Manley Chinook Owners Tube Rolling

Tubes of the same type made by different manufacturers do sound different to me. But in my experience differences don’t hold up over time. Then too, same tubes from same maker can sound different from one another; there’s a sample to sample difference. There is no substitute for understanding how the circuit works in the first place. But I admit there are some tubes and makers  I really dislike. In my Steelhead I use Siemens CCa for that one gain section. 

The is a certain amount of variability in tubes made by any manufacturer.
Buying untested NOS tubes is a crap shoot. The most important and noticeable characteristic is noise. The best tubes have to be selected out by testing each individual tube. The only company I know of that does this is RAM Labs here   http://www.tubeaudiostore.com/emission-labs.html
I use the Super Low Noise 6922's in my ARC phono amp and they are way quieter than the stock tubes and I mean Way Quieter. They are also super expensive @ $90. But you can choose Low Noise or Standard tubes. In a phono amp I think SLN tubes are a must. This is a difference you absolutely will hear. They have to test 100 tubes to get one SLN tube.

Mike

@fruitloopsr Yes, I use them. I only recommend stuff I've heard and/or used.  Rhodium on phono preamp and gold on subs. OFC copper and well made. A big improvement over stock. I keep meaning to add them to my monoblocks but they are hard wired. A rainy day project.

Hey Guys, Which 1 tube is in the signal path so i know for future reference and that would be the only one to try?
Thanks, Mike

Apparently the Chinook uses two 6922s per channel. If that’s not correct, stop reading this, because I don’t want to mislead you. If it is correct then you would mess around with the tubes closest to the centerline of the chassis. That’s if it’s constructed like my Steelheadwhich seems a reasonable bet. OR ask Manley which of the two tubes in each channel is part of the gain circuit. They’re cool.

As to SLN tubes, who could argue against the idea? Problem is that the SLN characteristic is transitory. And there’s no telling how long it will be before any given tube will go noisy. Also, in the particular case of the Chinook the single gain tube is part of a hybrid cascode where the bottom element is a FET. In such a topology the noise characteristic of the tube section is less crucial to output noise,partly because the tube per se does less work on gain. Not that it still isn’t a good idea to use a low noise tube.