[GirgleMirt]

amp n00b has a few questions

1) How can a meta42 deal with different headphones? Right now, I have a pair of Grado SR80, but I'll probably get another pair eventually, but it probably won't be a Grado; I'd like something more comfy/relaxing. So, the gain of meta42 for grado should be something like 3 I think, but the gain of other headphones, such as senn hd600, is like 10... So would it be a good idea to use a middle value? Such as 6.5?

2) DIPs Being that I'm not sure what resistances I'd use, the DIP-14 sockets look like a good idea. But what are they actually? You put the resistances in them, and no need to solder or something? And I'd need 4 of them, with a 'length' of 7 right?

thanks

 

[guzzler]

A gain of 10 will drive the Senn 600s to painful levels without a crossfeed circuit. I think your suggestion of a gain of around ~6.5 is perfect, and seeing as you're fixing the gain, there is no need to use DIP sockets...

incidentally, to answer your question, the DIP sockets are soldered onto the board, then you can easily plug/unplug different resistors from the spaces on the DIP socket, allowing you to tweak values...

g

 

[GirgleMirt]

ah cool

and if I understand correctly, with the grados with gain of ~6.5 (actually it will be twice that since I'll add crossfeed), the only negative side is that the volume knob will be very sensitive, and the grados would probably sit at around 1/4 of the way, MAX at 1/2 volume knob position, where a hd600 would usually sit at 1/2 and 3/4 or max to play the same volume as the grados. Correct?

If so, important not to forget to lower the volume after changing headphones!

else after going from Senn to grado, you'll go:

(MY EARS!!!)

 

[guzzler]

yeah, definately.. don't put the phones on till you've checked the volume and started playing something...

another thing to consider might be a gain switch, so you could just flick a switch to go to "Grado Mode", and flick it back for "Sennheiser Mode". You would need a DPDT switch and 4 global feedback resistors per channel, instead of the normal 2. You don't need to bother switching the local feedback resistors as it only adds complexity and their overall effect on gain is minimal!

g