Salas SSHV2 + Moglia hybrid mu-follower

[painted]

Type 27?

[merlin el mago]

Originally Posted by mogliaa

Hi Felipe
the gyrator doesn't change with "warm-up" time. It's pretty stable from a tempco point of view. I have not noticed any changes over time am afraid.
Perhaps is something else in your system. I'd also suggest trying without the cathode bypass capacitor, it will sound better in my view....
Cheers
Ale

Originally Posted by merlin el mago

Ale the Russian teflon caps were new when the lack of bass, now both hybrid mu-followers are sounding with high SQ. The cathode bypass capacitor adds bass so more clear without cap (I tried) thanks.

Sorry Ale, I had to say teflon capacitor "break in" not warm-up.

[mogliaa]

No worries Felipe. I think you may want to be a bit more careful and perform more research and tests before drawing to a conclusion that the 2 components “sound bad”. It gives the wrong impression which frankly isn’t useful when the issues could be anywhere in your system.

If you want lower gain, the 71a is a great valve to look for.
Cheers
Ale

[merlin el mago]

I know very well the 2 components, I was really surprised that using the 2 components togheter sounded bad because the 2 components are top notch SQ, so I was asking help to know what's happening. Thanks for 71a suggestion.

[euro21]

You have a fundamental fallacy.

Two individually good module (NOT component!) cooperation depends on good planning and implementation.

It's not "plug and play", it's requiring proper planning.
Each module output has an impact to other input, thus can change its operation, and vice versa, the parameters changing reacts module components.

If you look a gyrator as "module" and tube as "module", not cooperating component conglomerations, the final operation may be uncertain.

[merlin el mago]

Ale followed your advice: no bypass cathode capacitor and no SSHV2. I'm making a new one SSHV2 because I suspect is damaged.

[merlin el mago]

Well all is going OK with a new power transformer with more voltage.