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richbass939
Advanced Member
Username: richbass939

Post Number: 276
Registered: 11-2004
Posted on Sunday, May 29, 2005 - 6:05 pm:   Edit Post

Can someone explain the theory behind the sustain block? What are its dimensions? Exactly where is it? Is it brass? Are there any pictures of one being installed? Pictures of the hole it goes in? How is it installed? I would appreciate the info.
Rich
davehouck
Moderator
Username: davehouck

Post Number: 1826
Registered: 5-2002
Posted on Sunday, May 29, 2005 - 6:36 pm:   Edit Post

The sustain block sits underneath the bridge; and yes it is brass. The picture of the bass in progress on this page shows the routing for the sustain block along with the pickups. The routing in the picture shows the size of the block. On a bass with no sustain block, the bridge screws directly into the wood; thus there would be no routing as in the picture. The block is screwed into the body with a single screw; the bridge is then screwed into the sustain block with two screws. As far as the theory, it's been discussed before but I can't remember technical stuff. In fact, someone in the group did some experiments with sustain blocks of different materials and reported the results.
davehouck
Moderator
Username: davehouck

Post Number: 1827
Registered: 5-2002
Posted on Sunday, May 29, 2005 - 7:10 pm:   Edit Post

Found it! I looked at the FAQ section and found this thread that answers your question about the theory behind the sustain block. Oh, and it was Bob Novy who did the experiments with different block materials. Here's another thread on the subject.
bob
Senior Member
Username: bob

Post Number: 445
Registered: 11-2002
Posted on Monday, May 30, 2005 - 12:28 am:   Edit Post

... which reminds me, I haven't yet gotten around to posting my results, though it would probably be more than most of you want to read.

The simplistic answer is that the extra mass of the brass helps to keep the energy in the strings, rather than bleeding out into the body, so you get more sustain.

While I believe that's generally true, I'm convinced I hear differences using blocks that weigh the same but are made of different materials. This is perhaps more a difference in tone across the strings, than overall sustain (which was slightly less interesting to me personally).

But then again, using the same material for two blocks, and inserting some weights in one of them, I preferred the heavier one for more even response, which favors the argument that (for me, at least) heavier is better.

I've settled on a block I made that contains a high proportion of tungsten, and weighs 450 grams, versus the 300 gram brass block I started with (I was going for a full pound, missed by just a few grams).

I'm not sure I should admit this, but I actually tried 11 different blocks. In hindsight, brass is pretty darn good...

I wasn't able to compare the basic difference between having a sustain block, or just screwing the bridge into the body - that's a somewhat more difficult experiment. But I think it's safe to say that you will definitely get more sustain, and more consistent tone (balance of harmonics) across the strings. I also believe it will somewhat reduce the influence of the body woods, though these will still certainly make a difference.
davehouck
Moderator
Username: davehouck

Post Number: 1831
Registered: 5-2002
Posted on Monday, May 30, 2005 - 6:02 am:   Edit Post

Thanks Bob!
richbass939
Advanced Member
Username: richbass939

Post Number: 279
Registered: 11-2004
Posted on Wednesday, June 01, 2005 - 4:01 pm:   Edit Post

Well, itís taken a little while but I finally read and digested all the posts referenced above.
I previously thought that all Alembics had sustain blocks. I thought that my Epics had blocks that were buried in the body and the bridge-height adjustment screws were screwed into them. I never noticed on pictures of the other Alembics that there appears to be a block that is flush with the top.
So, if I finally have this right, neck-thru basses have them and set-necks do not. Block material does, as we would expect, have a significant effect on the sound.
Now back to my specific application. I am rebuilding a bass I made a dozen years ago. It is a fretless and will have flatwound strings on it. I am using maple for the body core to brighten it up a little. It has a maple neck. It is currently a bolt-on but I am going to make it a set-neck this time around.
I wanted to consider the sustain block early in the planning. It seems now that I might not even want to install a sustain block as none of the Alembic set-necks have them. I love to experiment but I trust the elves to know what helps and what doesnít. I donít want to spend extra time and money if there will not be any real effect. Besides, I suppose you wouldnít start out with a fretless if killer sustain is your goal.
A lot of the info in these posts can be put to good use in selecting a material for the bridge. It seems that some of the same theory applies.
Thanks to you all.
Rich
sfnic
Member
Username: sfnic

Post Number: 65
Registered: 3-2005
Posted on Wednesday, June 01, 2005 - 4:25 pm:   Edit Post

(Personally, I think a set-neck fretless with flatwounds is a _perfect_ candidate for a sustain block. It should brighten the string somewhat, and seriously increase the "mwah" factor.)
jagerphan84
Intermediate Member
Username: jagerphan84

Post Number: 188
Registered: 10-2003
Posted on Wednesday, June 01, 2005 - 4:40 pm:   Edit Post

I'd have to agree with your speculation there, Nic... [gratuitous link to my custom]

-Adam

[note: strings are now TI jazz flats.]

(Message edited by jagerphan84 on June 01, 2005)
bob
Senior Member
Username: bob

Post Number: 452
Registered: 11-2002
Posted on Wednesday, June 01, 2005 - 5:57 pm:   Edit Post

It looks like you're right, that the block is standard on a neck-thru and not on a set-neck. However, I wouldn't read that as saying they think it would be a bad thing on a set-neck.

Keep in mind this is a very large chunk of brass. Even on a narrow 4 string it will still be about half a pound, and brass isn't cheap. Oddly, you can't figure it out from the custom quote generator, but (don't quote me on this) I seem to recall that as an option it would be on the order of $250-300, so it would increase the price of the set-necks quite a bit.

My guess is that is more likely the reason, as opposed to "it doesn't work", and I'd also be in favor of adding one.
davehouck
Moderator
Username: davehouck

Post Number: 1851
Registered: 5-2002
Posted on Wednesday, June 01, 2005 - 5:59 pm:   Edit Post

"neck-thru basses have them and set-necks do not"

As far as new basses, I don't know the answer. But I don't think it necessarily holds true on older basses. Neither my 84 Spoiler nor my 90 Essence came with bridge blocks, though the Essence is currently in Santa Rosa and a bridge block is one of the mods it's getting.
smokin_dave
Advanced Member
Username: smokin_dave

Post Number: 222
Registered: 10-2002
Posted on Wednesday, June 01, 2005 - 6:55 pm:   Edit Post

Interesting.I was just going over the catalog that was supplied to me when I received my Rogue in 2003 and every bass discribed in there states that they have a sustain block.I think all Alembics,set neck or not,have a sustain block and alway's have.I'm not about to rip apart the top off my 94' Epic to find out but I'm sure it's there.Maybe Val or modder Dave can shed some light on the history of the block and when they were incorporated in Alembic basses.
davehouck
Moderator
Username: davehouck

Post Number: 1853
Registered: 5-2002
Posted on Wednesday, June 01, 2005 - 9:08 pm:   Edit Post

Dave;

I have no idea about the history, but looking at the Showcase section, it does appear that very early basses did have them.

But I don't believe your supposition, that all Alembics have always had sustain blocks, is correct. After all, the folks in Santa Rosa only just recently routed my '90 Essence for a block. And if you don't see that your bridge is screwed into a piece of brass, then it's probably not there. I do think that there have been exceptions where someone custom ordered a bass with a hidden sustain block; but I think the general rule is that if you can't see it, it's not there. However, I can understand why you would think it is there; even the basses without blocks sustain well. And I imagine the brass bridges are a big part of why they do. My Essence had very good sustain without the block. I'm just looking to add a little more!
trekster
Junior
Username: trekster

Post Number: 36
Registered: 7-2004
Posted on Thursday, June 02, 2005 - 4:41 am:   Edit Post

Hmmm..this brings up an interesting question in my mind. I have a book on Guitar Electronics and Modifications, where the author does the sustain block under the bridge. However, instead of a one-piece slug 'o brass, he used several plates stacked upon each other (I beleive his thinking was that he could experiment with different weights/sizes/materials).

It makes sense from the experimentation POV, but I wonder if doing it this way would take away from the sustain qualities vs a solid block? I'm supposing that, as long as the plates are perfectly flat and he has them compressed together with a single or couple screws, it would act as one piece.

Comments?

--T

(Message edited by trekster on June 02, 2005)
kmh364
Senior Member
Username: kmh364

Post Number: 892
Registered: 9-2003
Posted on Thursday, June 02, 2005 - 6:54 am:   Edit Post

Sorry, repeat post.

(Message edited by kmh364 on June 02, 2005)
kmh364
Senior Member
Username: kmh364

Post Number: 893
Registered: 9-2003
Posted on Thursday, June 02, 2005 - 6:54 am:   Edit Post

I don't know about all set necks, but my Orion definitely doesn't have one. The only set neck I actually recall seeing with one is this one (click below), but it was a custom option. Had I known beforehand that I could have gotten the block and the wide neck lams, I would have done so. I don't know about the effect on sound, sustain, etc., but I would have got them just cause they were cool and not everyone else has them, LOL!

http://alembic.com/club/messages/631/932.html?1031117669
smokin_dave
Advanced Member
Username: smokin_dave

Post Number: 223
Registered: 10-2002
Posted on Thursday, June 02, 2005 - 7:00 am:   Edit Post

Well,I guess the reason I'm thinking that way is because the photos of the Orion,Epic and Essence in the catalog don't show a block that the bridge is screwed into but rather the bridge screwed through the top wood.Very interesting.So,I guess that they haven't used a block all along since you had the mod done to your Essence but I am interested in knowing when they became standard on all Alembics.And on that note,I've just come to realize that it's my birthday today.Hmmm,should I call in sick to work and take the day off?Naaaa.I'll party a bit afterwards.
davehouck
Moderator
Username: davehouck

Post Number: 1855
Registered: 5-2002
Posted on Thursday, June 02, 2005 - 7:26 am:   Edit Post

Well then Happy Birthday!!
davehouck
Moderator
Username: davehouck

Post Number: 1857
Registered: 5-2002
Posted on Thursday, June 02, 2005 - 7:50 am:   Edit Post

Bob; as I have just posted in the "Alembic Basses & Guitars" section, I've stumbled across an Excel quote generator. According to this quote generator, the block is $125 on a new Excel.
lbpesq
Senior Member
Username: lbpesq

Post Number: 483
Registered: 7-2004
Posted on Thursday, June 02, 2005 - 7:54 am:   Edit Post

Happy B-day Dave.

Anyone know if Alembic ever puts sustain blocks in guitars?

Bill, tgo
davehouck
Moderator
Username: davehouck

Post Number: 1858
Registered: 5-2002
Posted on Thursday, June 02, 2005 - 8:09 am:   Edit Post

Bill; Jonathan's Little Bear has one.
kmh364
Senior Member
Username: kmh364

Post Number: 894
Registered: 9-2003
Posted on Thursday, June 02, 2005 - 9:48 am:   Edit Post

Yep, Jonathan's guitar has the block, but it's a neck-through-body, not a set-neck.
kmh364
Senior Member
Username: kmh364

Post Number: 895
Registered: 9-2003
Posted on Thursday, June 02, 2005 - 9:55 am:   Edit Post

Guitars like Tom's Ghost Crow (May's Custom O' Month)Skylark set-neck don't have the block.
bob
Senior Member
Username: bob

Post Number: 454
Registered: 11-2002
Posted on Thursday, June 02, 2005 - 10:24 am:   Edit Post

Hmm, took me a couple tries with that Excel quoter - I had to first deselect, update, then select and update again to get it to show up.

So much for my memory - I'd say $125 is a good deal.

trekster - I agree that if you were using multiple plates you would definitely want them perfectly flat and held together somehow. But that seems like a nuisance, and my bet (just a guess) is that a solid block will be better. And even then, you want the block to mate as closely and tightly to the body itself, i.e. do a very careful routing job.
sfnic
Member
Username: sfnic

Post Number: 67
Registered: 3-2005
Posted on Monday, June 06, 2005 - 2:57 pm:   Edit Post

From a raw construction perspective, a block made up of stacked plates will lose a fraction of inter-block transmission as the wave crosses material boundaries. The tighter you couple the plates, of course, the lower the mechanical impedence and so the lower the amount of loss. So you might notice a bit less sustain in a stacked block. But it'd still be much more sustain than you'd get with no block at all.

Where the stacked plate version becomes audibly problematic is where the individual plates aren't exactly matched for volume and mass. Each individual plate therefore provides a slightly different superharmonic resonant structure. These can, under perfect conditions, create sum-and-difference resonances in the audio band that can affect the tonal qualities of the instrument.

The difference isn't huge, and in most cases virtually inaudible.

From a practical standpoint, if you're set up to cut brass plates, odds are you're set up to cut blocks as well. So there's no advantage to the manufacturer to go with a stacked plate design, when it multiplies the tooling time.

Now, as Bob notes, the block-to-body contact plane is important. You do want that to be as tight a fit as is practical for maintenance purposes. Again, this is a function of the mechanical impedence of the joint. Fortunately, here you're dealing with one material that has a bit of compliance, in that you can compression-fit the block into the cavity to achieve makimum contact and thus minimum impedence. The downside of this technique is that it makes it virtually impossible to get the block out later.

Alembic doesn't go all the way to an "interference fit", but they do get a reasonably snug "slip fit" that, with proper tooling, can be disassembled. And, in general, the coupling they lose with the slip fit, they largely regain via the attachment screw that holds the block down.

Oddly enough, one of the weakest points in the mechano-acoustic chain from the string to the block is in the two bolts that hold the bridge on. By necessity, they're stainless steel, so there's a material dis-similarity at two boundary points. Plus, the screws have a proportionately narrow cross-section, and so present a relatively high mechanical impedence to the wave. This coupling has a greater affect on the overall tonality than might otherwise be thought, and is certainly a component in the "Alembic" sound.

nic
sfnic
Member
Username: sfnic

Post Number: 87
Registered: 3-2005
Posted on Wednesday, June 29, 2005 - 10:14 am:   Edit Post

Boy, can I kill a thread, or what!

<g>
jlpicard
Advanced Member
Username: jlpicard

Post Number: 218
Registered: 7-2002
Posted on Wednesday, June 29, 2005 - 1:22 pm:   Edit Post

Nic, Can you go into any more detail onthe effect on tonal quality rather than just sustain? mike
smokin_dave
Advanced Member
Username: smokin_dave

Post Number: 225
Registered: 10-2002
Posted on Wednesday, June 29, 2005 - 6:07 pm:   Edit Post

I'm still interested in knowing when Alembic started employing the sustain block on all of they're models.
sfnic
Member
Username: sfnic

Post Number: 92
Registered: 3-2005
Posted on Wednesday, June 29, 2005 - 7:48 pm:   Edit Post

When did they start? Damned near on day one, IIRC. I don't remember if Jack's #1 had a block (though I think it did), but I'm pretty sure Phil's Orange Osage did.

I'm running late today, but I'll try to post some thoughts on the nature of sustain block-based tonality tomorrow. <g>
davehouck
Moderator
Username: davehouck

Post Number: 1969
Registered: 5-2002
Posted on Wednesday, June 29, 2005 - 8:21 pm:   Edit Post

Nic; I don't think it's killing a thread. At some point I, and I'm assuming others as well, have to draw a line and cut the computer off and go to bed! (Which is what I'm going to do now!)

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