottosan]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

Right, but why not just use a 2nF ceramic instead of two 1nF?

right probably splitting hairs at that point. I think youd be fine

 

[psychodave]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

Right, but why not just use a 2nF ceramic instead of two 1nF?

I think it comes down to liking the tone of a specific cap. Then using 2 of said cap to create different values. It’s a rabbit hole, but I’ve heard first hand the effects of specific cap brands/formulas.

 

[FourT6and2]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

Right, but why not just use a 2nF ceramic instead of two 1nF?

I think it comes down to liking the tone of a specific cap. Then using 2 of said cap to create different values. It’s a rabbit hole, but I’ve heard first hand the effects of specific cap brands/formulas.

Right. So it's more about not having the proper value cap on hand. So someone ran two in parallel to get the value they wanted.

 

[scottosan]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

Right, but why not just use a 2nF ceramic instead of two 1nF?

I think it comes down to liking the tone of a specific cap. Then using 2 of said cap to create different values. It’s a rabbit hole, but I’ve heard first hand the effects of specific cap brands/formulas.

Right. So it's more about not having the proper value cap on hand. So someone ran two in parallel to get the value they wanted.

I dont know if thats the case. I've seen a Jose with a 2200pf bright cap, the but the (2) 1000pf series with (2) 1000pf in parallel seem to be consistant with alot of the mods.

 

[psychodave]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

Right, but why not just use a 2nF ceramic instead of two 1nF?

I think it comes down to liking the tone of a specific cap. Then using 2 of said cap to create different values. It’s a rabbit hole, but I’ve heard first hand the effects of specific cap brands/formulas.

Right. So it's more about not having the proper value cap on hand. So someone ran two in parallel to get the value they wanted.

I know that Cameron liked those little orange caps that were .001uf. Hence why you see him use them in a lot of amps in both series and parallel in the depth circuit and brute caps on the gain pots

 

[FourT6and2]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

Right, but why not just use a 2nF ceramic instead of two 1nF?

I think it comes down to liking the tone of a specific cap. Then using 2 of said cap to create different values. It’s a rabbit hole, but I’ve heard first hand the effects of specific cap brands/formulas.

Right. So it's more about not having the proper value cap on hand. So someone ran two in parallel to get the value they wanted.

I know that Cameron liked those little orange caps that were .001uf. Hence why you see him use them in a lot of amps in both series and parallel in the depth circuit and brute caps on the gain pots

Yeah that's because he doesn't order parts in the values he needs. He walks around giant electronics supply shops and pulls parts he likes and he's limited to the values they have on hand. So if he finds a bunch of 0.001uF caps he knows he likes in some random box on the bottom shelf of aisle 39 of some antique electronics shop, but he needs other values, he'll just run a bunch in series or parallel. It's not because two 0.001uF in parallel sound better than one 0.002uF.

Same reason why someone might run two 0.022uF mustards in parallel instead of sourcing a 0.047uF. Easier to find. It's not because running two caps in parallel is magic and running one isn't.

 

[technomancer]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

Right, but why not just use a 2nF ceramic instead of two 1nF?

I think it comes down to liking the tone of a specific cap. Then using 2 of said cap to create different values. It’s a rabbit hole, but I’ve heard first hand the effects of specific cap brands/formulas.

Right. So it's more about not having the proper value cap on hand. So someone ran two in parallel to get the value they wanted.

I know that Cameron liked those little orange caps that were .001uf. Hence why you see him use them in a lot of amps in both series and parallel in the depth circuit and brute caps on the gain pots

Yeah that's because he doesn't order parts in the values he needs. He walks around giant electronics supply shops and pulls parts he likes and he's limited to the values they have on hand. So if he finds a bunch of 0.001uF caps he knows he likes in some random box on the bottom shelf of aisle 39 of some antique electronics shop, but he needs other values, he'll just run a bunch in series or parallel. It's not because two 0.001uF in parallel sound better than one 0.002uF.

Yep, same thing with those grey box caps he uses all over the place. He likes them and got a shitload of them surplus and has been using them ever since.

 

[FourT6and2]

I recommend the lower resistor 27-33k. Also the consensus on using the multiple ceramics vs single larger dilms is that the gritty by-product of the ceramics adds to the character of the tone

Right, but why not just use a 2nF ceramic instead of two 1nF?

I think it comes down to liking the tone of a specific cap. Then using 2 of said cap to create different values. It’s a rabbit hole, but I’ve heard first hand the effects of specific cap brands/formulas.

Right. So it's more about not having the proper value cap on hand. So someone ran two in parallel to get the value they wanted.

I know that Cameron liked those little orange caps that were .001uf. Hence why you see him use them in a lot of amps in both series and parallel in the depth circuit and brute caps on the gain pots

Yeah that's because he doesn't order parts in the values he needs. He walks around giant electronics supply shops and pulls parts he likes and he's limited to the values they have on hand. So if he finds a bunch of 0.001uF caps he knows he likes in some random box on the bottom shelf of aisle 39 of some antique electronics shop, but he needs other values, he'll just run a bunch in series or parallel. It's not because two 0.001uF in parallel sound better than one 0.002uF.

Yep, same thing with those grey box caps he uses all over the place. He likes them and got a shitload of them surplus and has been using them ever since.

Exactly. He'll buy 1,000 of something he knows he likes and just mix/match to get whatever value he needs.

 

[FourT6and2]

Lowered depth cap to 0.0022uF from 0.0047uF. Nice mid boost. You do lose some of the deep low-end but you still get a decent thump. And you can drop the mids slightly to get back the deepness of the 4n7 cap.

Also settled on a 0.001uF bypass on the Gain voltage divider to tame some of the hash noise.

This thing is really coming along and I'm definitely learning a lot as I go.