Preamp difference : if it's not the frequency, not the slew rate, and not the harmonics, what is it ?

[RoadrunnerOZ]

I built a V76 with transformers from Ollie and NOS EF 804's, exact same circuit,

A friend bright over a real one and boy was I disappointed , they did not sound the same at all. His was better. What was the difference? I have no idea.

You could try swapping his tubes for yours see if that changes anything

 

[gyraf]

Those "replica" transformers were most hot air, perhaps?

 

[RoadrunnerOZ]

Sounds like it would be the transformers……

 

[PermO]

If the chemical composition of the circuit is not exactly the same, it will not sound the same.
It could measure the same though.

But still not sound the same.

 

[rock soderstrom]

I built a V76 with transformers from Ollie and NOS EF 804's, exact same circuit,

A friend bright over a real one and boy was I disappointed , they did not sound the same at all. His was better. What was the difference? I have no idea.

I think the inductors make the difference.

When I was young and did my basic EE training, we had two old men in our company (more than 3000 employees) who were experts in this field and they did nothing but wind mains & signal transformers and chokes. They had a hell of respect for the "Wickelgüter" in the V76 and related units even though they had the best machines and materials for the job.

Other experts, such as Gerhard Haas, also considered these inductors to be not fully reproducible at a justifiable economic cost.

It's not that simple, even if some would like it to be...

 

[DaveP]

I once followed a tip about the loading of an SM57 for drums. Instead of the normal 10x bridge impedance it suggested a 600 ohm load and boy did that make a difference. Maybe the impedance matching element is the main variable?
best
DaveP

 

[ruffrecords]

I once followed a tip about the loading of an SM57 for drums. Instead of the normal 10x bridge impedance it suggested a 600 ohm load and boy did that make a difference. Maybe the impedance matching element is the main variable?
best
DaveP

In what way was it different?

Cheers

Ian

 

[DaveP]

In what way was it different?

I would have to use the word "fatter" and it made the drums sound more like you might want them to sound, sorry its not much help!
The mic had to work much harder into 600ohms, so maybe that cut some frequencies?
best
DaveP