I would like to try at least the kt66s on the trp3 as well before saying. I only had a very small time with the 2 but ill try to compare then.
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The luck streak continues. Another blown fuse on the Lampi.
Either these are extremely sensitive to or i am just not sure. Whenever i plug and unplug the power, the next start up it goes on for a second then blows.
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Sorry for your streak of down luck. Thank god it wasn’t one of those high priced fuses, at least I hope it wasn’t!
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Not to sound like a broken record, but I strongly suggest you use a good power conditioner and power cord with the TRP. Maybe you’re getting surges.
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You sure the fuse is the right size. The most common issue at power on is incorrectly using a fast blow fuse instead of a slow blow one.
Most fuses are massively oversized for continuous use, usually at least 2x, but at power on the capacitors in the power supply effectively act as a dead short, which will blow the fuse, slow blow fuses are designed to blow slowly so survive the in rush.
The fact that replacing the fuse makes it ok until the next time you turn it on seems to imply it’s mis sized rather than a fault.
I guess the tube compliment could contribute to it as well, you might want to ping Fred at Lampizator NA, and verify the fuse size/type.
A big enough mains surge would certainly blow the fuse, but that seems less likely to me, unless your power is terrible.
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But surges that only hit when i power it on? I dont think so and i have never had anything effected.
Both fuses that blown were the stock 1.6AL 250VAC slow blow fuses that ship with it.
Yes, turning it on and off standby (the unit is plugged in and power switch on) hasnt affected it. The only thing I can think of linking it all is when its plugged into the wall.
Tbh the outlet is old, but doesnt wiggle. Not the tightest but its 15 years old I do wonder if there is the tiniest disconnect in the outlet and it just hits the lampi in a way it doesnt like.
1.6A?? We use a 3.15A in Lampizators.
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Looks like the factory fuse in 1.6A in Europe, bu it’s supposed to be 2A in NA.
And lampizator NA suggest 3.15, I assume because of some of the tube rolls requiring larger.
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Agreed. It’s 1.6A for 230V, 2A for 110V.
The 3.15A comes actually from the folks who roll Synergistic Research fuses since for a period a lot of people put SR Purple in their Lampis, and there’s an extra buffer that ended up as 3.15A.
From what I understand, Lampi has agreed 3.15A is safe despite not supplying one that large for N.A. units.
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The manial notes this…
"The fuses are 1,6A (or 2A for USA/Japan/Taiwan)
they are slow blow, and overrated by the factor of 3."
But also only mentions only 1.6A from there on in. I emailed lampi because i dont want to fuck around with this level of gear and tubes.
I also find it odd they would put a 1.6A in a dac going to the US without knowing it may blow unnecessarily.
These are all things I am still working on. Some PCs are in the works and I am always scouring for a Puritan but they fly in minutes.
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I just ordered a box of 2A and 3.15A and look forward to what your hear back from them. Mine is coming from Switzerland so might require changing.
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Consider yourself lucky if that’s the issue.
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All made in the same place, someone could easily have made a mistake, and from that thread it looks like the fuse size was changed after Lampizator NA lobbied for the change, probably because of people blowing fuses, so it may just be a timing thing.
In practice if 1.6A works in Europe your going to draw more than that in the US, while the fuse is rated at 240V, so it should “work” in practice it doesn’t quite work like that, the fuse gets hot and fails based on the power dissipated across just the fuse, not the circuit, and at a lower supply voltage, the voltage dropped across the fuse isn’t significantly different that it is at 240V, so the current rating likely has to be increased for the same safety margin.
This is probably why 3.1 gets suggested it’s roughly twice 1.6, 110V devices draw 2x as much current as 240V devices and the voltage rating on a fuse is not really relevant.
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Welp here we have it from the man himself…
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That’s good to know and I’m sorry you had to go through this!
I’ll switch to 3.15 when everything arrives. I’m not investing in a audiophile fuse for now
Ill have to see what is available here. 3A may be the closest. But yeah i will buy a bag of those for $5 and make sure they work for a while, and replace my outlet before spending on the nicer fuses. For $200 if it improves things then yeah it may be the keast expensive tweak at this point but it is hard to swallow if it pops again.
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I bought these for now
https://www.amazon.com/dp/B07X2K4NTQ
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Taking this opportunity to state that the Mojo DACs come with a thermistor instead of a fuse. Ben says they perform much better than a fuse. (not that I’d know if that was BS or not) but it’s a refreshing thing to know you don’t have to think about a blown or gasp… upgrading to an SR fuse.
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Who knows they are both supposed to be noops in a circuit so…
Ben also has a somewhat different problem he’s trying to solve, in tube devices you have high voltages that can kill your user, and it’s not just about preventing equipment damage or in the worst case a fire.
There are some active devices you can buy that replace the fuse with a solid silver or copper slug, and I’ve heard people espouse the use of slug in place of a fuse making a significant audible difference, but your taking your chances with mods like that.
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Yeah they warn specifically against “dead bolt slugs”.
With tube stuff i dont F around (or really most electronics). I would love to replace the volume pot in the EC but you have to make sure things are drained properly, and that doesn’t mean unplug it for a week. Some pieces can store huge charges for way longer than one may think.