[wgr73]

Well I couldn't squeeze everything in, but the tic tac container that joneeboi made up was a good one! Some of the first pics are of me assembling it, so it looks like a mess!

Sound Impressions: DiyiModNano

WOW! Thats all I can say. It sounds rediculously better than the headphone out, and even the lineout! The resolution has been upped by at least 5 times! I am in awe. I listened to a 128kbps song and it was that much better. You can really hear the low bitrate so be careful! I put my headphones back into the headphone jack just to tease and it sounded flat and muffled. This is just insane! And im not even using blackgates, im using another non-polar brand...not sure, I'll have to check. Here are some pics!!!!! Thanks joneeboi.

 

[CAvanessia]

wow. i'm very excited after reading the impressions.

unfortunately i am in the finals week too.

good job wgr73!

 

[wgr73]

Thanks CA! I'm actually in finals week too. I've been up for a little over 36 hours now! No joke, im super dizzy. It is now time for me to goto bed, so I'll have to talk to you guys later. See ya.

 

[joneeboi]

Great pics, wgr! We're going to have to do something about those caps though, now that we know it works

I hope this Tic Tac thing isn't a trend. *walks off in contemplation and mutters* I wonder if Juicy Fruit would work...

 

[joneeboi]

Salut, les amis.

I just came to report a successful diyMod 5G. Man, that was an annoying bug. Good news with this diyMod is that it's aesthetically identical to the original. Black Gates are shipping from partsconneXion tomorrow. Gotta sleep early for a full day of studying tomorrow. And I mean full. I will look back on this finals season and shake my head.

edit: devotees and others will want to regularly check the original post. I'm constantly updating it, trying to make it as streamlined and smooth as possible.

 

[fatman711]

that looks sweet guys! Just want to thank you guys once again for all the time that you guys spent on researching this stuff!

Everyone needs to go study! LOL. I have exams too and have been on this site all day....

 

[dumbears]

Good topic to research.

Months ago, I started my mod to iPod Photo. It might be wrong, since I just desoldered those Z caps (C84 & C86) and shorted the connections.

Instead of having the BGs inside the iPod, I installed it in the iPod dock/connector. Both have enough room for the caps.

BTW, I'm using 22uF instead of 47uF. Can sb advise what the differences between 22uF and 47uF used here?

 

[Jambo]

The capacitance determines the frequency response. The cap forms a high pass filter with your headphone speaker. The -3dB frequency of this filter is f = 1/(2 PI x Z x C) where Z is the impedance of your headphones. As you can see, a smaller capacitor will pass less bass - how much less depends on the impedance of your headphones.

 

[wgr73]

Quote:

Originally Posted by joneeboi /img/forum/go_quote.gif Great pics, wgr! We're going to have to do something about those caps though, now that we know it works

Lol, thanks! I will have to do something about this.

 

[joneeboi]

Quote:

Originally Posted by Jambo /img/forum/go_quote.gif The capacitance determines the frequency response. The cap forms a high pass filter with your headphone speaker. The -3dB frequency of this filter is f = 1/(2 PI x Z x C) where Z is the impedance of your headphones. As you can see, a smaller capacitor will pass less bass - how much less depends on the impedance of your headphones.

It's not just the capacitor and headphones though. You also have to take into account the input impedance of the amplifier you're using. I think a typical amp has about 10Kohm to 50Kohm of impedance, so that in conjunction with the headphones determines the bass response. Assuming you're using Grados at 32ohm impedance and an amp with 50K input impedance and 47uF BGs,

f = 1/(2*pi*(50,000+32)*47uf)
f = 1/(2*pi*50,032**0.000047)
f = 0.0677Hz

Like dumbears, I went with a slightly smaller capacity 22uF BG NX Hi-Q, but even that has a corner frequency of 0.145Hz with this theoretical setup. I think typical CMoy setups have around 20K input impedance. I'd say worry about the amp's impedance rather than the caps.

dumbears:

As for your iPod photo, if you could take an aerial shot of the WM8975 perhaps I can help you a bit better. From that angle I can't see the necessary traces. I don't think shorting the caps will make that much of a difference, as the goal is to completely avoid the internal circuitry. I haven't looked into it extensively, but I imagine you could solder the wires from the traces to the iPod's dock. I hadn't even thought of doing it that way. I'll look into it tonight. It would make things a lot cleaner. *wanders off in thought*

 

[barqy]

fantastic work

i just bought some BG caps off another member, hopefully I can do my 4th gen later~!

a little OT, but if someone is looking for a cheap silver 2nd gen Ipod nano (4gb) to purchase for testing on, give me a shout.

I have one (missing the plastic protect cover), I just installed a new LCD screen (works perfectly now), and I believe it needs a new battery too (battery doesn't hold). Everything works, except the body is a bit bruised (I have a new case for it though), and the click wheel turns flawlessly, but you need to press hard in order for the menu buttons to work.

 

[ishtob]

wouldnt anything under 20Hz be good since humans cant hear below that freq?

 

[joneeboi]

True, 20Hz is the maximum threshold. Even if it's the oft-quoted limit, I doubt many can hear or distinguish the difference between 20Hz from 30Hz from 80Hz without special equipment. But that's a whole other area we won't get into. All the same, the iMod, GPod and diyMod all have the potential for amazing bass.

Here's a startling reminder I had earlier today: the chip in the iPods all cost Apple under $5 each (from extrapolation). Be wary of the rave reviews of the iMod, GPod and even my own of the diyMod. In a match between the Wolfsons and, say, a Benchmark DAC1, my money is on the Benchmark (figuratively speaking, of course). I don't know what's inside a DAC1, but I'm guessing that the huge chassis isn't hiding anything smaller than the WM8975.

 

[vvs_75]

Did you track the (C84 & C86) with millimeter from the DAC chip?
I tried on my first ruined board and couldn't!

The WM8975 is on other side of the board and look like the caps you using doesn't go the WM8975.

In any way as joneeboi said you need solder wires from the pads to the iPod's dock or phone's jack directly to make a difference.




Quote:

Originally Posted by dumbears /img/forum/go_quote.gif Good topic to research. Months ago, I started my mod to iPod Photo. It might be wrong, since I just desoldered those Z caps (C84 & C86) and shorted the connections. Instead of having the BGs inside the iPod, I installed it in the iPod dock/connector. Both have enough room for the caps. BTW, I'm using 22uF instead of 47uF. Can sb advise what the differences between 22uF and 47uF used here?

 

[vvs_75]

Quote:

Originally Posted by wgr73 /img/forum/go_quote.gif Lol, thanks! I will have to do something about this.

I got my nano which was supposable need just to replace battery and its dead

but I have coming another one in a few days.

Also I took apart my nano and it’s possibly that I be able to squeeze two 47mF Simic II caps. Simic II is best ELNA electrolytic and quite few people prefer it to the BG.

In meanwhile I am working on second part of the mod, which is film caps dock for my nano.