Err not really. The resistors is so that the Tube amp see the load (the he-6) as close to 8 ohm as possible. Transformer tube amp behave badly if the load isn't as tapped (8ohm/4ohm) - also long time usage without the resistor may damage the tranny. This is less important with SS amp. In fact I haven't found any SS amp that changes sound sig with a resistor attached.
The attenuator is used between the source and the preamp/integrated amp input. Basically it is to reduce the output of your source. Speaker amp has varied input sensitivity (mostly around 1.5V), and when fed with "too hot" source (think 3V RCA output), coupled with too high gain leading to virtually no volume control, or worse - distortion. Not all source has variable output, even when the source has variable output, the Alps pot/whatever volume control mechanic may affect the sound (reduced signal strength, distortion, noise, channel imbalance, impedance mismatch). The line attenuator is used to reduced the source output so that doesn't happen.
The other use for attenuator is that many preamps are more accurate/transparent at higher volume/higher position on the volume pot. The attenuator then is used to achieve that position.
Edited by khaine1711 - 5/7/13 at 1:40pm