Question About Capacitor Upgrade in Tube Amp

Each type of capacitor has a specific frequency response and voltage related distortion.

It should stand to reason that better constructed capacitors should have a better frequency response and less distortion. Whether you can hear the difference in reality or it is simply a fresh capacitor not being run in yet that sounds different I do not know for sure. But it seems in my case there was an improvement in frequency response and lower distortion replacing the cheap factory caps with one of better and different material construction.

In this article the title seems to take the opposite opinion but have a read thru and there is some information that at least confirms capacitor construction does impact sound quality.

Resistors make a difference too. I tested half a dozen candidates with a rotary switch in my preamp. Nude Vishay resistors were the best, no-name metal films from Taiwan second, aerospace hyper-expensive last.

The Vishay Z-foils are very transparent and low-noise. These resistors can be ordered in arbitrary custom values from Texas Components. The latest version is the TX2575. These are only available in sizes from 10 ohm to 100Kohm. The older TX2352 is available from  1 ohm to 250K ohms. 

For higher power requirements or resistors outside these ranges, I like the Audio Note non-magnetic tantalums and silver-tantalums, but these can get pretty pricey.

Interesting.

NOS Allen Bradley Carbon comp resistors are all the rage for tube guitar amps. For their warmth and organic tone. I wonder how they fair in hifi? They do tend to drift in value a fair bit. So maybe not so good in hifi setting.

The nude Vishays are nice, use them in my 300B amps.