Hi Folks.
I still have this problem and I have swapped valves to GT EL34-M ( great sounding valves btw. ). The filter caps are new but at this stage I'm ready to swap them out. Is it possible that the grounding wire I used may be contributing to the problem ? I am not using solid core for the grounding the filter caps.
Ghost notes.
Moderators: pompeiisneaks, Colossal
Re: Ghost notes.
I'm having the same exact problem with my new express build. Maybe the mallory caps needed to be formed due to setting on the shelf too long 
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geetarpicker
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Re: Ghost notes.
I just did some comparisons. Yes my original Express and clones of it ghost a little bit, but coming from a '68 100 watt plexi the ghosting has never been an issue for me compared to a 4 input 100 watter. I just compared my Express amps to my recently built '70 era spec Marshall 50 and perhaps the Marshall ghosts just a tiny bit less but barely. I also have a Wallace JTM45 clone on hand and that ghosts just a little more than my Wrecks. I also got out my '68 Plexi superbass 100, which was recapped about 4 years ago and I also upped the screen caps to more like '70 values with dual 100s in the mains and screens. Even with that the 100 definately ghosts more than any amp in the house. Back to the Express, yes they do ghost a tad and it may stand out if you have been playing master volume amps lately and using pedals mostly for distortion with a moderately cranked amp. When you hit the power supply hard by cranking an Express it's going to ghost a little. That all said, I had a little hum issues with my Ultimate Attenuator but lifting the ground on it (with a 3 to 2 adapter) cures that. Any added hum in the signal will add to the ghosting. Also, if the guitar picks up any hum in the room that will add to the ghosting for sure. I can barely play my strats in the house without using the 2 hum cancelling positions unless I turn some breakers off in the house to lower the ambient hum fields from the walls. On a final note I would reform any PS caps that might have been on the shelf for a while, and it probably doesn't hurt to bring any new amp up slowly to fully form the caps. One of my two Express clones I built didn't sound as good as the other when I first fired them up, but in time they have evened out quite a bit and I barely have a preference any more. Maybe one needed the caps played in a bit more than the other as I didn't bring them up all that slowly?
Re: Ghost notes.
Good call, Glenn. Makes me think that the building code is working against us here - in my state, code requires that every wall have outlets every 6 feet.geetarpicker wrote:I can barely play my strats in the house without using the 2 hum cancelling positions unless I turn some breakers off in the house to lower the ambient hum fields from the walls.
Grrrrr...
Re: Ghost notes.
Ok , I am ignorant. What is Ghosting ? can some one post an audio clip of it? Please. I have heard the term many times, but , I don't know if I have ever heard it. I have heard a lot of strange noises coming from all kinds of amplifiers, but, I usually have a pretty good idea of the problem.
Is it a catch all phrase for when you don't know what is the source or problem ?
Is it a catch all phrase for when you don't know what is the source or problem ?
Re: Ghost notes.
In an earlier post you said.
In most cases, unless it is designed for speakers, shielded cable's center conductor is way too small for the amount of current that flows to the speakers.
You can use zip cord that is at least 16 gauge or better yet 14 gauge.
Or you can spend some money on a high quality spkr cable.
I bought a nice one from Lavacable for $30 which is a four conductor with two pairs wired together to make an even bigger gauge.
You don't need to run shielded speaker cable.One thing to note from the pictures is that the wire I used on the speaker jacks isn't shielded. The cable I use to connect from the speaker out to the 5150 box is rather thin, the shielding is not very thick either compared to other cables I've seen.
In most cases, unless it is designed for speakers, shielded cable's center conductor is way too small for the amount of current that flows to the speakers.
You can use zip cord that is at least 16 gauge or better yet 14 gauge.
Or you can spend some money on a high quality spkr cable.
I bought a nice one from Lavacable for $30 which is a four conductor with two pairs wired together to make an even bigger gauge.
Tom
Don't let that smoke out!
Don't let that smoke out!
Re: Ghost notes.
I did notice that the ghosting really starts when you turn it past 1:00
Re: Ghost notes.
I just noticed that the TW is not a touch sensitive amp like the D style amp I just built. When I play solft with the guitar on 10 is when I get the ghosting. I guess you need to play harder on the wreck.
MD
MD
Re: Ghost notes.
I'm starting to think that the grounding for the power and screen filter caps should be separated. The ghosting is about to drive me nuts. Any ideas would be appreciated.
MD
MD
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Markusv
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- Location: Toronto, Canada (yes it's friggin cold!)
Re: Ghost notes.
On my liverpool the grounding is seperated as you suggest, Leleduke.
I still have gosting on the 15th fret especially if the amp is cranked and I bend a note on the b string
Drives me friggin nuts
Does the same in 2 different cabs. Both have Eminence speakers though- is that the problem?
Does not happen with 10's- just 12's
I got the same ghosting from my 18 watt clone until I fiddled with some cap values . I think I changed the pf cap across the plates and I paralelled the 1st stage cath bypass cap with a small value poly (.001) -That was sheer desperation but I thought it may help to pass some high freq's better
Seemed to help. Not perfect, but better
Markus V
I still have gosting on the 15th fret especially if the amp is cranked and I bend a note on the b string
Drives me friggin nuts
Does the same in 2 different cabs. Both have Eminence speakers though- is that the problem?
Does not happen with 10's- just 12's
I got the same ghosting from my 18 watt clone until I fiddled with some cap values . I think I changed the pf cap across the plates and I paralelled the 1st stage cath bypass cap with a small value poly (.001) -That was sheer desperation but I thought it may help to pass some high freq's better
Seemed to help. Not perfect, but better
Markus V
.........Now where did I put it?
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geetarpicker
- Posts: 918
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Re: Ghost notes.
Compare to my video here especially on the sustained notes:
http://www.youtube.com/watch?v=Y2_12Ler9B8
Do your's ghost more or less than in this clip I did? My two clones are the same as my original in this department, minor issue in my book only audible when totally solo without a band. This clip was done in the studio so it's wide open to hear such things. My amps don't do it much worse totally dimed compared to on 1pm, though 1pm is already quite gainy. Coming from a Plexi 100 the wreck was almost a ghost free change of pace. That said, when Mark played me his amp over the phone it seemed to ghost excessively though a cell phone isn't the best way to judge such details...
I don't think it has a thing to do with grounding, and probably is more of a limitation of filtering mostly the 1st 80uf filters. That said, maybe a choke would sound better in this department?
http://www.youtube.com/watch?v=Y2_12Ler9B8
Do your's ghost more or less than in this clip I did? My two clones are the same as my original in this department, minor issue in my book only audible when totally solo without a band. This clip was done in the studio so it's wide open to hear such things. My amps don't do it much worse totally dimed compared to on 1pm, though 1pm is already quite gainy. Coming from a Plexi 100 the wreck was almost a ghost free change of pace. That said, when Mark played me his amp over the phone it seemed to ghost excessively though a cell phone isn't the best way to judge such details...
I don't think it has a thing to do with grounding, and probably is more of a limitation of filtering mostly the 1st 80uf filters. That said, maybe a choke would sound better in this department?
Re: Ghost notes.
It maybe my computer monitors but I can't hear any ghosting on that video.geetarpicker wrote:Compare to my video here especially on the sustained notes:
http://www.youtube.com/watch?v=Y2_12Ler9B8
Do your's ghost more or less than in this clip I did? My two clones are the same as my original in this department, minor issue in my book only audible when totally solo without a band. This clip was done in the studio so it's wide open to hear such things. My amps don't do it much worse totally dimed compared to on 1pm, though 1pm is already quite gainy. Coming from a Plexi 100 the wreck was almost a ghost free change of pace. That said, when Mark played me his amp over the phone it seemed to ghost excessively though a cell phone isn't the best way to judge such details...
I don't think it has a thing to do with grounding, and probably is more of a limitation of filtering mostly the 1st 80uf filters. That said, maybe a choke would sound better in this department?
MD
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geetarpicker
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Re: Ghost notes.
Try some good headphones. That clip was close miked with good mics and preamps, albiet dumbed down to mp3 on youtube. It's a good representation.
Mark,
Check your email. I just sent you a raw isolated track from my CD recorded dead flat no effects way up on the neck. I can't even hear a touch of ghosting, nada.
GK
Mark,
Check your email. I just sent you a raw isolated track from my CD recorded dead flat no effects way up on the neck. I can't even hear a touch of ghosting, nada.
GK
Re: Ghost notes.
Billyz
Ghost notes, as I understand the term, are notes or tones that shouldn't be there. Most often it sounds like when you are tuning a guitar and one string is slightly out of tune with the other and you hear that slight wavering sound. The thing is, this sound appears while only playing one note, which shouldn't have another note to be out of tune with!
(since we get 5 cents per word, I am going to make the most of this post, lol)
Strats are notorious for ghosting and as mentioned it is often referred to as stratitus. It comes from the pickups being to close to the strings, and since strats have three pickups, there are three sets of magnetic fields pulling on the strings. This can create a situation where the magnetic fields pulling on the strings have frequencies that they will resonate at, most often not a note in tune with standard tuning, but a note slightly off. Hence, the out of tune sound even on one string.
Another source on strats are the tremolo springs. The middle pickup especially can pick up vibrations from the springs just like they were a string.
Another source are the short little strings between the nut and the tuners. On a strat the G string is especially troublesome since it is of the exact length needed to be a high pitched harmonic of the G note.
These are all potential sources and we haven't even gotten into the amp yet.
Most often, ghosting that is being generated in the amp itself comes from power supply ripple. It's is usually easier to diagnose because of the pitch. If the power is 60hz, then there is going to be a 120hz ripple (and some harmonics of that frequency to a lesser degree) present. 120, 240, 480, etc. So, if you play an A note, which is 110, 220, 440, depending on the octave, you can see that it is close to the ripple frequencies. If you hear the ghost note and bend an A note and find that the ghost note "becomes in tune" with a note somewhere between A and B, most often it is an issue with power supply ripple getting into the signal circuit.
Finding the source, however, can be a real pain. It could be, but might not be an underfiltered powersupply. If it is a new design, a new build, then I would suspect the PS. But then again, it could be coming from the power supply only because something else in the amp is allowing a normal amount of ripple to be bothersome. (how's that paragraph for a bunch of hedging rhetoric?)
What I mean is, for example, something in the power amp that would normally suppress the ripple is not doing it's job. There is usually quite a bit of ripple on the center tap of the PT. But, because of the nature of the push pull circuit, it gets canceled out, usually. If one power tube is sub-par or way out of spec, then there could be more ripple present. Maybe not enough to be unacceptable hum in the speaker, but maybe when the amp is pushed the "unacceptableness" is exacerbated and ghosting occurs. Just one hypothetical example.
I think I must be up to about 3 bucks in words now, enough for tacos so I will yield the floor.
(edited typos)
Ghost notes, as I understand the term, are notes or tones that shouldn't be there. Most often it sounds like when you are tuning a guitar and one string is slightly out of tune with the other and you hear that slight wavering sound. The thing is, this sound appears while only playing one note, which shouldn't have another note to be out of tune with!
(since we get 5 cents per word, I am going to make the most of this post, lol)
Strats are notorious for ghosting and as mentioned it is often referred to as stratitus. It comes from the pickups being to close to the strings, and since strats have three pickups, there are three sets of magnetic fields pulling on the strings. This can create a situation where the magnetic fields pulling on the strings have frequencies that they will resonate at, most often not a note in tune with standard tuning, but a note slightly off. Hence, the out of tune sound even on one string.
Another source on strats are the tremolo springs. The middle pickup especially can pick up vibrations from the springs just like they were a string.
Another source are the short little strings between the nut and the tuners. On a strat the G string is especially troublesome since it is of the exact length needed to be a high pitched harmonic of the G note.
These are all potential sources and we haven't even gotten into the amp yet.
Most often, ghosting that is being generated in the amp itself comes from power supply ripple. It's is usually easier to diagnose because of the pitch. If the power is 60hz, then there is going to be a 120hz ripple (and some harmonics of that frequency to a lesser degree) present. 120, 240, 480, etc. So, if you play an A note, which is 110, 220, 440, depending on the octave, you can see that it is close to the ripple frequencies. If you hear the ghost note and bend an A note and find that the ghost note "becomes in tune" with a note somewhere between A and B, most often it is an issue with power supply ripple getting into the signal circuit.
Finding the source, however, can be a real pain. It could be, but might not be an underfiltered powersupply. If it is a new design, a new build, then I would suspect the PS. But then again, it could be coming from the power supply only because something else in the amp is allowing a normal amount of ripple to be bothersome. (how's that paragraph for a bunch of hedging rhetoric?)
What I mean is, for example, something in the power amp that would normally suppress the ripple is not doing it's job. There is usually quite a bit of ripple on the center tap of the PT. But, because of the nature of the push pull circuit, it gets canceled out, usually. If one power tube is sub-par or way out of spec, then there could be more ripple present. Maybe not enough to be unacceptable hum in the speaker, but maybe when the amp is pushed the "unacceptableness" is exacerbated and ghosting occurs. Just one hypothetical example.
I think I must be up to about 3 bucks in words now, enough for tacos so I will yield the floor.
(edited typos)
Last edited by Jana on Sat Apr 18, 2009 4:15 pm, edited 2 times in total.
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geetarpicker
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Re: Ghost notes.
A whole bunch of tacos nice job!
I just emailed Mark an isolated track from my CD played on my original '89 Express. I couldn't hear a pinch of ghosting even under heavy distortion all the way up to the 18th fret high E and plenty of higher notes a little under that. Not even a hint and this was a close miked track on a 4x12 with no effects or EQ, not even an amp attenuator.
Even I'm suprised by the TOTAL lack of it as I can hear a pinch in person on all my amps these days, but the recording was a few years back and with totally different tubes. Maybe the tubes are part of it...
Yep, I suspect maybe out of balance output tubes or I wonder if an out of balance primary wind on the OT could make a difference? Maybe even something up with the PI tube, filament wiring or filament grounds?
These amps are tricky...
I just emailed Mark an isolated track from my CD played on my original '89 Express. I couldn't hear a pinch of ghosting even under heavy distortion all the way up to the 18th fret high E and plenty of higher notes a little under that. Not even a hint and this was a close miked track on a 4x12 with no effects or EQ, not even an amp attenuator.
Even I'm suprised by the TOTAL lack of it as I can hear a pinch in person on all my amps these days, but the recording was a few years back and with totally different tubes. Maybe the tubes are part of it...
Yep, I suspect maybe out of balance output tubes or I wonder if an out of balance primary wind on the OT could make a difference? Maybe even something up with the PI tube, filament wiring or filament grounds?
These amps are tricky...