madox

Good question. Hopefully, the USB MIDI driver would not cost as much as their USB ASIO audio driver. If access to the driver comes with the chip purchase, that would be great. Did you find a schematic, or are you refering to the photo of the MIDI interface on their homepage? A reference schematic/datasheet for their chip would be handy.

Sounds like a promising chip, for a great price. I'm interested in making at least one stand alone PC midi interface out of one of these. My main DAW currently doesn't have one. Hope it works out. Is anyone else planning on using these chips for standard PC midi interfaces?

Hi mmaluck, That LCD looks really good. I just noticed that Electronic Goldmine has minimum order of $50 + shipping to Australia, where I am located. Anyway, I'm sure there are lots of midiboxers in USA and Canada who will benefit from this part. I might consider organising with 10+ other Aussies to go in for a bulk purchase, but I'll have to check if it would work out. Cheers mate, Madox

Hi mmalluck, any news on this LCD? I'm considering buying one as well. Cheers Dude, madox

Hi Jason, I have still not received an invoice from you for this sale. I just wanted to check if my order is still OK. The did receive an email enquiring about direct deposit payment (I'm an Aussie), but never received a final amount, or bank details. I have also just sent you an email about this. Sorry for badgering you, but just really don't want to slip between the cracks. Cheers Jason. Oliver

Thanks Wilba, looking forward to it. This is all much appreciated.

Hi, I do surface mount soldering every day at work, and I also think that video demonstration is pretty good. I find the drag method much easier than soldering pins individually. I find a really big, round (like hemisphere) nosed iron tip is best for drag soldering. As mentioned in the video, too fine a tip won't hold the solder as well, but can also catch on thin PCB traces or chip pins, and cause damage while dragging. The other method I use, which is not demonstrated in that video, is hot air soldering. Hot air works very well for small devices, such as SO8 packages. Just preload the pads with solder, apply flux, heat with hot air, place chip with tweazers, and heat just a little longer after placing chip. If this is done right, you can complete the whole process in just a few seconds. Surface tension snap down can also aid in device placement, so you don't have to be quite as careful with the tweazers. Hot air rework stations can cost a bit more than a good iron, but are useful if you do a lot of this stuff. It takes some practice though, and it is not uncommon for beginners to overheat chips this way, so don't start this method with any rare devices.

Yeah, I would also be quite satisfied if my (late) order could be filled from another bulk purchase down the road. Of course, don't know if that's likely to happen, or not. It sure would be nice to get the chips, either way. -madox

Hi Wilba, Just added myself to the list. I know I'm late on the draw, but here's hoping. Cheers, Madox

Hi Wilba, I know I'm really late on this (been away for some time), but I've added myself to the list. Here's hoping there are plenty of spares... Madox

I don't mean to be a pedant, but you are talking about AC voltage, right? Not current? Just on a side note, do you understand about voltage references? It's a topic which is a bit too often overlooked, even by some engineers and technicians I've worked with. I think it's worth reading about the fundamentals a bit, as it really helps to understand the different kinds of signals, like AC, differential, positive/negative/0V ground rail referenced signals. I guess you've been warned before, but make sure you take care with any mains voltage supplied equipment. Even experienced professionals make mistakes sometimes. It's too easy to do. There are too many horror stories. Just take it slowly, and think about every step before you do it.

Normally reading AC signals with a DC mode meter will give around 0V. At least my multimeter behaves this way.

I just wrote that pretty quickly. Actually, if people want information about this topic, there is a lot of it available online. Wiki has a brief description already. Just do a search for bypass or decoupling capacitor. It's really just a low pass filter. If I'm going to put the information somewhere more permanent, I will give it a bit more effort, and try to clarify the generalisations. Making simplifications and generalisations are a bit tricky on this topic, as in reality the situation is not as simple as often represented. I really appreciate your feedback, and I will give your suggestion more thought when I have some time (I'm actually meant to be writing my honours thesis at the moment). Cheers audiocommander! P.S. When I do my own designs, I pretty much always use bypass caps. I'm not an experienced engineer, and generally do this as a matter of caution. However, I tend not to rely on rules of thumb for capacitor values. Choosing appropriate capacitor types and values probably does take a bit more background in electronics though. If it is for a low frequency application, then the rule of thumb is usually fine. Basicly, you just don't want to have the filter resonating.

Hi, I was just wondering if you could please provide a reference for this material? I've studied noise, and the role of capacitors to some extent at uni, but would like to look into it further, as I haven't understood the basis for what you've written. Thanks a lot!! ---------------------- I know this has been covered before, but for people concerned about bypass capacitors, I will try to briefly summarise my understanding of the issues here: No DC supply is perfect, and random noise and changes in loading on the power supply cause the power supply output to vary from what is desired. With good power supplies, good circuit layout, good grounding, minimal EMF etc, this variation will be small, and not cause any manjor issues. If a voltage is changing too much, then it can cause problems, such as irregular behaviour of digital chips, or excessive audible noise from a synth (this is not the limit of problems). One precaution for this problem is to use to put a capacitor between the power input of a component, and the component's ground. Good capacitors provide very high impedance for low frequencies (DC), and very much lower impedance for high frequencies (noise). So, by using a capacitor, noise voltages are conducted to ground, and the component 'sees' a cleaner supply level. It's not really quite that simple, but that's the basic idea. So, if you are wondering where to put a bypass capacitor, you can generally just connect it between a power supply of a chip (close to the pin), and the nearest ground connection. It seems that some people were confused by the heat shrink tubing that Thorsten used. This is just a plastic tube which covers a metal leg, or uninsulated wire. When you heat the tube, it shrinks around the metal, providing DIY insulation. Think of it like high quality electricians tape. If you want to know if you need to use them: try without, and see if there are any noise/supply voltage related problems. It seems that most people can get away without them. Bypass caps are more important at high frequencies, when lead inductance comes into play, or when one is using noisy devices like motors etc. From my brief look over the MBHP circuits, it doesn't seem likely that this will be an issue. High frequency stuff is not so well suited for DIY anyway, and the standard rule of thumb about 10uF/100nF can really fall short for those applications.

Hi, I am interested in making a MBFM synth, and was just wondering if people have had any issues with old chips pulled from sounds cards? Have they proven to be reliable, and is the sound quality generally as good as unused chips? Does anyone have experience using both new (old stock, presumably) and second hand chips pulled from old sound cards? P.S. Love this site. Love the MBFM demos, and all the other kit here too. A truly amazing contribution to the electro diy community. Thank you so much TK. I was a member here a few years back, when I built a midi filter. Works brilliantly, and it solved some major problems I was having. Edit - OK, so as there has been no reply to this message, I will just assume that no one has had any problems with old chips. Please correct me if I'm wrong.

Hi, I've been soldering for more than 20 years, and it's my opinion that a good iron is very important in producing a circuit. This is not just because it's better for the joints and chips, but also because it makes the work much faster, and much easier. The condition of the element and the tip are also really important. The element is also probably the most expensive part to replace (this has been my experience so far). I've also had success with 25 Watt irons, and there are actually some pretty decent ones around. There are a few problems with them though. They can wear out more easily, and need more frequent replacement, which drives up the cost. It's important to have an iron both hot enough (temperature), and able to provide enough heat (energy). Ideally, you want to concentrate heat around the surface of materials to be joined. If the iron can't provide enough heat, or maintain the temperature, then the material will heat slowly, which allows more heat to be conducted deeper within a component. This can cause component damage. It also takes a lot longer, and if it's a bad case, you may have to wait longer between soldering joints within close proximity of eachother. A good iron allows you to go through the joints really quickly.