Okay, I checked. Nothing. I listened to all the piano sounds in Preset A and a couple of slow-decay pads. Nothing. I then got my wife to listen; she hears high frequencies much better than I do. I asked her if she heard anything during the decay that didn't belong to the patch, like white noise or a reverb tail that seemed bogus. Nothing. Two different headphones (not $300 phones, but the same brand I've been using forever).

Man, I just don't know what to say. I'd *like* confirm this anomaly, but it's just not there. I have no reason to to jive you or jive myself, and my wife certainly couldn't care less one way or the other.

Really, I have no clue. I've also recorded my XP digitally, and the engineer didn't say anything (it was a multitimbral piece, but still I would guess something would show up).

I'm not doubting you guys are experiencing this, it just puzzles me that I am not.

I've had my XP-80 for almost a year, long before I knew about this board or this discussion. I've noticed the distorted buzz a bit, but it isn't really a problem, and here's why. The sounds on the keyboard, example, acoustic piano, aren't good enough to be used solo. I wouldn't want to do a solo piano album on the XP. Once you've got guitars, drums, bass, etc, there is no way on earth you're going to hear this problem. None!

Hey all. You know, I was sort of upset when I first about this situation. Upon turning up the volume on my sytth, I noticed this right away. But then again, I had a Roland XP50 before this. I never heard that problem there and am aware that this doesn't affect owners of XP50s.

Also, after I recognized it, that was it. It never bothered me again. I write biug, huge arrangements. There is always so much going on that I never even recognize the problem anymore.

If I had to spend the money to buy another XP60, I would do it again (God forbid - I'm a college student and do not want to have to go through saving up again). As Jimmy Jam and Terry Lewis said themselves, the Roland XP60 is one heck of a keyboard.

The Infamous EPU.

Epu:

If my theory is correct, you will never hear the distortion in an arrangement, because it will not be there, not even theoretically..

To me, this fact reduces the problem to almost nothing. I can live with a very minor distortion at the end of each song.

Stig

Til deg du visne lyng om haug
der draumar sviv,
eg gjev min song om dimd og draug
og dulde liv!

Here is a useful test:

Go to PR-A and choose the patch "House Piano."

Play more than one note and hold the notes down.

Since the patch is programmed (as you'll see if you check the EFX Parameters) with MASSIVE compression, it will highlight and reveal this "decay noise" people have been worrying about.

It's been there in my XP-80 since day one, and I've never minded it.

The DACs on the XP-80 are, according to the service manual I have, high-quality Burr-Brown converters. You can buy a service manual for your synth directly from Roland and confirm this for yourself, with a little research. So this shouldn't be a problem; if it were the DACs, they'd have to be technology two generations behind the chip in the synth to even be theoretically capable of being responsible for the "problem" people are talking about.

You'll note that if you "gate" the "House Piano" patch, by reducing the decay using the sliders, by the _tiniest amount_, i.e. enough to affect the decay of the sound, but not enough to cut it out entirely, that this will reduce the sound significantly.

This is what I think the Roland UK office is probably referring to as "gating the sample."

Playing around with the programming of this patch will give you a good picture as to what the sound is, where it's coming from, _why_ it's there (it's got actual use in this patch, to give it a gritty, lo-fi quality appropriate for house music, so it must not be an accident that it's there), and so on.

I consider this "problem" an actual intentional part of the JV/XP sound. We all know that pure, clean digital can sound sterile. Introduction of a little noise can actually provide some "air" to the sound that would otherwise not be there, if it is handled in recording appropriately.

Steve

\\Playing around with the programming of this patch will give you a good picture as to what the sound is, where it's coming from, _why_ it's there (it's got actual use in this patch, to give it a gritty, lo-fi quality appropriate for house music, so it must not be an accident that it's there), and so on.\\


This isnt the grunge decay issue.


\\I consider this "problem" an actual intentional part of the JV/XP sound. We all know that pure, clean digital can sound sterile. Introduction of a little noise can actually provide some "air" to the sound that would otherwise not be there, if it is handled in recording appropriately.\\


Unwanted noise at the end of a sample that sounds like a dying toaster is not "flavor", its a *flaw*.

Well, this is the _only_ "grunge decay" "problem" I have on my XP-80, so I guess I must be one of the lucky ones!

Steve

BTW, one last piece of information, from a BBS back in 1997, when someone asked about the XP-80 DACs. More recently the Burr-Brown PCM69au's been replaced by the PCM1800, which are 20-bit. Same logic applies, though. Here you go:

From: WeAreAs1@aol.com
Date: Mon, 6 Oct 1997 20:44:56 -0400 (EDT)
Subject: Re: Re: [jv1080] XP-80 D/A convertors

The JV2080 does not have 20-bit D to A converters. It uses Burr-Brown
PCM69au converters (the same ones used in the XP-80 and several other
models), and these have 18-bit resolution.

It is important to understand, however, that the JV/XP series all have 16-bit
*data resolution*. Running this data through an 18-bit converter does not in
any way increase the resolution of the data. The additional two bits will
simply remain unused.

There is a slight sonic improvement when running 16-bit data through 18-bit
converters. This improvement occurs at the very lowest signal amplitude
ranges, such as decaying note fade-outs and reverb tails. The additional
bits will effectively correct for possible amplitude quantization errors for
signals that are at the lowest possible amplitude or are approaching zero
amplitude. Whether this effect is actually audible in the real world is up
to question.

Anyway, don't get all worked up about 18-bit this and 20-bit that. The JV/XP
is a 16-bit sample playback machine, and no amount of additional resolution
at the converter will be able to change that.

BTW - in answer to the previous question about the conversion of the effect
proccessor data: All signals in the JV/XP are digitally mixed within the
synth's tone geberator and DSP chips before going to the D-A converters.
There is only one generation of D/A conversion.

StevenA:

Let me begin by saying that I am not an expert in digital signal processing, D/A-converters etc.

The XP-series synthesizers have 16-bit samples, as do all current PCM-synths. It is however important to remember that much of the signal-processing is done at higher resolution. I would not be surprised if the filters, envelope generators, LFOs etc work with higher resolution to reduce errors in the calculations.

We do know that the effects-processor has 20-bit both in and out, and actually delivers a 20-bit audio-signal. The internal processing in the effects-processor is most likely done at 24-bit, again to reduce the errors.

I usually compare this to modifying a picture digitally in Photoshop. You can take a low-resolution image and "map" it in to a higher resolution. Now, the picture itself does not get better from this, but if you start using Photoshop-tools such as smudge in the picture, the higher resolution becomes apparent, and the result is much better than it would be otherwise.

This technique can easily be translated into the audio-world. If you take "low-resolution" sinal, map it into higher resolution, and then process it, the output signal WILL have higher effective resolution.

My conclusion is that the XPs use their 18- or 20-bit converters to their full extent, and that this enhances the quality of the sound. The new XVs all have 24-bit converters. Why would Roland add 4-6 more bits to be unused??!?

As i said, I am not a professional in these fields, but I think this description should be fairly correct..

Stig

[This message has been edited by stigf (edited 03-28-2001).]