fdegrove said:If the VR tube is wired up and run as it should, you can swap the load (tube) in and out and nothing is going to be damaged.
If it is wired as it should, it may well end up toasty after this. Like I said, if you have a large circuit of 80mA, it can be safely regulated, but removing that load puts all 90-100mA bias through the VR tube. Safe for short periods but will not last forever.
Conversely, you can pull the VR tube out while the circuit is live and all that's going to happen is a loss of B+ for the output tube.
This, however, is true, as long as the person remembers to use the internal link. Otherwise the voltage will soar (depending on current going into VR vs. circuit) and impedance will go kaput, probably leading to oscillation.
Tim
fdegrove said:White? Which one's that?
I know of orange and purple. (85A2-0A2)
Cheers,
0C3 is also more bluish as I recall. 0D3 is whitish at the center electrode.
What looks *really* neat is holding a 0A3 near a low output Tesla coil (I've made a 20W VTTC on the bench no problem). Blues and oranges, it's sweet.
Tim
Hi,
Yeah...You're correct. I had a series reg in mind...
The bleeder takes the heat while I swap a tube and of course doing so doesn't take long anyway.
Let's keep it that way.
Cheers,
If it is wired as it should, it may well end up toasty after this.
Yeah...You're correct. I had a series reg in mind...
The bleeder takes the heat while I swap a tube and of course doing so doesn't take long anyway.
Tim ( <-- more relaxed today)
Let's keep it that way.
Cheers,
voltage regs
Wouldnt dare I say it, Transistor regulation be a bit more predictable than the valve voltage regs talked about?
These valve voltage regs seem tetchy things to use, and just another weak link, --But what do I know--Ive never used them!!--Then again, I guess they emit a pleasing glow!
Feeding a pre-amp stage with a well smoothed cap and choke type PSU, and having a mains transformer with good regulation I would have thought more dependable, and probably just as sonically pleasing as the Valve voltage reg. PSU
Just my tuppence worth........:
Wouldnt dare I say it, Transistor regulation be a bit more predictable than the valve voltage regs talked about?
These valve voltage regs seem tetchy things to use, and just another weak link, --But what do I know--Ive never used them!!--Then again, I guess they emit a pleasing glow!
Feeding a pre-amp stage with a well smoothed cap and choke type PSU, and having a mains transformer with good regulation I would have thought more dependable, and probably just as sonically pleasing as the Valve voltage reg. PSU
Just my tuppence worth........:
SS regulation is not necessarily better at these high voltages. Transistor break too!
Also, many tube audio folks assert that they can hear the effects of SS in the PS. I don't have the experiences to know about this one either way.
A VR tube that is working properly is a very dependable regulator for what it's designed to do. And can last for many, many years. It's easy to figure out the biasing and it never has to change.
I agree with you about a good LCR based PS. For class A devices you don't need load regulation and it can be extra work and $$.
But again, many folks on this forum would argue that line regulation may be even more important than load regulation. In which case the basic, passive filter is not so good most of the time. MHO is that this is generally correct and regulators are useful for protection from line side problems.
And so, for DIY I would use regulated supplies even for a simple class A preamp if I had the few extra $$ to do it.
Also, many tube audio folks assert that they can hear the effects of SS in the PS. I don't have the experiences to know about this one either way.
A VR tube that is working properly is a very dependable regulator for what it's designed to do. And can last for many, many years. It's easy to figure out the biasing and it never has to change.
I agree with you about a good LCR based PS. For class A devices you don't need load regulation and it can be extra work and $$.
But again, many folks on this forum would argue that line regulation may be even more important than load regulation. In which case the basic, passive filter is not so good most of the time. MHO is that this is generally correct and regulators are useful for protection from line side problems.
And so, for DIY I would use regulated supplies even for a simple class A preamp if I had the few extra $$ to do it.
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