Topping Pre90 Switching op amps?

I have found that the pre90, in my system, renders many recordings beautifully transparent and many other recordings thin and brittle. It seems that swapping op amps might be a solution. Has anyone done this? If so kindly report on your experience. 


I tried about 6 amps on the Topping pre90. There was a volume issue with the following amps and the pre90. It was way too loud and did not have any granularity on the volume settings.

- LSA Voyager 350 GAN

- CODA #8

- KRELL K-300i integrated

- D-Sonic m3a 800s

The following 2 amps sounded very good with the pre90:

- Benchmark AHB2

- Parasound A21+

The last 2 have some gain adjustment that likely was able to deal with the pre90. There are a lot of comments on ASR web site about this volume issue.

I got rid of the pre90 because of this frustration and went back to the Benchmark LA4 preamp, which works with all amps and is also as transparent as the pre90.

I am not a Topping hater; I recently re-bought the Topping D90LE DAC after I sold it previously.




I had volume issues with my McIntosh MC152 until I changed to the lower input voltage of the RCAs. I left the outputs on XLR and it worked fine. My problem is that it seems to render roughly half of my recordings worse than my regular preamp, a Hegel P30.

If you want the sound of the pre90 without the hassle, then the Benchmark LA4 is the best bet.

If you want the sound of the pre90 without the hassle, then the Benchmark LA4 is the best bet.

True but the price differential was unacceptable.  (I needed 3, now 4.)

Nota bene:  The OP was asking about swapping op-amps in the Pre90, not amps to connect to the Pre90.

"Nota bene: The OP was asking about swapping op-amps in the Pre90, not amps to connect to the Pre90."

Thanks kr4. For a second there, I thought that I was losing it, and the funny thing is that the OP didn’t correct them.


Yes. It was a digression, but interesting nonetheless. My question is on op amps, not amps.

I am running the Topping PRE90 with a VTV Purifi Eval 1 and I agree with your assessment regarding it be the incredibly transparent to the source but can sound thin or brittle. I remedied that with a Jolida SSX tube buffer and it renders the music with more body and tightens the bass. It's the best my system has sounded. Maybe this might be a direction for you rather than swapping opamps.


Did the tube buffer reduce the transparency by a noticeable amount? The idea of a tube buffer occurred to me but I thought it would necessarily add some haze given tube equipment generally has higher s/n ratios.

@dbb Surprisingly, it did not not reduce the transparency. I can still hear all of the details. I am using Altec A7 speakers which are over 100db efficient and it added a slight bit to the noise floor but you need to put your ear up to the treble horn. Preamps I had before this were Pass Labs X1, Modwright LS 36.5, Black Ice Audio Fusion F360. All had a higher noise floor. I tried the Topping D70s direct which was excellent on it's own and lead me to the PRE90 which on it's own is dead silent. 



Does the pre90 remote work well on yours. Mine, as reported by others in reviews, works poorly. I wonder if this issue has been fixed in newer production models.

The remote is weak. Not great off axis. I use an infrared repeater and it works great!

Just a follow up of using the tube buffer with the PRE90. I changed the stock Tungsol tube to an Allen 12au7 and the noise floor is dead silent now with a nice balanced sound. So you can have your cake and eat it too! I have a Psvane Art series 12ua7-s on the way to compare. Let's see what it brings to the table?

@kr4 If this is Kal, I purchased a Topping Pre90 to replace a Schiit Freya (with tubes) based on your writeup in Stereophile. Love it. Yes, one does need to be a marksman when aiming the remote!


It is I and I really wonder about adding a "tube buffer" to the Topping.  Seems counterproductive.


@tomcarr ​​​​@kr4 I also replaced the Schiit Freya + with the Topping Pre90 with the Jolida SSX. I had some local audiophiles over and we A/B'd them and everyone picked the PRE90 and Jolida SSX over the Schiit Freya +. I just sold the Schiit Freya + and have a Yaquin SD- CD3 Tube Buffer on the way to compare as I have a good stock of 6SN7 tubes to roll in it. I'll report back. 

@rrboogie I look forward to hear your impressions of the Yaquin with the Pre90.

I did notice that the s/n ratio is listed at greater than 75db for the Yaquin. It seems it may be too noisy for the super quiet Pre90.

 I am hoping that it is not too noisy as well. My idea with that unit is to have a little more "tube flavour", midrange bloom so that I could switch between the two tube buffers for a different listening experience. I am contemplating purchasing an ifi itube2 on the used market. Much better S/N numbers at 119dB.

I sold the Pre90 and bought the A90 discrete for it’s added headphone capabilities which are fantastic with my Hifiman HE 1000v2 headphones. The A90 discrete sounds a bit warmer to my ears in comparison to the Pre90. In the last couple of months I have A/B it against the Border Patrol EXT 1 and the Rogue Audio RP-7 and decided to keep the A90 Discrete in my system along with the ifi itube2. The Yaquin buffer sounded too dark, lacking details. The Jolida SSX got beat out by the itube2. I do prefer the tube buffer in front of the A90 Discrete but only by a slim margin. I could live happily with the A90 Discrete without it as well but I hear a little more presence, body and 3D soundstaging with the tube buffer in the chain.

Thanks for the update. I found myself consistently preferring the way more expensive Hegel p20 and p30 so the pre90 will eventually go up for sale.