[MaxwellDemon]

I am cumulating sleepless nigts in fact
I just can't put it down... 4am last night (again).

The highest form of praise!! I am also really interested in seeing if anyone can do a DX320 Max comparison. Going to be looking from here being a bit jelly while I hope the units don't sell out before I can free up my funds for it.

 

[KrólArtur]

Tak!

W sprawie kumuluję bezsenne carnuchy
Po prostu nie mogę tego odłożenia ... 4 rano ottniej nocy ( ponownie ).
Jedną w tym DAP jest do, jak ważne jest, aby ... poznać technikę przeznaczoną dla wszystkich osób...

Sprawem RS8, N7 i wkrótce M9 Plus, Prawdopodobnie zatrzymam WM1ZM2 dla mnejszej formy, ale teraz za każdym raz, gdy wracam do innego DAP, dzielę, je schodzę do innej ligi. Byłbym naprawdany znanie kogoś z DX320 Max, który zrobiłby trochę A / B, myślę, preferowanie jednego lub legiego ługu zalegalizowanego od osobistych preferencji lub synergii.

@twister6 is probably already testing

 

[twister6]

@twister6 is probably already testing

Yes, I have. Sorry, have been overloaded with work and family stuff. I should have my shorter in-a snapshot review by the end of the day tomorrow.

 

[Andykong]

Shouldn’t need a load to heat the tubes. nutubes are not directly-heated. They have heater filaments. And realistically the idle heat dissipation should be sufficient for the amp to heat up rapidly if in class A mode during warm-up. In-fact in class A it should heat up faster with no load, since it would be at maximum idle and dissipating /everything/ — instead of part of the power being fed into a load.

The Nutube is LED-based technology, it won't heat up anyway, with or without load, but it drains current when it is operating, and the current generates heat.

Theoretically, Class A should heat up faster at no load. However, the headphone amplifier is only one of the heat sources of the DAP, there are other items such as the MCU, AK4497EQ, and Nutubes are generate a lot of heat or drain a lot of current during normal operation, If these items are left in idle, you can't warm up the DAP. In addition, the heat management mechanism will cool down the amplifier circuit effectively when it is the only heat-generating source, you probably won't feel the temperature even leaving it in idle in Class A.

IMO, you need a load to warm up the DAP promptly, loop a DSD track in Hyper mode with a high impedance load is the way to go.

 

[zoidbb]

The Nutube is LED-based technology, it won't heat up anyway, with or without load, but it drains current when it is operating, and the current generates heat.

Theoretically, Class A should heat up faster at no load. However, the headphone amplifier is only one of the heat sources of the DAP, there are other items such as the MCU, AK4497EQ, and Nutubes are generate a lot of heat or drain a lot of current during normal operation, If these items are left in idle, you can't warm up the DAP. In addition, the heat management mechanism will cool down the amplifier circuit effectively when it is the only heat-generating source, you probably won't feel the temperature even leaving it in idle in Class A.

IMO, you need a load to warm up the DAP promptly, loop a DSD track in Hyper mode with a high impedance load is the way to go.

No, Nutubes are based on VFDs (which are functionally vacuum tubes with a phosphor) -- not LEDs, which are solid-state silicon devices. They are direct-heated (i had a typo in my original post, they are direct-heated), similar to tubes like 300B. What this means is you're meant to send a base signal across the filament to heat the tube up for operation.

In fact, your player does exactly this -- or says it's doing exactly this -- prior to operation. Note how when you switch to tube mode, it says its pre-warming the tubes?Z
Anyway, the point of a pre-warm is to warm up the JFETs and Nutubes. They are the largest source of heat in the DAP. The other components will warm slightly during a pre-warm of the headphone amp, which is beneficial but not necessary given that those components aren't nearly as impacted by a cold start.

I can play a silent, no-sound song and the player will heat up dramatically despite delivering no power to any headphone. This isn't rocket science, Andy, and frankly responses like this are troublesome. If you guys don't think its worth implementing, that's fine -- its your product. But to make up a bunch of crap, even going so far as to call a Nutube an /LED/ to justify it, is pretty ****ed up.

 

[Andykong]

Drop a like on this if you want @Andykong to convince Cayin to produce a C9ii that utilize the epic new amplification circuit from the N30LE. Holy smokes is this thing hot, and if we could get a few more watts output? Wooooowwweeee!


Welp, guess I’m gonna get both Raven and MM. Oops

Sorry, can't discuss future products.

But we can discuss technology.

Gen 3 Nutube circuit will indeed play an important role in our portable technology roadmap.

 

[Andykong]

No, Nutubes are based on VFDs (which are functionally vacuum tubes with a phosphor) -- not LEDs, which are solid-state silicon devices. They are direct-heated (i had a typo in my original post, they are direct-heated), similar to tubes like 300B. What this means is you're meant to send a base signal across the filament to heat the tube up for operation.

In fact, your player does exactly this -- or says it's doing exactly this -- prior to operation. Note how when you switch to tube mode, it says its pre-warming the tubes?Z
Anyway, the point of a pre-warm is to warm up the JFETs and Nutubes. They are the largest source of heat in the DAP. The other components will warm slightly during a pre-warm of the headphone amp, which is beneficial but not necessary given that those components aren't nearly as impacted by a cold start.

I can play a silent, no-sound song and the player will heat up dramatically despite delivering no power to any headphone. This isn't rocket science, Andy, and frankly responses like this are troublesome. If you guys don't think its worth implementing, that's fine -- its your product. But to make up a bunch of crap, even going so far as to call a Nutube an /LED/ to justify it, is pretty ****ed up.

I was trying to explain "the idle heat dissipation should be sufficient for the amp to heat up rapidly if in class A mode". Nutube uses LED technology as filament, it won't generate heat like a traditional vacuum tube because the filament remains cool during operation. That's what I mean it won't heat up when the circuit is idle.

I have tried to operate our DAP with and without a load. it did warm up more quickly when I added the 300ohm adapter.

 

[Andykong]

@Andykong any chance Cayin would work out with UM a way to convert Amber Pearls to customs? They offer this service for Multiverse Mentor, and given that many folks are proclaiming the AP bundle as endgame it would be really awesome of you guys to get UM onboard with offering conversion.

Can I clarify your question before I channel your request? Do you mean converting an existing Amper Pearl from a universal fit to a custom fit?

 

[zoidbb]

I was trying to explain "the idle heat dissipation should be sufficient for the amp to heat up rapidly if in class A mode". Nutube uses LED technology as filament, it won't generate heat like a traditional vacuum tube because the filament remains cool during operation. That's what I mean it won't heat up when the circuit is idle.

I have tried to operate our DAP with and without a load. it did warm up more quickly when I added the 300ohm adapter.

No… it does not use LED technology as a filament. I don’t know where you got this idea, but it’s patently false. The light you see when it turns on is a phosphor. I suggest you read up on VFDs here: https://en.m.wikipedia.org/wiki/Vacuum_fluorescent_display

The filament does not stay cool
during operation. The filament /is/ the heater, as Nutubes are directly-heated. In a directly heated tube like the Nutube or 300B, the filament (heater) and cathode (electron emitter) are a single piece that serves two purposes. This is in contrast to indirectly heated tubes (6SN7, for example) where the filament (heater) is separate from the cathode (electron emitter).

All electron emissive devices need some amount of heat to free electrons for operation. The Nutube is a compact vacuum tube that uses a /tiny/ vacuum gap, along with low current (measured in microamps) to achieve valve behavior with very low voltages and dissipated heat. However, it still needs heated, and the filament gets warm. And there’s no LED anything inside to accomplish any of this.

 

[zoidbb]

Can I clarify your question before I channel your request? Do you mean converting an existing Amper Pearl from a universal fit to a custom fit?

Correct. I’m currently having them convert a universal fit Multiverse Mentor to a custom fit for me, I asked if they would do this for an Amber pearl and they said no due to it being a limited edition for you guys. It would be wonderful to have this option for folks. I’m considering making a move on an Amber Pearl combo unit myself if I see one in stock somewhere, but the ability to get it refit to Custom is important to me.

 

[Andykong]

Correct. I’m currently having them convert a universal fit Multiverse Mentor to a custom fit for me, I asked if they would do this for an Amber pearl and they said no due to it being a limited edition for you guys. It would be wonderful to have this option for folks. I’m considering making a move on an Amber Pearl combo unit myself if I see one in stock somewhere, but the ability to get it refit to Custom is important to me.

I can't promise anything at this stage, but I can channel the request, will keep you informed when I receive feedback.

 

[Andykong]

No… it does not use LED technology as a filament. I don’t know where you got this idea, but it’s patently false. The light you see when it turns on is a phosphor. I suggest you read up on VFDs here: https://en.m.wikipedia.org/wiki/Vacuum_fluorescent_display

The filament does not stay cool
during operation. The filament /is/ the heater, as Nutubes are directly-heated. In a directly heated tube like the Nutube or 300B, the filament (heater) and cathode (electron emitter) are a single piece that serves two purposes. This is in contrast to indirectly heated tubes (6SN7, for example) where the filament (heater) is separate from the cathode (electron emitter).

All electron emissive devices need some amount of heat to free electrons for operation. The Nutube is a compact vacuum tube that uses a /tiny/ vacuum gap, along with low current (measured in microamps) to achieve valve behavior with very low voltages and dissipated heat. However, it still needs heated, and the filament gets warm. And there’s no LED anything inside to accomplish any of this.

Phosphor is the right right. LED is a bad description.

Thank you for correcting me. I touched the glass surface of the Nutube of HA-S Nutube DIY Kit and it isn't hot like 300B or 2A3, so I was under the impression that the Nutube filament isn't generating heat like 300B or 2A3.

 

[zoidbb]

Phosphor is the right right. LED is a bad description.

Thank you for correcting me. I touched the glass surface of the Nutube of HA-S Nutube DIY Kit and it isn't hot like 300B or 2A3, so I was under the impression that the Nutube filament isn't generating heat like 300B or 2A3.

Ah ya, I can understand this misconception based on that observation. The maximum plate dissipation of a Nutube is about 1.7 milliwatts vs 36 watts for 300B — the 300B is designed to dissipate 21,000 times more power! This is why the cathode in 300B needs to get so hot. But since Nutubes aren’t used as a current source in Nutube amp designs, they don’t need to dissipate this much power!

 

[Andykong]

Ah ya, I can understand this misconception based on that observation. The maximum plate dissipation of a Nutube is about 1.7 milliwatts vs 36 watts for 300B — the 300B is designed to dissipate 21,000 times more power! This is why the cathode in 300B needs to get so hot. But since Nutubes aren’t used as a current source in Nutube amp designs, they don’t need to dissipate this much power!

Nutube won't drive a load like 2A3 or 300B, not even with IEM. That's why we only use it in timber circuits. It actually runs pretty cool in our DAP.

 

[kazekhh]

I can't promise anything at this stage, but I can channel the request, will keep you informed when I receive feedback.

Would definitely convert mine too if UM is nice enough to do it for a reasonable fee!