I used a resistor in a TO-220 case that can be heat sinked to the chassis. I got them at Mouser.
This resistor will get very hot. I'd recommend oversizing it. 4 in a series/parallel combination is a good idea unless you have a large heatsink. It's difficult to find standard axial carbon or metal film resistors at that power level. DON'T use wire wound inductive resistors. Make certain they are a non-inductive type.
I'm not sure what you're trying to do here. Are you trying to build a DC supply to run the filament of a 300B? If that's the case, then I suggest looking at an LM317 voltage regulator IC. Or you can follow what I did in this thread.
You will need a rectified DC voltage of at least 7.5 V at the input of the LM317 (or LMZ12002). Use a 9 VAC transformer that can supply the needed current (1.5 A per 300B). You'll need a diode bridge that can handle the current with plenty of margin - KBPC2504 would be practically indestructible in your application. Then add a 10000 uF cap on the output of the diode bridge. The cap should be able to handle at least 25 V.
The LM317 will dissipate up to 10 W so it will need a fairly big heat sink.
For the 6SN7 filaments, you can go with AC -- or if you insist on using DC, you can do the same as above. However, as the 6SN7 needs 6.3 V, you'll need a transformer that can supply 12 VAC. The feedback resistors on the LM317 will be different than those used for 5 V. There's an equation in the data sheet for calculating those resistors.
Does this help?
~Tom
You will need a rectified DC voltage of at least 7.5 V at the input of the LM317 (or LMZ12002). Use a 9 VAC transformer that can supply the needed current (1.5 A per 300B). You'll need a diode bridge that can handle the current with plenty of margin - KBPC2504 would be practically indestructible in your application. Then add a 10000 uF cap on the output of the diode bridge. The cap should be able to handle at least 25 V.
The LM317 will dissipate up to 10 W so it will need a fairly big heat sink.
For the 6SN7 filaments, you can go with AC -- or if you insist on using DC, you can do the same as above. However, as the 6SN7 needs 6.3 V, you'll need a transformer that can supply 12 VAC. The feedback resistors on the LM317 will be different than those used for 5 V. There's an equation in the data sheet for calculating those resistors.
Does this help?
~Tom
Google Translator say:
" hello I want to change the capacitors by better and if you can make some improvement in other components "
Yes, for sure...you can change cap's to better performance.
What X2 version do you have?there are X2 1's version, 2's and 3's version. And, avaliable schematic just for X2 1's version...
" hello I want to change the capacitors by better and if you can make some improvement in other components "
Yes, for sure...you can change cap's to better performance.
What X2 version do you have?there are X2 1's version, 2's and 3's version. And, avaliable schematic just for X2 1's version...
The X2 have a good capacitors inside, IMMO a step up capacitor (In quality) are too big for this unit (V-Caps or something like this). My advice is leave the unit like is, and make a new X2 with a proper size pcb for big capacitors.
P.S. I recently bought a Aleph L with a disastrous mod, someone changed the resistor level control by a Alps blue potentiometer, arggg!.
P.S. I recently bought a Aleph L with a disastrous mod, someone changed the resistor level control by a Alps blue potentiometer, arggg!.
Miguel Porfavor !
Please post in English it's an international forum and not everyone is capable of reading Español like you and I do.
It's not against your language but the fact that others can not understand you!
Thanks,
Muchas gracias !
José
Auidofanatic
Please post in English it's an international forum and not everyone is capable of reading Español like you and I do.
It's not against your language but the fact that others can not understand you!
Thanks,
Muchas gracias !
José
Auidofanatic
Have a stepped attenuator (resistor) (Much better track than a Alps) close to Goldpoint units
The v1.2 have the same attenuator with two circuits (Part of the run are in passive mode)
Yes, taste and preferences have unwritten rules, but the stepped attenuator was one of the highlights of this preamp.
I prefer the stepped
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