
While we're on the subject of passive little helpers, what's your opinion on the Defizzerator?
https://paulinthelab.blogspot.com/2017/10/amptweaker-defizzerator-stripboard.html
Cub wrote:That was incredible! Your tone got a lot closer to _that_ tone than I heard in many TS clone videos. Man, I want to build that box!![]()
While we're on the subject of passive little helpers, what's your opinion on the Defizzerator?
https://paulinthelab.blogspot.com/2017/10/amptweaker-defizzerator-stripboard.html
John G wrote:Hi,
Many years ago a dude by the name of Gil Ayan, made a similar box called (I think) SMOOTH AND SLIM.
He also came up with the input bass reduction mod to the Mesa MK I amp..................... Legend.
John
lcv wrote:Hi Phatt
Great concept!
One question: in your hipass implementation, why is it necessary to halve the output voltage after the series cap?
Thanks
Lcv
Cub wrote:Thanks again, Phil!for your detailed explanation, that'll be a fun little build to do.
A very interesting read on pickups as well. I have to sit and read it more thoroughly soon.
The Defizzerator goes in the effectsloop of modern tube amps to suck up some of the fizz, it sounds very promising in clips.
If you series connect a 1n5 cap directly into the Hi Z input of most guitar amps you would be hard pressed to notice any difference
lcv wrote:If you series connect a 1n5 cap directly into the Hi Z input of most guitar amps you would be hard pressed to notice any difference
Sorry , my question was not clear.
(I prepared a picture but apparently I can't paste them to posts....)
When asking "why is it necessary to halve the output voltage after the series cap?" I was referring to the voltage divider made by the two 68K .
The signal just after the cap is essentially (assuming the HiZ input load negligible ) the same signal you get from the divider (as per your original schematic) but without attenuation.
So my question about the necessity to attenuate it.
Maybe you wanted to emulate the "low input" kind of attenuation?
Thanks for the interesting links!
Lcv
.... you actually need a fair bit of attenuation. You don't want V1 to run hard.
John G wrote:Hi,
Many years ago a dude by the name of Gil Ayan, made a similar box called (I think) SMOOTH AND SLIM.
He also came up with the input bass reduction mod to the Mesa MK I amp..................... Legend.
John
phatt wrote:Cub wrote:That was incredible! Your tone got a lot closer to _that_ tone than I heard in many TS clone videos. Man, I want to build that box!![]()
While we're on the subject of passive little helpers, what's your opinion on the Defizzerator?
https://paulinthelab.blogspot.com/2017/10/amptweaker-defizzerator-stripboard.html
Hello Cub,, Yes I believe that this is how SRV got THAT tone. But of course no one will ever know
but His brother is still around and I'd bet he has the original splitter box and that would
be the most obvious place to impliment (hide) a couple of resistors and a cap.
Meanwhile the whole teck world has modded a thousand amps and still can't quite nail the sound.
I think the fact that it is just so dead simple they all missed it.
Technical minds tend to assume it must be complex but IMExperimentaion it may well have been this simple.
Here is a dwaring of what is in the box on my video.
[ Image ]
This drawing only shows 5 position so just add another stage for 6 positions.
I used 5n6 which gives you 5n6 down to 1n8 at pos 5,, (1n4 at pos 6 on my box)
Just plug that into a standard Hi Z input of any of those old Amps that Stevie would have used,,,
and Bob is your auntie's husband.![]()
I doubt it will work well on a lot of modern higain Amps as they are more about preamp gain distortion
but suck it and see.
Other stuff I wanted to mention but just not enough time on the Video;
I think this trick does more than just forming a hipass filter.
All Magnetic PU's are inductive and have a distinct hump when looking into a hiZ input.
Better minds can explain the terms but in general I think the hotter PU's and more wire turns the bigger the hump.
But if you load down that input (in this case lower than 100k) then that hump is gone it's then a flat response.
That hump may well be the brittleness I hear on some of those hotrod amp rigs.
Thanks to that very much missed man (Roly Roper RIP peace mate, I miss you)
He has a page on PU's at AVA where it clearly shows in graphics how the input Z loads down that hump.
Page is here; http://ozvalveamps.org/pickups.htm
about halfway down you find the graphs
It explains bare PU, then Cable capacitance,, then input loading.
It's the input loading that shows that hump I'm talking about.
At 100k input Z the hump is gone,, you are down -3dB and the bandwidth is limited to around 4khZ.
EEK we have lost all that treble.![]()
I say think again;
You have heard the clip I posted,, did it; improve treble? improve note definition?
Improve guitar amp interaction? My ears tell me it improves the treble.![]()
By adding the high pass cap you have Refocused the tone response. The treble is now focused in the area of the freq
that the guitar works best.
20/20 bandwidth for guitar amps is just going to make it so much harder to dial in tones,,too much clutter.
Sometimes better is the enemy of good.
IMH experience, this cap trick forms the core of the tonal signature of that famous Texas tone thang. (and likely used by other famous players in the know)
All the amp mod tricks I've heard do not capture the sound for reasons explained above. I'd agree that some are very close but anything on the market that sounds like SRV will cost you a fortune,,,meanwhile a capacitor costs 10cents.![]()
Re the *Defizzerator* best I can make out is that it's a hi CUT filter, not sure how the pot is connected?
I assume it would cut treble and lower the input Z.
Brand names escape me but some really old guitar circuits actually had switchable series caps,, how well they worked I have no idea?
Phil.
phatt wrote:Well Hope I have not caused too much confusion![]()
R2 was drawn wrong.
Here is the Corrected Drawing;
[ Image ]
Hey Moderator; Is there any way I can delete the Wrong Drawing at top of this page?
Phil.
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