Hi Guru's
I have recently finnished building a headphone amplifier very similar to the Nutshell Raven but the PSU is diode bridge rectified with transistor regulation.
I am running the amp fully balanced with my K701 (62ohm input) that I have modified with a new cable and a 4 way XLR for balanced connection. this way the audio will be fully balanced from the DAC IC to the headphone voice coil.
just to get the amp up and running I used some inexpensive,small UTC transformers I had knocking around, now having proved it works I am looking to invest in the permenant OP transformers but need to ensure I get it right before I spend what to me is a fairly large amount of cash.
My question concerns the Output Transformer, should I stick with the Lundahl ll1680 that is in the schematics or should I change it? if the consus is that I should use diiferent OP iron has anyone got any recommendations?
Am I right in saying that for the transformer calculations the input impedance of the headphones should be quartered because I am running them balanced? (15.5ohm) and the output impedance of the ECC99 should also be quartered?(575ohm)
Links to respective components:
http://www.jj-electronic.com/pdf/ECC99.pdf
http://www.nutshellhifi.com/Raven-MarkII.gif
http://www.lundahl.se/pdf/1680.pdf
Any advice I can get would be very well received.
I'll post some pictures if I get any interest :)
I have recently finnished building a headphone amplifier very similar to the Nutshell Raven but the PSU is diode bridge rectified with transistor regulation.
I am running the amp fully balanced with my K701 (62ohm input) that I have modified with a new cable and a 4 way XLR for balanced connection. this way the audio will be fully balanced from the DAC IC to the headphone voice coil.
just to get the amp up and running I used some inexpensive,small UTC transformers I had knocking around, now having proved it works I am looking to invest in the permenant OP transformers but need to ensure I get it right before I spend what to me is a fairly large amount of cash.
My question concerns the Output Transformer, should I stick with the Lundahl ll1680 that is in the schematics or should I change it? if the consus is that I should use diiferent OP iron has anyone got any recommendations?
Am I right in saying that for the transformer calculations the input impedance of the headphones should be quartered because I am running them balanced? (15.5ohm) and the output impedance of the ECC99 should also be quartered?(575ohm)
Links to respective components:
http://www.jj-electronic.com/pdf/ECC99.pdf
http://www.nutshellhifi.com/Raven-MarkII.gif
http://www.lundahl.se/pdf/1680.pdf
Any advice I can get would be very well received.
I'll post some pictures if I get any interest :)