The Topping pre90 preamp is nowhere as good as the HPA4 and LA4 preamps from Benchmark. I have had all 3. Even ASR folks agree about the short comings of the pre90 with certain amps. Though, one of the Stereophile reviewers uses the pre90 has his reference preamp over the LA4.
The Topping D90LE DAC is also not as good as the Benchmark DAC3B to my ears.
Here is an observation I had with 4 DACs and my RAAL VM-1a headphone amp. I tried the following DACs with everything else being the same:
1) Benchmark DAC3B
2) Lumin X1
3) Topping D90LE
4) Musetec 005
The DAC that stays in with the VM-1a is the DAC3B. The X1 was also excellent but there is something about the DAC3B and how it syncs with those VM-1a tubes that makes it my choice.
This weekend I was testing out the Lumin X1 direct to amp (LEEDH volume control) vs the Benchmark LA4 preamp connect to the X1. The LA4 was still a bit better. You could tell at low volume, and I even preferred it a louder volume. However, I decided to give the X1 a go over a second LA4 because I want to minimize boxes.
If I wanted the very best sound for the X1 system, I buy a second LA4 preamp over ANY other preamp at any price. At the moment the best sound is of secondary importance on the X1 system. I hated preamps that colored the sound. It irritated the heck out of me, don’t get me going on the noise from those preamps.
