the reason why i used the 0.6W metal resistors is that they are almost standard now. The suppliers where i order my
components (RS UK and Reichelt DE) carry them as standard for all available values. The costs are almost the same
compared to the 1/4W range. You surely can use 1/4W or 1/2W resistors except Rx = R6 and Rz = R4. Here i would not
go below 0.6W. 1W would be surely better for R4. This is highly recommended as even low ammounts of high frequency
signals can produce a high energy.
Carbon composition resistors (sorry that was a typo - it should read carbon composite) are the ones you surely know as
the "Allen Bradley" resistors which are also made by "Arcol" now (best make at the moment). The only resistors in the signal
path which could create some sorts of sounding are R6 and R7 where i'l assume that R6 is more important. It leads a part of
the output signal back to the neagtive input. This path is really "sounding". All others rather not.
The resistor from your picture (carbon composites - Allen Bradley?!?) surely can be used all over. Use what ever you want
except the cheapo 1/4W carbon composite resistors. A good carbon composite (A-B or Arcol) only makes sense for R6.
Think that they are not cheap.. Keep them for some other projects where you have to put them directly in the signal path.
Metal oxide or metal film perform well in all other sections.
The main part which forms a big portion of the "sounding" is the 2SK170 and how it's biased and set up.