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    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

6V6 line preamp

Official Court Jester
Joined 2003
Paid Member
right sim settings , even if I need confirmation that exact xformer data , regarding winding resistances , are put in file
 

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Official Court Jester
Joined 2003
Paid Member
none - if secondary can handle current

this way , wire is calculated for I/2

when having no CT , wire is calculated for I

anyway , having that winders aren't too kin to use hair thin wire , if space permit , we can hope that wire is thick enough for no use of CT situation

what's goal for final voltage ( slipped that info and lazy to search back ) ?

there is maybe a space for my fave - choke input
 
Xformer - Allied Electronics TRANSFORMER, PRI:110-120V, 50/60HZ, 500VCT @40DCMA, 6.3V @ 2.0A, LEADS

close call - its worth a try, it might be low speced but the double would be preferable. Id try it against a power resistor first in ZMs to be calculated choke loaded setup. Start with 10k (33 mA) and try to move down in steps to 6,8k. 7,2k or so is calculated load at 330 v. Listen to the tranny, if it start sounding or getting hot, shut down. Measure voltages on the different loads.
 
Xformer - Allied Electronics TRANSFORMER, PRI:110-120V, 50/60HZ, 500VCT @40DCMA, 6.3V @ 2.0A, LEADS

close call - its worth a try, it might be low speced but the double would be preferable. Id try it against a power resistor first in ZMs to be calculated choke loaded setup. Start with 10k (33 mA) and try to move down in steps to 6,8k. 7,2k or so is calculated load at 330 v. Listen to the tranny, if it start sounding or getting hot, shut down. Measure voltages on the different loads.

Yes, I have found that the Allied xformers (made by Hammond) are typically "over-rated"...
 
Ripple? Yes but lower you said? Probably because of a not so filtering C-R-C filter. Your trafo leaves, rectified in full wave with CT leaves just a few voltages over B+ wich means you hardly have room for any R in the chain. C-L-C is your chance configured that way and no room for regulator overhead, and then its speced by 40 mA per winding which should be ok.


Configured without CT as return, with a graetz bridge on 500 VAC it zappes both windings in both fases, hence you have only 40 mA in total, but a lot of voltages to filter away.


Thats why we suggested choke input. A graetz with cap as first component gives in theory 1,41 times AC as DC. A graetz with choke as first component gives in theory 0,9 times AC as DC, but a very good filtering. The spikes from rectifier diods when they close dont find their way to the cap and on from there, they get choked by the choke.


You wont know until you've tried. Holding thumbs