Output stage : Wiim Amp vs (disappointing) Wiim Amp Ultra

[Emilio75]

Hi,

I just bought a Wiim Amp Ultra to replace my dead Marantz CR610.

While I love the "Ultra" part (preamp, streamer, Roomfit, iOS app etc), I'm very disappointed by the "amp" part (the output stage), which makes my 25-year old Tannoy 636 SE sound depressed. Treble space is amazing, but there is no dynamics, and weak bass. The CR610 was overall way better. Even my old NAD312 drove them better.

So unfortunately I can't keem Wiim Amp Ultra.

Since I do want to keep Roomfit and HDMI Arc , the only alternative seems to be :
A. Wiim Amp (the non-Pro version without PFFB - plus Airplay 2, by the way).
B. Wiim Ultra + another power amp (Hypex nCore based for instance, like the Cambridge Audio MXW70 or Audiophonics)

My questions :

Q1 : Has anyone faced such issue with Wiim TPA3255 PFFB output stage, and what solution did you find in a similar budget ?

Q2 : Would the Wiim Amp (non pro) sound better ? (please don't compare watts, I barely listen loud, and it's probably all about impedance and reactive/capacitive response here)

Q3 : Do you confirm Hypex nCore would bring my Tannoy 636 SE back to life ?

Thank you !

 

[RandomEar]

It is very, very unlikely that the WiiM Amp Ultra sounds significantly different from your previous Marantz. The WiiM is also far more powerful than the Marantz (about 50 vs about 180 W) and has all the power down to 20 Hz and a flat frequency response. Further, it offers about 15 dB better THD + N, as far as I could find.

Unless there are some settings like EQ active, it's much more likely that due to the Marantz being dead and the consequential lack of a direct comparison, your impression is a little skewed.

In your position, I would just play with the EQ a little until you're happy with the sound. After all, that's what it's for, right?

 

[voodooless]

AMPs have no sound signature unless they are broken. They do not influence sound as you describe.

Very likely, what you experience is due to Roomfit. Generally, room correction would yield a much lower bass content in general. This may give the feeling of less dynamics. The fix is easy: use EQ to shape the sound to your liking.

 

[Marc v E]

Hi,

I just bought a Wiim Amp Ultra to replace my dead Marantz CR610.

While I love the "Ultra" part (preamp, streamer, Roomfit, iOS app etc), I'm very disappointed by the "amp" part (the output stage), which makes my 25-year old Tannoy 636 SE sound depressed. Treble space is amazing, but there is no dynamics, and weak bass. The CR610 was overall way better. Even my old NAD312 drove them better.

So unfortunately I can't keem Wiim Amp Ultra.

Since I do want to keep Roomfit and HDMI Arc , the only alternative seems to be :
A. Wiim Amp (the non-Pro version without PFFB - plus Airplay 2, by the way).
B. Wiim Ultra + another power amp (Hypex nCore based for instance, like the Cambridge Audio MXW70 or Audiophonics)

My questions :

Q1 : Has anyone faced such issue with Wiim TPA3255 PFFB output stage, and what solution did you find in a similar budget ?

Q2 : Would the Wiim Amp (non pro) sound better ? (please don't compare watts, I barely listen loud, and it's probably all about impedance and reactive/capacitive response here)

Q3 : Do you confirm Hypex nCore would bring my Tannoy 636 SE back to life ?

Thank you !

I'm sorry to hear the amp ultra doesn't live up to your expectations. I have the wiim ultra and like you, very much love what it does.

Anyway, back to topic. The wiim amp ultra has 100 watt per channel into 8 ohm; the marantz c610 has 60 watt. So on first impression that would seem enough.

One weakness of the wiim ultra amp I recollect is that it had its limitations when dealing with a 2 ohm load. If you check your speakers specs or online review, you can find if this is the case.

If that isn't the likely cause, I would not buy a new amp, but measure first with Rew plus umik or Wiim's Roomfit.
Dial in an eq target curve that matches the Harman house curve. That made a world of difference in my setup.

I you decide to buy a stronger amp, I would recommend this one, since it matches the case of the wiim ultra perfectly: https://internetofmusic.nl/product/iom-ultra/

 

[RandomEar]

Good point about the impedance. Luckily, the Tannoy 636 specs I could find list 6 Ω nominal and 4 Ω minimum, which would be unproblematic.

 

[ehabheikal]

Good point about the impedance. Luckily, the Tannoy 636 specs I could find list 6 Ω nominal and 4 Ω minimum, which would be unproblematic.

Did you use a calibrated mic with roomfit?

 

[Mart68]

One weakness of the wiim ultra amp I recollect is that it had its limitations when dealing with a 2 ohm load. If you check your speakers specs or online review, you can find if this is the case.

The Marantz CR610 is hardly a powerhouse into low impedance loads so there's no way that's the cause of the difference. I'd bet money the Wiim is better at that even though it's no Krell.

Probably the problem is the DRC set up.

 

[Emilio75]

Thank you all for your answers.

The main lack is about dynamics, which has nothing to do with the frequency response (EQ).

I know my songs, I know my Tannoy for 25 years, I’ve had the CR610 for 10 years, and well… When a perfectly-known big impact or orchestral fortissimmo is expected but just « pschitt », it is what it is.

I noticed this immediately (first minutes of listening, even though I was amazed by the nice and very welcome treble space, and the great Wiim application).

The day after I used Roomfit for the first time. Roomfit corrections are useful, and indeed lowered the bass response - for a flatter, more homogeneous response, which is good and I fully agree with.

After this, the dynamics is still poor and, yes, my loudspeakers do sound depressed. That’s it.

The bass response is strange, sometimes completely ok, some other times completely lacking.
I don’t know why.
All I know as an engineer is that a loudspeaker is not only a R load but also a LC load, with L and C varying with frequency. Power output at 8 or 4 ohms is the ‘R’ part and I trust every measurement. My Tannoy dip at 3 ohms, and I’m convinced it’s not an issue at all. But the L and C part might be very challenging for amplifiers and I think that’s where the Wiim falls short.

Thank you @Marc v E, I’m going to check this amplifier.

 

[RandomEar]

I'm sorry, but there is no "dynamics" if the FR is flat and your amp has enough power. As far as I can see from the specs, your speakers are not difficult to drive and you say yourself that you are listening at low volumes. This is not a challenging situation for any amp to drive.

All the differences you describe are easily explained by you unintentionally listening at a slightly lower volume with the WiiM. More volume = more "dynamics". As long as there are no clear objective indicators that something is wrong with any device in your chain, I would assume that this is simply a case of 100% sighted bias and uncontrolled, non-level matched testing in action.

Please don't take this as a personal attack. We see cases like this literally every single day here on ASR and I can't remember the last time anything at all was actually wrong with the amp, the DAC or whatever else. It was always either some unnoticed change in some setting or the user got the wrong impression from sighted testing. How else would you logically explain that the bass is sometimes good and bad the next time (for the same music, I assume)?

 

[Marc v E]

Are both speakers connected in phase? Ie is not one accidentaly canceling the other?

If you, for example connect only 1 speaker, do you get the dynamics you'd expect?

 

[Emilio75]

Are both speakers connected in phase? Ie is not one accidentaly canceling the other?

If you, for example connect only 1 speaker, do you get the dynamics you'd expect?

Yes I tried this too - I didn't see a huge difference actually.

 

[Sir Sanders Zingmore]

Lower perceived dynamics could simply be because like most auto-eq algorithms, Roomfit probably lowers output levels to avoid clipping.
So this could all be really a level matching “issue”. The old amp might sound more dynamic because it’s actually louder.
Try cranking the wick on the Wiim and see if you regain the wham

 

[Emilio75]

How else would you logically explain that the bass is sometimes good and bad the next time (for the same music, I assume)?

the L & C part of a loudspeaker seen as an electrical load.

+ about dynamics : response time, current ability vs L & C etc... High efficiency D-class chip tuning comes with a lot of constraints and is an art by itself.

Overall, I spent hours trying to find an explanation and a fix. I couldn't. Now I just want to feel the music, to enjoy my hifi system, and I don't with this amp. Believe me, I'd be so happy to keep this nice little box and just forget it.

We all know that a hifi system sits somewhere between science and art. No equation exists to say "sounds good or not". That's it.

 

[Emilio75]

Did you use a calibrated mic with roomfit?

I used my iPhone’s mic. I get this disappointing sound with and without RoomFit.

By the way Roomfit is great ! That’s why I want to keep a Wiim device for the preamp/streamer part.

 

[voodooless]

the L & C part of a loudspeaker seen as an electrical load.

Yes, we know... Speakers have impedance. Amps are generally tested with various load configurations, and the WiiM does more than well enough.

+ about dynamics : response time, current ability vs L & C etc... High efficiency D-class chip tuning comes with a lot of constraints and is an art by itself.

No art, just engineering. All of this is in the measurements; there is no hidden magic.

The damn thing does 250W into 2R. There is no limitation there!

 

[Emilio75]

Your point of view.

My ears.

This forum with passionate music and technology lovers, and this worldwide Hi-fi market with hundreds of small passionate manufacturers.

And a big, an incredible news : TI just killed the market with a $5 chip.

 

[voodooless]

Your point of view.

Those are the facts in evidence.

My ears.

No, not just your ears! That’s the whole problem.

 

[Svend P]

Thank you @Marc v E, I’m going to check this amplifier.

Make sure you get it with an option to return it when disappointment sets in. It will not solve your perceived problem. All properly constructed amplifiers sound the same.

 

[Emilio75]

No, not just your ears! That’s the whole problem.

Funny, but not very kind.

 

[Ruediger]

I believe there are some things missing with a new amp. For the better.

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