Ruby line in buffer ?

[mat]

I'm building a Ruby amp combo with overdrive+stage center reverb. I would also like to include a line in for mp3 player. What kind of buffer should I put in if any ?

I will power it with 12V motorcycle battery. Will post pics when ready.

Matti T.

[mat]

I'm building a Ruby amp combo with overdrive+stage center reverb. I would also like to include a line in for mp3 player. What kind of buffer should I put in if any ?

I will power it with 12V motorcycle battery. Will post pics when ready.

Matti T.

Anyone ?

I tried few different OD circuits in there and ended up with the BSIAB2. It worked best with the Ruby.

Here is the complited amp (lacks the back panel still):

http://www.pichotel.com/pic/16028B31e/162753.jpg
http://www.pichotel.com/pic/16028B31e/162754.jpg
http://www.pichotel.com/pic/16028B31e/162755.jpg

Soundsample (no processing):
http://media.putfile.com/rubybsiab2stagecenter

I hope the closed back will give some more bass content to the sound. I'll put tremolo circuit in also.

[Minion]

Are you talking about a Buffer before the Ruby but after the pedal curcuit?? If so then you don"t need a buffer because the Pedal acts as a Buffer to give a low impedance output for the LM386 chip in the ruby...If you are talking about the MP3 input then a Buffer may or not be used as the output impedance of a MP3 player is still pretty low but the problem you might have with an MP3 player is that it outputs a stereo signal and your amp is mono, to solve this you could use a summing stage to sum the left and right into a mono channel ,you can use a single opamp with a couple 100r resistors from the left and right MP3 channels to the input of the opamp ,I would also put the output of the opamp directly into the LM386 bypassing the OD curcuit as you don"t want to distort your MP3 signal.....

Just a few suggestions...

Good luck

[mat]

...If you are talking about the MP3 input then a Buffer may or not be used as the output impedance of a MP3 player is still pretty low but the problem you might have with an MP3 player is that it outputs a stereo signal and your amp is mono, to solve this you could use a summing stage to sum the left and right into a mono channel ,you can use a single opamp with a couple 100r resistors from the left and right MP3 channels to the input of the opamp ,I would also put the output of the opamp directly into the LM386 bypassing the OD curcuit as you don"t want to distort your MP3 signal.....

Yes, I meant buffer for the mp3 player. Could it work if I just connect the mp3 players two channels and put them directly to ruby in parallel with the and reverb circuit ? .. or do I need a buffer between mp3 player and the ruby ? Yes, I dont want the mp3 stuff to go trough the BSIAB2   

[Minion]

I don"t think you will need a Buffer but you should use a summing network to sum the left and right channels into a mono channel...You can simply use Two closeley matched resistors (10r-100r at 1% tolerance) one from each the left and right channel...this will make it so one channel doesn"t over power the other if there is a Slight gain mismatch between Left and right and it also makes it so excess current doesn"t flow from one output to the other output which can cause dammage to one or both channels....

Cheers

[mat]

I don"t think you will need a Buffer but you should use a summing network to sum the left and right channels into a mono channel...You can simply use Two closeley matched resistors (10r-100r at 1% tolerance) one from each the left and right channel...this will make it so one channel doesn"t over power the other if there is a Slight gain mismatch between Left and right and it also makes it so excess current doesn"t flow from one output to the other output which can cause dammage to one or both channels....

Cheers

Minion, big thanks !

This seems to be very simple solution for the amp. I'll report back when I have gotten the proper miniplugjack.

Thanks again,
Matti