Got metal film resistors from two different shops, yet they looks very different. Both 1W, metal film, 68k. 1 - Big blue one, looks a lot like the other metal film resistors I see in amp kits on the internet. Bought from Modulus Amplification, dedicated to valve amp building. Link here. 2 - Tiny grey one, looks more like those small pedal resistors, but grey instead of blue. Bought from Farnell, brand is Welwyn, but I've seen Vishay's that look exactly the same. Link here. Most important question really is: can I use the small ones on valve amps as well?