Bypassing A Preamp With Volume Pot In Amp

@Ptmconsulting, @Atmasphere: RE: DIY passive preamp - That's pretty much what I am aiming for but having it built into the amp with only one pair of single ended inputs. I just can't use another interconnect if its not as good as the pair of Hidiamond D9 interconnects that I already have. It would really hurt my wallet to purchase another pair.

@Georgelofi: Someone recommended to use a 50kohm attenuator. Would that possibly work better than the 10kohm passive that you mentioned in your example?

@Jetrexpro: Can you please tell us about your experience and opinion with having the Goldpoint stepped attenuator in your amp. Did you use a preamp before the Goldpoint? What are the benefits and detriments of the Goldpoint attenuator?

I did it! I just finished installing the Khozmo stepped attenuator. It's easy to hear the difference immediately. The sound stage has tremendously improved in depth, layering, background noise, focus, and dimension. There's no doubt that this is an upgrade. Considering the cost and effort for installation, the stepped attenuator proves to be major bang for the buck. The Khozmo is using Kimber TCSS wire and a Z-Foil TX2575 resistor per L/R channels @ 50Kohm. I also changed the cheap female RCA plugs for Cardas GRFA so I am unable to accurately measure how much each component helped to improve the sound.

I did notice that the attenuator is turned to 12 o'clock with merely average listening level. Does that mean that 10Kohm resistors would allow for more head room with volume?

Yesterday, I replaced the Kimber TCSS wire that connect the female GRFA RCA jacks in the amp to the Khozmo attenuator. The results: major improvement in tonality. The Kimber TCSS wires use teflon insulation that obviously colors the signal. This is my second test with teflon insulated wires. Both tests resulted in unfavorable opinions of teflon insulated wires within the signal and incoming A/C power. If I ever need another leap in tonal transparency, I'll switch the remaining Kimber teflon wires that connect the Khozmo to the amp. For now, I am content with the current tonality.

Revisit to my previous post: Currently, there are no issues regarding absorbed heat into the attenuator.

I forgot to mention the wire I used to replace the Kimber TCSS is the Neotech solid core, UP-OCC, 20 AWG wire with PVC jacket.

The silk tubing was purchased from Parts Connexion. Their parts numbers are: SLKTUBE-72530 (small gauge) and SLKTUBE-72531 (slightly larger guage)

You can also purchase bare copper and/or silver wire to use with the silk tubing. Let us know what you have concluded if you decide to experiment.

I would like to add that this upgrade also removed an "electronic glare" that was plaguing my system. This upgrade made a huge difference as much as my Hidiamond D9 ICs and bypassing the amp's PS electrolytics with .22uf V-Cap CuTF caps.

One point of concern: The attenuator is placed on the side panel, towards the rear of the amp, about 3 inches from the heat sinks. I noticed that the volume pot and knob does adsorb heat. I highly doubt that the sound quality will be affected do to the low temperature coefficient of the resistors (TX2575 TC is at 1ppm). I'm concerned for the attenuator's ability to stand the test of time with continuous heating and cooling.

I recently posted regarding sonic dielectric differences including Teflon Neotech copper wire which I believe, also, colors the music. See post from 03-30-14.

http://forum.audiogon.com/cgi-bin/fr.pl?fcabl&1388352260&openfrom&1&4#1

You are correct about there being "more involved than just the dielectric". The TCSS wire is stranded and the Neotech is solid core. However, the 2 experiences I've had with teflon wire resulted in very similar or identical coloration.

I'm interested in the silver wire now. I might buy a couple of feet and replaced the remaining TCSS wire.

Ouch!

Please explain your post, Tbg. Are you in favor of active pre amps? Are you in favor of teflon dialectric?

@Salectric - Thanks for letting us know about your upcoming trials. Let us know what you hear or not hear.

Tbg - I don't think you read the whole thread. Please read my post and Georgelofi's post from 06-03-14.

My idea with having a passive stepped attenuator in the amp is to eliminate the costs of the pre amp and interconnects while shortening the signal path and ultimately improving sound quality.

Guess what? I tested the idea and it works...for me

If Conrad Johnson makes a boom box, I would love to hear it.