Topping D90 as preamp

• • Share

12 hours ago, all300b said:

I purchaseda Topping D90 to compare with my now aged Eximus DP-1. Had to usethe discrete attenuator on the Eximus to level match between the two - I tried to obtainidentical SPLs at the listening chair withwhite noise. Not sure if this is ascientifically correct approach, but theEximusoutput is 3V single ended and theTopping 2V.

A small surprise was that I liked the Topping better than mypreviously5X more expensive DAC - it's easier to hear small details,highfrequencies are more present, andthe presentation has a greater sense ofspaciousness. This is going into a tubed integrated amp. But abigger surprise was how nice upsampling to DSD in Roon could be for many, thoughnot all, PCM recordings.

As I understand it, DSD bypasses much of the new AKM chip in the Topping, which isa key selling point of thisDAC. This throws a wrench into a search for nextDAC upgrades. Forexample, highly regarded DACs such asHolo and Denafrips look awesome, but if DSD software upsampling ends up the winner- and I have not even TRIEDHQ player yet - then would be wasting money on abeautiful set of discreteresistor networks that would never be used.

Any thoughts on this? Thanks!

Bryan

Is it really wasting your money if you like the way they handle DSD too? There are always features in things we don't need and would prefer to not pay for. Alas...

• • Share

In the Holo audio DACs there is a discrete converter for DSD, and a separate discrete converter for PCM, so regardless of what format you play, you are always not using one set of the discrete DACs. Holo audio also sells two versions of their more simple DAC, the Cyan. If you just want to play DSD, you can get the CYan DSD, and DSD is all it will do, so no worries about paying for circuitry you will not use.

As for the AKM chips, they have direct DSD mode, which bypasses all of the DSP, oversampling, and the delta sigma modulator, and just sends the incoming DSD stream directly to the conversion stage. THis approach sounded fantastic to me with the D-90 and DSD 256. Best performance with the AKM 4499 is with DSD 256 as far as I am concerned.

• • Share

5 hours ago, barrows said:

As for the AKM chips, they have direct DSD mode, which bypasses all of the DSP, oversampling, and the delta sigma modulator, and just sends the incoming DSD stream directly to the conversion stage. THis approach sounded fantastic to me with the D-90 and DSD 256. Best performance with the AKM 4499 is with DSD 256 as far as I am concerned.

Hi Barrows,

I own also a Topping 90 feeded by the Allo Usbridge Signature with Uptone IsoRegen.

Using always Hqplayer [ poly-sinc-ext2 and ASDM 7 orASDM5EC]for upsampling DSD 256 of 512 depending which filter I use.

• • Share

19 minutes ago, w1000i said:

it measures better with 256 instead of 512

I have askedBarrows for an explanation especially i dont hear any kind of difference and for somemusic Dsd 512 sounds better. At the end it handles Aboutaleb SQ.

• • Share

5 hours ago, ambre said:

Hi Barrows,

I own also a Topping 90 feeded by the Allo Usbridge Signature with Uptone IsoRegen.

Using always Hqplayer [ poly-sinc-ext2 and ASDM 7 orASDM5EC]for upsampling DSD 256 of 512 depending which filter I use.

Can you explain why at DSD 256 is better?Is that in terms of[ASR]measurementand/or by listening?

Very best regards, Andreas

Hi Andreas. I looked at the data sheet for the AKM 4499 chip used in he D-90. The data sheet has specifications for the chip's performance with different DSD rates, it can clearly be seen that at DSD 256 it performs very well, but that noise noise and distortion actually rise with DSD 512 input. I have heard Andreas Koch [DSD expert and designer of Playback Designs DAC] discussing different DSD rates, and his point of view is that the "switches" used to convert DSD are not really fast enough to cope perfectly with sample rates as fast as DSD 512, so this may be why the AKM 4499 chip performs better with DSD 256 [the converter tech in the AKM 4499 is a switched resistor converter].

See section 8.1.2 of the attached data sheet for details.

AK4499_Feb2019.pdf

• • Share

4 minutes ago, barrows said:

Hi Andreas. I looked at the data sheet for the AKM 4499 chip used in he D-90. The data sheet has specifications for the chip's performance with different DSD rates, it can clearly be seen that at DSD 256 it performs very well, but that noise noise and distortion actually rise with DSD 512 input. I have heard Andreas Koch [DSD expert and designer of Playback Designs DAC] discussing different DSD rates, and his point of view is that the "switches" used to convert DSD are not really fast enough to cope perfectly with sample rates as fast as DSD 512, so this may be why the AKM 4499 chip performs better with DSD 256 [the converter tech in the AKM 4499 is a switched resistor converter].

See section 8.1.2 of the attached data sheet for details.

AK4499_Feb2019.pdf 1.7 MB · 2 downloads

Hi Barrows,

many thanks for this kind of explanation.

I don't have a technical background but understand what you are pointing.

I [my real life] don't hear differences of SQ maybe because I am using another kind of filter to lower CPU capacity. Especially when using the EC filtersmy Mac Mini I7 [6 Core] sounds.... like an Apple hairdryer.

But the Topping 90 is a real bargain compared to my previous dacs and sound much more detailled resp. especially in combination with Uptone ISORegen,EtherRegen and the very nice Allo UsBridge Signature.

Best regards, Andreas

• • Share

2 hours ago, OldBigEars said:

Barrows,

Do you happen to know what's the spec of the fuse in the D90. I think you've mentioned elsewhere that this DACreponds well to upgrading with an audiophile grade fuse?

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.

• • Share

19 minutes ago, w1000i said:

How do you evaluate the D90 compare to other DACs you tried ?

Please note this is specifically referring to the D-90 in "DAC mode" with DSD 256 input from a Signature Rendu SEoptical, with a Synergistic Orange fuse in the D-90.

It is a giant killer. Not the best I've heard, but very, very good. It probably needs to be paired with a good preamp to really shine, as the "DAC mode" defeats the volume control, and I do not think the output stage is quite beefy enough [current headroom] to drive amps directly, but at the price, heck, it is a no brainer.

There are better DACs, but the ones I know of all cost 10x as much or more...

• • Share

1 hour ago, w1000i said:

Do you think it's better than Audio gd R7 [r2r] ?

Never heard it...

• • Share

There is no preamp cleaner than no preamp! I prefer to not use a preamp at all, so I choose a DAC with a beefy enough [enough current headroom] to drive my amplifier directly.

• • Share

1 hour ago, w1000i said:

and FYI Topping is about to lunch P90 as preamp and going to be the cleanest in the world

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!