Building an F5 Turbo v2 (in-Progress)

Yes sure... but when I listen to music I almost never tie hot to gnd...

The reason why I'm asking is when I connect the B1 the DC offset goes up from 5 to 60mV. Should I calibrate then to zero again with the B1 connected or is it totally stupid?



meaning - you need to gnd input of F5 (tie hot to gnd) , before commencing biasing procedure ;

that way you can connect candelabra or boeing or caterpillar to input , it doesn't matter

:clown:
 
AMAZING

After first time finished bias procedure I was able to do first listening tests with my F5T V.2

Here some technical facts:

Bias - 390mV over a pair of 0.68R source resistors -> peak 169W Class A at 8 Ohm (correct Audiosan?)
DC offset - ~2-3mV (without B1 connected)
Heatsink temp - ~51 degree celsius max.

I know I'm still not really ready with the bias and offset adjustment. I'm also waiting for some final chassis bodywork. As soon as I'm ready
with it pictures will follow. And that thing is dead quiet! I could rest my ear on the speaker and I recognized not a single small hum or buzz or..... nothing, fantastic.

Regarding the sound quality, it's amazing. Much more punsh control, more details, better three-dimensionality wow..... I was blown away.

Cheers,
Mallard
 
The B1 has an output DC blocking capacitor.
If that capacitor is not leaking then the F5 input will not see any offset from the B1 Source.

Check your B1 output capacitor. It better not be a paper in oil nor an electrolytic.

As I have said in very many Threads, a DC coupled amplifier needs protection for the expensive speaker.
Omit protection at your peril.
 
F5 source resistor choice

Hi! Please i'm choosing the source resistances for my future F5 V2 turbo version , and my choice fell on the Mills Resistor 5W (0.91R), in parallel would 0.455 Ohm, might it be a good choice, without having any problem of bias or stability?
I must also say that I could choose for a value that is slightly above ...1.2 ohm in parallel, so 0,6 ohm vs 0,455 ohm !
Any advice is well appreciated!
Thanks in advance

Regards!

Antonio
 
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