Gainclone vs Tripath T Amps Vs Nelson Pass F5

[gobble]

Quick question - what is the output impedance of this GC? Google isnt throwing any quick answers ...
And a noob question - Will it depend/vary on the voltage supplied by the Trafo?

Cheers

 

[hemantwaghe]

Sorry - I was down with a viral

Very bad joke...

It is beleive that linux is virus proof ,so it must be damn "powerful" and "potant" and "intelligent" virus!hyeah:hyeah:hyeah:

Sorry for bad and off topic joke! Get well son!!

 

[linuxguru]

Quick question - what is the output impedance of this GC? ...
And a noob question - Will it depend/vary on the voltage supplied by the Trafo?

Hi Gobble - the output impedance is a bit tricky to calculate for this topology, since it's a Howland Current Pump (high impedance) with an outer feedback loop with significant loop gain. As a first approx., it's the output impedance of the Howland divided by the closed loop gain (~1000..10000).

I can get an approximate number from the LTSpice simulation, but I don't have a good simulation model for the LM3886 - I usually substitute an LM1875 model to get a ballpark number for parameters that don't depend on the specific chipamp used, like this case.

 

[gobble]

Hi Gobble - the output impedance is a bit tricky to calculate for this topology, since it's a Howland Current Pump (high impedance) with an outer feedback loop with significant loop gain. As a first approx., it's the output impedance of the Howland divided by the closed loop gain (~1000..10000).

I can get an approximate number from the LTSpice simulation, but I don't have a good simulation model for the LM3886 - I usually substitute an LM1875 model to get a ballpark number for parameters that don't depend on the specific chipamp used, like this case.

Thanks Linuxguru

I want a high output impedance because I use fullranger enclosure that is an overdamped design. Is there way to tweak the output impedance and fine tune it by ear to give me lower damping factor? (where Damping Factor = (Load Impedance) / (Output Impedance)).

I mean to say, run some calculations, stock some parts with the specific ratings, and swap then in and out and listen to them until the right ballpark is arrived at?

Thanks