Hi gang,
somebody just gave to my brother a DX7 and a Korg M3r. When you power on the DX7, the display says "memory protect/change battery!". When doing the battery check as the manual proposes (oh yeah, I r.t.f.m'ed ) it says the battery voltage is 0.8 volts (where it should be 2.2 - 3 volts). The sounds coming out of the thing are... well, obscure, non-musical bleeps that don't really change when you press a higher or lower key.
It does send MIDI, however. That's what brings me to the question: as my brother is certainly not going to use the blurps and beeps, will the DX7 continue to function as a MIDI-controller when the battery is completely emptied or will it shut down in that case?
Is replacing the battery something you can do yourself with little electronics knowledge?
I guess we're not going to go through the hassle of sending it to an Yamaha dealer to repair it, not to speak of the price.

Oh, by the way: the acoustic pianos of the M3r have such an incredible crappy sound it's hard to believe someone ever played them. Gosh!

The DX will continue to function as a MIDI controller with a low-voltage battery, but will not persist any settings when you power it off. However, at that age, it's important to remove/replace the battery before it leaks and ruins the synth.

Replacement involves soldering (I'm guessing this is the original DX7, not the newer DX7II series?). Details can be found here, with the obvious caveat that you should know what you're doing with a soldering iron before you begin.

Good luck.

There is a much easier way to replace a battery on a DX7 than those instructions. Grab a 3 volt button battery from anywhere - Walmart for example. Open the top and desolder the the leads on the battery itself. Then gently resolder the leads on the new battery. It's been twenty years but I don't think there's any disassembly involved. The battery is right there in front of you.

This trick was taught to me by a keyboard tech back in the 1980s. All I can say is that it works.

Hi guys,

thanks for the answers.

Sven, yes, it's the original DX7.
Bill, that sounds like a nice workaround. However, I'm to soldering what "Light My Fire" is to Dave Horne's jazz piano routine. If you know what I'm sayin'.

I'm still wondering: is the DX7 an instrument to be preserved? Would it really be that bad if it was ruined?
What do you think might a technician charge, in the unexpected case that he has a replacement battery? 60$ and more?

And on a little more serious note: could the low battery voltage be the reason for the strange sounds the synth makes or is this a completely different issue?

If you also have any of the original ROM cartridges a low battery DX7 should play those sounds. But the internal sounds would be scrambled.

I think. Don't hold me to it.

It wouldn't be that bad if it was ruined. I'd suggest replacing the battery yourself - or have someone who solders do it. It's not worth having a tech do the job - and guess what - he'll probably use the workaround anyway. It takes less than 1/10 the time.

So many were made, it is not worth going through 'Giant Steps' to preserve. Besides, the scrap metal could come in handy.

But, if you can get the battery replaced inexpensively and use the DX7 as a sound source/MIDI controller, go for it.

Oh yeah, good idea. I haven't checked the cartridge sounds so far.
I think I've found out what the problem with the sounds is: they are all pitched about 5 or 6 octaves to low. I have no idea why.

If you're going to use the DX7 as a controller remember that it only transmits on MIDI channel 1. I learned that the hard way trying to use one to drive a module out in the middle of nowhere many years ago!

Dx7s make a fine addition to your trebuchet bucket when hurling X stands and Roland KB amps.

I had to look that one up.

http://en.wikipedia.org/wiki/Trebuchet

Also, the DX7 does not transmit full velocity (127) it only goes to like 100 or something close to that. If you are controlling a module you will need a midi processor to get the full velocity. Midi solutions or the old anatec company (spelling) made little boxes that would adjust the velocity.

A DX7 also only transmits MIDI velocities up to 100 - not the entire range. This was a big deal back in the 1980s.

MoWorst try initializing a voice and see what you get. It should be a sine wave. It's a function marked on the front panel and really easy to do on a DX7.

edit: e-keys beat me to the punch.

MoWurst,
I brought my DX7s out of retirement (along with myself) to trigger a Voce module and it worked great. Great keybed on those things.
Regards,
Joe

Again thank you guys for the wealth of information.

@MonksDream: Damn, I was planning on using it as second organ manual for my Electro. It would have been a very nice contrasting effect.
@Moe: Guess on which kind of stand it's going to sit? Right! And a white one, too.
@e-keys: I knew the word trebuchet from "Age of Empires"...
@Bill: I just tried the Init function. It did change the notes a bit, and I could fiddle around with the parameters (what an incredible PITA. No wonder everyone used only the one preset sound) but there wasn't a substantial change in the sound quality, so I guess there' something "broken".

I'm glad there's something like FM8...

Which doesn´t sound like a DX at all.

1.)
Battery:CR2032 w/ soldering lugs,- available from Yamaha

Alternative:
Cut the lugs that way you can solder a battery holder to the lugs and buy cheap CR2032 in future.
If battery is replaced, reset the memory of the DX, download tons of patches from the web, make a good selection and load/play.

2.)
Midi transmission on midi ch. 1 only:

Alternative: Replace the OS
(Route 66 Studios offer this as a kit p.ex.,- USD 28.-)
http://www.route66studios.com/synthparts.html >Yamaha
Is just only replacing eproms.

3.)
If the keybed is in good condition,- congrats !
DX7 action is the best synth action ever made.

4.)
Velocity value, max. 100 only:
Solution:
Your in germany,- try to find a EES M3 velocity transformer.
Comes w/ midi-in, thru (transmits original velocity) and 2 midi outs transmitting any user selectable velocity curve on both midi outs.
Offers freely selectable midi split point for the keyboard on the next higher (n+1) midi channel.
Original channel adressed to midi out 1 then and n+1 channel to midi out 2.
But eventually needed only if you won´t decide to exchange the OS (see features)

A DX can sound killer w/ the right patches and the lo-fi DA converters are responsible for it´s charme.
DX can be noisy, but a single ended noise reduction does the trick.

I´ve seen Jens Johansson of Stratovarious http://www.stratovarius.com/ using a DX as his only one masterkeyboard just because of the action and I´ve seen Ricky Peterson w/ Markus Miller using DX7 and D50 as his only synths. He had killer sounds w/ the DX which wasn´t midied up w/ the D50.

I enjoy playing my DX, TX816 and TG77 up to now,- all great FM machines.
Well, I´m using FM7 and FM8 too by other reasons.

A.C.

THe DX7 has the the best stock marimba sound I've ever got from a synth. I used it for many years in a salsa band and musos came up at the end of every set and asked how I got "that great marimba sound". This was the mid-90s and they were stunned when I pointed at the DX. Also putting a DX through a decent reverb, delay, overdrive, or chorus unit can give it a whole new life. That's true of any synth really.

FM synthesis is very powerfull if done right,- but complex and hard to understand for the common musician. You can even create analog sounding pads, leads and basses w/ FM.
But what I like most since decades is what the combination of a DX7 and Oberheim Xpander offers,- or the low budget DX/Matrix-1000,- just ideal partners.

A.C.

Dude, get it fixed. The DX7 is a classic. I may be biased since it was my first synthesizer, but I love FM synthesis. I currently own a SY77 (DX7 on steroids), SY99 (even more steroids), and FS1r (DX7 on crack).

If I lived anywhere near you, I'd do it for free just so the instrument could LIVE AGAIN!

And yes, FM is great for emulating analog sounds. This is a gratuitous plug, but the bulk of spacey/pad sounds on my upcoming solo electronic/ambient disc (click the bottom link in my signature) are created in FM, from the SY77.

Put the DX7 through a good multi-EFX unit and you'll have a very useful synth.

And besides, whether or not it transmits full velocity or not is inconsequential if you're going to play organ on it!

If all you want's a controller, send the DX7 to me, I'll send you a controller, I'll fix your DX7 and enjoy a piece of (arguably dismal) keyboard history. Any $150 controller will probably make a better MIDI controller than a DX7.

The DX7 may be many things (limited, frustrating to program, almost impossible to tweak on a dark stage) but dismal isn't one of them. The DX9 I had before I got a DX7 on the other hand...

A DX7 was my main keyboard for years - paired with a CX3 or Poly 800, or sometimes both. Back in the '80s Keyboard Mag classifieds had lots of custom patches for the DX. A guy named Bo Tomblyn, I think, programmed some pretty good bass/piano splits I used when playing left hand bass.

When I play it now, though, the old DX7 sounds a bit lame.

When soldering the battery please be carefull not to overheat it, it might explode. Al Coda's idea is the best solution: buy an appropriate battery holder, solder it to 2 longer wires and fix it somewhere inside DX with duct tape/glue. Your next battery replacement will be much easier; OTOH my first (original) battery from 1984 I replaced 2 years ago.

DX7 is my first polyphonic synth and I still enjoy it's keybed...
and it's got channel aftertouch as well.

Bata K.

There is no factory reset, so when the battery goes down, all the sounds go bye bye too. You will need to load Rom Cartridge #3 Bank A to internal memory, or download the sounds via a website and bulk dump them back in. The cartridges have been discontinued for years and are no longer available unless you try ebay/craig's list.