Any new AD1 feedback, or at least successful setup for evaluation by other members? Looking forward to impressions.
About burning in tubes, while burning in a Psvane WE274B replica in a TRP, I was wondering if it matters whether or not music is playing, or just having the dac on sufficient. Is the answer the same for the output tubes, such as KT66s?
Justin get a heater circuit like LAMPI does now it’s not complex really and it makes the heater for 5 tubes perfect as in .2 volts correct and never above. It even has a delay voltage at turn on to keep all tubes even lower for a 5 seconds. This allows the filaments to get hot and no cold shot at startup. By the way most all tube circuits have such a delayAt the moment 4V and 5V tubes run not far off. But the power supply is unable to supply enough Watts for some tubes.
It's not good. Hence the rework for this and other reasons.
I would guess older Lampis with the two position switch show a lot more variation in SQ when tube rolling. Which in a way is no bad thing.
A recti is cooking at all times as it feeds a capacitor bank but the load on them varies to tubes As they get used. It’s why if you swap a hot recti it keeps playing until or starts to get lower as they discharge. never ever swap output tubes if the dac is on period. This is for many reasons both your dac and systemJust having the DAC on should do it. TBH I doubt the Psvane will change much.
Burn in for older valves is more of an issue and more necessary if unused for many decades.
A better tube heater circuit like lampizator is well regulated in fact it can go to 90 volts and some models up to 230 voltsHad them all, globes and ST, RCA, Arcturus, Majestic, Cunningham etc and they are glorious in the midrange and perfect imo for old horn Speakers and older music but sadly not for modern music or great speakers.
I sold them all, mainly to Asia.
My tube of choice is solid plate Globe EML45V4 or sp ST EML45V4. Not sure I’d go back to a 4 pin version now.
All this in amps rather than a DAC.
And if you’ve built an amp you’ll know how the mains voltage can swing the operating point of the tube so all these compares between units at different voltages and are any of these tubes actually operating at their best point?
cheers
Blue58
A 45 is 2.5 volts but at 1.5 amps45 is a 2.5v tube with 1.5 amp current, no?
Not sure if any Pac setting is 3v...but is anything kr242 would be closest.
I tend to agree that heater voltage is the control mechanism in a pac.