Interconnect Inductance vs. Capacitance

Vett93 -- It's been too long since I studied Thevenin's Theorem. It looks like I was right, and bandwidth will be greater when the attenuator is set for 12db attenuation, compared to when it is set for 6db attenuation.

The Thevenin equivalent circuit for the preamp output with the attenuator set for 6db, at the mid-point of its resistance range (what I've referred to as "50K/50K"), is a voltage source equal to one-half of the voltage being applied to the attenuator, in series with 25K.

The Thevenin equivalent circuit for the preamp output with the attenuator set for 12 db attenuation (what I've referred to as "75K/25K"), is a voltage source equal to one-quarter of the voltage being applied to the attenuator, in series with 18.75K.

Therefore the higher attenuation setting will result in a lower source impedance, resulting in a smaller RC time constant and a wider bandwidth.

-- Al

Shadorne's example of dynamic and lively sound is a good one. I am not sure what electric characteristics can be used to describe it.

I am not sure either but I suspect it has to do with the current drive capabilities of the output stage of the line level component. I have observed it many times and it is quite audible on long runs of say 30 feet or more. If the current is insufficient to drive the higher capacitance of long interconnects then the slew rate of the signal will be less (at least that would be my guess)

You were right, Al, as Thevenin was on your side. :-)

It is the parallel of the two resistors that determines the output impedance. Good memory!!

Cheers!

Vett93

My higher capacitance Audio Horizons IC's sound better from my Dude pre to Samson amps then the much lower capacitance Blue Jeans IC.

No rolling off of the highs at all with the AH IC's. They are simply more full bodied and refined sounding while retaining all the highs and air in my system.

The Blue Jeans cable only cost $39 and they were still very good indeed. Anyone looking for a great cable for very little money - the Blue Jean is a great choice.

Seems my TRL Dude and Samsons like the AH cables better - at least to my ears. Again, the highs were not rolled off at all.

Bill

"... and I need 10 ft of ICs between preamp and power amp."

So I gotta ask - why do you need 10' between pre-amp and power amp. I think you'd be better off with 2' between your pre-amp and your amp and 10' between your amp and your speakers. Do you have power amps integrated in your speakers?

Agree that if you are stringing your own cable - you gotta think a bit about impedances - resistance, inductance, and capacitance. And the requirements are different on the IC side than the speaker side.

Almarg/Redkiwi - this is a fun thread. I've been reading through Ramos "Fields and Waves in Communication Electronics" - and while it's a great source and touches on basic cable configs (co-ax/parallel) and covers electro-statics, Maxwell equations, impedance calculations, skin effects, and group delays, etc. at low and high frequency - it still doesn't quite make the jump to impacts on sonics. I'm looking for some good references on acoustics (room/speakers/etc.) as well as something that might deal with some more complicated cable geometries like for instance Litz twisted pairs, Litz helicals, or Litz counter helicals. CHELA?. Any info, references. (PS - I only have one BSEE degree - perhaps the emphasis is on the BS end).

Anyone playing with mag wire for ICs or speaker?

BTW - I've got some Neotech 3m NES-3001's and a 1.2m NEDV-1001 on order ( http://www.neotechcable.com/product.htm ). Unheard and unseen - but I'm a little psyc'ed (that in itself will make the cables sound better I'm told!). Will wait to hear before I consider the NEI-1001. System is - Oppo 983H -> CI Audio VDA-2 DAC -> Jeff Rowland Concerto Integrated (Note: No external distance between pre-amp and amp per comment above) -> Dali Euphonia MS-5. I was trying to avoid the cable game and jump from my $0.33/ft Home Depot 12 AWG OFC tri-wire to wire nut to dual 12 AWG to amp speaker cable - all with RS spades(heh - I needed something to hook up to the MS-5s in a pinch) to the end game - something that I'll not be thinking of replacing, if for monetary reasons only. Any thoughts? This is a leap of faith and perhaps a rather expensive gamble.

Gotta share this too - my speakers are tri-wired and the NES-3001 I'm getting is bi-wired (11 AWGx2x2 at speaker end). So I need jumpers for one of the poles. Lots of thoughts on what to do there - I'm leaning toward putting the bi-wire on the Treble/Mid and jumping to the low - better coherency by word of mouth, but nothing to support it given audio frequencies and lumped impedances. You might or might not believe what I'm putting ($) into these DIY jumpers - decided on Furutech FP-218R Spades cold krimped to 18AWG Neotech cryro treaded wire with 10 strands to get 8AWG effective. Why? Because you can for one? And Rhodium sure does look like silver even if it's not. But second, thinking that the NES-3001 is 8 AWG (about 17AWGx8 x2) and if I decide bi-wire is myth - I'm running an 8 AWG cable and just will need two more jumpers for the tri-wire.

Tell me I'm nuts.