HiFiMeDIY T2 with iPhone as source

I have a HiFiMeDIY T2 amp that has been sitting around waiting for a project and figured I will finally build something with it for my son's birthday. I have a few questions I was hoping you all may be able to help with:

1) My limited understanding is that this amp is set up for standard line level input, but my son's source is likely to be his iPhone or iPad most, if not all, of the time. I can evidently replace the R3 and R5 resistors with 40k resistors to compensate but I'm wonder how hard this will be. I have a fair bit of through hole soldering and de-soldering experience but I have never messed with SMDs. What are odds I screw it up and just make a mess of the amp?

2) Alternatively I could use a preamp - is there a way to build one into his system so the amp would automatically bring his iPhone input to standard line level prior to going into the T2, if so, any recommendations?

3) Is one of these approaches (swap SMDs or use preamp) better than the other?

4) Finally, I'm going to build a DIY speaker set to go with it and was thinking of using the Overnight Sensation MTM design. Does that seem like a design that would pair reasonably well with this amp?

Thanks in advance for any help and suggestions!
 

saniiiii

Member
2015-06-15 9:18 am
hard to tell for the smd-resistors :D
soldering the new ones in should not be of a problem, yet, desoldering might be.
you have to apply heat simultaniously to both ends of the resistor, this will be a bit difficult with a single soldering iron.

using a preammp should be possible too, there are several ne5532-based boards on ebay. im not sure, what gain they use, be careful. also, the ne5532 is not really "audio grade", but it should be replacable by any more audio-made opamps
 
Raising the gain on the board will increase the noise floor (hissssssss from tweeter).

A pre-amp is a better solution as far as sound quality goes, but it adds a significant amount of complexity because of the additional power supply requirements.

The specs for the amp say it has a 50k pot. I would change that out for a 10k.
 
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