Speed of CD player messes up practice with steel

Don R Brown · From: Rochester, New York, USA

A very helpful tool for beginners like me is a CD player to play tunes to practice along with. I have one here, and between that and Youtube there is an incredible amount of stuff to work on.

We have a weekend place and I have a second seat and a practice amp out there so all I have to transport is my S-10 steel itself. (I know, the pros lug around a D-10 5 nights a week. But it's more about space in the truck when we go). So I went to KMart and bought a $40 CD player for out there.

Well, the first time I used it I about had a fit, things just didn't sound right. I re-tuned the steel with the Strobo but it still didn't help. I finally decided the songs from the CD sounded a bit sharp. I made the best of it, turned out the light and practiced in the dark and it actually worked a little better than with lights on. Frets? Who needs frets?

So I took a CD and played a song out there and timed it with a stop watch, twice. I got 3:07 and 3:08. I played the same cut on the same CD here at home and got 3:10, two times. Conclusion is the player at the second house is spinning a bit faster than it should. You would not think 2 seconds would make a difference but it does.

No particular question or point, just thought I'd throw it out there for comments, and as info for others who are at the same stage in the learning curve, in hopes of saving them some head-scratching down the road.

Ken Pippus · From: Langford, BC, Canada

Used to be a big problem with cassette players, haven't had an issue thus far with CD's.

Denon used to make a line of CD players which would fine tune the speed, made it easier to play with Flatt and Scruggs and Miles Davis Kind of Blue, which weren't necessarily very close to concert.

William Lake · From: Ontario, Canada

I have a Teac with adjustable CD speed. They are out there, but they're not cheap.
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Bill

Chris Lucker · From: Los Angeles, California USA

Do you or anyone else want a Tascam CD guitar trainer?
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Chris Lucker
Red Bellies, Bigsbys and a lot of other guitars.

Chris Lucker · From: Los Angeles, California USA

When you got home did you use the same CD player? Did you plug into the wall socket at your weekend home? Have you checked the current?
Two seconds over three minutes is two thirds of a second fast over a minute. That is not very sharp. I wonder if I was ever in a band that was dead on?
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Chris Lucker
Red Bellies, Bigsbys and a lot of other guitars.

Bill Howard · From: Indiana, USA

i have a tascam cassette recorder a pro line crystal clear with Speed tracking I can slow down or speed up any tape so I could record CD and...

Don R Brown · From: Rochester, New York, USA

Peter den Hartogh · From: Cape Town, South Africa

Don, is your weekend place at a different altitude?

Chris Lucker · From: Los Angeles, California USA

Anyway, the Tascam can adjust. I can just send it to you and you figure it out or go online to read the manual. Tascam cd guitar trainer. I do not use it as I use an mp3 version.
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Chris Lucker
Red Bellies, Bigsbys and a lot of other guitars.

Scott Duckworth · From: Etowah, TN Western Foothills of the Smokies

Kinda along the same line, I play at a local nursing home, and their piano is never "in tune". After a song or two, I get used to compensating and I begin to sound OK.
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Earnest Bovine · From: Los Angeles CA USA

Shorty Rogers · Posted 8 Aug 2013 7:21 am

A CD player does not work like a record player, where the speed of the turntable can effect the pitch of the notes. A CD player plays data which is linked to an internal digital clock. At each given time increment, a specific piece of data is processed and a tone generated. This is all controlled by a computer program. The spinning CD just stores the data and and the CD player will read that data much faster than it will process it. Each player has a storage buffer which holds data before it is time to play it. The problem arises when the when the buffer size is not large enough, as often happens on inexpensive CD player (bigger buffers cost more). A full buffer will result in the next data piece being lost, and therefore never processed. Usually, occasional data fallout is not really audible to most listeners, so really is not a major issue.

Problems do arise when trying to sync the CD player with other recordings of the exact same performance. I encountered this when editing video which was lip- synced to a cheap CD player and needed to have the audio track replaced with the master recording of the CD on a studio quality machine. The music captured on the video could not be synced with the master because the CD player had dropped small bits of data throughout the shooting of the video. I lost about 3 seconds over the three minute recording and that really caused problems. I suspect that may be part of your problem.

Chris Lucker · From: Los Angeles, California USA

How long does data remain in the buffer. Does it pass through or is it stored until a reboot?
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Chris Lucker
Red Bellies, Bigsbys and a lot of other guitars.

Don R Brown · From: Rochester, New York, USA

Peter - no, the two places are fairly close in altitude to each other.

Earnest and Shorty - thanks, that makes sense. Guess I'm dating myself, still thinking in terms of a record on a turntable.

The new CD player was not meant to be a big deal, I just wanted something to play music while I'm at the place. So I went cheap but apparently went TOO cheap! Altho this one was about the same price as the one at home, just a different brand.

Ray Anderson · From: Jenkins, Kentucky USA

Thank you Shorty, This has been a rewarding few minutes of my time. You cannot buy that kind of explanation anywhere. That clears a lot of wonderings I've had about this subject. These are the kind of threads that are worth looking into. Whoa!

Don Drummer · From: West Virginia, USA

I have found this in the guide tones on practice CD's. The A pitch and or the Bb pitch are usually a bit sharp. Not by much. No more than ten cents. I've wondered about the same thing

Jimmy Gibson · From: Cornwall, England

Not sure if any of the forum members are familiar with the Roland MT90U it`s an amazing piece of kit because it will play CD`s Floppies USB Memory sticks all you need is an external CD Drive and an external Floppy disc player.

With this bit of kit you can slow the speed down on CD`s and Floppies and you can change keys also plug your steel into the unit add delay adjust the volume of the backing tracks and the steel separately. And phono outputs to plug into an amp or a PA sounds superb.

It is midi has a headphone input so you can practice without making any noise ,brilliant bit of kit.

Jimmy.

John Limbach · From: Billings, Montana, USA

Convert the tune to mp3 and use a piece of software called The Incredible SlowDowner. Simply incredible!

Shorty Rogers · Posted 13 Aug 2013 7:36 am

Chris: The buffer is dynamic, much like a stack. The player processes a piece of data at the bottom of the stack and then that piece falls out of the stack. As long as the buffer is not all the way full, new data enters the buffer at the top of the stack and the processed data leaves at the bottom of the stack. When the buffer fills up (i.e. is too small), there is no room at the top of the stack, so data is lost at the top until the bottom of the stack is processed and the entire stack drops down one level. You might want to think about it as a funnel that fills faster than it flows out. Once the data leaves the stack (is processed) it is replaced until all the data that makes it into the stack is processed and the buffer is then empty.

Chris Lucker · From: Los Angeles, California USA

Shorty, for playing music applications, is their a minimum buffer size we should look for?

Thank you for the explanation. My trained chimp even understood it. Well, actually he explained it to me.
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Chris Lucker
Red Bellies, Bigsbys and a lot of other guitars.

Helmut Gragger · From: Austria

For those into PCÂ´s or laptops or whatever, there is a piece of free software called "bestpractice" that letÂ´s you slow down, speed up, pitch shift recordings (mp3Â´s or direct from CD). You can even loop over certain finicky phrases.

Great practising tool!

-helmut
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Shorty Rogers · Posted 14 Aug 2013 10:32 am

Chris, I really don't know enough to tell you about buffer size. I would imagine it would be dependent on the processing speed of the player and you would have to determine that speed and also the speed of the internal bus. For listening pleasure, most players with border line buffer size will not drop enough data at any one time to really be noticeable to most individuals. Problems do arise when you are trying to sync with another recording of the same performance or, apparently, play along. This last is a little surprising to me, but someone with really goods ears could very well hear little glitches. If there are dropouts, then it is reasonable to think that there would be some very slight tonal issues if one were to try to play along, but only very slight.

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