Edit: My thread title was supposed to be a question not a statement, but I can't edit it accordingly.
Hi All,
Firstly, let me apologise if what I am about to say is completely incorrect. I am very new to this and know nothing
Always keen to be set straight.
I have been informed that modern IRF9610s are not as linear as the older versions due to differing manufacturing techniques. Whether this is significant or not, I have also been thinking that perhaps the 9610 is over rated as an input fet for the Aleph amplifiers, and that a smaller signal fet may be more linear in this application.
It seems to me that using any fet that is significantly overrated for a task means also dealing with more gate capacitance which is a bad thing. NP pushes the running of fets at high currents ideology, and it seems that the 9610s are also not being pushed in this application. That said, I know NP has his reasons for everything, and I am sure there is a good reason why he chose the 9610 that I am not aware of.
Anyway, I have been looking for a direct drop in improvement that will not require any resistor/bias changes. This rules out any JFETs.
I have stumbled across the ZVP3310, which is cheap, readily available and has less than half the input capacitance of the 9610 (50 pf vs 170pf). It can easily be dropped into existing boards by simply twisting the pins around and should require no resistor changes. NP also used it in ZV4, so I guess it can't be too bad. Edit 2: I also see in the ZV4 article that NP actually tried several fets and found the 3310 to be superior to the 9610 in that application, which is promising
Any thoughts on the suitability of the ZVP3310 to this task, and how it would perform both objectively and subjectively?
Your advice is appreciated!
Greg.
Hi All,
Firstly, let me apologise if what I am about to say is completely incorrect. I am very new to this and know nothing
I have been informed that modern IRF9610s are not as linear as the older versions due to differing manufacturing techniques. Whether this is significant or not, I have also been thinking that perhaps the 9610 is over rated as an input fet for the Aleph amplifiers, and that a smaller signal fet may be more linear in this application.
It seems to me that using any fet that is significantly overrated for a task means also dealing with more gate capacitance which is a bad thing. NP pushes the running of fets at high currents ideology, and it seems that the 9610s are also not being pushed in this application. That said, I know NP has his reasons for everything, and I am sure there is a good reason why he chose the 9610 that I am not aware of.
Anyway, I have been looking for a direct drop in improvement that will not require any resistor/bias changes. This rules out any JFETs.
I have stumbled across the ZVP3310, which is cheap, readily available and has less than half the input capacitance of the 9610 (50 pf vs 170pf). It can easily be dropped into existing boards by simply twisting the pins around and should require no resistor changes. NP also used it in ZV4, so I guess it can't be too bad. Edit 2: I also see in the ZV4 article that NP actually tried several fets and found the 3310 to be superior to the 9610 in that application, which is promising
Any thoughts on the suitability of the ZVP3310 to this task, and how it would perform both objectively and subjectively?
Your advice is appreciated!
Greg.
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