Zum ACS changer

memphislim · Post by **memphislim** » 11 Nov 2013 12:28 pm

Will those of you who have/had a guitar with this changer please comment as to the effectiveness of the ACS system on cabinet drop? I'm considering one but need some feedback please. Please let us know if you have a D10, SD10, S10 or U12 and how much it cures the problem and whether or not it affects playability.

Pictures that detail the mechanism would also help out.

Thanks in advance.

Slim

Dean Holman · Post by **Dean Holman** » 12 Nov 2013 12:31 pm

Deleted.

John McClung · Post by **John McClung** » 13 Nov 2013 1:48 am

I'd also like to see photos.

Mike, how's Austin treating you?

jay thompson · Post by **jay thompson** » 13 Nov 2013 4:32 am

Here you go. Brilliant simplicity.

Regards, Jay Thompson

memphislim · Post by **memphislim** » 13 Nov 2013 6:12 am

John, Austin is great. Much improved gig wise over SoCal.

Jay,thanks for posting the pic. Is there anything underneath the guitar you could take a pic of that shows ACS hardware? How is it adjusted?

Jim Palenscar · Post by **Jim Palenscar** » 13 Nov 2013 8:03 am

Nothing under the guitar- it is adjusted utilizing the 2 set screws that you see.

memphislim · Post by **memphislim** » 16 Nov 2013 1:30 pm

Thanks for the clarification Jim. So I'm assuming that the ACS mechanism doesn't really eliminate cabinet drop, it's just a support that keeps the changer axle from flexing, thereby possibly reducing drop caused from the changer. Not really counter acting or affecting drop caused by the cabinet flexing?

I've read else where that the tuner barely moves on these Zum's when the pedals are pressed but no one is quantifying how much. One person's "barely moves" is another's "big drop". What we really need is a measurement so one can use for comparison's sake. A new guitar is s big investment and drop is an issue for a lot of us so it would be great if players could post what their Zum is dropping in terms of cents. I realize guitars will vary within the same model and make but if a few people would be kind enough to measure on an ACS and Hybrid, we could get a general idea so as to make an informed decision when buying a Zum. After all, everyone who orders one will have to make that decision so this thread could really help.

If you have a Peterson tuner it's real easy to measure. Just tune the E string pedals down so it is straight up on the Strobe. Then on your tuner, go to where you can adjust the cents function and with pedals up increase the cents until you're straight up again on the strobe. The number you arrive at when the strobe stops is your cents of cab drop. Of course if you have the Boss tuner you just read direct how far the needle drops.

CrowBear Schmitt · Post by **CrowBear Schmitt** » 16 Nov 2013 1:41 pm

my 2006 D10 Zum 9/7 has that gizmo
w: pedals A&B down i tune my Es to 442
release them & cabinet drop is 3 cents according to my Peterson Stroborack

Jim Palenscar · Post by **Jim Palenscar** » 16 Nov 2013 2:14 pm

Actually the set screws contact the activated raise scissor at the end of the throw and, in a sense, deflect the changer axle a titch (it doesn't take much) thereby sharping the nearby strings a bit counteracting the tendency for them go flat (all this is IMHO ). I've built one for a guitar at the shop so that's how I did it. Ultimately it woulda been easier to simply install compensators for the involved strings and been done w it.

chris ivey · Post by **chris ivey** » 16 Nov 2013 3:22 pm

here's how i judge it. did john hughey need this mechanism to play anything he played with conway?

if music could affect me that much without some special device or auto tuner, then i don't want or need it.
i didn't even need some special medical device to give me goosebumps.

memphislim · Post by **memphislim** » 16 Nov 2013 4:42 pm

John Hughey, and a host of others, have far more talent than I do and have found a way to play in tune despite cabinet drop. For those of you with that talent, no need to read this thread. This thread is for us mere mortals who can hear the difference on their steel when the strings de-tune after pushing the pedals, and they are tired of compensating for it with their bar hand. This topic is also for those interested in advancing the art of steel building.

I'm sure if you offered John a guitar that did not detune and sounded and played the same, he would choose it.

chris ivey · Post by **chris ivey** » 16 Nov 2013 6:03 pm

i know, but wouldn't this be a good opportunity to just learn to play better?

leave your strobe tuner in your practice room and go out and play with other live musicians. clubs are looking for bands to play for free all the time, so you don't even have to stress over how you sound. and playing to a free band is not like trying to play to perfect pitch. a band is an approximation of everyone's concept of pitch. you only need to be close and learn to make it blend.

Dean Holman · Post by **Dean Holman** » 16 Nov 2013 9:42 pm

Deleted.

Douglas Schuch · Post by **Douglas Schuch** » 17 Nov 2013 2:55 am

I do not see why no one is willing to answer the man's question. Are there really that many players who do not have a digital tuner right by their rig, probably in use every single time they sit down to play? He did not ask how you deal with it, or if you consider it significant. He asked for a very simple measurement.

Slim, I do not have an ACS, or a Hybrid. I do have a standard Zum U-12. Like the others with standard Zums who've answered, with A+B pedals pressed I get about 3 cents drop on the E's and string 6. This measured with a cheapo Korg CA-40.

I suspect if you got hold of Bruce Z he could give you some specifics.

This got me interested in how much difference is detectable to humans, and led to this test:

http://tonometric.com/adaptivepitch/

I then used this page to calculate the difference in pitch into cents (second box down, enter frequency of tone in first box, then add result from the test on the first websit. It spits out the difference in cents.

http://www.sengpielaudio.com/calculator-centsratio.htm

I test slightly better than average - I can detect a 4.67 cents difference in tone. My guitar has a 3 cents cabinet drop.

This means that if I play my E-string, then depress A+B, and play it again immediately, I can not detect the difference. This is NOT the same thing as hearing that string played along with others that might have different relative tunings - I might hear that. But, if I tune my A + B pedals to compensate for the cabinet drop, then they are in tune with the other strings and I should not be able to detect the 3 cents difference. If, however, my band mate is playing an electric piano, well, then again, I might hear it.

If you want to hear some tone differences together, go to the bottom of this article where you can hear sound files of 1 cent, 6 cents, and 10 cents differences, both one after the other, then together. I certainly notice differences more when played together:

http://en.wikipedia.org/wiki/Cent_(music)

I was experimenting with playing a note (open string) then a quick slide to the a major third above (combination of visual and aural input on when I thought I was on it) and checking with the meter where I ended up, and I found an accuracy of 3 cents was about the best I could expect, and often it was more. Interstingly, I tended to be sharp, not flat.... just intonation is actually slightly flat from what a meter that displays ET will show at the major third. 3 cents also seems to be about what a minimal vibrato varies - any less and I don't really hear it. So, I would conclude that yes, I wish that 3 cents drop was not there, but I can live with it. Like Memphis Slim, I wonder exactly what an ACS changer measures - although I am not rushing out to buy one even if it is 0.

If you've read this far, you may want to go back to the original link above and take their "tone deaf" test. It's fun!

OK, I answered the OP's question as best I could... then strayed way off topic. Well, inquiring minds want to know!

Doug

jay thompson · Post by **jay thompson** » 17 Nov 2013 4:12 am

Chris,
The Zum ACS does exactly the same thing as the Emmons
Anti Detune Device. Note that both approaches are located dead center of the changer axle on both necks. The Zum approach does not interfere with the pedal action or under carriage mechanics as the Emmons approach does.
Regarding John Hughey. I saw John at a guitar show in Blountstown, Fl. a few years ago. In discussing his guitar, I asked if he was playing an Hybrid, his response was no, I have a new Zum with Bruce's new Anti Detuning Device.
Comparing early cuts with Conway Twitty and later with Vince Gill how many "cents" difference do you hear?
Regards, Jay Thompson

Greg Cutshaw · Post by **Greg Cutshaw** » 17 Nov 2013 6:43 am

A few things to consider. Cabinet Drop effects can put some pedal changes MORE in tune and put others more out of tune. If your guitar's open tuning or pedals has already drifted a few cents out of tune due to temperatures, mechanics, slippage, stage movement (etc, there's a long list of things than can cause even the best guitar to slip a few cents in 40 minutes), you've now got 2 cents of drift added to 3 cents of cabinet drop and it now becomes noticeable!

Greg

memphislim · Post by **memphislim** » 17 Nov 2013 7:15 am

Chris, I get paid to play out live 2-3 nights per week and that's precisely why drop bothers me. Its a distraction that prevents me from playing from the emotional side of my brain.
At home it is not an issue that plagues me.

Douglas I can barely hear 4 cents but 5 is where it kicks in for me. Unless of course you add the other instruments than even 3 can be heard.

I guess Hughey did care about drop after all.

CrowBear, you say you have the ACS changer and still 3 cents drop? Have you tinkered with the ACS adjustment screws to see if you could dial it out?

I still would love for more ACS owners to step up and do a measurement for us.

chris ivey · Post by **chris ivey** » 17 Nov 2013 9:50 am

i've found over the last few years that i have better luck at a gig by setting up, strumming my open strings, and if i don't hear any noticable clunkers, things start out pretty well. when i bring my stuff in, set up and tune up, i'm usually tweaking it all night.

i think if you took a reading of two notes from every instrument on stage, you'd find a wide range of discrepancy. that width then becomes your tonal center for the band tuning. nothing will ever be perfect no matter what 'you' do.

Dean Holman · Post by **Dean Holman** » 17 Nov 2013 1:14 pm

Deleted.

memphislim · Post by **memphislim** » 17 Nov 2013 1:30 pm

We may be drifting off topic here. The question at hand is not whether we can, and do compensate for cabinet drop when we play. We all try our best. That has been covered to great extent else where. The question is, how much cabinet drop do late model Zum's have, and does the ACS cure or just lessen it? That way a prospective buyer can choose between the ACS or Hybrid changer if he has a cabinet drop concern. Opinions on if it matters and advice on how to play around it won't answer this question. Measurements taken from several of these guitars with results posted here, will.

Gary Lee Gimble · Post by **Gary Lee Gimble** » 17 Nov 2013 1:40 pm

If a perspective buyer is prepared to plunk down thousands, a good test drive should be a must, opinions or not. Meanwhile, I own two Zums, one with and one without said ACH. And yes, it works just fine...and hasn't help me play any better either....opinion or not

memphislim · Post by **memphislim** » 17 Nov 2013 2:14 pm

Gary, does the ACS eliminate your cabinet drop? To zero?

Dean Holman · Post by **Dean Holman** » 17 Nov 2013 2:16 pm

Deleted.

Gary Lee Gimble · Post by **Gary Lee Gimble** » 17 Nov 2013 2:17 pm

engaging A & B pedals along with striking ether E's on my D-10, there is absolutely no movement on my tuner strings 4 or 8...

memphislim · Post by **memphislim** » 17 Nov 2013 2:23 pm

ACS is standard, the Hybrid is optional. So you do have a choice of 2 changers, knowing if one drops and the other doesn't is helpful. Does someone want to measure their Hybrid so we can compare?

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