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gtrfinder
04-12-2007, 08:34 AM
What exactly is a "ghost note".
I have heard this term associated with 2 types of phenomena here at TGP. One appears to be positive, while the other is negative.
The first (negative) instance is associated with preamp tube problems, and is described as annoying and undesirable.
The second ("ghosting") comes from some descriptions of vintage Marshalls that are dimed, and appears to be a desirable aspect of these amps.
What is up with ghost notes and can anyone give some explanation of these 2 instances and how they are related.
Thanks

57tele
04-12-2007, 09:07 AM
To confuse things further, there's actually a third meaning that I've come across, usually from inexperienced players. In a fingerstyle piece when there is a defined melody played over a quieter obligato, those quieter obligato tones are often referred to as 'ghost notes.'

billyguitar
04-12-2007, 10:01 AM
Ghost notes are never good but usually you can't hear them when the band's playing. A ghost note is a lower dark toned note that follows what you play but is not as loud and worse is always out of tune.

Madsman
04-12-2007, 10:54 AM
Well, the term "Ghost Note" predates the cone cry sound etc. Ghost notes are notes that take up space (have rhythmic function) but are either very quiet or are even absent entirely.

The amp/speaker phenomenon we refer to as ghost notes are also called "double noting" or "cone cry." The preamp tube problem you're referring to... I've heard of microphonic preamp tubes, but I have never heard of "ghost notes" as a result of preamp tubes. The "positive" effect you mention... is not something that most people consider positive. When you play a note (usually most evident on higher notes) at a very loud volume, your speaker may exhibit a second pitch, owing to the resonance of the speaker itself, or some other vibration. This sound is typically horrendously out of tune with what you're playing, and in my experience, it can stand out like a sore thumb even with the band. Certain speakers seem more prone to this sound than others... V30s for example. Greenbacks much less so. The only cure that definitely works is turning down. On the bright side, usually the sound is occurring when you're playing at levels much louder than are required for band rehearsals or performances.

I've also been told that the "speaker goop" you see on some speakers can help with this problem.

Jackie Treehorn
04-12-2007, 11:36 AM
Generally, I believe the ghost noting is caused by the power supply modulating the signal a bit. I think ghost noting is great! It's an integral part of the my-amplifier-is-about-to-blow-up sound, IMO. It gives you some swirl and seems to fill in the middle with some extra harmonics.

You have to use small filter capacitances. Of course, you might make them big enough so there's no motorboating/oscillations.

billyguitar
04-14-2007, 11:22 AM
Cone cry or edge yowl is a bit different than ghost notes. It's usually louder and more erratic. It always startles and distracts me so I stay away from Celestions in general.
My Dr Z Route 66 has very apparent ghost notes but I can't hear them when the band plays. I haven't tried rebiasing the amp, that may help. This amp design is rather known for this. It can be reduced by using speakers with less lows and low mids. My favorite cab is the Z 2x10. Unfortunately it is very strong in these frequencies and accentuates the problem with the Route 66 head. But that's exactly the sound I want in a cab, along with the small size and light weight, so I ignore it. None of my other Z amps do it.

AdmiralB
04-16-2007, 05:56 AM
My Dr Z Route 66 has very apparent ghost notes but I can't hear them when the band plays. I haven't tried rebiasing the amp, that may help. This amp design is rather known for this.

There are two versions of the 66 - the first version has less filtering and more bass in the preamp. The current version has, well, more filtering and less bass in the preamp - an attempt to address the ghost issue, I understand.

jakob
04-16-2007, 06:48 AM
I read everything but I'm still confused....
Maybe that says alot about me...:jo

tremolux
04-17-2007, 04:46 AM
Madsman is correct about "ghost note" re: guitar tablature and as billyguitar said, cone cry from a speaker is a different animal, tho they often get mistaken for the other in the use of the general term "ghost notes". I havent come across the term 57tele refers to, but it sounds like another use of the term (to add to the confusion.)

Ghost notes ride shotgun "on top" of the guitar note and are'nt usually in tune harmonically with the note being played, tho some people are more inclined to say a ghost note "follows" shortly behind the desired note.... and in certain amp designs they can be a real pain the butt and in others more tolerable....what AdmiralB is saying about the Dr Z Rt66 amp speaks to the ghost note thats usually caused by an underfiltered power supply.... and thats the type of ghost notes amp builders deal with and use the phrase in reference to. Most of the time the problem can be partially or fully remedied by increasing the filtering in the power supply.

When its bad and difficult to live with, its usually appears to be the most exaggerated on the D, G and B string above the 10th/ 12 fret, tho it can crop up about anywhere. Ghost notes caused by inadequate power supply filtering usually have a freq at around 120hz modulating the signal (60hz ripple in the supply supply X 2 based on full wave rectification = 120hz) and creating the ghosting. If youre in Europe it would be a 100hz freq since the standard is 50hz in the supply. Its also somewhat related to something called "intermodulation distortion" which occurs in all tube driven amplifiers being pushed hard at higher volumes, but is not nearly as noticeable as the out of tune ghost notes created by an underfiltered power supply (also more evdident when the amp is being pushed toward the max end of its output.)

A poorly designed bias circuit can be an ingredient in the ghosting problem mix also, for the same reason (being underfiltered and allowing ripple in the supply to pass.) There are also proponents of bad grounding and lead dress, the way wires are routed and components are situated, adding to the problem with an underfiltered power supply. In some amps with triode/pentode switching, the problem can be so pronounced in the triode mode thats almost or is, unuseable without more filtering.

In essence, in some amps it can be tolerable and be considered part of the overdrive/distortion mystique....some players tend to live with it better than others while its waaay annoying to others depending on a number of variables. If its a problem, as said...it can usually be helped with added filtering.

kimock
04-17-2007, 05:38 AM
To confuse things further, there's actually a third meaning that I've come across, usually from inexperienced players. In a fingerstyle piece when there is a defined melody played over a quieter obligato, those quieter obligato tones are often referred to as 'ghost notes.'

To further confuse things, you can hear them on an acoustic guitar.
they're just easier to hear with a distorted amp.
Any two tones in an overtonal relationship will sum to their tonic, you can see that with a guitar tuner when you play a double stop.
They're only out of tune if you are. . .
Combination tones.

kimock
04-17-2007, 05:49 AM
What exactly is a "ghost note".
I have heard this term associated with 2 types of phenomena here at TGP. One appears to be positive, while the other is negative.
The first (negative) instance is associated with preamp tube problems, and is described as annoying and undesirable.
The second ("ghosting") comes from some descriptions of vintage Marshalls that are dimed, and appears to be a desirable aspect of these amps.
What is up with ghost notes and can anyone give some explanation of these 2 instances and how they are related.
Thanks
http://users.rcn.com/dante.interport/winckel.html

hasserl
04-17-2007, 09:23 AM
This can also be a problem inherent in certain guitars, which is aggravated when the pickups are set too close to the strings. Most common among Strats and other single coil pickup guitars.

Galo
04-17-2007, 11:49 AM
This can also be a problem inherent in certain guitars, which is aggravated when the pickups are set too close to the strings. Most common among Strats and other single coil pickup guitars.


That would be a wolfe tone...I believed...

vibroverbus
04-18-2007, 07:51 AM
Ghost notes caused by inadequate power supply filtering usually have a freq at around 120hz modulating the signal (60hz ripple in the supply supply X 2 based on full wave rectification = 120hz) and creating the ghosting. If youre in Europe it would be a 100hz freq since the standard is 50hz in the supply. Its also somewhat related to something called "intermodulation distortion" which occurs in all tube driven amplifiers being pushed hard at higher volumes, but is not nearly as noticeable as the out of tune ghost notes created by an underfiltered power supply (also more evdident when the amp is being pushed toward the max end of its output.)


Well summarized Trem. Confusion comes from the same name being used for 3 different things.

All I'd add is that PS driven Ghost Notes are intermodulation distortion, just IMD between the signal and ripple, whereas IMD alone usually refers to multiple audio signals inside the amp interacting. Ripple-ghost-notes ALWAYS sound terrible in my experience - although I'm sure there's some note where 120hz forms a melodious harmonic, I have yet to find it...

tremolux
04-19-2007, 04:38 AM
Good point vibroverbus, where one is interactive the other is more like interference, situated in between the signal and ripple in the line.

If you ever find that "beautiful, rosy bloom of ultra-low midrange harmonics" that an underfiltered amp is supposed to be known for delivering (according to a fairly well known amp designer that under-designs filtering for that very response as he desribes it), let me know!!

I've yet to hear 120hz sound harmonically "rosy" to other fundamentals in the signal either, I agree. Thats why I had to add that "some players tolerate it better".....:confused:

Jackie Treehorn
04-19-2007, 11:05 PM
If you ever find that "beautiful, rosy bloom of ultra-low midrange harmonics" that an underfiltered amp is supposed to be known for delivering (according to a fairly well known amp designer that under-designs filtering for that very response as he desribes it), let me know!!

Ha ha! I love that quote! He's right, of course. Who said it?

tremolux
04-23-2007, 02:07 AM
In retrospect, I want to say that it was Mark S when the very first Matchless DC-30 hit the market in 91? I know that after hauling several to a guitar show and having various people try them out that he booted the mains filtering up by about 30/40uf. But I asked a friend about it and he thinks it was the Kendrick guy in an ad for a tweed deluxe knock-off in a mag in the mid-90s? It could be.........?? A good one wherever it came from! :D

rmconner80
04-23-2007, 11:09 AM
I like the tone of smaller filters (within reason) over larger filters in the power supply in certain amps. I tried 100uFs, 50uFs, and 32uFs in a 50 watt marshall super lead clone and vastly prefered the midrange and low end of the 32uFs in that amp. I don't think it is all BS and marketing.

Interestingly, most of Mark Sampsons amps, according to the schematics, are pretty stiffly filtered.

In any case, if I recall correctly, you can hear a good example of recorded PS ghost notes on the big bends at the very end of Rush's "Working Man". If you listen closely, you'll hear an underlying descending howling note on each bend.

tremolux
04-24-2007, 04:43 AM
Yeah, the early DC30s were demo-ed long before he had schemos printed up and ready...I think he learned a lot from the Hellcasters at the Arlington show in 92 and redesigned his thinking on filtering after that, which probably followed on future Matchless amp designs.

They (Hellcasters) used them for the Sat eve jam in 92 and sounded great, but none on them were too crazy about the out of tune harmonies they were playing......with themselves. Donahue ran over and grabbed a DR halfway thru the show and used it for the remainder while Ray and Jorgenson continued with the DC30s.

tremolux
04-24-2007, 04:44 AM
oooppppss....Arlington...Texas show in 92!

vibroverbus
04-24-2007, 08:19 AM
I think there's a lot of misunderstanding about under-filtering, and confusion with cause & effect attribution. I think much of what people think they like about low filtration can actually be attributed to other softness in the power supply - sag effects in other words. Interestingly many of the modern worshipped gurus designs are actually very carefully and highly filtered - see Dumble, Trainwreck, and KOC's stuff...

riffmeister
04-25-2007, 10:16 PM
My understanding of a "ghost note" is that it is an off harmonic lower pitch that results from underfiltering in the power supply. I certainly have experienced this in several amps, very slightly and in what I would call a "good way" with a couple of TopHat amps, and in an exccessive way with a Dr. Z amp. The ghosting was most easily heard when bending a D played at the 7th fret on the G string, although the ghost notes could be heard at other locations, too. When bending the D on the 7th fret of the G string, as the note was bent sharp, the ghost note would actually *drop* in pitch. Crazy sounding stuff, and annoying when the ghost note was fairly prominent as it was on the Dr. Z amp. The ghosting was always more prominent with humbuckers than with Fender single coils. I sent the Z back to the good doctor and he tweaked something (wouldn't tell me what). When it came back, the ghosting was greatly reduced, but not emliminated, and it sounded quite good to my ear.

zoooombiex
04-26-2007, 08:26 AM
Interesting and timely thread. Just recently I was playing through one of my amps when I suddenly noticed this subtle undertone when playing around in the upper register. Thought it might be the cab, but put another amp in front of the cab and it went away. Then tried the first amp with another cab - still there. So it seems to be the amp, not speakers or guitar. Also, it happens on single notes, so it doesn't seem to be an inherent overtone of a harmony.

It's pretty subtle and I obviously went for a good while without noticing it at all. But of course, once my ear caught that sound it became fixated on it ... kind of like learning a new word that all of a sudden shows up everywhere. At least based on this thread, I'm guessing it's the power supply filtering. It's probably not worth messing with the amp, but just for the sake of curiosity - how much of an impact does increasing the filtering have on the tone/feel of an amp?

riffmeister
04-26-2007, 09:47 AM
for the sake of curiosity - how much of an impact does increasing the filtering have on the tone/feel of an amp?

huge!

a lot = stiffer feel with strong fundamental
a little = sloppier feel w/ ghost notes

different people like different things, so what's "best" is largely a subjective matter. I like it somewhere in the middle.

tdu
04-26-2007, 10:44 AM
I just took an amp into the tech . This was before I found this thread. I was having a lot of the problem mentioned here.

I was hearing the exact notes described, but when playing almost any single note on the guitar. The higher I played, the worse it got. I didn't hear it as much with chords. I definitely would not describe it as subtle either. I described it in my note to the tech as 'like having a weak octave pedal on'.

I tried every different guitar I own, and new patch cords and it didn't help. The problem was there with every guitar.

The other problem I noticed is that the amp had a lot of noise going on. More then normal amp hum.

This amp took a bit of a ding in shipping, and I had assumed it was something relating to that. Unfortunately the tech is busy and I won't even hear back from him till next week about what's going on.

zoooombiex
04-26-2007, 01:03 PM
huge!

a lot = stiffer feel with strong fundamental
a little = sloppier feel w/ ghost notes

different people like different things, so what's "best" is largely a subjective matter. I like it somewhere in the middle.

Interesting ... i tend to lean towards a stiffer feel, so maybe some added filtering would be a double benefit.

Is this a complicated procedure? I'm no expert, but I'm decent with a soldering iron and know what not to touch in the amp...

tremolux
04-27-2007, 02:58 AM
The basics in general...It all depends on the amp and how its laid out (how components are physically situated in the amp). In most Fender amps from 54 thru the end of the silver panel line in the early 80s, its fairly easy because the caps are usually housed underneath a rectangular cover on the underside of the chassis or can be found somewhere on the circuit board in some older and newer designs. Or.....sometimes there will be a circuit board set up inside the chassis just for mounting all or a few of the filter caps with the wire leads running off to the supply points.

In amps that use "can caps" (where the individual caps are stacked inside a can all together ie: Marshalls, etc etc) it becomes much more difficult (and costly) to make quik experimental changes. Changing these can also effect preamp stages in some amps, while not in others that have can caps dedicated to a specific portion of the circuit. Soooo, it depends on what amp you have and the design, which you can check yourself (by looking) or post here for some assistance...after reading the last paragraph.

You want to increase the uf value of the mains/power filters (first area to change) by whatever it takes to filter out the ghosting (unfiltered ripple stamped on the signal) to the point you can live with it. I usually start with a 30-40% increase. The amount of uF increase also depends on the type of rectifier the amp has, as most tube rectos have a limit/range they function properly within. Solid state rectos can tolerate much more filtering in general, tho too much can cause the dreaded "motorboating' effect :) !

This will also have an effect on the how the amp responds (subject beyond this discussion....but the audio symptoms of (over/under) filtering have been well described by several posters here.) All in all, its important to study this subject well beyond the content of this thread. There are websites that cover it much more thoroughly.....as well as cover the other fundamental aspects of what "capacitors" of all types do in an audio circuit....they also store charges that help the amplifier respond when B+ demands are high and those charges can be a pain if they find your hands.

The first issue to consider is the fact that these caps can and will hurt you...even after being in an amp that has'nt been played or plugged in for weeks....they can hold a charge that can knock you down or kill you and sometimes even after discharging them properly they can rebuild a partial charge that will bite you. That is the first area to read up on and study thoroughly so that ANY caps you touch are completely drained using prescibed methods developed by techs and engineers thru out the history of electronics. There are places where these caps terminate that are far removed from the cap itself, so knowing what not to touch on certain amps can be pretty difficult to discern.

cram
11-14-2007, 08:34 AM
The first issue to consider is the fact that these caps can and will hurt you...even after being in an amp that has'nt been played or plugged in for weeks....they can hold a charge that can knock you down or kill you and sometimes even after discharging them properly they can rebuild a partial charge that will bite you. That is the first area to read up on and study thoroughly so that ANY caps you touch are completely drained using prescibed methods developed by techs and engineers thru out the history of electronics. There are places where these caps terminate that are far removed from the cap itself, so knowing what not to touch on certain amps can be pretty difficult to discern.

Found this thread because it's happenning to my amp or atleast I finally noticed it the other week.

Your quote there is why I read these threads with the sole purpose of being more informed in a decision to take it to an amp tech and then when I do take it, our conversation can be more efficient in describing the problem. Not to start jamming instruments into my amp (for sure)!

Experts are people who know what didn't happen when something goes wrong. That comes from qualifications and experience.

At any rate, thanks for the clear input on the thread.

ghostnote
11-18-2007, 04:04 AM
Talk about ghostnotes... All I can add to this thread is to suggest that you listen to the last note on Doyle Bramhall II "Green Light Girl". I believe you will hear a very pleasant ghostnote as the song fades out.

MikeMcK
11-18-2007, 08:01 AM
The ghosting was most easily heard when bending a D played at the 7th fret on the G string, although the ghost notes could be heard at other locations, too. When bending the D on the 7th fret of the G string, as the note was bent sharp, the ghost note would actually *drop* in pitch. Crazy sounding stuff, and annoying when the ghost note was fairly prominent as it was on the Dr. Z amp.

That's inter-mod distortion... you'll get the sum and the difference of the two frequencies.

I read through this thread because of a single ghost note on a new Ceria Liverpull... when I play the C# note on the 9th fret of the high E string, I'm getting a ghost note an octave lower. Didn't make sense until I realized that the fundamental of that note is just about on the 5th harmonic of 120 Hz.

drezdin
11-19-2007, 07:31 AM
Boo!