How much is the time life of these Triodes in this position?
They last longer or shorter than in the output position?
newbie here, want to build 24V 5A vacuum tube power supply
newbie here, want to build 24V 5A vacuum tube power supply i don't know if this is the right thread, please guide me to the right one if it's not. I just built my first power amp(Amp Camp Amp) built my first power supply(UNIVERSAL PSU) from DIYaudio store. I was gifted big boxes of NOS tubes for the 40's 50's 60's all new in boxs. I have been cross ref all the numbers and just open one box seem to be all diode rectifiers,5U4GB,5R4GYB,5V4GA,5U4GTB,5V3,5Z3 ECT. My question is if I have the right tubes can I build a 24V 5A power supply for my Amp Camp Amp?. If so can someone point me to a page of a schematic or build guide for my power requirements. thank you.
I got the bug to build.
newbie here, want to build 24V 5A vacuum tube power supply i don't know if this is the right thread, please guide me to the right one if it's not. I just built my first power amp(Amp Camp Amp) built my first power supply(UNIVERSAL PSU) from DIYaudio store. I was gifted big boxes of NOS tubes for the 40's 50's 60's all new in boxs. I have been cross ref all the numbers and just open one box seem to be all diode rectifiers,5U4GB,5R4GYB,5V4GA,5U4GTB,5V3,5Z3 ECT. My question is if I have the right tubes can I build a 24V 5A power supply for my Amp Camp Amp?. If so can someone point me to a page of a schematic or build guide for my power requirements. thank you.
I got the bug to build.
The tubes you mentioned are not going to supply the 5A, that is mercury vapor Tungar rectifier territory. and those wil have a voltage drop of around 15 volts. the overall efficiency is going to be around 30% all things considered.
There was a later development that is perfect for this kind of application: A silicon bridge rectifier.
There was a later development that is perfect for this kind of application: A silicon bridge rectifier.
Through my recent reading I was coming to the conclusion I may have the wrong tubes for high amperage. I have already built a silicone rectifier bridge using DIY audio store PC build . I know tube rectifiers are highly inefficient but I was just going for that old timer nostalgic look and I just wanted to teach myself more about tubes. I wouldn’t mind building a mercury vapor power supply just for the learning experience. Still if you or somebody can point me to a schematic or build project that fits my voltage and amperage application, I know it is not cost-efficient it’s just the self satisfaction of doing it at least once in my life that I can periodically use and turn on in place of my silicon rectifier diode power supply or LCLC Power supply that I may end up building even though it’s large and bulky and monetarily impractical.
Your going to have to engineer that yourself, tungar rectifiers require choke input supplies, because they cannot supply the peak currents required. Your best bet is trying to find a 30's battery charger schematic.
But still, Why? 24V is a common industrial bus voltage, plenty of surplus linear stuff available. the transformers alone are gonna run into the three digits easily.
I'd start building a tube regulated high voltage supply first, you'l thank me later.
100-300V at about 100mA is not that difficult. plenty of schematics online. please open your own topic for this.
But still, Why? 24V is a common industrial bus voltage, plenty of surplus linear stuff available. the transformers alone are gonna run into the three digits easily.
I'd start building a tube regulated high voltage supply first, you'l thank me later.
100-300V at about 100mA is not that difficult. plenty of schematics online. please open your own topic for this.
Yes I’m well aware there’s many old linear power supplies around but this is purely for nostalgic look and self gratification in the accomplishment that I built something completely impractical from my bypass era and lost technology built with my own two hands from scratch . This will be used on Nelson pass amp camp amp and it requires 24 V 5 A . I did find a website that explained the calculations and the math but my math skills are not that high and when I looked into it further honestly my eyes just glazed over. But I’m willing not to give up if I can just copy hey already in existence power supply from long ago .
Just updating this thread to say I'm still getting better sound out of PSUs with mesh rectifiers. Could be other factors - different chokes in the supply, though they all have the same all-motor run polypropylene capacitors.
I have two PSUs - one for my 300b outputs, one for my EL33 driver stage. For the 300b, I preferred my PSU with two AZ11 to a similar one with 5R4GY. For the driver stage I preferred an AZ11 to a 6BY5G. In both cases a little more low level detail and a softer, more liquid sound. Not a night and day difference but I'd say it was audible, and the mesh rectifiers were a little more "alive" and involving.
I have two PSUs - one for my 300b outputs, one for my EL33 driver stage. For the 300b, I preferred my PSU with two AZ11 to a similar one with 5R4GY. For the driver stage I preferred an AZ11 to a 6BY5G. In both cases a little more low level detail and a softer, more liquid sound. Not a night and day difference but I'd say it was audible, and the mesh rectifiers were a little more "alive" and involving.
Agree. I prefer rgn1064 for driver stages. For power stages, I went from 866 to 872a over Mesh and other rectifiers. A perceived more in resolution with mercury. Bit dont tell anyone...Mesh rectifiers became insanely expensive in the last years...by coincidence, I found out that preheating the rgn types with the 872a, so 2 min preheating, avoids any sparks...mesh need preheating
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Thanks for that. The first cap is 40uF, so within the 60uF stated.
But anode-anode resistance is only 26 ohms. Looks like I need a resistor in there. I can't see exactly what the data specifies but from the graph the range is 100-800 ohms. So I could add 100 ohms. Do I assume 200mA for a 300b stereo output stage drawing 70+70mA? This would give a part like 100 ohms, 12W which would drop 20v.
But anode-anode resistance is only 26 ohms. Looks like I need a resistor in there. I can't see exactly what the data specifies but from the graph the range is 100-800 ohms. So I could add 100 ohms. Do I assume 200mA for a 300b stereo output stage drawing 70+70mA? This would give a part like 100 ohms, 12W which would drop 20v.
Forget the data sheet specs.
These specs are for fully warmed up tubes AND Non-Mesh versions. Thats simply how it is.
I tried all kind of games with resistors etc....no....still you may or not may experience sparcs. Jacmusic did some white papers on it...good stuff...but in the end I can summarize for you:
Warm them up. Long ideally. Or use a 3k resistor on the CT of your heater transformer and a switch /time relay which surpassed it after 10 sec. That will get rid of those damaging sparks.
These specs are for fully warmed up tubes AND Non-Mesh versions. Thats simply how it is.
I tried all kind of games with resistors etc....no....still you may or not may experience sparcs. Jacmusic did some white papers on it...good stuff...but in the end I can summarize for you:
Warm them up. Long ideally. Or use a 3k resistor on the CT of your heater transformer and a switch /time relay which surpassed it after 10 sec. That will get rid of those damaging sparks.
Indeed. But a rgn1064 is available in both types and the normal plate types do not have these issues. It comes with the Mesh. Someone here explained once, in the old time you simply did not care as rectifiers were cheap and after many sparks, when they failed, you simply exchanged them and did not bother.
There is a nice book written in German from the WII ages with lots of tips and hints how to prolongie tube life, how to re-generate tubes etc when during WII tubes actually became rare resources which were seen as critical to win the war....this goes down the the greatest detail how to treat tubes correctly...seldomly found these advises in data sheets...
For your convenience an introduction to the white spark problem you find here:
Technical Bulletin 11. Cathode Issues
There is a nice book written in German from the WII ages with lots of tips and hints how to prolongie tube life, how to re-generate tubes etc when during WII tubes actually became rare resources which were seen as critical to win the war....this goes down the the greatest detail how to treat tubes correctly...seldomly found these advises in data sheets...
For your convenience an introduction to the white spark problem you find here:
Technical Bulletin 11. Cathode Issues
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I wonder what was the technical reason to make a mesh plate back then? For sure it's much harder than a stamped piece of metal.
As a first hint, a mesh can have more surface area.
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