B1 with Korg Triode

[AnthonyA]

Hey there, I am having mixed results with the Meanwell PSU, it seems to randomly start oscillating and radiating really nasty RF, which gets picked up by various other components in the chain. I have a krell preamp, which is particularly susceptible. anyone else having problems with those little Meanwell powersupplies?

Is it a long high pitch ringing?

Try a different amp.

 

[Hadox]

Hey there, I am having mixed results with the Meanwell PSU, it seems to randomly start oscillating and radiating really nasty RF, which gets picked up by various other components in the chain. I have a krell preamp, which is particularly susceptible. anyone else having problems with those little Meanwell powersupplies?

Mine was working just fine but has started buzzing, or humming.

Which is great as it is forcing me to seek an alternative so I've signed up for the SSLV1.3 UltraBiB group buy and have scored a nice fat Toroidy donut in preparation for what will be my second ever DiY build.

 

[konst]

@Hadox, I signed up for that too, seems like an elegant solution.....
@AnthonyA, it is not really a ringing, I get that if I tap the Nutube, applying some bitumen damping resolved that. It is a RF ringing, similar to using a cellphone near a radio. Once I reset the PSU it goes away for a while and reappears usually after a few hours. That being said, it hasn't done it in the last two days.

@Mark Johnson, that is awesome, thank you. This should probably be a group buy....

 

[ihear21khz]

I used to also get the occasional high pitched ringing. Switched to a medical grade Meanwell SMSP.

On another note, any issue with putting a high quality cap across the 9.1v zener that sets the filament voltage? Zeners I believe are by nature noisy.

Cheers,
David

 

[ihear21khz]

Well I did add a 0.1uf Blackgate HiQ cap across the 9.1V zener. I would recommend doing similar with your own favourite small value cap.

 

[ghitus]

Well I did add a 0.1uf Blackgate HiQ cap across the 9.1V zener. I would recommend doing similar with your own favourite small value cap.

Interesting! Can you show a pic, please?

Gaetano.

 

[ClaudeG]

Interesting idea...

Did it make any change to the sound?

Claude

 

[ghitus]

Sorry for the silly question, but should be series or parallel with the Zener?

 

[sov]

Could 0,5w zener suffice? I believe they are less noisy.

 

[Nelson Pass]

They are quieter if you increase the current through them.

 

[sov]

Ah! Is it advisable to bypass the zener? Is for measurement or fun?

 

[6L6]

The Zener makes the filament voltage. I'd suggest leaving it alone.

 

[Nelson Pass]

Yes, you don't want to cook your filament.

 

[ghitus]

Do you think that adding a small cap across the Zener can cook the filament?

 

[Nelson Pass]

No

 

[Zen Mod]

only if it's biiiig small cap, and already filled with 500V

 

[ghitus]

We can have a nice barbecue on our korg B1...

 

[sov]

Correct question brings correct answer.
Instructions: "Buy 4 buns. If they have tomatoes, buy 2."
Result: 6 buns
🙂

 

[sov]

I can’t follow my own instructions.

Instructions: "Buy 4 buns. If they have tomatoes, buy 6."
Result: 6 buns

 

[soi]

Just out of curiosity, the heater voltage seems to be developed seconds after the plate voltage is developed during power on (due to the 270 ohm/1000 uF before the zener). Will there be any degradation in the nutube during this time? In real tube amps, sometimes a delay circuit is put in so that the filaments are heated up before HV is switched on to preserve the life of the tubes. Does it mean it is best to leave the nutube on all the time once it is powered up?