Topping D90 great but question future

[ambre]

On 5/14/2020 at 8:37 AM, barrows said:

I am not sure I remember...  I think it was a 250 mA maybe?  Anyway, the fuse is marked.  Topping uses a dirt cheap glass body fuse, even a good quality Littlefuse ceramic body model would likely sound better.  

It is definitely a 5 x 20 mm size, slow blow.

I have asked Topping a few weeks ago about the specs of the Fuse.

 

It is fastblow, 0.2A 5x20mm. 

So not a Slow Blow.

 

Like Barrows I will try at short notice also the attached fuse.

About why or is measurable etc. is and remains on ongoing debate. But I will trust my ears and especially my family If we hear really a difference and/ or improvement. But it is  a very high price😇

[ambre]

7 hours ago, Blake said:

 

So you say the D90 is a "perfect" DAC and the upcoming Topping preamp will be the cleanest in the world.  As long as you believe this stuff, I suppose that is all that matters.  Enjoy!

 

9 hours ago, w1000i said:

 You mention the peramp in D90, and FYI Topping is about to lunch P90 as preamp and going to be the cleanest in the world alongside A90 a headphone amplifier.

That is indeed a statement that cannot be underpinned.

 

But  like Barrows it is a giant killer. but at the price, heck, it is a no brainer. And maybe with a better fuse ???

 

Best Regards, Andreas

[OldBigEars]

1 hour ago, ambre said:

I have asked Topping a few weeks ago about the specs of the Fuse.

 

It is fastblow, 0.2A 5x20mm. 

So not a Slow Blow.

 

Like Barrows I will try at short notice also the attached fuse.

About why or is measurable etc. is and remains on ongoing debate. But I will trust my ears and especially my family If we hear really a difference and/ or improvement. But it is  a very high price😇

 

Thank you for getting the exact spec.  Apos were not especially forthcoming when I asked them.  If I keep the D90 I'll probably add the upgraded fuse. Looking forward to hearing how it works for you.

[barrows]

6 hours ago, ambre said:

I have asked Topping a few weeks ago about the specs of the Fuse.

 

It is fastblow, 0.2A 5x20mm. 

So not a Slow Blow.

 

Like Barrows I will try at short notice also the attached fuse.

About why or is measurable etc. is and remains on ongoing debate. But I will trust my ears and especially my family If we hear really a difference and/ or improvement. But it is  a very high price😇

Wow!  That is really, really weird.  Typically, in every product I have ever been aware of over my 40 years of being an audiophile, I have never heard of any product which used a fast blow fuse for its main AC inlet fuse (fast blow fuses are often used internally in amplifier power supply rails to protect the output devices from burning at clipping).  The reason for this is that most components will draw the most current on the initial power up, because the power supply is entirely uncharged at this point, and the power supply capacitors act like a dead short until they are charged, hence there is a very "fast" and large inrush current, briefly; a slow blow fuse allows for brief periods of over current without blowing..  I am very surprised a 200 mA fast blow fuse could even survive as an AC input fuse in this DAC.

Sometimes "Audiophile" fuses blow more easily than their standard counterparts, probably because the Audiophile fuse makers err on the side of safety.  I have seen "Audiophile" fuses of the correct blow when they should not have, and sometimes it is necessary to raise the fuse value by one step to keep them from blowing when they should not.  Given the expense of these "Audiophile" fuses, i ma not sure I woudl put a fast blow, 200 mA, Synergistic Orange in this DAC, as I woudl be afraid it might blow at power up.  One might consider upping the value a little if they are going to use an "Audiophile" fuse.

 

Main AC input fuses basically protect the device from further damage if there has been an internal problem, they should only burn when there is an internal problem (a broken DAC which draws too much current, typically some kind of short somewhere in the circuit).  The fuse then fails to protect both the component from further damage, and from the possibility of catching fire.  I would not advise to change the fuse value recommended by Topping though...  but I know what I would do here.

[ambre]

13 minutes ago, barrows said:

Wow!  That is really, really weird.  Typically, in every product I have ever been aware of over my 40 years of being an audiophile, I have never heard of any product which used a fast blow fuse for its main AC inlet fuse (fast blow fuses are often used internally in amplifier power supply rails to protect the output devices from burning at clipping).  The reason for this is that most components will draw the most current on the initial power up, because the power supply is entirely uncharged at this point, and the power supply capacitors act like a dead short until they are charged, hence there is a very "fast" and large inrush current, briefly; a slow blow fuse allows for brief periods of over current without blowing..  I am very surprised a 200 mA fast blow fuse could even survive as an AC input fuse in this DAC.

Sometimes "Audiophile" fuses blow more easily than their standard counterparts, probably because the Audiophile fuse makers err on the side of safety.  I have seen "Audiophile" fuses of the correct blow when they should not have, and sometimes it is necessary to raise the fuse value by one step to keep them from blowing when they should not.  Given the expense of these "Audiophile" fuses, i ma not sure I woudl put a fast blow, 200 mA, Synergistic Orange in this DAC, as I woudl be afraid it might blow at power up.  One might consider upping the value a little if they are going to use an "Audiophile" fuse.

 

Main AC input fuses basically protect the device from further damage if there has been an internal problem, they should only burn when there is an internal problem (a broken DAC which draws too much current, typically some kind of short somewhere in the circuit).  The fuse then fails to protect both the component from further damage, and from the possibility of catching fire.  I would not advise to change the fuse value recommended by Topping though...  but I know what I would do here.

Hi Barrows

Ok this make a lot of sense. Will contact  again Topping about this issue.

Ps. I am not willing to spend €150 + en it blows within a few minutes.

 

Please see attached the reaction by Topping.

Regards Andreas

[barrows]

6 minutes ago, ambre said:

Hi Barrows

Ok this make a lot of sense. Will contact  again Topping about this issue.

Ps. I am not willing to spend €150 + en it blows within a few minutes.

 

Please see attached the reaction by Topping.

Regards Andreas

I am not trying to deny that they use a fast blow fuse for AC input, I just find such spec very, very curious if it is so.  Note that a slow blow fuse is typically marked with a "T" designation on the endcap (the "T" denotes time delay).

 

If one does not want to spend a ton of cash on an Audiophile fuse, a high quality standard industrial part should still be a nice upgrade of the cheap fuse Topping uses.  I would recommend a ceramic body fuse from Littlefuse of the appropriate rating, these are around $1.50.

[ambre]

1 hour ago, barrows said:

I am not trying to deny that they use a fast blow fuse for AC input, I just find such spec very, very curious if it is so.  Note that a slow blow fuse is typically marked with a "T" designation on the endcap (the "T" denotes time delay).

 

If one does not want to spend a ton of cash on an Audiophile fuse, a high quality standard industrial part should still be a nice upgrade of the cheap fuse Topping uses.  I would recommend a ceramic body fuse from Littlefuse of the appropriate rating, these are around $1.50.

Hi Barrows,

 

Already sent an rmail to Topping for clarification. May be a mistake?

Ps. I didn't removed the fuse yet may be the printing (if readable) gives the solution.

 

Do you still have the old fuse? What can you read on it ?

 

Regards, Andreas

[barrows]

1 minute ago, ambre said:

Hi Barrows,

 

Already sent an rmail to Topping for clarification. May be a mistake?

Ps. I didn't removed the fuse yet may be the printing (if readable) gives the solution.

 

Do you still have the old fuse? What can you read on it ?

 

Regards, Andreas

No, I sold the D-90...

[Rinaldi]

On 5/14/2020 at 10:53 PM, OldBigEars said:

Other than that I'm 4 days into testing the D90 vs my Hegel HD25.  Did you experience much break-in change?

I'm looking forward to the result of the comparison between the D90 and the HD25 ...

[4est]

18 hours ago, barrows said:

Wow!  That is really, really weird.  Typically, in every product I have ever been aware of over my 40 years of being an audiophile, I have never heard of any product which used a fast blow fuse for its main AC inlet fuse (fast blow fuses are often used internally in amplifier power supply rails to protect the output devices from burning at clipping).  The reason for this is that most components will draw the most current on the initial power up, because the power supply is entirely uncharged at this point, and the power supply capacitors act like a dead short until they are charged, hence there is a very "fast" and large inrush current, briefly; a slow blow fuse allows for brief periods of over current without blowing..  I am very surprised a 200 mA fast blow fuse could even survive as an AC input fuse in this DAC.

Sometimes "Audiophile" fuses blow more easily than their standard counterparts, probably because the Audiophile fuse makers err on the side of safety.  I have seen "Audiophile" fuses of the correct blow when they should not have, and sometimes it is necessary to raise the fuse value by one step to keep them from blowing when they should not.  Given the expense of these "Audiophile" fuses, i ma not sure I woudl put a fast blow, 200 mA, Synergistic Orange in this DAC, as I woudl be afraid it might blow at power up.  One might consider upping the value a little if they are going to use an "Audiophile" fuse.

 

Main AC input fuses basically protect the device from further damage if there has been an internal problem, they should only burn when there is an internal problem (a broken DAC which draws too much current, typically some kind of short somewhere in the circuit).  The fuse then fails to protect both the component from further damage, and from the possibility of catching fire.  I would not advise to change the fuse value recommended by Topping though...  but I know what I would do here.

The main AC fuse between the power transformer and the wall is not to protect the device, but to prevent fire and is required by UL and other organizations. By time it has blown the damage has typically been done to the unit. If they are looking to protect the device, they will put an additional one(s) inline between the power supply and the circuit and they are almost always fast blow. For that matter, most are fast blow IME, except for tube gear and big amps or oversized power supplies with lots of storage.

[barrows]

3 hours ago, 4est said:

The main AC fuse between the power transformer and the wall is not to protect the device, but to prevent fire and is required by UL and other organizations. By time it has blown the damage has typically been done to the unit. If they are looking to protect the device, they will put an additional one(s) inline between the power supply and the circuit and they are almost always fast blow. For that matter, most are fast blow IME, except for tube gear and big amps or oversized power supplies with lots of storage.

Umm, that is exactly what I said???  the fuse will only blow (if correctly specified) if there is already damage to the device.  Primary purpose of the AC line is to prevent fire, as we both stated.  The secondary purpose is to prevent further damage to the device:

For example:  If the D-90 were to develop a shorted output stage component, it would then draw excess current, which, primarily, could cause the unit to catch fire.  So primarily the fuse protects against that "large" problem.  But secondarily, a properly sized fuse will also blow early enough such that it usually prevents further damaged parts in the component.  This allows the component to survive, and only need a minor repair to be returned to proper working order (in may cases, not all of course, every failure mode is a little different).

I am certain we both know and fully understand this.  I am only posting more details for those who may not.

 

But you are mistaken if you are saying most AC line (input) fuses (in audio components) are specified as fast blow.  They usually need to be slow blow so that they do not blow with the higher current inrush at initial power up.  I have never seen a single audio component, be it line level or power amplifier, with a fast blow fuse specified for its AC input fuse before the D-90.

 

 

[ambre]

3 hours ago, barrows said:

Umm, that is exactly what I said???  the fuse will only blow (if correctly specified) if there is already damage to the device.  Primary purpose of the AC line is to prevent fire, as we both stated.  The secondary purpose is to prevent further damage to the device:

For example:  If the D-90 were to develop a shorted output stage component, it would then draw excess current, which, primarily, could cause the unit to catch fire.  So primarily the fuse protects against that "large" problem.  But secondarily, a properly sized fuse will also blow early enough such that it usually prevents further damaged parts in the component.    I am only posting more details for those who may not.

 

But you are mistaken if you are saying most AC line (input) fuses (in audio components) are specified as fast blow.  They usually need to be slow blow so that they do not blow with the higher current inrush at initial power up.  I have never seen a single audio component, be it line level or power amplifier, with a fast blow fuse specified for its AC input fuse before the D-90.

Hi 4est & Barrows, 

 

A lot of discussion and confusion now and not a straight answer yet.

What will it be: Fast Blow or Slow blow? What now is the safest type and functions well?

Please an understandable advice for a laymen.

 

Ps. Barrows promoted the Synergistic Research Orange.  If there is an underpinned measurement, blind test etc.... is a complete other kind of discussion. First of all I will trust my OldEars🤩.But it too costly to blow €155 within a few minutes of time.

 

Ps. In my Shanti Lineair Power Supply as counterpart for the Allo USBRidge they also describe Fast Blow (20mm fuse 500 mili amps Fast blow).🤭 

 

Please see attached today's reaction by Topping. They might also be confused. 🤯

[barrows]

9 minutes ago, ambre said:

Hi 4est & Barrows, 

 

A lot of discussion and confusion now and not a straight answer yet.

What will it be: Fast Blow or Slow blow? What now is the safest type and functions well?

Please an understandable advice for a laymen.

 

Ps. Barrows promoted the Synergistic Research Orange.  If there is an underpinned measurement, blind test etc.... is a complete other kind of discussion. First of all I will trust my OldEars🤩.But it too costly to blow €155 within a few minutes of time.

 

Ps. In my Shanti Lineair Power Supply as counterpart for the Allo USBRidge they also describe Fast Blow (20mm fuse 500 mili amps Fast blow).🤭 

 

Please see attached today's reaction by Topping. They might also be confused. 🤯

You should use whatever type and (fast or slow) and whatever value is recommended/specified by the manufacturer.  Any other approach would likely void your warranty.  If you decide to use an "Audiophile" fuse, of the correct type and value, and it blows, you should then demand a warranty replacement from the (fuse) manufacturer, and see if they recommend upping the value a little.

And, the provided fuse is marked with both type (fast or slow) and value (mA).  If you cannot read it, get a magnifier and a bright light and post the markings here.  These will be stamped into one of the end caps.

[ambre]

9 minutes ago, barrows said:

You should use whatever type and (fast or slow) and whatever value is recommended/specified by the manufacturer.

Hi Barrows, it was you who questioned the choice of a Fast Blow fuse. Can't handle this way of reacting. Back to the end.

Have a nice evening.

[barrows]

3 minutes ago, ambre said:

Hi Barrows, it was you who questioned the choice of a Fast Blow fuse. Can't handle this way of reacting. Back to the end.

Have a nice evening.

And I still do, but I am not going to recommend to anyone to use a different type and value of fuse than what the manufacturer recommends.  Please understand this is both a safety and a liability issue.

 

Given the small amount of overall capacitance (energy storage) in the D-90, I can see that they could get away with a fast blow fuse.  Most DACs of my experience have many times more capacitance internally than the D-90, hence why most DACs are almost certain to have a slow blow fuse at the AC line input.

[ambre]

Just now, barrows said:

And I still do, but I am not going to recommend to anyone to use a different type and value of fuse than what the manufacturer recommends.  Please understand this is both a safety and a liability issue.

Ok 🤠

[Morph]

 A very timely thread for me as I should receive the D90 in the coming week. 

So would it be ok to add an SR Orange ( or Blue ) Slow Blow instead of a Fast Blow? Also can I ask Barrows if one were to replace the mentioned 0.2A fuse, what would you recommend as an alternative?

 

Thanks 

Morph

[barrows]

I hope that someone with a D-90 will actually read the included OE fuse and post the markings here, then we will have less confusion!  I am sorry to have contributed to that confusion.

 

One other thing though...  The D-90 is universal voltage, with an input voltage switch on the underside.  It may be that the fuse Topping includes is specified for 230 volt countries.  Typically, an AC line input fuse would be 1/2 the mA value for 230 volt countries than for here in the US (1115 Volts).  Perhaps Topping includes a fuse specified for 230 volt countries, to be safe in those countries, and then the value is a bit low for US voltage (but safe, as the fuse will blow even sooner).

 

An example:

 

For Sonore Power Supplies, I specify a 315 mA fuse for the US (115 VAC) and a 160 mA fuse for EU (230 VAC).  These supplies are fairly high in capacitance (hence there is a high inrush current when powering up), so these fuses are slow blow types. 

[OldBigEars]

15 hours ago, Rinaldi said:

I'm looking forward to the result of the comparison between the D90 and the HD25 ...

 

absolutely, should be interesting.  I don’t want to rush to conclusions so I won’t say much now.  Only 6 days in with D90.  I’m a little underwhelmed, frankly, after expectations raised by the rave reviews and the whole ‘measurements’ thing.  All I care about is how it plays music.  I’m entirely neutral about the outcome. If it’s better than my Hegel, wonderful. If not, it goes back.  Note, I use coax on my HD25, via a Schiit Eitr.  And an SR Orange fuse and a decent AQ power cord.  It sounds pretty great, so I’m really not sure what the margin for improvement is. Using the Eitr makes it super easy to switch cables to compare. But many people say that the D90 works best via USB so I’m testing it that way too.  I’m not a fan of upsampled music so I play everything at its native value. Hopefully the D90 will settle down and improve.  If I had to choose today, I think it would be back in its box. 

[Miska]

3 hours ago, OldBigEars said:

I’m not a fan of upsampled music so I play everything at its native value.

 

With these kind of DACs, Hegel included, you have no choice about whether you have upsampling or not. You can only choose if it's the DAC's algorithm or something else.

 

[BobSherman]

8 hours ago, barrows said:

And I still do, but I am not going to recommend to anyone to use a different type and value of fuse than what the manufacturer recommends.  Please understand this is both a safety and a liability issue.

 

Given the small amount of overall capacitance (energy storage) in the D-90, I can see that they could get away with a fast blow fuse.  Most DACs of my experience have many times more capacitance internally than the D-90, hence why most DACs are almost certain to have a slow blow fuse at the AC line input.

I think allot of talk about the fuse for a $700 dac. IMO the fuse will make little difference. Not worth spending $150 for in this application IMO. Fast blow is also fine, it is not a power amp. Currently using the D90 I2s from a pi2aes, clearly better than usb imo.

[barrows]

1 hour ago, BobSherman said:

I think allot of talk about the fuse for a $700 dac. IMO the fuse will make little difference. Not worth spending $150 for in this application IMO. Fast blow is also fine, it is not a power amp. Currently using the D90 I2s from a pi2aes, clearly better than usb imo.

As I mentioned, the fuse did make a difference here, and also that i would suggest a ~$1.50  quality, Littlefuse ceramic body fuse would likely be a nice improvement over the el cheapo glass body OE fuse, so no need to necessarily go with an expensive "audiophile" fuse to get an improvement.

[BobSherman]

43 minutes ago, barrows said:

As I mentioned, the fuse did make a difference here, and also that i would suggest a ~$1.50  quality, Littlefuse ceramic body fuse would likely be a nice improvement over the el cheapo glass body OE fuse, so no need to necessarily go with an expensive "audiophile" fuse to get an improvement.

I don’t disagree with using a better fuse than the stock one. In my experience usually these differences are relatively small in the big scheme of things. 

[OldBigEars]

10 hours ago, barrows said:

As I mentioned, the fuse did make a difference here, and also that i would suggest a ~$1.50  quality, Littlefuse ceramic body fuse would likely be a nice improvement over the el cheapo glass body OE fuse, so no need to necessarily go with an expensive "audiophile" fuse to get an improvement.

 

@Barrows, hate putting the burden on you.  I can only imagine it wouldn't take much to improve on the quality of the standard fuse in the D90.  I took mine out and it's not a premium product.  I tried to read the text scrawled on in - albeit I didn't run around the house to find our magnifying glass, which was lazy - but couldn't figure out the spec on it. The Littlefuse tip looks interesting, although their website is not exactly consumer-friendly.  If I keep my D90, that's a possibility with nothing to lose (once we find out the real, confirmed specs

 

On another topic....power cable.  At about midnight last night I decided to put the original AC cable back, replacing the AudioQuest Blizzard that I normally use with my HD25.  The D90 bass was truly awful - horribly bloated.  Stuck the original cord back in, and voila....so much better. It was hard to stop listening at 1am.

[ambre]

20 minutes ago, OldBigEars said:

 

@Barrows, hate putting the burden on you.  I can only imagine it wouldn't take much to improve on the quality of the standard fuse in the D90.  I took mine out and it's not a premium product.  I tried to read the text scrawled on in - albeit I didn't run around the house to find our magnifying glass, which was lazy - but couldn't figure out the spec on it. The Littlefuse tip looks interesting, although their website is not exactly consumer-friendly.  If I keep my D90, that's a possibility with nothing to lose (once we find out the real, confirmed specs

 

On another topic....power cable.  At about midnight last night I decided to put the original AC cable back, replacing the AudioQuest Blizzard that I normally use with my HD25.  The D90 bass was truly awful - horribly bloated.  Stuck the original cord back in, and voila....so much better. It was hard to stop listening at 1am.

Hi NewBigEars,

Please try dsd 256 with HqPlayer and you will notice where the Topping 90 is designed for and a next step SQ and hires via usb.
Very best regards,Andreas