Filburt

Someone posted this on head-fi: http://homepage.mac.com/marc.heijligers/audio/ipod/comparison/measurements/measurements.html

I don't understand the point of all that other hardware for something that has such high distortion and, in this configuration, probably a nice bit of aliasing too. Then again, I'm not an 'NOS' faithful so maybe I just don't 'get it'.

Is this a TDA1543-based dac?

It looks OK. I'm not exactly enthused, though, as the output stage is AD823+NE5532. I don't really understand this selection, other than it being cheap. At first I thought it used the PCM2902, but I see some chip on top that I can't exactly make out based on the pictures. Looks like a Cirrus Logic chip (such as a CS4398) if I were to guess.

lol glad you like it

I vote no on PicoDac or whatever. It makes it sound DIY and second-tier and you know how image and buzzword conscious they are >.< Euphoria? I do think it'd be funny to see people talking about how they bought their euphoria from Justin. Besides, how could anyone choose something other than euphoria in a poll on which is best. It's better to choose a name that is just easy to remember and evokes some sort of marketable image that people like to propogate. Actually, I'm a big fan of Justine RPG-7 and Mindslaughterer X-6000. I think Skullrapist or Aquarius is OK too.

The pricing seemed rather high to me as well. Although, it also seems as though modders commonly charge a few hundred dollars, or more, for these sorts of operations. On the other hand, though, it seems as though one has to price high enough in this hobby that people think you're selling a quality product. Over at head-fi, at least, I've gotten the impression that some folks genuinely like buying expensive products.

AD825 is a decent chip, at least. I find it's one of the better performing fet-input chips; probably one of the very few I'd even consider using in an audio application (a group that _doesn't_ include the popular AD8610 and AD8065). I imagine it probably sounds better than whatever dreck is in that thing stock.

I see. It sounded like they meant they were going to use so-called "passive" I/V, and that they stripped the active stages. BUF634s aren't exactly performance hot-shots. Why didn't they use the LMH6321 if they wanted to use an open-loop IC buffer? Which op-amps do they use for I/V?

I'm not impressed by the mods described. It seems the myth of minimalism is still going strong in the audiophile community. While the other stuff is sort of "yeah, okay then", tearing out the analog stage and replacing it with some caps and some wire sounds like a great way to bring in distortion. The d/a converter probably needs a buffer on its output to perform correctly. RAM doesn't indicate whether they make a replacement buffer, but 'minimalist' seems like it suggests otherwise.

Replacing tantalum capacitors with blackgates doesn't magically change the WM8975 into something other than a low-power codec, probably buffered by a micropower CMOS op-amp, nor does it change whatever DSP is being done. The length of the leads to and from the capacitor is also a concern to me. As I've mentioned, I've used imodded ipods, and I still think people are exxagerating about the performance. I certainly wouldn't take it over some of the DACs and CD players I could acquire for under $1K, if sound quality is the objective.

At least to me, it looks like what is being done is tapping the L/R outputs of the Wolfson and subbing in blackgate caps in place of the tantalum caps. It seems like to me this will turn it into an antenna for RF interference, in addition to facing inductance on the leads and increased ESR etc. Tantalum caps (in my experience anyhow) do not provide particularly linear performance, but I don't know whether or not this makes an improvement over it. I haven't managed to try an iMod side by side with an unmodified iPod, but I have tried it side by side with other sources and, while I thought it sounded OK (sounded mostly like an iPod to me), I wasn't finding myself thinking that it was the equal to an external dac or good deck in that price range, or a $1000 CD Player.

I have an small mini-mini IC from Alex. It was very nicely soldered and assembled; very clean work, overall. Don't know if that's any help.

What's the estimated build cost on this thing?

The NOS Cartel is going to have your head, justin! the explanation seems to be fairly accurate...though it's the 1543 in particular that seems to be the easy one

Welcome to headcase socrates

Okay. I figured it didn't include the iPod since the original iMod was $199 just for the mod alone. That seems like quite a lot of money to be investing in something like an iPod. Then again, people are spending over $150 on simple dock cables, so I guess $375 isn't particularly surprising.

I don't think it's as difficult as it's made out to be. If you're experienced in SMD soldering, it's probably something doable for you. I can't say I'm surprised about the partnership with ALO. Does the $375 include the iPod?

I guess if you're really wedded to the iPod then it's probably an improvement to use the BGs over the pretty lousy tantalum coupling caps that Apple uses. I don't think the iPod is a very good source, though, so I find it a bit awkward to shell out that kind of money on it when ~400 dollars can get you quite a bit more elsewhere unless you have some burning desire to make your iPod your 'high quality' source. I took apart an iPod the other day and while it's not the easiest modification it didn't look that bad. I may modify it for the hell of it *shrug*. Won't really fix it still being an iPod but I guess it would be somewhat entertaining to do...at least until I go back to using something else.

You mean the Opera will no longer be around?

Alright, I'll contact you when I get back over there How does it work?

How long do you get to keep it? I'll be back around those parts in about a week and a half to two weeks.

If that's your logic, why did you even suggest that we could know if Ray told us. You just said that someone who x-rays it knows for sure, but then said a person who is told about it, by someone who x-rays it, doesn't know. Well, then if that's the case, the person wouldn't know any better if Ray were to tell them, since you put Ray in the same position as someone who x-rays it in terms of knowledge of the components. Ultimately, this sort of position means everything is based in inference and you only have a spectrum of strong to weak inferences. As such, while my suspicions about the content about one or more of these amps is less strong than the inferential basis I would have per x-rays or Ray telling me what is used, it doesn't mean it's necessarily useless in discourse about these products.

Well, Ray didn't paint over the circuit board, so it's not like people can't tell what the schematic on the thing is. Also, if you think x-raying a chip doesn't give conclusive results, I'd like you to come up with a scenario (other than defective equipment) where you've got a scan of the metallization layer, and reference materials, but your results are going to be inaccurate. I didn't claim I knew with absolute certainty what the Hornet uses, but Ray practically spelled it out in front of me with his description of the op-amp when I was at the San Jose meet in 2005, and from what I understand, people found other evidence thereafter.

Sometimes, it seems like it's difficult *not* to get banned for all sorts of things. Thanks to restrictions on discussion about the design of products, I pretty much have to be so vague that people like trose get to openly insult me for it Oh well, I'd rather endure that than not be able to still try to be helpful to folks over there