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

[joneeboi]

There is a lot that I have to work on, but I'm publishing it as is for now since I've been procrastinating this for years. I'll work on adding stuff like guides on how to open each device, but for now, there should be enough to go on to do your own diyMod.

https://www.instructables.com/id/DiyMod/

 

[Ad-Astra]

I heard people started to add capacitors to iPod

 

[stellarelephant]

Hi Jonesboi,
Thank you for spending your time creating a valuable resource for the community! I particularly like the educational primer at the beginning. As for the individual mod instructions, I think one helpful addition would be the inclusion of recommended capacitance values.

Personally I want to mod my 5.5 gen. Are you are up for fielding questions here? I would like to know what cap values are needed to get a suitably low corner frequency (hopefully circa 2Hz).

Also curious about exactly how to wire them in. I can easily read that the first pic says "remove" over the stock SMD caps. The resolution makes it hard to tell...does the next pic also say "remove" over the pair of chip resistors?

I can see how wires are used to bridge the gap here between the old cap pads and the resistor pads in pics 1 and 2. That much is very clear.

The next picture doesn't make sense to me though. This one:

Can you elaborate on what the arrows mean and what they are pointing to?

 

[Slater]

I too have a 5.5, and would love some clarification as to the items @stellarelephant mentioned above.

Also, some guidance sizes of caps that will 100% fit inside of the case, particularly when using the stock hard drive (or in my case, a 120gb ssd drive of the same dimensions as the stock mechanical drive).

Thanks so much!

 

[CH23]

To clarify for the people going by the old images:
don't remove the capacitors and resistors.
there's no need for it.
as for the green arrows, those are the testpads for the L and R line out. In case the pads come loose below the 2 resistors that are where the red arrows are.

When i find time i'll upload some better pics.

 

[stellarelephant]

Thanks, CH23. That clarifies things partially. So you are saying no components need to be lifted from the board whatsoever? Wouldn't this result in two parallel signal paths to the output pins...one stock and one upgraded?

Or are you recommending that we remove only the resistors under the red arrows in the pic I attached? And then if we lift those pads we actually get two (larger!) bonus pads to solder the wire to? I think this makes more sense but please confirm.

To follow your wiring start to finish...Looks like you are feeding those wires from the original cap pads down through a hole to the other side of the board. And then I presume that this end of the wire gets soldered to the positive leg of the new cap, correct? So then the final run of wire connects the negative cap leg to the either the test pad or the resistor pad (red or green arrow). How to know which is right and left channel?

One final question. Does this mod replace the capacitor on the way to the headphone jack or the LOD pins? BTW It occurs to me now that my earlier question to Jobesboi about recommended capacitance was stupid, since really it all depends on the load impedance.

 

[CH23]

Thanks, CH23. That clarifies things partially. So you are saying no components need to be lifted from the board whatsoever? Wouldn't this result in two parallel signal paths to the output pins...one stock and one upgraded?

electricity always chooses the way of least resistance, so it'll go down the DIYmod wires.

Or are you recommending that we remove only the resistors under the red arrows in the pic I attached? And then if we lift those pads we actually get two (larger!) bonus pads to solder the wire to? I think this makes more sense but please confirm.

I believe no components at all need to be removed.

To follow your wiring start to finish...Looks like you are feeding those wires from the original cap pads down through a hole to the other side of the board. And then I presume that this end of the wire gets soldered to the positive leg of the new cap, correct? So then the final run of wire connects the negative cap leg to the either the test pad or the resistor pad (red or green arrow). How to know which is right and left channel?

the wire from the DAC goes to the POSITIVE marked side of the capacitor, the NEGATIVE side goes to the 30 pin connector.

on the DAC side, Left cap is Left channel, Right cap is Right channel
on the Line Out side, Right resistor is Left channel, Left resistor is Right channel
don't know about the testpads.

One final question. Does this mod replace the capacitor on the way to the headphone jack or the LOD pins? BTW It occurs to me now that my earlier question to Jobesboi about recommended capacitance was stupid, since really it all depends on the load impedance.

the only irreversible modding i did was to the front case (i'll show pics)

as said, nothing gets replaced, however, the DIYmod bypasses the capacitors on the board, to the LOD.

 

[CH23]

Pic 1 & 2: full overview of wires on front + channels. I used cyanoacrylate (a type of glue) to hold the wires down. results may vary, depending what your wires are made of. mine were teflon.



Pic 3 & 4: close ups of DAC wiring + LOD side wiring. (I am not 100% sure if I should have wired them after the smaller resistors?) solder south of L2 and L3 (L2 is Right channel, L3 is Left channel)



Pic 5 & 6: wiring on the backside. put the caps anywhere you like, just think of the HDD and battery that'll have to fit in there.



Pic 7: here the iFlash Quad has been installed



Pic 8 & 9: just above the scrollwheel 'gaps', I burned the plastic away, so that the wires that go through the holes, have the space to be. Be sure to remove the excess plastic or it won't sit flush. And finally a working iPod video running rockbox from my 200GB µSD card

 

[stellarelephant]

Killer description and photos. Thanks. How does it sound with those Silmics compared to stock?

 

[CH23]

Killer description and photos. Thanks. How does it sound with those Silmics compared to stock?

thanks!

the line out is now louder(when on same volume), clearer, warmer.
bass has actual impact now.

the value of the Silmics i used: Elnas Silmic II, 47µF, 6.3v.
I actually got a kit from iflash.xyz because i can't find such a small gauge teflon coated wire on spool for a good price, shipping to the Netherlands.

I'd like to know if i soldered the wires near the 30 pin connector on the right spot.
i most definitely did. the 2 testpads go above the tiny resistors.

also @joneeboi feel free to use those pictures and description as you please, modify as you see fit.

 

[stellarelephant]

I've been looking closely at your pics. The mod procedure is finally becoming clear to me for the first time!

I'd like to know if i soldered the wires near the 30 pin connector on the right spot.
i most definitely did. the 2 testpads go above the tiny resistors.

You're talking about soldering right onto the L1 and L3 resistors, on the terminals closest to the edge of the PCB, correct?

And if I soldered the wires to the test pads instead, then the resistors would not be bypassed unless I removed them...is that what you mean by "above"?

 

[CH23]

I've been looking closely at your pics. The mod procedure is finally becoming clear to me for the first time!



You're talking about soldering right onto the L1 and L3 resistors, on the terminals closest to the edge of the PCB, correct?

And if I soldered the wires to the test pads instead, then the resistors would not be bypassed unless I removed them...is that what you mean by "above"?

It's actually L2 and L3 (but that's probably just a typo on your side, i hope?)

i've made a drawing of how exactly this part of the PCB is stuck together.



the black+grey things are the big and small resistors, dark green is the traces, yellow is the test pads, and white are the wires I added.
red is where i thought i should have soldered the wires to, but because it was mentioned to use the testpads if soldering to the big resistors failed, that would be wrong.

If i had soldered above the big resistors, i would not have bypassed them. But I was thinking that I had to bypass the small ones.

I believe I soldered the wires in the right place.

 

[stellarelephant]

Awesome...Paint to the rescue! L2 and L3, right. OK, so there is nothing but copper trace between the test pads and the L2 and L3 resistor terminals you used! I will probably use the test pads just because they are a little bigger with extra space to work around them.

With 47uF, you should have a very generous margin of capacitance for driving even low impedance amp inputs with total bass extension. And Silmics are some of the best electrolytic caps I have listened to, probably the absolute best in the bass department. Its cool to hear that your output is not only clearer now but also louder. Time to get a spudger tool

 

[CH23]

Awesome...Paint to the rescue! L2 and L3, right. OK, so there is nothing but copper trace between the test pads and the L2 and L3 resistor terminals you used! I will probably use the test pads just because they are a little bigger with extra space to work around them.

With 47uF, you should have a very generous margin of capacitance for driving even low impedance amp inputs with total bass extension. And Silmics are some of the best electrolytic caps I have listened to, probably the absolute best in the bass department. Its cool to hear that your output is not only clearer now but also louder. Time to get a spudger tool

The reason I didn't use the testpads is because allthrough this thread, i've seen people saying that the copper lifts quite easily from the PCB. That's also the reason why it's advised not to remove any components.

Good luck!

 

[CH23]

It was brought to my attention that I had the polarity of the capacitors reversed, which I did.

I have changed the post to reflect this.

While it's never good to have polarised capacitors in reverse, as long as the voltage remains way below threshold, it should not damage anything in the circuitry, but if you do see a chance to change this, then by all means do so.


What I had written before:

The capacitor negative lead should be attached to the DAC, the capacitor positive lead should be attached to the line out

What is right:

The capacitor positive lead should be attached to the DAC, the capacitor negative lead should be attached to the line out

Another misconception of mine, is that the 'z' capacitors can't be removed, because you would lose the ability to use the headphone output.
As it turns out, the wolfson DAC has 2 outputs, and the headphone output is separate from the line out output.

So you can remove the 'z' capacitors, but be careful not to damage any of the other components, and not to overheat the pads, as this would most likely lift them.

Thanks Tarkan et al.