| Author | Message | ||
| bimmer
New Username: bimmer Post Number: 1 Registered: 3-2008 |
Hello, I'm having some trouble during some Gig's. In some places I have a very annoying "Beep" on top of my sound. It gets harder when I turn the volume-pot up. It really hurts some ears, people are really complaining about it. At home and in the studio I don't have any problems at all. I was thinking about bad power at some Gigs. Do you have some advice for solving this problem? | ||
| mica
Moderator Username: mica Post Number: 5181 Registered: 6-2000 |
Hi Chas, I talked to my dad about this, and it doesn't sounds like a problem he's heard of before, so we'll need some more information from you to help troubleshoot. Is the "beep" intermittent or is it more constant like a squeal? If you can try at a sound check, so you don't sure the patrons ears, see if the sound is the same in both pickups. Your email today indicated this was an EVH model, so try the pan at both ends to see if the sound is the same or changes. Do you use the same equipment at home/studio/gig? | ||
| bimmer
New Username: bimmer Post Number: 2 Registered: 3-2008 |
The Beep is constant. The Beep sounds the worst at the bridge-pickup. If I turn the pickup-selector totaly towards the neck-pickup, the beep is almost gone. Also if I pan the sound, it doesn't really matter. I play always over the same equipment home/studio/gig. The Glockenklang Heart-rock amp/Take Five (4x10") | ||
| dela217
Senior Member Username: dela217 Post Number: 883 Registered: 6-2002 |
Cell phone in your pocket perhaps? | ||
| mica
Moderator Username: mica Post Number: 5185 Registered: 6-2000 |
Is the sound directional? Meaning, does it change depending on which direction you (and your bass) face? And just to clarify: When you say the beep is constant, is it like, "BEEEEEEEEEEEEEEEEEEEEEEEEEEP" or like "BEEP BEEP BEEP BEEP BEEP BEEP BEEP"? And one other clarification: Your electronics are volume, pan, filter & Q for neck pickup, filter & Q for bridge pickup, mono output. | ||
| bimmer
New Username: bimmer Post Number: 3 Registered: 3-2008 |
The sound is like "BEEEEEEEEEEEEEEEEEEEEEEEEEEEP" and it's a very high frequency It isn't my Cell phone, that's for sure. oke, if I pan towards the bridge-pickup the high beep is the worst. If I use the filter, the beep gets softer by closing it. But the beep still remain above the bass-sound. Question: Are both pickups the same, or are they made to sound different? Because the neck-pickup sounds more Hi-fi than the bridge-pickup. That one sounds more aggressive. Behind the backplate I did screw both trimpots totally open, because I like the sound of it. And it fits my playing style. Maybe it infects this problem, but I think it doesn't suppost to do this?? (Message edited by bimmer on March 04, 2008) | ||
| adriaan
Senior Member Username: adriaan Post Number: 1811 Registered: 6-2002 |
I think Mica's question was if the beeeeep sound was the same in both pickups, not if the pickups have the same natural sound. Does turning down the trimpots make the beep disappear, or does the beep volume go down as much as the normal volume? Does it make a difference which of the two trimpots you turn down? There should be a big difference in the natural sound of the pickups, because they're looking at different sections of the strings, which offer totally different vibration patterns. In fact both pickups are exactly the same (at least on most Alembics) so the neck pickup reproduces the string movements with the same high fidelity as the bridge pickup does. (Message edited by adriaan on March 04, 2008) | ||
| paulman
Advanced Member Username: paulman Post Number: 278 Registered: 2-2005 |
Cell phone was first thought I had about that. The disgusted look from bandmates when that cell phone noise eminates from my Skylark or Further in the middle of a jam is a harsh reminder! Could it be a microphonic p/u that gets touched when played, causing the beeeeeeep? Sometimes I acidentally tap my p/us when playing and can hear the "tap" in recordings. | ||
| davehouck
Moderator Username: davehouck Post Number: 6290 Registered: 5-2002 |
Hi Chas, welcome to the board! EVH's are cool basses! The comment about the cell phone was not to suggest that the cell phone was making the noise, but that the cell phone may be causng the noise in the bass; i.e. causing interference. The simple test here is to take the cell phone out of your pocket and place it somewhere away from your bass and rig. The trim pots in the control cavity do not change the tone of the bass, they increase or decrease the amount of signal being sent to your amp. If turning the trim pots up changes the tone, it's because you are overdriving your amp; which may indeed be your intended effect. As Adriaan said, there is no difference between the pickups. The only exception would be if a standard Alembic AXY had been replaced with an Alembic Fatboy pickup. And as Adriaan said, the pickups will sound different because they are looking at different vibration patterns. Also, changing the height of the pickups will change the tone. Here are a couple more tests to give Mica more info. - Turn the trim pots down to halfway. This will test to see if overdriving the amp may be causing the noise. - Inside the cavity, gently (by grasping the housing and not the wires) unplug the pickups from the PC board and switch them. Now try moving the pan again and see if the noise is still in the same place relative to the pan knob, or if it moved to the other end of the pan knob. This will see if the noise relates to a pickup, or if it is in a preamp or further down the signal chain. Are you using a wireless setup? You said the noise only appears at "some gigs" and not at home. - At home, have you tried playing at the same volume as at the gigs? - And is the volume the same at the gigs with the noise as it is at the gigs without the noise. - Between gigs with noise and gigs without noise, are there noticeable differences in lighting around the stage? - Are you using a power conditioner in your rig? - Does changing cables between your bass and amp change the noise? - Can you try a different amp at the gig (perhaps during sound check) just to determine if the noise is related to the bass or to the rig? | ||
| olieoliver
Senior Member Username: olieoliver Post Number: 1785 Registered: 2-2006 |
I had similar thing happen when I got my first Alembic (MK with Eurpoa electronics). It only happened when I played it thru my Eden Combo not my SWR rig. It fried the fuse to the horn in the amp twice. This made me think that maybe I had the high hz up too high or the horn cranked up too high. The beep (almost a squeel) stopped by either turning down the horn or the high hz on my EQ. Is your beep coming from your amp or the PA? If your amp try turning down the high end or horn (if you have one) and if the PA try using the EQ to pull down the highs some. Also if you run your bass thru the floor monitors (if used) it may be them reacting with the bass. I assume this is due Alembics have a greater ability to reproduce all freqs. where other basses or guitars are less responsive. It's worth a try Olie | ||
| olieoliver
Senior Member Username: olieoliver Post Number: 1786 Registered: 2-2006 |
Another thing that made the beep go away on mine was turning the filter on the bass down (counter- clockwise) to not allow the higher hz thru. Olie | ||
| bimmer
New Username: bimmer Post Number: 4 Registered: 3-2008 |
Thanks you all for the response! I'm really loving the sound of the bass, when both filters are fully open and just the Q from the bridge-pickup is active. And the pan is exactly in the middle between the neck- and bridge-pickup. some anwers on questions: - the beep-sound sounds the worst at the full sound of the bridge-pickup. only when I pan totally towards the neck-pickup, the beep "seems" to disappear. - I'm not using a wireless setup. - At every Gig I'm playing with the same volume. - I'm not overdriving my amp, because the gain doesn't hit the red zone. - I'm not using a power conditioner in my setup. - changing cables doesn't make any difference. - the beep does come out of my amp, and if I connect it through it's DI the PA does Beep too. I hope you have some better information... | ||
| mica
Moderator Username: mica Post Number: 5187 Registered: 6-2000 |
Still collecting some more details here. In each location, are you standing the same distance from your speakers? We're not sure we understand the character of the noise because of language. If you are able to make a recording of the "BEEP" you can send it to my email so we can hear exactly what you are hearing. | ||
| adriaan
Senior Member Username: adriaan Post Number: 1812 Registered: 6-2002 |
How would you describe it in Dutch? Perhaps I can come up with a more fitting translation than "beep". | ||
| bimmer
New Username: bimmer Post Number: 5 Registered: 3-2008 |
okee, in Dutch language for Adriaan: Ik vind het zelf ook moeilijk om dit technische probleem te vertalen. Allereerst wil ik vertellen dat de "piep" heel hoog is, waarschijnlijk boven de 6 Khz. het is geen fluiten, het lijkt op het rondzingen van een microfoon. Alleen dan constant en constant op dezelfde frequentie. Als ik aan de filters draai c.q. langzaam dichtdraai, gaat de piep niet weg. Enkel word de frequentie van de piep verplaatst. Ik heb van alles al geprobeerd, Gsm uitgezet, zangmicrofoon weggehaald, zang-monitor uit, electriciteit van een andere groep gehaald, andere kabels, direct voor me versterker staan...3 meter ervan af staan... ik moet wel zeggen dat de "piep" het zwaarst is op het brug-element volledig open met (pan) pas als ik helemaal naar 't neck-element swith, is de "piep" vrijwel weg. Dus misschien heeft het met het brug-element te maken? Ik moet wel zeggen dat het brug-element wat aggressiever (rauwer) klinkt aangezien beiden even hard staan afgesteld. Ik zit alleen met de handicap dat ik er thuis en in de repetitieruimte er geen last van heb, waardoor ik geen opname kan maken van het probleem. Als ik via krachtstroom werd aangestuurd heb ik er nooit last van gehad, enkel op 220v. ik hoop dat het nu wat duidelijker is? | ||
| adriaan
Senior Member Username: adriaan Post Number: 1813 Registered: 6-2002 |
He Chas - now I notice you said that the bridge pickup sounds more aggressive (raw) than the neck pickup, not the other way around. These descriptions are always difficult: I would say that normally the neck pickup sounds more raw (ronkend) and the bridge pickup sounds more aggressive (fel). Does your EVH have the soapbars, or JJs or PJs or PPs? Returning to the beep - it's a high-frequency squeal, like when a microphone goes into feedback but at a very high frequency. The freqency of the squeal is steady, but it changes as you turn the filter. Panning to the bridge pickup, the squeal is at its loudest. Panning to the neck pickup, it goes away almost completely. The problem only occurs at certain venues - not at home, not in rehearsal space. I don't think the 380V or 230V situation makes any difference, as your rig should always run on 230V. Post some pictures if you have any! EVHs go under the Signature models on the Showcase section. | ||
| 0vid
Intermediate Member Username: 0vid Post Number: 126 Registered: 4-2003 |
From this description it sounds like a filter capacitor is dead. A beep is usually thought of as an intermittent sound and a squeal is a more prolonged sound. If the squeal is continuous a filter capacitor in your circuitry is dead - that is the most likely diagnosis I can offer. BTW Adriaan, I have returned home after some time away in Asia and will send you the item I promised. | ||
| adriaan
Senior Member Username: adriaan Post Number: 1814 Registered: 6-2002 |
Hi 0vid - welcome back in these parts (or thereabouts). Really looking forward to the item in question! | ||
| olieoliver
Senior Member Username: olieoliver Post Number: 1790 Registered: 2-2006 |
I got home last night and thought just for kicks I'd see if I could get my MK to beep again thru the Eden. Well no matter what I did it wouldn't. Then I remember that I sent the electronics in for an upgrade so Ovid may be on the right track. Olie | ||
| bimmer
New Username: bimmer Post Number: 7 Registered: 3-2008 |
If a filter capacitor is dead, how can I test it? Chas | ||
| davehouck
Moderator Username: davehouck Post Number: 6313 Registered: 5-2002 |
I'm not an electronics guy. I ran a search for "how to test a capacitor" and found - that I'm not an electronics guy. But first, you can open the control cavity and do a visual inspection. A bad capacitor might look like it's bulging or even have a split. And you can run the test I mentioned above about switching the pickup leads to see if the problem stays with the pickup (the problem is associated with the pickup) or moves to the other pickup (the pickups are not the problem). (You can do this for the gig; just remember the pan points in the opposite direction than normal.) And then one of the electronics experts here on the board may notice this thread and give some advice on actually testing the capacitors. From my very quick search, it seems that a good capacitor when charged should show infinite resistance when tested with an ohm-meter; but I'm not comfortable telling you whether or how you should do that. Your best bet is to see what Mica comes up with. After that, if you've eliminated all other possibilites, you may want to have an electronics tech check the circuits. | ||
| 811952
Senior Member Username: 811952 Post Number: 1360 Registered: 10-2003 |
I've got a couple of spots on the filter pots where I get that if the Q is on full, and I can feel something intangible in the pots at those positions. I think in my case the pots are just nearly shot.. John | ||
| dfung60
Advanced Member Username: dfung60 Post Number: 309 Registered: 5-2002 |
bimmer - I'd try a few different things. First, I believe your pickups should plug into the EQ board using molex connectors. If so, the first thing you should try is swapping the pickup leads. This will cause the bridge pickup to go through the neck pickup's EQ preamp and vice versa. After you do this, if the beeping is still on the same extreme of the blend pot, then this means it's the preamps rather than the pickups. If the problem is in the EQ circuits, then I would definitely reduce the trimpots (actually, I would do this in any case). Your Alembic can generate an enormous amount of output level compared to most basses, so your amp doesn't need (and probably doesn't want) such a high input level. More on this below. If the beeping switches to the other extreme of the blend pot than before, then the problem is in the bridge pickup - perhaps it's gone microphonic in your playing conditions. I think this is less likely than a preamp/EQ problem, but it's possible. When you crank the trimpots all the way up you radically increase the output gain (we're talking about more than +20db from typical levels I would guess which is huge). This will also have the effect of reducing the dynamic headroom on that preamp channel, so you'll probably drive the preamp into clipping before it gets to the output jack. You might prefer the edgier/distorted sound, but there are probably better ways to get it after the onboard preamps. A clipped signal has the effect of creating more high harmonics, which is more content for the (stressed) preamp to amplify, which makes the problem even worse. I suspect that this is actually the core problem that you have, since the problem diminishes when you filter off the high freqs. A lot of times that you get these beeping and scratching noises are when you are overdriving the preamps with frequencies that you can't hear and that your amp can't amplify. The Alembic circuits are a purist design which doesn't seem to filter off lows below the fundamentals or highs above the regular harmonics. So, I woudln't be surprised if the problem is that your setup is creating a lot of 10KHz+ content at high boost and causing the preamp to overload for feedback creating the beep. If the characteristics of the beep change when you change the battery, this is an overload problem. Changing the battery will increase the headroom of the preamp, raising the level that it can operate at before it clips and causes this feedback problem. This may also be an overload problem past your bass, in your amp or effects if you use any. You can easily test this by plugging into another amp (even your guitarists' or keyboard amps). They'll all have slightly different input sensitivity which will cause the frequency and pitch of the beeps to change. Just as the onboard preamps can be driven to overload with high output levels, the preamp of your bass amp can also suffer exactly this problem. If you like a more grindy, distorted tone, you'll probably have better luck returning the trimpots to their mid-range, then finding a post-bass effects unit that gets you a workable tone. I know this might not seem very satisfying compared to what you you're doing now (I generally don't care much for external effects units). But it's better than beeping! Actually, if the problem is "supersonic overdrive" (overdrive happening a range that's higher than you hear), you may be able to fix the problem with a low-pass filter set at 5KHz or so. If, after trying all this stuff, the neck pickup preamp is still beeping, I think you may have a failed op-amp. If the IC is failing, it will exhibit the same sort of problems we're talking about here - reduced headroom, feedback and resonance, etc. This is a relatively inexpensive socketed component in most Alembic boards, so it's not too horrible to fix either. There's actually no filter caps in your preamp boards. Filter caps are part of the power supply circuit that converts AC to DC power. Your preamp is powered by a battery which is DC. There are caps that are part of the EQ circuit network, but if they fail the tone control would probably become completely non-functional. It would be hard to test the caps without removing them from the board (you would do this with a big, expensive filter cap in your power amp, but not with the little ones in the EQ). More food for thought, anyway, David Fung | ||
| davehouck
Moderator Username: davehouck Post Number: 6323 Registered: 5-2002 |
Thanks David! | ||
| 0vid
Intermediate Member Username: 0vid Post Number: 129 Registered: 4-2003 |
Quote:"There's actually no filter caps in your preamp boards. Filter caps are part of the power supply circuit that converts AC to DC power. Your preamp is powered by a battery which is DC. There are caps that are part of the EQ circuit network, but if they fail the tone control would probably become completely non-functional. It would be hard to test the caps without removing them from the board (you would do this with a big, expensive filter cap in your power amp, but not with the little ones in the EQ). " The preamp circuitry operates on a limited bandwidth, probably up to 7khz or so before it starts to trail off. The filtering of high frequency content to limit the operative bandwidth and RF is achieved via a capacitor. If this capacitor goes , squeal is possible. That part of the circuitry is not part of the EQ. |
