Sound quality issues with phono preamp into line in

[CapnKengaru]

I just recently purchased a Wiim Ultra and am having some issues with the Line In output sounding much quieter than if I plugged my turntable directly into my amp.

Here's my setup: Technics SL-D2 with MM Audio-Technica AT71 cartridge and Pickering style stylus -> Fosi Audio Box X5 phono preamp-> Wiim Ultra Line In -> Line Out to Fosi Audio ZA3 Amp -> ELAC Uni-fi 2.0 UB52

I currently have the preamp gain toggle set to 48db. If I plug it directly into the amp it sounds great, and can get plenty loud. Once I plug it into the Wiim Ultra Line Input it gets at least 50% quieter and starts to sound very compressed. This compression is even more evident when the music crescendos and multiple instruments/vocals are happening at once, the sounds starts to get distorted. I'm not the biggest audiophile, so I don't know if "compression" is the right word to describe the sound. It sounds like if you put a youtube video on 144p. If I increase the db on the preamp, the sounds does get louder but it's completely blown out and sounds even worse.

So I'm wondering, has anyone else experienced this when connecting an external phono preamp to the Wiim Ultra's Line In? Is there possibly some settings I can adjust to fix this? Is this just due to the quality of the ADC in the Wiim Ultra? I really wish they just had an analog passthrough option

As a side note: My TT and my Wiim Ultra are a bit too far from each other for me to test out directly hooking it up to the Phono In. From what I hear, some degradation can happen if you run a cable too long before it gets the phonostage.

 

[Mr Ee]

Welcome.

What sampling rate / bit depth do you have for line in?
I'd suggest trying 96 khz/24 bit.

What's your line out level set to? e.g. 500mv, 1v, 2v?

 

[CapnKengaru]

Welcome.

What sampling rate / bit depth do you have for line in?
I'd suggest trying 96 khz/24 bit.

What's your line out level set to? e.g. 500mv, 1v, 2v?

It’s currently set to 24 bit/192 kHz. I’ll give 24/96 a try and report back!

Line out level is set to 2 vrms.

 

[Mr Ee]

It seems quite likely that the Ultra's line in sensitivity is higher than than the Fosi's, explaining the significant volume difference.
It could be that the 48db gain is providing too much input voltage, causing the ultra adc to clip.

Maybe try lowering the phono gain. Yes, this will further reduce the ultra's volume, but it may help with the sound quality and it may still goes loud enough

 

[r5yk5]

If I plug it directly into the amp it sounds great, and can get plenty loud. Once I plug it into the Wiim Ultra Line Input it gets at least 50% quieter and starts to sound very compressed.

I think you have your answer right there. I love my wiims but my record player sounds better to me straight into the amp.

 

[CapnKengaru]

Ok reporting back after tweaking for a little bit. I lowered the preamp gain to 33db, increased the Wiim pre-gain to +6db, and switched to a Stanton 500 cartridge which drives a bit more output. It definitely sounds much better and can get louder, but I do still notice some lost low-end and clipping. Also, I did move my turntable closer and try the direct Phono In to compare, but it actually sounded worse than my external preamp did.

I'd suggest trying 96 khz/24 bit.

I switched between 96hz and 192khz and couldn't really hear much of a difference honestlly

I think you have your answer right there. I love my wiims but my record player sounds better to me straight into the amp.

This is exactly what I was hoping wasn't the case. Outside of this one issue, Wiim Ultra meets all of my needs.. but this might be a dealbreaker for me. The goal was to have one box I can connect my Spotify, TV, and turntable to for ease of use. Might end up testing out a proper name-brand receiver to compare phono sound quality.

 

[Mr Ee]

I switched between 96hz and 192khz and couldn't really hear much of a difference honestlly

No worries, me neither
Some reported issues with 44.1 / 16 in the early days. Couldn't recall if this had been fixed.