I use this technique on a 5G Nano / ALO SXC LOD / Mustang / JH13 rig, and it does, in fact, work.
OK - let's go through this, step-by-step:
1. On your iPod, open Settings app - select iPod / EQ --> then select "Rock"
2. In iTunes, select the playlist you will be working with. Then, go to menu on top: select View / View Options... --> then, select "Equalizer" (now, you will have a blank column, titled Equalizer, in your playlist - View Option selections only work for the playlist you have up on the screen at the time - for other playlists, you will have to repeat this step)
3. In iTunes, select "Rock" for each song you want custom EQ'd. (in playlist's Equalizer column)
4. In iTunes, go to Window --> select Equalizer (a pop-up window appears)
5. Be sure the on/off "switch" on the "Equalizer" pop-up window (in upper left corner of pop-up window) is set to "On".
(there will be a check mark in the box - to confirm "EQ On")
6. In the EQ pop-up window, twiddle the EQ slider bars, to achieve your desired Custom EQ.
- the name of the EQ setting changes to "Manual" (when you move the slider bars)
7. After desired EQ settings achieved, in EQ pop-up window, click & hold on "Manual" then scroll up, and select "Make Preset..."
(when you click & hold on Manual, in the EQ window, a pop-up menu appears - scroll up - select "Make Preset...")
8. Type in "Rock" - hit return - screen will say:
"An EQ Preset already exists with the name "Rock". Do you want to replace it?"
- select Yes
- Now, your custom EQ settings are stored as "Rock" - overwriting the factory Rock settings.
9. Unplug LOD from iPod / amp rig
10. Plug iPod into computer / iTunes - synchronize
11. After sync is complete, eject iPod (in iTunes - click the little arrow to the right of your iPod name, on left side of iTunes screen)
12. Unplug iPod from computer (remove USB-to-iPod)
13. Plug LOD from amp rig, back into iPod
14. Select a song that has EQ previously set to Rock in EQ column of iTunes Playlist. (see step #3)
- also, make sure your iPod EQ is set to "Rock"
15. Hit Play (make sure your amp is on)
16. Enjoy your custom EQ setting!
Couldn't live without it.