I give a lot away, but some of them get rebuilt into other things. I don't have as much time as I used to these days so I've slowed down a great deal.
Yes, the Meanwell S-25-12 datasheet states hiccup mode for overload protection, which exactly turns out as the behaviour you've observed. It's also an effective slow start for the heaters, btw.
Best regards!
Best regards!
I don't like these type of sockets. But since I had to get 16. I figured it would be ok this time.View attachment 1156505
beautiful work Bas:
You have some bigness going on there, it covers a fair bit of shelf space with all those 6p1p tubes. Do they need to be matched in any way?
Could you post a circuit diagram when you get a chance.
You have some bigness going on there, it covers a fair bit of shelf space with all those 6p1p tubes. Do they need to be matched in any way?
Could you post a circuit diagram when you get a chance.
Here is the original thread with the “Stupendous” schematic by @kodabmx
https://www.diyaudio.com/community/threads/the-stupendous-6p1p-4pp-amplifier.317395/
Bas’ deviations from thie schematic are in #63.
Matching Is not needed since each output tube is independently biased.
https://www.diyaudio.com/community/threads/the-stupendous-6p1p-4pp-amplifier.317395/
Bas’ deviations from thie schematic are in #63.
Matching Is not needed since each output tube is independently biased.
This is the general idea. The output transformer is replaced by a choke. (In my case I'll use little guitar output transformer primary as choke). The exo-173 is not made for dc. Hence a "parafeed" capacitor.
My rset for the lm317 is 33 ohm so the current through each tube is around 39mA. Got this advice from kodabmx because my output transformer is the Lundahl LL1620 (3.3k)
@kodabmx why do you use the triode-strapped pentode for voltage amp and the triode for splitter instead of the other way around? I know it works very well, but is there a specific reason? The pentode section can handle bigger power, would not that be better for driving output tubes?
I started it this way... It may or may not make a difference.
Originally, it was set up as pentode input but I didn't need the gain, and I found it was easy to make an oscillator by accident so I strapped it.
In my modular amp, the 6F12P triode drives 6N8S (6SN7) drivers for the outputs anyway... I even replaced 330R with 1.9Vf LED in some of them 🙂
Originally, it was set up as pentode input but I didn't need the gain, and I found it was easy to make an oscillator by accident so I strapped it.
In my modular amp, the 6F12P triode drives 6N8S (6SN7) drivers for the outputs anyway... I even replaced 330R with 1.9Vf LED in some of them 🙂
Makes sense, especially if it started as a pentode. And tbh the 6F12P is a weird tube, the triode is very powerful (3.5W, big currents) and with u of 100, like 5 12AX7 in parallel. I have not been able to find a western equivalent.
@jcalvarez is there a double triode tube with mu=100 but at least twice as powerful as the 12AX7? First option is parallel both section, but I’m curious to know if there’s another solution.
Thanks!
Thanks!
