Been looking at building a line stage and come across this design here:
https://audioxpress.com/article/High-Quality-Tube-Type-Control-Unit
![Tube%20Type%20Control%20UnitFigure1[1].jpg](https://www.diyaudio.com/community/attachments/tube-20type-20control-20unitfigure1-1-jpg.1048232/ "Tube%20Type%20Control%20UnitFigure1[1].jpg")
Any thoughts on the 5687?
It seems to have a low impedance and this is using it wired in parallel.
Could it be modified easily enough to use an EF86 as a triode? I think EF86 output impedance is around 15K which would be higher than the 5687 in parallel.
I dont have a good supply of 5687, but ive got tons of NOS EF86 and 12AX7 and was wondering if it would be possible to substitute V2A for a 12AX7, since they are similar spec tubes but not 100% identical.
https://audioxpress.com/article/High-Quality-Tube-Type-Control-Unit
Any thoughts on the 5687?
It seems to have a low impedance and this is using it wired in parallel.
Could it be modified easily enough to use an EF86 as a triode? I think EF86 output impedance is around 15K which would be higher than the 5687 in parallel.
I dont have a good supply of 5687, but ive got tons of NOS EF86 and 12AX7 and was wondering if it would be possible to substitute V2A for a 12AX7, since they are similar spec tubes but not 100% identical.
"This control is especially designed for tone control “haters.”"
No, it is not. Rather get rid of the silly gimmick and the weird pot.
If you have tons of useless for line stage duties tubes it is perhaps smarter to sell them and buy something more appropriate.
Similar in what respect? Visually? How many 12AX7 would you need to supply 16mA?
No, it is not. Rather get rid of the silly gimmick and the weird pot.
If you have tons of useless for line stage duties tubes it is perhaps smarter to sell them and buy something more appropriate.
Similar in what respect? Visually? How many 12AX7 would you need to supply 16mA?
I dont see any way to easy modify this circuit to 12AX7 or EF86. Their current capability are no way near 5687. Other specs like output resistance and mu-factor too.
If you need alternatives to 5687 they would be 6N6, ECC99 or 6N30 for eg.
If you need alternatives to 5687 they would be 6N6, ECC99 or 6N30 for eg.
It's just an actively-loaded triode stage, similar to an SRPP. Google "SRPP line stage" and you'll find loads of similar options, using every tube under the sun.
Just to avoid confusuon, I meant soviet 6N6P tube. Still available at deacent price.
Western 6N6 is different thing.
Western 6N6 is different thing.
The article gives justification for avoiding 12AX7. (I don't swallow the logic, but it is clear that this author rejects the 12AX7.)
My CD player has 47r output impedance. How far must I turn this 250k "BAL" pot to have any effect? (Even on the lower impedance of his phono plan, it probably can turn 8% to 92% no difference.)
My CD player has 47r output impedance. How far must I turn this 250k "BAL" pot to have any effect? (Even on the lower impedance of his phono plan, it probably can turn 8% to 92% no difference.)