Author Topic: The Dragon's Wing (Read 2421 times)

rami · « **Reply #30 on:** April 25, 2006, 07:48:07 PM »

Hey Roger,

There's some really good advice here regarding how to deal with the unstable neck. The only idea I can add that seems to help calm it down (at least a little) is to loosen the truss rods, making sure the Bass is tuned to maintain the tension, and lay it flat on its back (in its case) when not playing it. I also recommend the .045 - .105 guage strings- their extra mass helps with stability and (in my opinion) provides a fuller overall sound. The only time I go with extra light guage strings is when I want to relieve some tenson on the neck (with a concave bend) and when adjusting the truss rod isn't enough. That helps a little with the convex bend issue - at least for me. It also helps to store it in a room with a de-humidifier. I know how humid it can get in London. I've seen sun and rain (sometimes heavy) cycling all day at times!
As for the Signature/Series electronics, I personally prefer blending pickups and adjusting tone controls (tone shaping) rather than Bass and Treble controls. I leave that to the amplier (or mixer). I feel that I get a purer sound from the Bass that way.

Good luck,

Rami

rogertvr · « **Reply #31 on:** May 21, 2006, 08:14:21 AM »

Well, it's been a month since I started the exercise to address the DW neck.

Firstly, I started using Joey's instructions and applied them over the course of a week or so. I thought that there wasn't much I didn't already know regarding bass guitar set-up, but I did learn a couple of things so they're definitely worthwhile! Sadly, no-one has told the DW neck about Joey so nothing changed!

Secondly, in desperation, I then took the strings off the damn thing, released the truss rods and left it sitting on the stand for a week. I then fitted new strings (same type and gauge as it had on it a week earlier), then set about applying Joey's instructions again. They really are spot-on and give an easy way to follow a set-up for a bass - all credit for Joey for them!

Everything was going well, I've been logging temperature, humidity and atmospheric pressure. I've been making small adjustments, logging everything that I have done, when I have done it, all of the weather data at the time I made the adjustments.

The whole instrument eventually became really sweet! Then last week, 16 May, the whole thing was unplayable! Literally overnight - strings on the frets from the 4th fret to the 14th fret. I was expecting the humidity to have changed but it hadn't - however, from my test dates and times over the whole time I've conducted this experiment, the only change overnight when the whole thing became unplayable was the atmospheric pressure. If the atmospheric pressure is around the 1000mb mark (which is generally where it has been as I've made adjustments to the bass), it all stays pretty stable, regardless of humidity. The atmospheric pressure went up to 1014mb (no change on humidity) and it all became unplayable.

I've waited until the atmospheric pressure dropped and that the humidity is the same as it has been throughout the whole experiment, and lo and behold the whole instrument is sweet again.

Does atmospheric pressure really affect instruments in this way? Please can someone shed some light on this, I really am at a loss now!

Cheers,

Rog

bob · « **Reply #32 on:** May 23, 2006, 11:21:33 PM »

Well, it's been more than a couple of days, so someone has to respond :-)

I don't have an answer for you, Rog, just more questions. Frankly, it would not have occurred to me to record atmospheric pressure, though maybe it's good that you did. Still, 14mb isn't an outrageous amount, and I am at a loss to explain why it might matter.

So for now, maybe we could just clarify a few things about your procedure. I'll propose a sequence of events, and you can correct as needed.

1) You took off the strings, released truss rod tension for a week, then put on new strings. Fine - probably overkill, but at least you know you were thorough.

2) You got comfortable with Joey's technique, especially the parts about making small adjustments and measuring, and things got better. No questions here either.

3) At 2-3 weeks with the new strings, things got really sweet. So here's the first question: was the bass then stable? Were you able to play for several days or a week, without making any further adjustments?

4) Pressure increased, and the neck suddenly straightened out. I assume you mean that you started buzzing from the 4th to 14th frets, so you suddenly lost some relief, right? Were you able to measure the change in relief?

5) Pressure returned to normal, and the instrument is sweet again. Important question here: did you make any adjustments after step 3? I.e., did you attempt to adjust when the pressure increased, and/or when it returned to normal, or did you just leave it alone without making any adjustments during this peak? It would be very interesting to know if the neck - without any manual adjustment - went from proper relief, to not enough relief, and then back to proper.

Just for perspective, when it was sweet, what were the measurements for relief and string height?

And if we have a meteorologist or something out there: if I measured 1014mb at sea level, how far up would I have to go to read 1000mb? (I need to get up early, and am not going off to research this tonight...).

-Bob

adriaan · « **Reply #33 on:** May 25, 2006, 07:30:27 AM »

How good is your hygrometer? Did you ever check against the Meteorology Office website or whatever it's called over there - they should have local readings available from all over the country.

David Houck · « **Reply #34 on:** May 25, 2006, 05:53:13 PM »

Bob; thanks for reviving the thread. When I first read about the pressure change, I ran several searches of the site looking for a past thread that had talked about air pressure in relation to shipping a bass in the hold of an airplane; I thought it might be on point, but I couldn't find it.

I might be completely misreading and misunderstanding this, but a quick search finds that as a rule of thumb .. pressure decreases with altitude .. 1 millibar for each 8 meters of altitude gain .. for elevations or altitudes of less than two or three thousand feet. Source.

Here is a table showing that if the pressure at sea level is 1013, then the pressure at 1000 meters is 900 and at 2000 meters is 800.

And there is a really cool looking formula here.

Thus it would appear that in answer to your question, the increase in elevation required for a pressure drop of 14 millibars from a starting point of 1014 at sea level would be approximately 112 meters or 367 feet.

David Houck · « **Reply #35 on:** May 25, 2006, 06:00:13 PM »

Roger; to address your question, given my post above, it seems unlikely that a pressure increase of 14 millibars would be enough to have a substantial effect.

rogertvr · « **Reply #36 on:** May 26, 2006, 04:28:06 AM »

I'll try and answer this lot! Thanks for responding, first of all!

The measurements I've been using are from the local weather centre, which is about 5 miles as the crow flies. They're updated every hour, so I note the playability of the bass, the time, then wait an hour to get the weather conditions.

Interestingly, using Joey's instructions to get the bass sweet, it was then stable for quite sometime - I'm writing this at work so I don't have the measurements/dates to hand. But it was interesting that the atmospheric pressure didn't really change much during that whole time.

When the pressure went up, the humidity remained the same. To answer Bob's question about measuring the relief in the neck at this point, that's a pretty easy answer - very little! It had all disappeared.

At this point, I made the decision to leave it alone, and wait for the humidity and/or atmospheric pressure to change. The humidity was all over the place but it made no difference, so I kept testing the bass until the atmospheric pressure reduced (which happened one night, overnight, a few days ago). Lo and behold - one playable, sweet bass.

The humidity has been all over the place again but that has made no difference to it at all.

I've waited for another high pressure, high humidity day, and I've set it up as I like it. It's been fine since, so I'm keeping my eye on it.

It's definitely atmospheric pressure that's making the difference to it. I find it hard to believe but that's what the data is telling me. What I need now is a high atmospheric pressure day where the pressure goes to something like 1025mb or 1030mb and see what it's like then. Maybe if we get a summer this year, then I'll be able to find out!

adriaan · « **Reply #37 on:** May 26, 2006, 05:24:08 AM »

Roger,

My thoughts on humidity were that perhaps you had been logging readings from a hygrometer inside your home. Humidity indoors or out can be completely different, and it's not really clear from your description whether it was your indoor hygrometer or the local weather centre's outdoors humidity reading that was all over the place.

One would expect the indoor humidity to follow the outdoor humidity, with perhaps lesser extremes. Perhaps you have air conditioning, and it has been on-and-off? Usually has a big impact on indoors humidity.

spliffy · « **Reply #38 on:** May 26, 2006, 07:55:52 AM »

Roger, I feel your frustration. Your bass is exquisite and to have this sort of thing happen is terrible. I do not expect this sort of thing to happen to a Fender, never mind a custom Alembic! I would stop wasting time and send her back to Alembic to investigate.
just my 2 cents.

Al

lidon2001 · « **Reply #39 on:** May 26, 2006, 08:22:49 AM »

Hi Roger,

May I suggest Rotosound Funkmasters? I sent Alembic a set of Status strings to install on my MK, but the strings just wouldn't let the neck setup. My bass is short scale, so I don't know how far one can take the comparison. They put on the Roto's, and it plays like a dream. Of course, they are only good for about 5-10 hours of playing before going dull. It was a compromise I was willing to make. If you're not, I understand.

Tom

rogertvr · « **Reply #40 on:** May 26, 2006, 11:48:02 AM »

To answer the questions here...

1). Adriaan - I've been taking measurements from the local weather site. I have no way of measuring anything for myself. However, the house has no air conditioning and is centrally heated. The central heating is permanently switched on, so the temperature stays fairly constant unless the weather pushes it above 18C (not at the moment, not in this country!!!!).

2). Tom - it's behaved like this from day one. It had Alembic strings on it then, then it had Elites, now it has Status Hotwires. None of the strings have made any sort of difference.

Interestingly, I last set it up on 23 May - humidity at 70% and atmospheric pressure at 1011.9mb. There was little relief in the neck, the action was low and it played beautifully. Today, the humidity is 69%. the atmospheric pressure has dropped to 1004.7mb. It still plays wonderfully, but on noting the relief in the neck, there is, relatively speaking, a lot! The action is higher too, I could tell from the first three notes I played that the action is higher.

Any further suggestions anyone? It is definitely atmospheric pressure that is causing this movement in the neck. From what I can see, this instrument is never going to settle.

bob · « **Reply #41 on:** May 26, 2006, 12:28:03 PM »

So now you have one time where the pressure increased by 14mb and the neck became straighter, and a second case where the pressure dropped by about 7mb and the relief increased, right? That would be consistent, but it still makes no sense - I can't see how pressure could have this effect, and certainly not such small changes.

Could you be a little more specific, regarding The humidity has been all over the place again but that has made no difference to it at all?

And what type of heating do you have? Personally, I would go out and buy a hygrometer to monitor indoor humidity for a week or so, comparing it to what you get from the local weather station. I think we're missing something here.

bsee · « **Reply #42 on:** May 26, 2006, 01:04:47 PM »

Interesting. I think you need to get a little humidity measurement device if you really want to know. The humidity in your house with central heating always on probably doesn't match the outside world measurement. I know that the more the heat is running in my house, the drier it is, regardless of what's going on outside.

rogertvr · « **Reply #43 on:** May 27, 2006, 01:53:06 AM »

By the humidity has been all over the place I mean it has varied from 45% to 95%.

This whole thing makes no sense to me. Either I am missing something or this business with atmospheric pressure really is having a drastic effect.

I'll carry on monitoring it.

georgie_boy · « **Reply #44 on:** May 27, 2006, 04:40:11 AM »

Hi Roger
I would go 100% with spliffy & lidon 2001's view!!
I own a Series 1 . I use extra light strings 30 50 70 90 and it was set up by the bass centre in London nearly 6 years ago.
It is still as good as it was when it arrived, action great and sounding just like a Series bass.
What I'm trying to say is, that I live in Scotland, where the weather is always suspect and generally very humid.
I leave my windows open all year round, with the bass sitting on a stand in the corner of my living room and she is NEVER up nor down, so all this talk about humidity etc. really baffles me
Simple answer--if mine is OK then most other Alembics should be OK as the temp and humidity in Scotland would really test an instrument.
Solution----difficult, but as the previous guys said, I think the problem is inherent and that really, the only answer is to send the bass back to Valhala and let them figure out what is going on. I agree with rogertvr, as the humidity here goes mad nearly every day, and I have NO ill effects