Inductive resistors for source resistors

[bbakota2000]

What is wrong with inductive resistors as source resistors in Alephs?
I searched the forum but nobody explained it, everybody are just prefering non-inductive resistors. Why is that?

 

[jh6you]

Personally, I prefer the wire-wound resistors here and there.
People say that they are concerned about the inductance.
But, the amount of the energy being stored in the magnetic field in the region surrounding the current-carrying wire-wound is considered too small and ignorable to interrupt audio frequencies, IMHO

 

[bbakota2000]

Do you prefer wirewound because of their better sound or because of their reliability?

 

[jh6you]

Because of both.

 

[grataku]

It's good to have inductive resistors in the CCS side because they increase the CCS impedance, minimally at audio freq. Anyway, at the very least any amount of inductance there is a plus.

 

[Nelson Pass]

I've never had so much inductance on the resistors that it
showed up as an issue.

 

[mikelm]

Can I suggest that you try constantan wire - I have used this as emitter resistors on my JLH type amp and also in my crossovers. It sounds very good to me - much better than the caddocks thick film that I had been using and is very cheap.

I was using wire of about 4.2 ohms per meter

available from here

http://www.wires.co.uk/

mike

 

[eLarson]

Did you wind it around some kind of former? Or did you just use a straight length of the wire?

 

[mikelm]

For the values that I needed on the amp the wires were about 25mm so I just used the wire straight

in the crossover I used some blank veroboard 30mm square, inserted some PCB pins either end and zig zagged the wire back and forth

|\|

like that only stretched higher...

 

[peranders]

I've never had so much inductance on the resistors that it
showed up as an issue.

I'll guess this is an issue the faster you want the output stage to be and/or the more feedback you apply.

 

[jh6you]

Originally posted by peranders ... the faster you want the output stage ...

Gee…… here, the phase angle between the sinusoidal emf and current is so big to metion the faster or the slower??????

You post resemble a god-damn spam mail.

Poor moderators are sleeping??????

 

[joensd]

Slightly off-topic but with wirewound (or inductive) resistors in series with the output you might get unwanted oscillations.
The original crescendo was quite "famous" for it and people changed the wirewound for 5 metall-oxides in parallel.

 

[jh6you]

Hi

I don't understand very well.

Once I saw a picture of Goldmund power amplifier. It had a pair of small coil (inductunce) // resistor, which was connected in series with the speaker terminal. I think that the L//R was to decouple any capacitive load, so to prevent oscillations at high frequencies.

I would like to see the wirewound resistor as a pair of L//R (L value is very low enough to be ignored, tho). Then, how could I explain that the wirewound resistor connected in series with the speaker terminal might be the origin of the oscillations?

Regards