The best preamplifier

[quanghao]

Hi quanghao,

i have some questions. At the output is used a 4,7uf Capacitor. Why are you using this large value?
The capacitorat the grids are 1k. I think its the protection for oscillation. So this value is not critical. I want to use 150 Ohm, cause i have this in stock.

with best regards

Well ! thank you!

parallel installation of multiple tube, with my experience 4.7uF or greater value to 6uF, will sound impressive bass solution, more capacitors 0.01uF create the subtle sound high!

You can use the R value from 100 to 2K, no matter what!
Wish you success!

 

[frankwilker]

Hi,
thank you. I will tell you about the sound.
with best regards

 

[lorienblack]

What is the approximate cost to populate this board? I'm looking to build a good valve pre. Was considering the Bottlehead foreplay, but it is quite expensive to get shipped to UK.

Many thanks - LB