2. amps-preamps
  3. 168746-161963

New Preamplifier Testing (Poor sound)

Looking for help...

I got a new preamplifier to replace my integrated amplifier, but the sound is extremely underwhelming. Biggest issues are sound distinction and clarity (sounds dull) and field depth (sounds narrow/flat) with less depth and width regarding the sound field when listening to stored digital music.

Old set up:
Innuos Zenith -> (USB) Gustard X26 Pro -> (XLR) Cambridge Azur 851a -> (RCA) Cambridge Azur 851w -> KEF LS50 Meta's and Kube 12b subwoofer.

New set up:
Innuos Zenith -> (USB) Gustard X26 Pro -> (XLR) Rotel 1590MKii Preamp -> (XLR) Cambridge Azur 851w -> KEF LS50 Meta's and Kube 12b subwoofer.

I'm really surprised this new preamplifier was such a drop off in sound quality compared to my older, cheaper integrated amp, but wondering if there are any tests I could do to maybe change something to better figure out if its the preamp, or rather something I'm doing. Looking at all the extra digital inputs in the Rotel that my 851a doesn't have makes me think that maybe the 851a is just a more adept component at passing along my DAC's signal, where the Rotel is geared towards using it's internal DAC.

The Rotel is run in a "Tone Bypass" mode via the XLR connections to bypass the internal DAC.

Just wondering why the Rotel would choke off the sound so much while the older integrated amp make things sound so deep and bright when paired with the power amp?

A friend suggested running my DAC straight to my power amp and see if the sound was back to old (or at least better).

Any other suggestions I should try before I send the preamplifier back?
128x128ja_kub_sz
oldhvymec
5,101 posts
 
Can you leave it on for 24/7 or 14. Quick break in. Blanket a pair of speakers and put it on 10-30 % and let it play.. You'll be well within the window.. Use some good cables too. Hook it up and let it percolate.

In 48 - 72 hours if it isn't a LOT better. You gotta wonder..
Cables need a bit to settle too. But don't listen.. Then pull the blankets at 48 and 72..

I can tell if it's going to change the volume will go down around 36-48 hours and back up by 72 hours. Every time for me.. Everything just gets cleaner, tighter, the brightness goes away...(mids come forward more actually)

Regards
ja_kub_sz's avatar
ja_kub_sz OP
254 posts
 
@sns @oldhvymec @yyzsantabarbara

Thanks for the suggestions! Never thought about leaving it on.

I too want a preamp (or integrated amp) as opposed to just running my DAC to an amp.
jond's avatar
jond
5,694 posts
 
Maybe give the Dac in the Rotel a shot while you're trying stuff?
vladedelman
10 posts
 
I used to have a Rotel 1570 preamp (not the same, but close enough) and there are a couple of things that I remember the most: 

1) Soundstage was very hard to get and required speakers to be set up "just right" or it sounded flat.
2) Sound changes for better after being on for an hour or so. After a while, I was leaving it on 24/7
3) Noise floor was crazy high, which made it seem less dynamic than others. (Plugin headphones directly in, and see if you can hear it)
4) Built-in DAC was just OK. To me it sounded like everything going through internal DAC had some EQ applied to it, and I did not like what it did.
5) Extremely sensitive to power sources. Tested with few power conditioners, surge protectors, and a regenerator, and each one sounds very different from another and worse than directly into the wall in most cases. Just having a backup power supply (Eaton 9px) plugged in on the same circuit (even when not feeding preamp), generated terrible distortion in the midrange.
hshifi
572 posts
 
Hello,
First: Is your volume all the way up on the DAC or in fixed mode. Sometimes when you attenuate the volume on a DAC or streamer you will lose some of that great sound. Second: sometimes some preamps do not sound great with some amps. See if you can borrow another brand of preamp from a friend or store or maybe see if you can find something on the forums to let you know what works and what does not. Last but not least: Try a thicker gauge power cord. It can be an inexpensive $50 cord but try get up to 14 or even better 12 gauge. Maybe you have a friend or a store that will let you borrow or demo one. I have tested this several times. You will need about three days of it being plugged in. This is because you need to charge the capacitors and let it settle plus have time to do some critical listening. So try to leave it powered on during that period of time. Please do not plug it in and right away do your listening test. If you are in the Chicagoland area this store I frequently buy from lets you demo or try before you buy. https://holmaudio.com/
Not just cables but all gear except turntables. I hope this helped. 
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