Does a real Fender Twin Reverb do this?

[DolurumMafikala]

Since I've had the Pod HD500X I've always noticed some high-end fuzzy digital-sounding noises on the Twin Reverb model and I think on the other Standard Pack vintage Fender models too.

 

Recently I tried Peter Hamner's presets http://www.peterhanmer.co.za/hd500x.htm after stumbling across his demonstration videos. His Fender Twin Reverb patch, which runs the Drive at 57%, shows the effect I had noticed. I isolated it in the attached file, which is me plucking the G string. It sounds like a buzz, as if a string is vibrating against a fret (it isn't) or a speaker was loose (this was recorded over USB, no speaker involved).

 

I found I could remove the noise by turning down the Master DEP to about 60%. By default, it is set to 100%, presumably to model the fact the original Twin Reverb does not have a Master Volume knob.

 

Reading some comments by companies that have modelled these early Fender amps it does sound like they have power-amp distortion which is subjectively unpleasant. Maybe what I was hearing was correctly-modelled power-amp distortion and by turning down the invented Master DEP I was removing it by reducing the signal going into the power amp stage. If so, it is pretty cool that the model would do that.

 

If anyone has a real Twin Reverb or Deluxe Reverb or similar I'd love to know if you get a similar distortion/artifacts to the one in the attachment when you turn up past 5. Just out of interest about the model accuracy.

 

Some related comments that got me thinking along those lines:

 

This is from a Line 6 Forum post about invented controls in Helix, talking about the DR rather than the TR:

 

https://line6.com/support/topic/19961-helix-amp-model-gallery-real-controls-vs-invented/
We matched the knob positions in the amp models. If anyone here has used a Deluxe Reverb you know that after about 4-5, the amp stop getting louder. Once the amp goes past 7-8 it can get pretty ugly. The model behaves the same. Once the drive passes 40% or so, it'll never be a clean amp. Cranking the drive will never give a tight distortion, it'll blow out the power amp. Some think this sounds awesome, some think it sounds ugly. That's totally subjective. But if you are using a model and you want more drive, think of how that model would sound when cranked. Sometimes it sounds a lot better to put a drive pedal in front of an amp than to push an amp to its limits.

 

And another from Fractal Audio, again talking about the DR:

 

https://wiki.fractalaudio.com/wiki/index.php?title=Amplifier_models_list#DELUXE_VERB_NORMAL_.28blackface_Fender_Deluxe_Reverb.2C_AB763.29

 

(fuzzy lows) "That's what those amps do. Always been that way. Just to be sure I just compared the Deluxe Verb model with the reference amp and it's correct. Those are old designs. Simple circuits with minimal frequency shaping. As such there's a lot of bass going into the power amp. That coupled with the resonance magnification of the speaker impedance causes frequencies around the resonance (in the 50-100 Hz region) to distort early. The low E string is 82 Hz so it's right in that zone." [160]

 

Artifact.mp3

[stormstudios]

I have a Twin Reverb 65 Reissue and it definitely does not make that sound even at 8 or 9  (my ears couldn't handle 10).

 

I plugged into both Input 1 and Input 2 (attenuated 6db) on Channel 1 all the way up to 9 and nothing like that.

"Once the amp goes past 7-8 it can get pretty ugly." -

I don't even know what that is meant to represent. Never heard my amp get ugly. Maybe I'm 'doing it wrong' lol

 

I cannot speak for a Deluxe Reverb.

[DolurumMafikala]

Thanks for taking the time to do the experiment @stormstudios I appreciate it.

 

Just a quirk of the model then perhaps.

 

I'm just happy it is a simple twist of the Master DEP and not a string of PEQs :)

 

[JohannDaart]

On 7/3/2021 at 11:36 AM, DolurumMafikala said:

Recently I tried Peter Hamner's presets http://www.peterhanmer.co.za/hd500x.htm after stumbling across his demonstration videos. His Fender Twin Reverb patch, which runs the Drive at 57%, shows the effect I had noticed. I isolated it in the attached file, which is me plucking the G string. It sounds like a buzz, as if a string is vibrating against a fret (it isn't) or a speaker was loose (this was recorded over USB, no speaker involved).

 

Hi, it's funny that you've stumbled upon the same doubts about "HD fizz" as me, while using Peter's Fender patches.

 

If you want more info, check out my topic about:

 

In short... This fizz/sizzle is supposed to be a modeled "crossover distortion".

Lots of people call this "squirrels". Helix has them too, but they are more subtle.

Other modelers like Fractal and Kemper have "squirrels" too, but they are more dependent on Power Amp (Master) setting and even smoother and less prominent (as they should be).

 

Crossover distortion is part of the guitar amp tone, but... it should only stand out this much and be as harsh as on HD's Fender, when the power amp section is cranked.

Good example is Eddie's tone from Drop Dead Legs intro, you can clearly hear heavy "squirrels": https://www.youtube.com/watch?v=-EwJ9PkcZk4

But it should sound like this, because his volume on guitar is turned down, while the power amp is probably still dimed.

 

Meanwhile on POD HD, the power amp control is not working as it should, because Drive and Power Amp controls seem to be connected and result in "overall gain".

If you turn down the Power Amp, then you get less "overall gain" and "squirrels" go away, but... your tone stops being overdriven and it's not anymore "on the edge of the breakup" that you aim for. Then you turn up the Drive to compensate for the loss of gain and your tone starts to break up as it should... but you get "squirrels" again ;)

 

You also can't really edit those "squirrels" out with EQ blocks, because they sit in the "fizz" range of frequencies that are important for guitar tone. You can smooth it out a bit, but if you overdo it, you are making your tone suck too.

 

Edge of the breakup tones and power amp section modelling are the biggest POD HD flaws (IMO).

 

[DolurumMafikala]

Thanks @JohannDaart for the link to the earlier thread. I followed @hurghanico's advice in it to google "tube amp crackle on note decays" and found many references to this in real amps and in modellers.

 

The standout for me was this thread where they are talking about the Amplifire. This specific post links to an A/B test between a Fender modelling amp and a real Champ-style amp:

 

https://www.thegearpage.net/board/index.php?threads/fuzzy-distortion-when-the-notes-tails-off-is-my-amplifire-faulty.1636667/post-20938332

 

For me the real amp sounded fuzzier than the modeller!

 

I'm not worried about all this in La Pod, I just find it interesting and educational. I'm concluding that real amps (especially older designs) do this to various degrees and so the modellers do it too, to various degrees. The extra clarity from the modellers (and suspicion of them) might make the noise stand out more.

[JohannDaart]

@DolurumMafikala I think it's also important to remember, that the "big" tone you get from HD/Helix/Fractal usually replicates the sound of a loudly cranked amp. If you would get a real Fender Twin, you probably couldn't crank it so loud at home. Then if you could at a rehearsal, you then wouldn't put your ear close to the speaker to hear squirrels and those details like crackling would blend into the ambiance of the room/venue.

They are there, but not as present while experiencing "real amp in a room".

This sizzling also blends in mixes.

 

You can also check Johan Segeborn vids, he uses real vintage Marshalls and you can often hear crossover distortion (sizzle/squirrels) in his tones:

https://youtu.be/d8NWQSjHQHs?t=104

[DolurumMafikala]

I love Johan Segeborn's vids. All those vintage amps, amazing chops and his relaxing Swedish diction :)

[JohannDaart]

@DolurumMafikala I like the relaxing vibe of his vids too :)