Lampizator Valve / Tube Rolling Review Thread
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Just measured only R of my both ad1n and at both its spot on 2.5R. Can't really measure the voltage as i need to remove the cover of the DAC for this exercise and I'm not into this at the moment (don't have ux4 to ux4 extenders as such).
Both tubes measured by Luke at 100% emission.
Both tubes measured by Luke at 100% emission.
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The bad tube has a lower resistance then. They don’t pull actually they push back lol.
Measure the tubes cold as well. I’m guessing the bad tube is not bad do to heater voltage draw. the set tubes have an isolated heater circuit. you can measure the same way on tiny pins. It’s voltage is about 400 volts ac not dc when no tube is installed. Play a 1 k test tone to be good. Now compare both tubes. Bad tube voltage should be higher
Post if you can.
This is cold will be lower then hot but should be closer then what you show. Use ohms law to show res
Example r= E/I
Example r = 5/ 1 amp
R = 5 ohms
This is what they shoukd be when hot. Use this to determine the rest
Guys never let the tube voltage at pins be above the spec voltage
Why are you using 1 amp as an example Al it's a 2 amp 4V tube? Therefore 2 Ohms should be the reading when hot.
TBH my meter was all over the place trying to measure the resistance. I am not confident in the actual value. But I did see lower readings on average as the valve cooled, as you would expect.
I am quite happy with running at 4.5V because all my AD1 work no matter what and sound excellent. They certainly didn't work at PX4/101D switch position at the time of the last Lucasz modification - you definitely get the problems with output drop the other guys see.
Not quite, only the f pins do the heating.
But yes only four pins are used. To verify your socket is OK use the continuity feature with no valve in it to follow through from the inside of the socket to the UX4 pins.
I am beginning to wish I had never 'discovered' this valve, LOL.
Let me say this it’s a bad idea to go above the rated tube voltage period. you will kill the tube for sure
Also you making the tube be out of spec as well. More distortion and it may add more gain
Lower tube voltage is far safer and any damage can be reversed over time of corrected
voltage at tube leads is the most accurate way to know tube is getting correct voltage.
Conventional wisdom but if the tube doesn't work on spec voltage it's all a bit pointless.
I have been running AD1n for hundreds of hours well above 4V and see no change in the tube tester so far. And they're cheap.
Fair trade I reckon. It's robust enough.
One more thing. The adaptors are AD1n to 300B.
That's a 4V tube versus 5V. Is something happening inside the adaptor to drop the voltage the tube sees? Seems unlikely (but the obvious thing to do) but hey it would explain a lot, let's face it!
Whoever made them must be aware of this.
I know very little about electronics I am a software guy BTW.
That's a 4V tube versus 5V. Is something happening inside the adaptor to drop the voltage the tube sees? Seems unlikely (but the obvious thing to do) but hey it would explain a lot, let's face it!
Whoever made them must be aware of this.
I know very little about electronics I am a software guy BTW.
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Don't worry Al.
Both the chap that did the mods and I both think the Tesla AD1n needs more than 4V to work properly. We've just been discussing it. This is backed up by adamely and dminches experience. That's why I am running at 4.5V.
It's a bit like writing software where you have to code around errors in library code sometimes.
The sockets don't have voltage regulators in.
We're seriously skeptical about the Pac switch labelled 101D/PX25 but hey, what do I or he know (he knows a lot more than I do LOL).
Both the chap that did the mods and I both think the Tesla AD1n needs more than 4V to work properly. We've just been discussing it. This is backed up by adamely and dminches experience. That's why I am running at 4.5V.
It's a bit like writing software where you have to code around errors in library code sometimes.
The sockets don't have voltage regulators in.
We're seriously skeptical about the Pac switch labelled 101D/PX25 but hey, what do I or he know (he knows a lot more than I do LOL).
I don’t think my experience is a good data point since I believe one of my tubes is bad. Until I have a good pair of AD1s I won’t know if the 101D position is appropriate. The RD27AS run great at 4V (on the 101D setting).
Here is my thoughts
heater voltage must be correct period but I’m not saying you don’t hear it better higher
I feel the reason to not be optimized is not heater it’s tube topology used. A tube is always under a load per say as it’s biased in a given circuit it’s needed or the tube will have runaway and burn up.
My guess is that tube is under biased as such an increase of heater excitement helps.
So again I’m not being a tube cop lol. there is a resister about 10k if I recall it’s used to set bias
a varying of it would better optimize this tube
All pacs have a far better circuit now but still do better at some tubes. I hate 101d tubes.
But I heard a balanced Lampi sound wonderful on them.
All over lamps were made for a given tube most 300 b. Mine was 2A3
New ones are far better at all tubes but still have a sweet spot
On the spec sheet is the tube used to voice a given dac it’s a clue to follow
Enjoy the music
heater voltage must be correct period but I’m not saying you don’t hear it better higher
I feel the reason to not be optimized is not heater it’s tube topology used. A tube is always under a load per say as it’s biased in a given circuit it’s needed or the tube will have runaway and burn up.
My guess is that tube is under biased as such an increase of heater excitement helps.
So again I’m not being a tube cop lol. there is a resister about 10k if I recall it’s used to set bias
a varying of it would better optimize this tube
All pacs have a far better circuit now but still do better at some tubes. I hate 101d tubes.
But I heard a balanced Lampi sound wonderful on them.
All over lamps were made for a given tube most 300 b. Mine was 2A3
New ones are far better at all tubes but still have a sweet spot
On the spec sheet is the tube used to voice a given dac it’s a clue to follow
Enjoy the music
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