what resistors are in the aikido signal path

[jarthel]

see title.

thanks for the help.

ps. looking at the schematic (http://www.tubecad.com/2006/04/27/aikido_high_impedance_headphone_amplifier.png) and my limited knowledge,

I am thinking: R1, R3, R4, R8, R9 and R14.

 

[mourip]

I would say R3, R9, and R8.

 

[Nixie]

I'd say, simulate it. There are plenty of free spice models for tubes.

 

[SY]

"Signal path" is a marketing term, not a technical one. Define what you mean precisely by that and the answer will be evident.

 

[Nixie]

I think he means that signal current is going through them. That's what I take it to mean at least, that the simulation shows current waveform correlated with the signal through the resistors.

 

[SY]

Well, then that's every resistor in the circuit.

 

[Nixie]

Really? Interesting, I've never simulated a circuit that had signal current in all its resistors (at least that wasn't many orders of magnitude lower).

If you read Borbely's articles, he points out which resistors to spend money on as are in the signal path; for examle, http://www.borbelyaudio.com/pics/405borbely2506.pdf in the parts list notice some say RN60 as the type.

 

[SY]

Well, then, you haven't defined things. Give a threshold at which you say "yes, signal current" or "no signal current." And think of the tiny signal currents involved in RC coupling...

See what I mean about this being a marketing term?

 

[Nixie]

Something bugs me about that circuit. As someone told me in the IRC channel, C4 carries a lot of signal current. So how is that any better than using an output cap then? Seems to me it would be better to have no cap and a very low output impedance regulator instead.

I remember Borskie from Tubecad Journal once tested a regulator and though it sounded better without a cap after it. Hmm.

 

[jarthel]

accordign to Mr. Broskie, r2, r3, r4, r8, r9 and r11 are the most important resistors in the circuit

 

[Nixie]

What about those capacitors on B+? Simulate it and check the current through them. That electrolytic is probably not out of the signal path.