• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

6.3V rectifiers....

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Well I need a good one and I really have not dealt with many. The 6x5 being the primary one. I am building a 6dj8 headphone amp (Morgan Jones Headphone amp www.headwize.com), why not I have some old amprex e88cc from an old osilloscope which tested good and some nice potted transformers, but the power transformer has only 6.3V secondaries. Two actually (kind of like the ones for my we407A preamp shown here early) but with more amps to work with. And I do have some more 6x5gt's to use but I would like some else. Something maybe you guyz have used with good results, (something cool lookin?). My power supply is going to begin with a 500V 60mA tranny, rectifier in question, 5uf oil, 8H-10H choke, 20uf oil, 10H-15H choke, 50uf oil. For a grand total of 220V, hopefully. So what do you guyz have in mind?

Guiness
A guiness a day keeps the doctor away :drunk:
 
What about...

An 84?

Guiness
 

Attachments

  • t-84_6z4.jpg
    t-84_6z4.jpg
    12.6 KB · Views: 708
i use a 6BY5 in my 6922/6197 headphone amp. although not originally designed as an ac to dc rectifier (used somewhere in tv's from what i remember), its a pretty rugged tube. i have it running as one half of a full wave bridge, other half being solid state, works well.
 
mig-ru said:
i have it running as one half of a full wave bridge, other half being solid state, works well.
That's a really good idea! The vacuum rectifier turns off noislessly and the SS rectifier in series then recovers noislessly by *recombination*, not by having the charges swept out till they come to an abrupt halt, twanging every bit of stray inductance and capacitance into self resonance momentarily at the end of every half cycle. Gets my award for idea of the week. :nod:

Cirlcotron / - doesn't realise this is common knowledge among tubeophiles. :cannotbe:
 
Shifty and mig-ru are correct with their suggestions IMO, using any standard 5V rectifier in a Greatz (hybrid) bridge, if the trans were single secondary. However, a CLCLC filter is going to give a hell of a lot more than 220V. A quick simulation in PSUD2 gave 660V.

If the trans is 250V-0V-250V, ie 500Vct with a fullwave tube rectifier I still ended up with around 320V for a 26mA draw.

I used 5V4G rectifiers, and Hammond 193G chokes with a common supply for the two channels.

A smaller first cap, <1uF (or none) will give almost correct 233V in the FW. Not having experience with the Hammond chokes in the 157/158 series, the 193x series might be a better option for the first choke, though the cheaper ones could be readily subbed for the second one. They might buzz or run too hot otherwise. The voltages would be a bit lower too, due to higher internal resistance.
Perhaps others can comment from personal use of the 157/158 in LC filters.

And before the anal retentivves comment, this was a rough sim, based on guesses, so the voltages are only approximate.
 
Power supply revised...

Thanks Brett, I just ran the power supply in PSU Designer 2, and it is running alittle hot. I am not sure how much I do trust that program but it should get me in the ballpark. I change the power transformer to a 450V 60mA and I got around 230V into a 45ma load. Which will work great. I am still interested in trying the 84 rectifier. Hell for only 5 buck why not and if all else fails I will just change it to a 5V with a drop resistor.

Thanks again for the input guyz
 
The last two I modelled in PSUD and built were both about 15V lower in the sim, than in circuit, but I used different diode tubes than in their options list. I don't have the circuit in front of me, but I don't think it's that critical, and if you want it exact, add a resistor in series with one of the chokes, or another RC stage. I'll look closer tonight.

I personally think the 83 would be a PITA, but try it if you like. With such a small current draw, I don't think it will glow much either.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.