Volume Control As Preamp

[Dogruff]

I use mainly digital source from a CD player.

Is there any reason why I should need an expensive pre-amp between the CD player and Power Amp. I have never understood why this is necessary in a simple set up. Why not a decent volume pot wired into the Analogue input.

I understand that some Integrated amps e.g Pioneer a400 effectively used such a simple solution to great effect ?

[Vinyl Grinder]

I use mainly digital source from a CD player.

Is there any reason why I should need an expensive pre-amp between the CD player and Power Amp. I have never understood why this is necessary in a simple set up. Why not a decent volume pot wired into the Analogue input.

I understand that some Integrated amps e.g Pioneer a400 effectively used such a simple solution to great effect ?

You can do that no prob (Passive Pre amp)..Some will argue that sounds better with an active stage..Keep your interconnect short if your doing the passive route & be carefull what Quality & value pot you use even the internal wire, as all have a marked effect on the overall sound.

[Filterlab]

Or.... buy my passive!

Some agree they are wonderful, others don't. Some say they affect drive, others don't. I used to use a passive and the result was bloody marvellous; so free and natural and clean.

However there can occasionally be impedance matching issues, but with modern CD players / DACs having a low impedance output it's normally not a problem.

What player and power amp are you using? You're welcome to borrow mine to try it out if you'd like.

[WikiBoy]

I use mainly digital source from a CD player.

Is there any reason why I should need an expensive pre-amp between the CD player and Power Amp. I have never understood why this is necessary in a simple set up. Why not a decent volume pot wired into the Analogue input.

I understand that some Integrated amps e.g Pioneer a400 effectively used such a simple solution to great effect ?

Once again it is all about LCR and interface.

An active has a fixed LCR (or should have, more or less) and gain, a passive has variable LCR and no gain. A pot or resistor based passive has mostly variable R, a TVC or transformer based passive has mostly variable L.

A cable (interconnect) has LCR and if litz construction or leaky dielectric and close spacing or is twisted then has high C.

A power amplifier if it has been designed for an active pre-amp input has low R but quite high C and low L to comp RF at the input. A power amplifier specifically designed for a passive has high R and low C and the extra gain built in to compensate for that lost in a passive.

So to cut a long story short if you wish to get the full benefits of a passive you must have low C interconnects otherwise turning the VC acts as a simple tone control, and you must have a power amp designed for variable LCR input without going unstable.

If you get this right then a passive will outperform any active made and cost much less in comparison. Reason - getting blockage out of the signal path. ANY active or passive component in the signal path corrupts what comes in IT CANNOT IMPROVE IT by the laws of physics.

Now there are variations in passives sound. Pot passive depend on the sound of the pot. Stepped attenuator passive depend on the resistors in the ladder. A TVC depends on the winding quality and size of the transformer, cheap frame ones ring and cause higher R. Get a good large toroid (expensive) and we might be getting somewhere with these.

[Vinyl Grinder]

Dogruff: Just build yourself a cheap stereo in/stereo out passive with short interconnects & see what you think or your never gonna get anywhere, if your happy you can build one with specialist parts with specialist tecniques ie Lin Pot/LFR..Use say 10K Log pot.

I wouldn't advise Litz interconnects.

[spendorman]

My Hi Fi is now PC based, a 100K Ohm log pot is between the PC sound card (soundblaster) and the power amp. I have not heard such good sounds in my previous systems using preamps.

It works well with all my power amps, including valve Radford STA25, Quad II, Transistor Quad 303, 405-2, Radford SPA50.

It will cost virtually nothing, worth a try.

[WikiBoy]

If anyone is struggling.

LCR = inductance, capacitance, resistance
TVC = transformer volume control
pot = variable resistor track volume control
SA = stepped attenuator, fixed resistor ladder volume control
litz = thin insulated wire woven in a braid when the positive and negative legs are woven together to bring all the wire in close proximity.
RF = radio frequency
frame = a transformer wound on a square plate core
torroid = a transformer wound on a doughnut shaped plate core.

It is then self explanetary. There is no yes and no answer to his question, if he has some ability to ask question about his power amplifier and cable he will find if it will work, if not try it and see, and if it doesn't then the reason why is in my post.

[Rick O]

To be honest, why don't you listen and see which you prefer? Then post your findings on here.

Theory is all well and good, but nothing can beat an actual test.

[Filterlab]

You're welcome to borrow my passive and have a go Dogruff, it's TVC based, might be your cup of tea. What CD and power amp are you using?

[Vinyl Grinder]

My Hi Fi is now PC based, a 100K Ohm log pot is between the PC sound card (soundblaster) and the power amp. I have not heard such good sounds in my previous systems using preamps.

It works well with all my power amps, including valve Radford STA25, Quad II, Transistor Quad 303, 405-2, Radford SPA50.

It will cost virtually nothing, worth a try.

Paul although you choose to completely ignore my e-mails fore some reason, jut because i blocked it for reasons nothing to do with you!!! (Why is beyond me??)i can 100% guarentee you your PC soundcard is of shite quality. Look at another option please!