Top resistors

I'm in the process of building a phono stage with TX2352 in the signal path. It'll be hard for me to say "ah ha" since I haven't heard it any other way, but everything I've read says bulk foils and nude Vishays are quieter. In my opinion, it makes sense to use them when dealing with small voltages like in a phono stage or preamp. I'm sure you've seen Michael Elliott's comments on the subject:

About Vishay resistors

When I asked for help to tweak my amps, most of the tube DIYers at Audio Asylum said Vishay's in the signal path would be overkill and/or sound sterile. They recommended carbon comps in that situation. FWIW, I don't know if these same folks would ever use bulk foils. They may approach things from a more budget-conscious perspective. It would be useful for me to try it both ways to find out for myself.

Rodman, thanks for the link to Aiken Amps. That was an excellent tech note! There's a slew of other fine reading where that came from:

http://www.aikenamps.com/TI_Aiken_adv.htm

I'm placing an order for some TX2575 today.

I'm a newbee when it comes to circuit tweaking, but I recognize the importance of low noise resistors in critical positions like input stages. As I said above, the folks at Audio Asylum steered me toward carbon comps. I took their advice and used them in a position that connects the coupling caps of my amp's input stage to the power stage. This is obviously in the signal path. For those that like details, here's the circuit diagram and resistors in question: R18, R19, R20, R21.

After reading the article: Resistor Types - Does It Matter?, and hearing what others have said, I realize these are the worst possible resistors I could be using... especially with a 1/2 watt power rating.

The article states:

Contact noise is dependent on both average DC current and resistor material/size. The most significant contributor to noise in guitar amplifiers is the use of low-wattage carbon composition resistors. Since the noise is proportional to resistor size, the use of 2W carbon comp resistors will improve the performance over that of 1/2W resistors. Studies have shown a factor of 3 difference between a 1/2W and a 2W carbon comp resistor operating at the same conditions.

Another interesting quote:

Wirewound resistors are the quietest, having only thermal noise, followed by metal film, metal oxide, carbon film, and lastly, carbon composition.

So I want to replace the carbon comps. My question is whether TX2575 or TX2352 are overkill for this situation. They aren't cheap at $10 and $7 a piece. I need a total of eight. Would Mills MRA-5 wirewound be a decent option? They're less than half the cost.

Many thanks Kirkus. I appreciate you taking the time to look at the schematic and offer such a thoughtful reply.

I have PRP's in the positions you mention. In your opinion, would it be worth swapping in low noise resistors or will the benefit be marginal? It's probably hard to know the results for sure, but thought I'd ask anyway. I'm willing to upgrade if it offers an improvement, but don't want to throw money at the situation when it doesn't do anything.

I don't think Michael Percy sells TX resistors. I asked recently and he said no.
You can buy direct from the manufacturer:

http://www.texascomponents.com
resistorinfo@texascomponents.com
713-468-3882

It's a small company with helpful and friendly staff that actually answer the phone. It's a pleasure doing business with them.