Different tubes in the real world!!

[Sinaisid]

Ok, I've been running my Yaqin MC-10L with Winged C EL34 tubes, but today one channel started buzzing alarmingly!!! so back to the original Shuguang tubes while replacements are ordered. Interestingly, after an hour or so of listening I thought these are not so bad!!!! I'd already recorded the in room frequency response with the Russian tubes so did the same with the Chinese. Ok, so it's an in room measurement (from my listening position), but effects will be the same on both measurements. Take a look, not a lot of difference - The Chinese tubes are the green plot!! (Pink Noise measurements taken with a calibrated Behringer microphone). If anything the Chinese tubes sound like they have a smoother mid range and slightly better bass.

So the question - Have I been favouring the more expensive winged C tubes just because I belived the higher cost must sound better????

 

[JonL]

I don't have any experience with room response measurements but I have to wonder how much variability you'd find from time to time even with NO changes in tubes or anything else. Seems to me that many things could affect the response curve to the magnitude you've shown... things like tiny differences in where you place the mic, the temperature and humidity in the room, the position of drapes on the windows, even the clothes you are wearing and where you are in the room when you make the measurements.

I'm not sure the audible differences when tube rolling can be fully quantified by a single frequency response comparison.

 

[Sinaisid]

I do agree - I think the differences in the tubes I've compared are lost in the real world of furniture and curtains and carpets - I guess I've come to the conclusion I can make more difference to the sound by moving a foot or so along the sofa and closing the curtains than investing a whole lot of money in new tubes!!!!

 

[luvvinvinyl]

At the very least, your hypothesis holds true for these two tubes. It might be interesting to try to discover if a different pair of tubes exhibit greater or lesser differences, under similar measuring techniques.

 

[Ty_Bower]

Have I been favouring the more expensive... tubes just because I believed the higher cost must sound better?

It happens more often than you can imagine, and is regrettably a common trap that is difficult to avoid. Also remember that we have not yet uncovered all the measurements necessary to fully quantify what we experience during actual listening. What we hear may be more or less than what we can measure.