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Double Bass Upton Bass C-Extension

P

pat1151

Jun 22, 2004
79
0
Montreal, Quebec
#1
Over the past few months, I have been shopping around for a C-Extension, and about a month and a half ago, I decided to go with an extension from Upton Bass in Mystic, CT. A few weeks ago, my extension was completed and I brought my bass back home.

During my extension search, I couldn't find very much information about Upton's extensions anywhere online except for a few odd photos found on Talkbass and of course the product page on Upton Bass' website.

From my initial discussions to gather information to the day I took delivery of my extension, the team at Upton has always been very friendly and generous with their time and were able to answer all of my questions. When putting in my order with Eric we had the opportunity to discuss options in materials and configurations (maple with an ebony cap vs solid ebony, number of gates, C or B extension etc.), and any possible issues that could come up with playing due to the geometry of my bass' scroll that I may not have thought of. In the end, I decided to go for the maple C-extension (with their double-pulley system) with an ebony cap and gates at the E and D. In addition to the extension, I also asked them to make me a set of leather-capped ebony bumpers.

Since I was travelling to Mystic to get this work done, scheduling was very important to me. Upton was very flexible in accommodating my schedule and I was able to book a drop-off date within a month from the date I put in my order which worked perfectly with my busy summer schedule.

The work only took a bit under a week to complete for both the extension and the bumpers. When returning to Mystic the next week to pick up my bass, I was very impressed by the extension Jack and Eric built for me. They went beyond my expectations by making the extension both functional and aesthetically attractive with some additional artistic carving on the underside of the extension. The curve below the extension is in the perfect spot so that when my thumb is resting against it, my first finger is in the right place to play the D flat much like your first finger would be in the right place to play a D on the G string when your thumb is at the bottom of the neck (with a D neck of course). As for the bumpers, they did a great job in measuring them to be the perfect heights and shaping them to look good as well. My bass is quite "twisted", and has very narrow shoulders (like a Quenoil pattern) and would never be able to rest on the floor on its side without tipping over onto the top. This was a huge source of frustration for me as I would always have to find a chair to prop the bass up against. Now the bass rests perfectly balanced on its own and the leather caps add a nice touch to the look of the bumpers and also gives the bass a bit of cushion when on the floor which helps to prevent scuffing the floor with the bumpers.

Visiting the shop was also an awesome experience and it was really impressive to see the team hard at work building some of these Upton basses we see all the time on Talkbass. The upstairs showroom was really cool to visit as well as Upton has a great collection of both new and old basses. I had the opportunity to look at some of their completed basses and I really enjoyed playing on the Upton basses. In the future, I will definitely consider making an order for a new bass from the guys at Upton because they are doing a great job on these instruments.

After having the bass back and getting to know the extension for some time, I am glad I made the choice to go with Upton. The extension plays very well when the C is engaged. At first we were afraid that the string height would be very high on my bass when the C was engaged, but the guys did a fantastic job adjusting it so that in the end, the height difference between the open E and open C is really not much at all, and the low string is super playable. Playing on the extension is easy as they made sure I always had a comfortable place to rest my thumb and shifting in and out of the extension is a breeze. When the gates are closed, there are no rattles and the closed notes are very well in tune. Finally, the extension is very lightweight and the bass feels the same as it did before the extension was installed.

I would definitely recommend any bass player to go down to Upton for an extension as they are very affordable and the guys at Upton really deliver a high quality product with many options so that it can really be customized to how you want it to be.

If anybody has any additional questions about my experience, I'd be glad to help answer them, just post a reply or send me a PM!

extension1.jpg

extension2.jpg
 
#7
pat1151 said:
I took a quick and rough measurement, the string length to the E is just under 41" and the C is just under 51".
Click to expand...

Hi Patrick,

The acid test is for both the stopped E and open C to be in tune with each other.
First, (using a bow), tune the A, D and G strings, normally, using a tuner, if possible.
Then, tune the stopped E string, as if it was not part of a C extension - using the A string harmonic that sounds an "E" and the harmonic on the E string that sounds the same "E". You can use an electronic tuner to verify both pitches. ( If you're new to C extensions, I would recommend releasing the stop on the E when tuning the string- that is, don't try to tune the string with the E stop "locked").
Now that both harmonics are in unison, unlock the E stop and play the open C string. The open C should be in tune. Use a tuner to read the low C fundamental, if possible.( Don't "correct" it at this time). The harmonic that occurs at the low G ( in half-position, with the E stop "unlocked"), is a G - a unison - the same note as your open G string. It should cause your open G string to "sympathetically vibrate". You should see the open G string vibrate, and hear it as a perfect unison to the harmonic G. Measure the harmonic that occurs at the low G. It should be exactly in tune. You should see the tuner verify that pitch as an "in tune" G. If that harmonic is not an "in tune" G, the fundamental low C is not in tune. ( thank you Physics!). You can also measure the low C string with a tuner, using the harmonic that occurs at the halfway point of the C string. The first 3 harmonics on a low string can be used to " hear"or "read" the fundamental pitch of an open string - most electronic tuners fluctuate when the low C string is first sounded. It can take a few seconds for the string to "stabilize", before the tuner can read it. Using the first 3 harmonics can lead to a more accurate reading of the fundamental pitch.

A second test is to now tune the open C string,( if it is not in tune using the test above), using both the fundamental and using the same harmonic that occurs at the low G. Tune the open low C string and then "lock" the E stop. The fundamental "E" should be in tune - you can verify using a tuner and by checking the two unison "E" harmonics that we began with. They should be absolutely tune with one another.
If any of the above tests result in a tuning "failure", (out-of-tuneness), it is an indication that the C extension length was not calculated correctly.
You should be able to have both the open low C and the stopped E in tune with each other.

Also, If your measurements are accurate, 51 inches is "short" for a 41 inch E string, even using the archaic "add 1/4 the length of the E string" to determine the C extension length, which should produce a C string length of 51.25 inches.( still "short" IMO).
Thanks for your time and interest.
 
#8
iona bass said:
Hi Patrick,
Also, If your measurements are accurate, 51 inches is "short" for a 41 inch E string, even using the archaic "add 1/4 the length of the E string" to determine the C extension length, which should produce a C string length of 51.25 inches.( still "short" IMO).
Thanks for your time and interest.
Click to expand...

Like I said earlier, this is a very rough and quick measurement that I took this morning before work.
 
#10
robobass said:
I think the guys at Upton know how to determine proper extension length.
Click to expand...

robobass - If the open low C and stopped E are both in tune, then they calculated it correctly. End of story.
If not, the length of the C extension would be the first issue to address.
As recently as 2007, I corresponded with 2 well known Luthiers who both indicated that they still used the "add 1/4 of the length of the E string" to calculate the C extension length. My own dissatisfaction with the "tuning" of my first extension 20 years ago, led me to investigate and re-calculate the extension about 10 years ago.
I don't mean to disrespect anyone, but I think there may still be Luthiers who were trained that way and I know firsthand that it leads to real, audible and measurable discrepancies in tuning.
Again, I don't intend to disparage the work of any of the fine Luthiers mentioned on this site, I only intend to open a discussion regarding the accuracy of the calculation.
Thanks for your time and interest.
 
#11
True. When my extension was refitted after fingerboard replacement at a major NY shop the C was quite sharp after tuning the closed E. That was also twenty years ago, though. I hope most repairers have progressed since then. The extension length on my Pfretz is actually 126.3% of the mensure and is perfectly in tune. Hard to know why this is exactly.
 
#12
Sorry for the late reply. I am really unsure about the measurements I posted earlier, I will definitely investigate when I have more time.

I just ran through the test you mentioned and the extension passes the test which really makes me question the accuracy of my measurements.

All things aside, the guys at Upton are doing a great job as so far this extension is working well. I had a chance to play some of their basses when I was down there and it's clear they have a good thing going on, I'm excited to hopefully own one of their instruments in the future.
 
#13
pat1151 said:
Sorry for the late reply. I am really unsure about the measurements I posted earlier, I will definitely investigate when I have more time.

I just ran through the test you mentioned and the extension passes the test which really makes me question the accuracy of my measurements.

All things aside, the guys at Upton are doing a great job as so far this extension is working well. I had a chance to play some of their basses when I was down there and it's clear they have a good thing going on, I'm excited to hopefully own one of their instruments in the future.
Click to expand...

pat1151-

Good for you. It sounds like the calculation is correct. As I said before - " End Of Story".
Now go rattle some windows!
Thanks for your time and interest.
 
#14
robobass said:
True. When my extension was refitted after fingerboard replacement at a major NY shop the C was quite sharp after tuning the closed E. That was also twenty years ago, though. I hope most repairers have progressed since then. The extension length on my Pfretz is actually 126.3% of the mensure and is perfectly in tune. Hard to know why this is exactly.
Click to expand...

robobass-

I just did "your" Math on my C extension:

My numbers:
E string length - 42.250"
C string length - 53.375"
C extension length - 11.125"

I then ran your "126.3%" formula:
42.250 x 26.3% = 11.111"( C extension length).
42.250 + 11.111 = 53.361"( this is the C string length calculation, based upon your "126.3%" formula).

So, your "126.3%" calculation yields a C extension length of 11.111"(!)

I arrived at a C extension length of "11.125", and a resulting C string length of 53.375", using first, a Fret Calculator,(Stew Mac website), and then Tuner, Trial and Error /Earror.

I realize that 53.375 does not EQUAL 53.361, but it is fairly close(!).
(.014" = less than 1/64").

Thanks for your time and interest.
 
#15
is there anyone who is using this extension? I was given a review of this extension that was...not positive and its making me think about if I'd like to go with upton or somewhere else? Anyone use it and are happy with it (or not?). There aren't many reviews of the extension out there.
 

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