H! I have a Bravo Audio hybrid tube amp with transistor output.. I would like to get some more output from it into some 4ohm high sensitivity speakers.
Atm it has almost enough output level to drive the speakers at at nearfield listening levels. So I was wondering if I could use an audio transformer to boost output a little? And perhaps skip the DC blocking cap at the output?
Thanks for any replies!
Schematic: (It uses 24V,not 12V.) http://i30.photobucket.com/albums/c306/oohms/bravo12au7/shem.png
Also found on Ebay, EI-14 Audio Output Transformer 1K:8 to 32 ohm.
Atm it has almost enough output level to drive the speakers at at nearfield listening levels. So I was wondering if I could use an audio transformer to boost output a little? And perhaps skip the DC blocking cap at the output?
Thanks for any replies!
Schematic: (It uses 24V,not 12V.) http://i30.photobucket.com/albums/c306/oohms/bravo12au7/shem.png
Also found on Ebay, EI-14 Audio Output Transformer 1K:8 to 32 ohm.
Based on R8 (and R10) values of 47R, you would get maximum power with a 47 ohm to 4 ohm transformer.
If the drive circuitry (Q1/IC1) was able to drive the 47R by itself (voltage swing not limited by load) and assigning a 100% efficiency to the 47R:4R transformer, then you would get 5.4dB increase in power to a 4R speaker using the transformer compared to driving it direct.
The transformer would need to have a 11.75 impedance ratio and the one you selected is greater than 30 (1000/32)
It would also need to be rated for about .3W
good luck
If the drive circuitry (Q1/IC1) was able to drive the 47R by itself (voltage swing not limited by load) and assigning a 100% efficiency to the 47R:4R transformer, then you would get 5.4dB increase in power to a 4R speaker using the transformer compared to driving it direct.
The transformer would need to have a 11.75 impedance ratio and the one you selected is greater than 30 (1000/32)
It would also need to be rated for about .3W
good luck
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