[bh357]

I'm looking at building a Mini3 amp in the near future, and would like some guidance on what gain level to select.
My player is a Philips.  I currently have a pair of Alessandro MS-1, and will have a Head-Direct RE0 very soon.  Both 'phones are low impedence, so I'm thinking a gain of 4 or 5.
 
Thanks,
Brad

 

[nikongod]

Unless you have a particularly low output source gain of 2 is the way to go. 
MAYBE 3, but 2>3 in this case.

 

[Avro_Arrow]

I agree with Nikongod.
Most sources are pretty loud already, gain of two
is plenty in most cases and keeps the noise floor low.
I would only go with a gain of five for op amp rolling
and in a mini^3 that is impractical.

 

[ShinyFalcon]

With a 2Vrms source and 2x gain (and 32 ohms/100 dB/mW headphones), I can't go over 8:00 without feeling uncomfortable, and this is with a 50k ohm RK27 volume pot.

 

[bh357]

I forgot to mention that the Mini3 would occasionally be used with my TT setup.  The cart is a Denon DL-110 HOMC, and the preamp is a VSPS set at 40 dB gain.

 

[cobaltmute]

I'd agree on the low gain.  In my Carrie (Mini^3 + grubDAC), I did a gain of 2 and have no issues on my high impedance phones, so on low impedance phones you should be good.

 

[gimble]

Don't overspec gain, it's not free.
 
Through-hole resistors are also kinda easy to desolder if you need to up the gain later.