Jose-style Build: Thoughts?

[FourT6and2]

I've built a bunch of Jose-style builds. All of them slightly different. Put this schematic together for another one but I'm going back and forth on some voicing options. Any thoughts?

V1a plate will probably be 330K or 390K. Not a huge difference either way (I've tried both in the past).
Clipping/clamping options: I'm still up in the air. I might try 18v and 9.1v or 18v and something like 11-12v.
Will use a switch for the resistor on Gain 1 to ground. Some call this a "focus" control. I rarely use it. Have always used 82K here but maybe something lower, like 68K might be a nice option.
I play a very bright guitar with no tone knob (Mayones Duvell), and I've found I like the 0.001uF "dull" cap on the grid of the second stage to kill some highs. But some say it's better on the other side of the grid resistor?
Another option is to bypass the plate resistor with a small cap, like 330pF or so. But I have a question about this:

Should I bypass the 330K plate resistor, or should I split it up into two resistors like a 100K and a 220K, and then bypass just one of them? And if I do that, does the order matter?
I assume people who mod existing stock Marshalls add a second 220K resistor and leave the original 100K in the circuit either because it's easier or to retain the original parts of a vintage amp? But is there a sonic difference?

B+ --> 100K (bypassed) --> 220K --> socket
B+ --> 100K --> 220K (bypassed) --> socket
B+ --> 220K (bypassed) --> 100K --> socket
B+ --> 220K --> 220K (bypassed --> socket
B+ --> 330K (bypassed) --> socket


Larger version: https://orig00.deviantart.net/7970/f/20 ... ckc5mf.jpg

[Reeltarded]

It'll work. I have had all the similar circuits in my mule amp.. I love the CF master, I love independant gain controls per stage..

You might find that you don't need such a high first plate even though you are trying to squeeze the gain out there.

I think that 5kp over the gain limits what the amp can do.

What I discovered about clipping is that it's best to throw a 25k pot at a pair of N914s to moderate the squash and to my ear those sound best. (10k and the .22u then 25k pot)

I can't remember what I never liked about the 68k split but that I liked larger values 50/50 there. I have three similar but different builds with many similar ideas.

Um. 56k CF if your tube can take it. FAAATSO

[FourT6and2]

You might find that you don't need such a high first plate even though you are trying to squeeze the gain out there.

I've built a few similar amps as well and I think I've never gone lower than 330K plate load. I started super high, at like 470K and worked my way down lol.

I think that 5kp over the gain limits what the amp can do.

In my other amps, I have a couple caps on switches for each gain control and I've found I always have one off and one set to 4700pF. So I figured why not just hardwire it in and simplify the build. This amp will be for modern metal, not an '80s thing. Just going for a single-channel, one-trick pony type of thing

What I discovered about clipping is that it's best to throw a 25k pot at a pair of N914s to moderate the squash and to my ear those sound best. (10k and the .22u then 25k pot)

100v zeners? That seems pretty high. Won't offer much clipping will they? I was thinking something along the lines of 18v on one side and like 10-12v on a switch. I bought a bunch of zeners from 4v up to 24v and I'll put them on a 12-position switch to make a zener decade box then just test 'em all out. Then pick the two I like the most and hardwire them.

I can't remember what I never liked about the 68k split but that I liked larger values 50/50 there. I have three similar but different builds with many similar ideas.

My other amps have an 82K on a switch for a "feel" or "focus" control and then 150K on the grid instead of 68K/68K. I find the 82K to be slightly too much gain/low-end reduction. Haven't played around too much with the grid stopper value on the second stage. What do you recommend?

[sluckey]

100v zeners?

A 1N914 is not a 100V Zener. It's a small signal diode with a 100V PIV rating.

[FourT6and2]

100v zeners?

A 1N914 is not a 100V Zener. It's a small signal diode with a 100V PIV rating.

Oh you're right! I glanced at the data sheet too quickly. How do these compare to a pair of zeners? Why use one over the other?

[Reeltarded]

Have you ever played through a Randall RG 80/100/120? That whole amp is about the N914. It's thumpy and flat/dry and LOTS of reduction. (umm.. 5v?) They look like honey bees made of glass.. a plus. They are about as freaking clippy as anything could ever be. (err.. bee)

Commonly, I will engage the clipper circuit full sqaush and turn the master up until it's right at the edge of defeating them.

I think my bag is marked 5.1v.. the compression knee is way different from 4001 or similar. Very smooth and spongy with a teeny capacitance.

[Reeltarded]

100v zeners?

A 1N914 is not a 100V Zener. It's a small signal diode with a 100V PIV rating.

STOP GIVING ADVICE THAT PEOPLE DONT EXPECT, GAAAHHH!

[sluckey]

100v zeners?

A 1N914 is not a 100V Zener. It's a small signal diode with a 100V PIV rating.

STOP GIVING ADVICE THAT PEOPLE DONT EXPECT, GAAAHHH!

N914 is a rinseless wash for your car. There are ZERO N914s in a Randall RG80 or RG100 amp. However, there are several 1N914 small signal diodes with a 100V PIV rating. They are not zeners. If you have a bagfull of 'em marked 5.1v you may want to examine exactly what you have in that bag.

[Reeltarded]

Nope! They are the clipping circuit in the treble pull models that everyone is looking for but don't know that.. it's just the bag. I have enough to build 250 more amps.. at least.

[FourT6and2]

Have you ever played through a Randall RG 80/100/120? That whole amp is about the N914. It's thumpy and flat/dry and LOTS of reduction. (umm.. 5v?) They look like honey bees made of glass.. a plus. They are about as freaking clippy as anything could ever be. (err.. bee)

Commonly, I will engage the clipper circuit full sqaush and turn the master up until it's right at the edge of defeating them.

I think my bag is marked 5.1v.. the compression knee is way different from 4001 or similar. Very smooth and spongy with a teeny capacitance.

Nope, I've never played a Randall. Wait... I think I played one of the models that Mike Fortin had input in designing. But only briefly in a music shop years ago.

You can also wire up two transistors to do the same thing. I've got an amp here with a pair of 2N5401s wired up for their inner base-to-emitter zener. Although I have no clue why anybody would do that instead of just using actual 5v zeners... unless there's some sort of tonal variation?

So you're saying these 1N914s have a certain sound to 'em?

As far as how they look, in photos they appear to look exactly like zeners.

[Roe]

its too gainy for me with 320k anode resistor and a 68k/68k voltage divider. Also there is a fair amount of hiss

[Reeltarded]

That's it, Roe.. same here. I like 220k plate with 220k to 270k divider.

Yeah. The 914 is smooth and huge squash. It dumps an undetectable bit of highs and sounds flat and fat.

I have only terrible examples, but I just found me playing a black guard telecaster on Van Halen's birthday through an amp with 1N914 setup and it sounds like the record, but HUGE-ER. Very fat.

[FourT6and2]

its too gainy for me with 320k anode resistor and a 68k/68k voltage divider. Also there is a fair amount of hiss

Interesting. I've gone up to 470K plate load. Doesn't seem that different from 330K to be honest. I can try 220K of course.

What about what I have in parenthesis with an 82K off the gain wiper to ground and a 150K grid resistor instead of 68K/68K?

[FourT6and2]

That's it, Roe.. same here. I like 220k plate with 220k to 270k divider.

So the higher plate resistor puts more voltage on the stage, decreasing a bit of gain. And a 220K/220K divider to V1b grid also reduces gain?

Keep in mind I'm not going for a Van Halen or '80s sound here. More like '90s hard rock to modern metal. Here's the last amp I built. This one has a 390K plate load with a 150K grid stopper on V2a. It does have an 82K from gain wiper to ground on a push/pull. But it's not engaged in this clip. Cathodes are 2K7/.68, 2K7/.68, 820R/.68. 0.047uF caps in the PI, tone stack is 36K (maybe 39K I can't remember) and 500pF.

[Reeltarded]

You can do less plate and less stopper and get more open tone.. but yeah.. if that sound is what you are after use the pair of opposing n914s.. they make ANY amp sound like that without any other change lol...