STRIKER SMOOTH MOD

[Striker Amplification]

Here is one that has never been done, this particular "mod" is part of my amplifier production. This is a great mod you can do to your amplifier, it creates a very solid sound and throw's out the "shrill" to a point where power chords........crack ribs!!

[Striker Amplification]

CORRECTION!

[R.G.]

Quick question: how does the sound change if you connect the two caps to ground instead of B+?

[Joe]

Looks like a good idea, especially for EL84 amps that can have some pretty painful treble sometimes.

[Striker Amplification]

Hello R.G. The tone is only slighy brighter when grounded, other than that no other issues.

[Striker Amplification]

Hey Joe, yes that is true. hopefully this will help you out! 

[electrosonic]

It reminds me of the Vox treble cut control, except in that case the cap is across the out-of-phase drive signals going to the power tubes.

Andrew.

[SISKO]

Hello R.G. The tone is only slighy brighter when grounded, other than that no other issues.

I once did this with a 800v plate voltage El34. Be carefull with the capacitor voltage or you may not get any sound at all :O.. Too risky to play in there

[Striker Amplification]

As long as your not using an ELECTROLYTIC capacitor your going to be fine 

[Johan]

Fender pro.jr does the same....might have had a small r too...i dont remember
J

[earthtonesaudio]

You could alternatively use a cap from Plate 1 to Plate 2, half the value, double the voltage rating.

[R.G.]

Hello R.G. The tone is only slighy brighter when grounded, other than that no other issues.

As noted, this requires caps with higher voltage ratings though. Presumably the extra brightness could be dealt with by increasing the cap size a bit.

So if putting the cap to ground from the plate works, it seems like this is a simple treble cut. So could you get the same effect by cutting treble *before* the plate? Perhaps by a cap from grid to ground? That would need an even lower voltage cap, and if done on the one input, only one cap would be needed.

[Striker Amplification]

No you cannot get the same results from the control grids instead of the plate(s).You have to try this first, otherwise, you could not compare the two. Your expecting less when you will get more

[Striker Amplification]

In fact the two cannot even be compared to side by side, you need rto try it, i promise guys its something different

[PRR]

> You have to try this

Why?

> So could you get the same effect by cutting treble *before* the plate?

No. This is an old-old-old technique. Speakers go inductive above 1KHz. When we used triode power tubes (back in the 1930s) it didn't matter much. When we switched to pentode power, the high plate impedance into inductive load causes a rise in treble response. On 78s or AM radio, this could be horrid. It became common to shunt pentode OTs with R-C networks.

At one extreme, pure C, the response peaks a little and then turns into an L-C low-pass, 12dB/8ve response, which is useful on hissy/scratchy sources. With some R in the loop (try R ~~= nominal load impedance) it tends to a damped response with 6dB/8ve initial fall-off.

As this directly interacts with the loudspeaker self-inductance in holistic ways, there is not a simple low-level replacement.

At extreme drive conditions ("normal" loud guitar playing) the treble self-inductance changes over the audio wave. This adds various types of harmonic, intermodulation, and FM distortions, which may or may not be euphonic in this application. In musician terms, it adds "scream", which may be useful.

Problem with using a pot to user-adjust response is that worst-case the pot must dissipate the full output of the amplifier. Typical-case, 1/10th of output. 1W radios could get away with 1/4W pots, although they (AND the cap) did tend to fail after hard playing. The same trick in an 18W geetar amp could possibly need a 30-Watt pot. Which is not a common or cheap part.

And if there's truly a blindfold A/B difference using two caps instead of one, now we into a _dual_ 15W ganged pot.

Oh, if the amp has NFB from output plate or from speaker, the need-for and effect-of this cap becomes much less, negligible; and of course at high NFB such a trick will surely cause loop oscillation.

[duck_arse]

This adds various types of harmonic, intermodulation, and FM distortions, which may or may not be euphonic in this application

for about 3 weeks in high school, I "played" a euphonium in the school brass band. euphonic, it was not. it may have been because it only had 3 keys.

[Striker Amplification]

Your going to have alot more issues trying to understand it, just listen to it.......try it, it does not create a screaming effect, in a quick response it takes a thin treble dominated amplifier signal and converts this output signal into a very solid creamy saturated signal, instead of being harsh and full of treble.

[DougH]

Conjunctive filter. Old news. Zoebel network has similar effect. Google.

[Striker Amplification]

Ok once more, IN A GUITAR AMP. thats the point.

[DougH]

Ok once more, IN A GUITAR AMP. thats the point.

Yup. In a guitar amp. Old news.