Xduoo MT-603 tube buffer/passive preamp

Move this if needed. I’m not sure as I can not see the full category heading.

Anyhoo, I love my Xduoo TA 26 with my DT1990 Pros or DT150’s, DT990 600ohm or KPH40i. Not so much my DT880 600ohm for some reason although I’ll give them another shot a bit later.
I digress.

Get on with it!

I was wondering if I could do something to improve/widen/fatten the soundstage a bit & I might have found a fairly inexpensive solution. An Xduoo MT603. Granted it took 2 or 3 months from the time I ordered it to get it, but it finally arrived today. It was literally saying “out for delivery” for over a week, on Amazon tracking. They had delivered an MT602 in an MT603 box a couple of weeks ago. I sent it back.

Im off track again. I’m listening to Holst The Planets as a write. First impressions are it makes the sound bigger I think, richer, but I’ll have to set up my 2nd TA26 & do side by side comparison at a later date. I’m not hearing anything to complain about. Still has plenty of detail. Things are just bigger, warmer sounding, maybe more 3D, is the simplest description I can make.



Epic Score Winterking & wow these sound good. My Sennheiser HD599SE really like tubes I think. I haven’t put them on in a long while as they were not competing well against my various Beyers, a few months ago, but I must say now that I don’t know why. They are sounding fargain awesome now.

On another post I mentioned the Topping E50 was making popping noises when the digital input was changed, or even when the source was turned off, so that isn’t acceptable. I was using the E50 remote for volune control into a Singxer SA1 into my Hafler 9505. I changed the E50 out for a Geshelli J2/AKM. It doesn’t have a remote so I switched the Singxer out for a Topping A70 Pro. The 9505 remains in the chain. No more popping noises. However, for these speakers, the sound is just too clean I guess, for movies & such. The solution is the Xduoo MT-603 connected in between the J2 & A70. Now it sounds fuller, but it’s still clean; just not too clean. Note I’m not complaining about the J2 or the A70. The A70 I’ve used a lot but with 600ohm DT990 mostly & that sounds winners.

So Xduoo MT-603 doesn’t add anything to the signal except some subtle warmth I think. No extraneous noise that i can detect. One thing though, is it seems the MT-603 created a loss of volume. Setting the J2 on it’s highest gain output solved that issue.

It was July 2nd 2024 when I first noticed that the Xduoo MT-603 isn’t really a passive preamp. It will pass signal through even with it turned off. You best not have the volume cranked on your source or other preamp with volume control because if you turn the MT-603 on, it’s going to add at least 10db of gain to whatever you’re listening to.