Discrete DI-Box

[Guest]

[quote author="Wavebourn"]Fender-style amp distortions can't be viewed without fender-style wooden axes with steel wires on them in the magnetic field. Leo clearly knew what he was doing, he took resonating deck out of a gutar and made it remote, i.e. speaker cabs and amps were parts of guitars that did not have resonating decks, they were dumb and could not sound good without proper resonating deck that was called from now "Speaker Cab".
.[/quote]
Sorry coming back to that - but surely Leo built the amps before he built his guitars!
Weren't they all for Lap Steels first

(sorry for sideline)

 

[Samuel Groner]

Stuffed the second board I have. Works like a charm as well with the additional 120 ohm resistor (output stage bias is within 5% that of the first board).

Samuel

 

[Samuel Groner]

I edited the first post to include a few THD+N measurements I've made.

Above 80 Hz and below +20 dBu the THD+N plots show the noise floor rather than actual distortion. At +20 dBu the residual shows some frequency-independent asymmetric distortion, probably associated with the input stage. At levels where this design will usually be used distortion of the active electronics is essentially unmeasurable without resorting to more elaborate measurement methods.

Output noise has been measured as -116 dBu for a shorted input, though this perhaps represent the measurement floor of the equpiment used and not actual noise.

Samuel