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The Apple diyMod: My Take on the Famous iMod [56k killer] Featuring 3G, 4G, 5G and nano 1G! - Page 8

post #106 of 3000
Thanks for the heads up vvs and wgr!

Got it! Wasn't even that bad. Just had to know where to look. Ok and I'm sure this is mentioned in the thread but I've already been over it so many times and can't remember, if I take out 53,54,86,87 caps and reconnect to 53,54 pads, does this still preserve the regular headphone jack or not?
post #107 of 3000
Quote:
Originally Posted by wgr73 View Post
dcc84, look at my pictures. You'll notice the black bar going across the ribbon cable slot, that flips up(both of mine are open in the pics). Just use a jewelers flathead screwdriver to flip it up. Its easy!
I though that you need to take apart some peaces to get access to the cable. And you just needed to unlock the connector! LOL!
post #108 of 3000
Thread Starter 
Quote:
Originally Posted by dcc84 View Post
Thanks for the heads up vvs and wgr!

Got it! Wasn't even that bad. Just had to know where to look. Ok and I'm sure this is mentioned in the thread but I've already been over it so many times and can't remember, if I take out 53,54,86,87 caps and reconnect to 53,54 pads, does this still preserve the regular headphone jack or not?
If you take out all four caps, you disconnect both the lineout and headphone jack. The advantage of the nano 1G is that the solder pads are huge compared to the 4G, so you don't need to disconnect anything. Unless you're using huge gauge wire, you don't need to remove any of the caps. Even the 4G solder pads were big enough that I didn't have to remove anything. I truly don't understand this insistence on removing the four caps.


Quote:
Originally Posted by vvs_75
If after modification you still can regulate volume with the click wheel it will degrade the SQ.
This isn't necessarily true, but either way you don't want to be regulating the volume of your line out with the click wheel; that should be the amp's job. In any case, leave the caps in so that the line out and headphone jack will still work.
post #109 of 3000
Does anyone know what value the output coupling caps are in an unmodified 4G iPod to the headphone jack?
post #110 of 3000
Quote:
Originally Posted by vvs_75 View Post
I though that you need to take apart some peaces to get access to the cable. And you just needed to unlock the connector! LOL!
Yep! Its easy
post #111 of 3000
well my 4gig 2nd gen nano is open, guts on the table. I had already smashed the end of it by dropping a weight on it, causing the clickwheel to cease functioning (but the ipod to work otherwise).
Anyways, she's a test subject: anyone care to point me in a direction to work with>? I'll gladly guinea pig this one if you guys are down to put together some plans/suggestions
post #112 of 3000
Thread Starter 
If you could snap some close-up macro pics of the Apple 66AJSTB sound chip that would help me a bit. I have a picture but getting in real close would make it easier.
post #113 of 3000
joneeboi
I'm going to try and snap some higher-rez pics later on tonight.
First little problem I encountered though- the small ribbon cable that connects the top hold slide button has snapped out. I'll take pictures to show what I mean, but this will probably result in a bit of backtracking
In general how is the Apple 66AJSTB?
post #114 of 3000
Quote:
Originally Posted by joneeboi View Post
This isn't necessarily true, but either way you don't want to be regulating the volume of your line out with the click wheel; that should be the amp's job. In any case, leave the caps in so that the line out and headphone jack will still work.
That is true. You see everybody have different approach. To tell the truth I am perfectionist with everything. And sometimes it hurt me but there is nothing I can do!

I just remember reading thread were Vinnie was asking returned their iMods. Apparently he forgot some how he doesn't understand remove the caps and folks were reporting that by increasing the volume they could hear not increasing the loudness but quality in sound. So he said that after fixing the problem it will sound even better! That was 4th gen ipod.

That said if I am see just theoretical potential downgrading the SQ I won’t think twice.

Anyway it also depends on your choice of needs. If you want to leave phone jack in working condition then you:
-take your signal through the dock line-out
-drill a hole somewhere to take the signal out
in any case you need to use external case for the caps.

I personally don't care about phone jack since I will use it only in combo with my amp, so I sacrifice the jack if I see potential in doing it.

my 2c
post #115 of 3000
joneeboi one more question:
will I have to remove the battery on the board to get to the connections? Or is the 66ajstb nearer to the bottom of the board?
post #116 of 3000
Thread Starter 
The 66AJSTB is on the side opposite to the battery.



post #117 of 3000
Thread Starter 
Quote:
Originally Posted by vvs_75 View Post
I just remember reading thread were Vinnie was asking returned their iMods. Apparently he forgot some how he doesn't understand remove the caps and folks were reporting that by increasing the volume they could hear not increasing the loudness but quality in sound. So he said that after fixing the problem it will sound even better! That was 4th gen ipod.
My line out is unaffected by the click wheel volume control. Are you saying that removing the caps will increase the sound quality? I'm sorry, I'm just having trouble piecing together what you're saying here.
post #118 of 3000
Quote:
Originally Posted by vvs_75 View Post
Quote:
Originally Posted by joneeboi View Post
Here is a nano 1G disassembly tutorial.

iPod Nano 1st Gen. Disassembly: Installing Battery & Logic Board - Removing Rear Panel (page 1/6)

I'm sure if Vinnie could have fit caps into the iMod nano, he would have done it. The nano 1G measures 3.5" x 1.6" x 0.27", or 88.9mm by 40.6mm by 6.89mm. The iMod's BG NX Hi-Q measures as small as 4mm x 7mm. It will be very hard to get that kind of clearance inside the super tiny casing. I'd try squeezing it underneath the battery. That would be my first guess, but I still doubt you could fit it there. Maybe you could drill two holes that will let the caps stick out of the casing. Just spitballing here, try at your own risk.

As for sonic impressions, I'll try my best. My setup is the 4G click wheel (with WM8975 CODEC) to 220uF Nichicon UPWs from Mouser to a Kobiconn 3.5mm stereo jack also from Mouser. The amp I listened most intently with was my Millett Hybrid MAX. The MAX's settings are a supply voltage of 27.0VDC with 12FK6 biased to 13.5VDC, Toshiba 2SC3422/2SA1359 BJT diamond buffers biased to 110mV. My boutique caps are 1000uF Panasonic FC at CA2 and CA7 with 5.1uF Solen bypass caps at CA8 and CA9. Mini-mini cable is generic. Headphones are Grado SR60s with rescreening, sticky tack driver mod, GS1K pads with glue mod. Indeed a very personal setup, nothing any of you might have, even within MHM builders and SR60 owners. My files are encoded to MP3 320kbps VBR.

Plugging straight into the WM8975 (the datasheet says headphones can be plugged straight into the DAC if 220uF caps are put in series first), I listened to the very first time, as Nigel Kennedy played Sibelius' Violin Concerto in D minor, the performer's breathing. I had heard this sound before and I suspected it was hard breathing, but the clarity and intensity of his breath was very evident. I assure you I'm not exaggerating, as I've heard people exclaim that x piece of equipment allowed them to hear performer y breath and they could tell which nostril they were breathing from and performer y had a cold for the past two weeks. It's impossible to ignore this breathing. Switching over to some Hillsong's Savior King for some Marty Sampson singing In Your Freedom, I heard a portion of a drum beat I'd never heard before. It's just the snare going away on a regular system, but with the diyMod + MHM + SR60s, I could hear the hi hats going off in the distance. It was fairly not but overly subtle on this setup, but it's unnoticeable even in the car where we listen to this track plenty of times. The instrument separation was very precise, as I could switch from focusing on the drums and go to the acoustic guitar in one ear and then to the electric in the other ear to the piano in the back very smoothly. Loads of detail were available to me as though I were at a detail buffet and I could choose to listen to anything I wanted. On this setup, the highs sparkle quite nicely, balancing out the Toshiba BJTs' punchy bass. The corner frequency for this setup is ridiculously low, so bass rolloff isn't a concern (much lower than 1Hz). In fact, I think I've struck a nice balance between punchiness and extension. I prefer a fun, impactful bass, and this setup delivers it almost as well as I had heard with the Ayre Evolution CD player + Stax SR404 + SRM006tII listening to the same track. The noise floor is very quiet. Plugging in the iPod charger and pausing the music and turning the volume knob all the way up makes the AC noise only barely audible, so at listening volumes it's not a problem at all.

Overall, the take home message here is the separation. I really felt like I was onstage, walking between the performers to hear what they had to offer, although I'm sure volumes onstage are orders of magnitude larger than what I was experiencing. I like how everything meshes together right now, which is why I'm hesitant to even try the Black Gates. Even within the MHM builders, my setup is pretty far from what they recommend. My SR60s are one-of-a-kind, and I'm using Nichicons (220uF no less) as my diyMod caps. In other words, your mileage will vary greatly from mine as I'm sure no one will ever have this setup. That should be the caveat for a lot of reviews.
thx for those 2 guides, i found it very easy to try now...

Quote:
Originally Posted by dcc84 View Post
How do you guys think this mod compares soundwise to building an ipod dock connector to access line-out?

Also, hows the nano 1G mod goin vvs?
x2

Quote:
Originally Posted by dcc84 View Post
When you say "straight out of the WM8975" is that the same as soldering to C86 and C87? Or does that literally mean you have to solder to the tiny pins of the WM8975 chip? Dumb question, but I've read the posts a couple times and still can't figure it out. Thanks.
x2

Quote:
Originally Posted by joneeboi View Post
If you take out all four caps, you disconnect both the lineout and headphone jack. The advantage of the nano 1G is that the solder pads are huge compared to the 4G, so you don't need to disconnect anything. Unless you're using huge gauge wire, you don't need to remove any of the caps. Even the 4G solder pads were big enough that I didn't have to remove anything. I truly don't understand this insistence on removing the four caps.




This isn't necessarily true, but either way you don't want to be regulating the volume of your line out with the click wheel; that should be the amp's job. In any case, leave the caps in so that the line out and headphone jack will still work.
still listening (reading?!)...
post #119 of 3000
Quote:
Originally Posted by joneeboi View Post
My line out is unaffected by the click wheel volume control. Are you saying that removing the caps will increase the sound quality? I'm sorry, I'm just having trouble piecing together what you're saying here.

If you are using phone jack or dock line out pins to take signal out of your ipod, then I believe so. But it doesn’t mean that I am right.
Anyway if you are satisfied with the result then I am happy for you!

By the way could you please take a shot to show how you soldered wires in your 4th gen ipod?
post #120 of 3000
Thread Starter 
vvs_75:

Please refer to original post for the picture. I removed two components that were sitting where the wires are now, but I can't identify what they were. They looked kind of like diodes, but that doesn't make any sense to me.

iQEM:

As long as you solder the wires after the audio chip and before it goes through any other circuit element, you essentially follow the iMod's design philosophy. Other than the length of the copper trace on the circuit board, there isn't much affecting the sound signal. The WM8975 in the iPod 4G and the nano 1G and the WM8758 in the 5G/5.5G come in QFN packaging, so they are insanely small, making it near impossible to solder to two adjacent pins. Find the electrical equivalent of the pins, such as the solder pads between the chip's pins and some capacitors and you should be fine.
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