My MT-32 is (very) noisy, and that's not hiss!

[Alistair]

So, my question would be, am I likely to achieve worse recordings with my Roland MT-32 if I continue to use this Roland AC adaptor, 9V, 500 mA?
I don't want unnecessary hiss/distortion if I can buy a 10-buck adaptor to fix it..

- Alistair

[Maxime]

I just checked my unit, its set at negative polarity.

Okay, thanks.

I'll wait until wednesday as I'll be able to go to a specialized store, after that I'll surely buy an adapter on the internet if I haven't already found one.

I'll keep you informed of the results.

[Maxime]

Sorry to bother you again, guys, but...

Thanks to Ari's positive experience about replacing the adaptor to get rid of the noise, I was about to buy a new adaptor, but I remembered that I actually tried to power my MT-32 with some other consumer adapters which were pretty low-end and standard (eg. the kind of adapters you can find bundled with most consumer products, such as computer speakers), and that the noise was still here (and the same), even with another adaptor.

And, as I've already said, I've also tested the outputs jacks of the unit by plugging a pair of earphones into one of the L/R outputs of the MT-32, using a 3,5 to 6,35 jack adapter, and the noise was still here. That way, I got a proof that the noise was not coming from the 6,35 -> RCA cable I'm using to hook up the MT-32 to my soundcard, using an RCA -> 3,5 jack adapter.

I know that I should have asked this question before, but, do you think that buying a new adaptor could help to eliminate the noise from my MT-32, given that I've actually tried with other cheap adaptors, and that the noise was still here? Or do you think it's a coincidence that the noise actually appears with a low-end adaptor (which is relatively new, approximately 1.5 year old) and the original Roland ACB-220 adaptor (which may be quite old now, more than 15 years old I think), and that it could be solved with another higher-quality adaptor?

And, which adaptor to choose, actually, without talking about the polarity/intensity/amperage/whatsoever? I often see "stabilized", "regulated", "switching power supply", I have a little idea of what those expressions mean, but could somebody tell me which characterictic(s) is (are) important to avoid noise? Ari said that he had noises because his previous power supply wasn't "filtered and regulated"?

Kaminari, I've searched on the French website you mentioned for the SNG 1500 adaptor, I found it the day you posted your message, but I can't find it anymore?! Instead, I've found another power supply which looks great at JR-International.fr: Electris brand, 1200 mA, universal, referenced as "T1200" on the website. A good power supply, according to you?

Again, sorry for all those questions, but I'm sad to have a noisy MT-32 without actually knowing what is the problem...

[Ari]

I don't quite understand from your post if you tried a regulated and filtered one, or not?
I don't know much about electronics, but the way I understand it, a regulated unit means that the voltage is constant and not prone to spikes in the current.
I don't know what the filtering does, but a friend of mine said it was necessary as well.

[Zemus]

The electric current is at either 50Hz or 60Hz, depending on where you live. A filter simply stops everything at other frequencies. There's usually a lot of noise on the network, so this may help in some cases.

[Kaminari]

Conrad's website has been redesigned lately. You'll find the correct page here. The model you need is the Voltcraft SNG 1500/12.

I have to say here that I can't take any responsibility if the new power supply doesn't resolve your problem -- which I will be sorry to hear about. In worst case scenario, you'll have at least a stabilized PS that will be very convenient for many electrical devices

Good luck.

[Maxime]

Okay, thank you, I've just ordered this adaptor as most other ones you can find on the internet have nearly the same prices...

But, of course that I'll not sue you if this doesn't solve the problem
Having such adaptors is always handy...

Let's hope that I'll fix the problem...
But to be honest, I'm not very optimistic...

I'll keep you informed of the results.

[moturimi1]

I don't think that the power supply is the reason for the sound problems.
I have a MT-32 that came with a 9V 500mA supply and I don't have any problems. At the moment I use the Conrad power supply described. (Voltcraft SNG 1000/12)

I don't think that the new supply will help you to eliminate the noise!!!!!!

[Ari]

It helped me. One never knows...

[Maxime]

Damn, I was nearly sure of it...

I received my new PS today, tried it with the correct specifications, and it didn't solve the problem

The noise is still here! And absolutely the same than with the old power supply...

So, as I've already tought, it seems to come from the unit itself, as I've tried to:
- use a new power supply
- test the L/R outputs with different cables (actually, a pair of earphones using a 6,35 > 3,5 jack adapter)
- use the MT-32 in totally different conditions (at my father's home, new location, new room, away from any electronical equipment)

I'm tired of this problem, so tired...

I do not know anybody who could help me to find the origin of that noise!

And I can't afford to send it for a repair, I'm sure it would cost me almost the same price as another unit I could find on eBay or somewhere else...
And even if I could, where to send it, as I'm in France? I must be sure that it'll not cost me a lot of money, that the repair service will be trustful and competent... it's absolutely not easy!

I have the impression that there is no solution...
I'm totally desesperated...

[HondaSiR]

I'm sorry to hear about your predicament, I was also hoping that the problem  was simply with the PS and/or its polarity or something.

I guess the only solution would be to buy another unit. Don't despair, they don't cost so much now...around $25 to $40 range. You'll probably pay more for shipping to France from the US. Surface mail can be used to bring the cost down.

[Maxime]

Well, I think that it'll be what I'll finally do... unfortunately

But I don't want to bother myself about that in the meantime.
Even if it's cheap, I'm a student and I don't want to spend money for it currently. Having paid for a new adapter which I'm not using (for the moment) is already enough for me!

I'll maybe consider a new buy when I will find a real opportunity for it; not exclusively from France, as, having a new adapter (sic), I'm only needing the unit...

I think that I could take advantage of having two units to increase polyphony and have 16 channels, but I'm lacking information about it.

For the moment, I'm playing around with it, as I've just discovered this unit more deeply, I've just found how to edit my own General MIDI SysEx bank with the excellent LA Synth Editor for Windows 3.x.

After some practice I'll surely be able to build a good bank for this synth, like I'm doing since more than a year with my SB Live!

But I need some additional information about it, like how to connect it so that I can send AND RECEIVE SysEx messages. With my current setup using my USB keyboard as a MIDI-Out interface, I've only managed to send data to the MT-32, not capture from it; I have a DB15 MIDI cable connected to my soundcard's MIDI port, but as it was shipped with my USB keyboard, I'm wondering if it could be an non-standard cable...

I'll probably start a new thread here in a few days, so that I can be helped

That said, in case you'd have some new info or advice about that weird noise, don't forget to post them here! I'm still hoping for a miracle...

[Marten]

I hope that you are able to find a solution to your problem.

I've always had a slight electrical "hum" noise from recordings on my MT-32, which was easily solved with a ground loop isolation cable, and I am afraid I missed listening to the sound sample you had posted previously, so I cannot comment on whether this would also help your situation.

But, if the noise is a very loud one, then I doubt any cable would solve the problem.  With my MT-32, the hum was never very loud, just "noticeable."

[Tom]

You'll need a 100% MPU-401 compatible MIDI interface for sending and receiving MIDI data.  I don't know of any sound cards that can send and receive MIDI data at the same time, which is what you need to do in order to retrieve data from a MIDI device.

[Maxime]

You'll need a 100% MPU-401 compatible MIDI interface for sending and receiving MIDI data.  I don't know of any sound cards that can send and receive MIDI data at the same time, which is what you need to do in order to retrieve data from a MIDI device.

Thanks Tom, I'll look at that. But as I've said, I'll open a new thread for that, it'll more appropriate, I think.

[Marten]

Hmm.

That soft but high pitched whine in the background sounds similar to a grounding issue, but it is much higher pitched than I would expect.  In the US, our electrical currents operate at 60Hz; in Europe and other countries, at 50Hz.  These are audible frequencies and can produce a hum in recordings when the equipment has a feedback loop through the ground.

The hum in your recordings sounds like it has a base frequency of almost exactly 2000Hz (I used a free utility at http://www.nch.com.au/tonegen/index.html to compare).

There are two ways to approach grounding issues.  

One method is to improve on the electrical grounding of the device(s) involved, as described at http://www.alexandermagazine.com/recordingeq/weeklytip/05tip06-3a.asp .  The MT-32 power adapter doesn't use a grounding plug though, and if you are recording to a computer, no matter how clean you make the ground to your PC it is still likely to generate some buzz on the RCA cable between the MT-32 and the PC.

A solution to that, and the one I employ, is to use a ground loop isolation cable, such as the one at Radio Shack for about $18 US, here:  www.radioshack.com/searchsku.asp?find=270-054 .  A ground loop isolation cable runs between the output of your MT-32 and the input on the device where you are making the recording.

Now, I don't want to tell you that grounding is the problem, see you spend effort and money, and then find that it won't solve the issue.  So, please take my recommendations at the value you've paid for them (free).  Because your output doesn't sound like a 60Hz hum, I don't have a lot of confidence that the $18 cable will help you... although I personally think it is a good investment to have anyway.

One good thing I can tell you is that even without a hardware solution, a good editing program or a free utility such as "wavhum" at http://www.mymusictools.com/audio_editors_6/wavhum_25043.htm might be able to isolate that noise and virtually remove it from your recordings.  You might want to try a utility like this one first.

[Zemus]

Tom: You mean dumping sysex from the MT-32? I could do that with both my SBLive and my current Audigy 2 in Windows. I don't know of anything else you can receive from the MT-32.

[Tom]

When you edit sounds in the MT-32, the software needs to send and receive data, simultaneously.  Were you able to do that?  I've never been able to from a sound card MIDI port.  Though I don't think I've ever had problems just receiving a bank from the MT-32 using a soundcard MIDI port.  It's just been when I'm in an editor and working with sounds; making changes to them.

[Maxime]

Interesting analysis, Marten.

Like you, many if not all people I've asked so far have said that such a noise is much likely a grounding or electrical issue. That's actually one of the reasons why I've decided, along with the experience of Ari which was positive, to buy another power supply.

Now, it's true that it did not solve the problem and thus, I'm quite reluctant to buy another audio cable (it's actually an home-made cable from the person who sold me the unit), as I've already tried to listen to both L/R outputs using a pair of perfectly-working earphones, and the noise was still here. So I'd rather suspect something wrong inside the MT-32, but it's hard to find as I'm not an electronics specialist

Tom and Zemus, about the SysEx dumping issue I've started to talk about, I've made a (big) thread about it: http://www.queststudios.com/forum/viewtopic.php?p=13272

[HondaSiR]

I'm quite reluctant to buy another audio cable (it's actually an home-made cable from the person who sold me the unit)

I remember something. When I received my module two years ago, I  first used a cheap audio cable to hook it up to the back of my sound card. It had a background noise to it so I replaced it with better cables (thicker actually). The noise disappeared!

It's worth a shot. Try to borrow or acquire better cables. You may have tested the unit with headphones but you may as well leave no stone unturned. For all we know, the headphones may not be shielded as well.