Search options (Page 122 of 137)

Responded!

You're not supposed to record audio from the link. Rather, there's a special mode that allows Nanoloop to output data as audio through the audio jack. I have no idea how to use that data, though.

Sure. That's stupid, but not from an ESD standpoint. (In short, ESD hazards mainly affect digital inputs CMOS inputs, and not pure outputs.) The hazard there has more to do with accidentally grounding the outputs and frying them, which is of course bad in its own right. But I'm under the impression that this is not the most common may of doing a Prosound. Soldering to an SMD pin is more difficult than soldering to the potentiometer. And in the case of epoxy blob boys, you'd have to solder to a via on the board. I think most people do it the conventional way. And when doing it the conventional way, there's a 50 ohm resistor that adds some protection.

The scare tactic part was a response to the quoted comment by low-gain.

Increased power consumption means increased ripple, true, but that can be solved with more decoupling caps. But the problem on the other hand is to get that -18V. My point is that a DMG with a Prosound is "good enough". Redesigning the DC/DC, which would be a hassle, is overkill if all you want is reduce the noise.

I think the main problem with GBP is the choice of battery type, (AAA instead of AA) not the DC/DC. Bibin did a modification where he used a Li-Po (IIRC) battery, which increased stability greatly. EMS carts are notorious though, because they have a design flaw which makes it eat more power than it should.

low-gain: If you want to eliminate the need for an extra jack, the idea of using a new amplifier does make sense. But the current "Prosound" modification is easy to do, especially on stock consoles, and works well enough.

As long as you use the modification for high impedance inputs only (mixers/soundcards etc) there is absolutely no problem. In fact, it's not much different from the high impedance input of the DMG's own amplifier.

The DC/DC converter then... It does produce some ripple, but I don't think it's the main source of noise, at least not when bypassing the DMG's own amplifier. Where this is really a problem, it can probably be solved more easily with more filtering. The main problem with replacing it, though, is that provides -18V for the LCD in a small form factor, which you'd have to make up for.

This is just a scare tactic without much basis in reality. How about a real argument? Unless you're looking to eliminate the need for a dual output, or you're very keen on getting noise-free headphone sound, I don't see the need for a new amplifier.

Arfink: Picking up noise from address lines: Marginal problem. Insofar that this is a problem, it can be improved by tapping ground off of a location near where you tap the signals.

The ESD argument... No, just no. If you want me to elaborate on why this isn't a problem, I could.

It works well enough as it is, at least when driving a high impedance, like a mixer/soundcard input/an amp. Don't fix it if aint broke.

Well... I used to believe that, until I heard the difference myself. It's true that DMG doesn't sound as horrible as GBC when unmodded, and that the modification doesn't (and doesn't really need to) improve frequency response. But what it does do is improve the signal:noise ratio, by both bypassing the amplifier, which adds noise, and providing a higher nominal voltage. This comes at the cost of higher impedance though, which does make the output unsuitable for headphones, but, again, works just fine for high-impedance inputs. If you're actually serious and want a clean recording, or less background noise when performing on a big PA, the mod is the way to go. If you're just starting out and hardly know how to use LSDj, it can wait.

There's a designated way of adding ground planes (or other planes for that matter.) If I remembered how to do it, I would explain to you here and now.

Hmm, I don't have a DMG open to compare with, but I'll get back to you on this one.

It's good practice to have a big one near the power supply connection, and a couple of small ones spread out across the board, close to the other chips.

Yeah, but then there would be no space for ROM, graphics memory or anything else. The idea is based solely on the fact that there's an unused area of "mirror" RAM, which basically means that if the two top bits are set (as they are for all addresses in the $Cxxx-$Fxxx range) the external RAM is selected. But the third highest bit is simply ignored, which means the same area is repeated. Actually, it's a little more complicated than that, since the highest 512 bytes, which would otherwise be in mirror RAM, are actually used for other things and don't reach the external memory bus.