An illustrated guide to building an F5

[Kofi Annan]

Originally Posted by evanc

Kofi,
Post 53 by Jumna in the thread preamp ideas for f5 is tiny simple and sounds good to my ears. I have a preamp that uses his circuit for a couple of inputs and uses a DCB1 for the others so I have choices.....
Evan

Juma not jumna

Thanks! This looks perfect.

Originally Posted by jacco vermeulen

Common, Kofi has people to look for him, he never learned how to do that himself.

Have you seen my keys?

Kofi

P.S. Seriously, I can't find my keys. Please help.

[AudioSan]

Originally Posted by Kofi Annan

Thanks! This looks perfect.



Have you seen my keys?

Kofi

P.S. Seriously, I can't find my keys. Please help.

on the other hand. i just tonight maxed out my aleph P1.7 with 10db gain on my F5 and was stil missing alot. damn those low level downloads

have to ad one thing. it was not close to cliping. even with a good level recording.

you will hear that a good CD player or DAC can put out 2V. yes it CAN. but the recording WILL hold back.
in the real world, you will see about 0.32V avrage.. or 0.5V if you are lucky. nothing near 2V rms.

[AudioSan]

another solution is a F5 mini. running on +/-15V and 0.8A bias. with a J-fet boz preamp.
that will give you alot of good sound for a smal amount of power.

[6L6]

Change R5 R6 R7 R8 to 150 or 220 ohm. You will get more gain, at the expense of a bit of feedback. I built one F5 stock, one with 150ohm resistors, and they sound identical, but the one with 150R is noticeably more sensitive. People who have build them with 220R report wonderful sound and the ability to clip it with a CD player.

[AudioSan]

yes that is a solution raise the gain to about 22-23db

[Indiansprings]

Outstanding "How To"
Makes me want to build an amp. Im not at that level though.
Good Job.

[bobodioulasso]

Go on! F5 is a piece of cake.

[KWS1]

I built a new board as the other was mangeled from being pulled in and out oft he enclosure. All the voltages seem to check out, however I am still unable to draw current through R11 &12. I am not sure what to do from here.....

[Itsmee]

What is the gate - source voltage of Q3 & Q4?

[KWS1]

24.75 volts...