Sylph Audio FB360 Mono Amplifier Kit Review

[amirm]

This is a review and detailed measurements of the Sylph Audio mono amplifier kit. The kit costs US $145 for the amplifier module itself (you are responsible for the power supply, case, connectors, etc.).

I asked for a finished product so it was easier to test. As noted, that is not what you get. Here is the module itself:

Seems like a very clean build.

The amp is built on the popular TI TPA3255. The included power supply is 48 volt from Moorsun.

Let's see how well this implementation measures.

Sylph Audio FB360 Amplifier Measurements
As usual, we start with our dashboard:

This is excellent performance though below company's 106 dB spec:

These little chip amps sure perform in the right (designer) hands!

The noise level is quite low especially at full power:

Distortion is kept under control until higher frequencies:

Frequency response shows some of the best tuning of PFFB I have seen:

Measured power beats specifications by a bit while showing remarkably low noise and distortion:

Even 40 Hz power is respectable:

We see the typical rise in distortion with frequency with this platform:

Finally, the amp is ready on power up:

Conclusions
If you ever wanted to build a high performance amplifier with very little cash outlay, your search is over. Add a switching power supply to the FB360, make sure you don't hurt yourself with respect to AC mains wiring, and you too can have an amplifier you can be proud of. You have lots of power, and very low noise and distortion.

I am happy to recommend the Sylph Audio FB360 monoblock amplifier.
------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[amirm]

Package Includes
1pc SylphAudio FB360 mono
1pc JST Input connector
4pc Female Faston Tab

Specifications:
Supply Voltage: 26V DC min to 52V DC max
Unclipped Power (<1% THD+N, 52V): 115W-8Ω, 210W-4Ω
Input sensitivity: 5V RMS
Voltage gain: 15dB (5.6V/V)
Input configuration: Fully Differential
Load impedance: 4Ω, or 8Ω
Footprint: 110mm x 100mm x 45mm (L * W * H)
Overcurrent /short protection: Yes
Over voltage protection: No
Overheat protection: Yes
Turn on-off pop suppression: Yes

Recommended Power Supply
(NOT INCLUDED)
– Single supply 52V SMPS, 300W or higher per module.
– DO NOT use power supply with split rails.
– MEAN WELL RPS-500-48-C or SE-450-48 adjusted to 51V to 52V
– Use 48V for unregulated “linear” supplies

 

[amirm]

Here is a picture of what is inside:

 

[RogerSmith]

Nice little amp.

 

[daniboun]

Finally it got reviewed ))) thanks @amirm
I built the ASH400 project months ago based on the Sylph module as well checkout :

"ASH-400 Project" Sylph Audio FB-100 Stereo Module with advanced PFFB

Hi amigos, I'm coming back to the forefront with a new project. This time I focused on the Sylph Audio FB100 module, based on a TPA3251 and an advanced implementation of the PFFB. Voltage Gain is factory set @ 14dB (5V/V) on this module. So I intended to couple it to my DAC SMSL D6s which has...

www.audiosciencereview.com

 

[daniboun]

BTW so you can compare amigos : the Sylph D100 has been measured here : https://www.audiosciencereview.com/...sylph-d100-p02-amplifier-module-review.46613/

 

[suttondesign]

[jaw drops]

 

[Hayabusa]

droop 2Khz -> 20Khz

 

[kyuu]

droop 2Khz -> 20Khz

As noted in the review, it's negligible.

Really quite an incredible amp module for the money.

 

[Sokel]

Really quite an incredible amp module for the money.

For a bare module without a power supply, no.
For 100 euro more one can get way better amp with integrated power supply module, certified, tested, etc. but a little less power.

Nice one though, thanks Amir!

 

[amirm]

For a bare module without a power supply, no.
For 100 euro more one can get way better amp with integrated power supply module, certified, tested, etc. but a little less power.

And far worse performance:

 

[Sokel]

And far worse performance:

That's the old,15 yo module, the new one from 2026 I posted is far-far better.

 

[daniboun]

That's the old,15 yo module, the new one from 2026 I posted is far-far better.

View attachment 545197

The Genuine IcePower 125ASX2 = 239€

Order ICEpower 125ASX2 Amplifier module

Buy the 125ASX2 online at SoundImports ✓ Same day shipping ✓ Low shipping rates

www.soundimports.eu

 

[Sokel]

The Genuine IcePower 125ASX2 = 239€

Order ICEpower 125ASX2 Amplifier module

Buy the 125ASX2 online at SoundImports ✓ Same day shipping ✓ Low shipping rates

www.soundimports.eu

Yes, exactly 100 euro more, as I wrote, with integrated power supply.

 

[amirm]

That's the old,15 yo module, the new one from 2026 I posted is far-far better.

View attachment 545197

Based on what independent measurements and with what measurement settings?

Even going by that, you can add a power supply to the FB350 and be similar pricing. So what is the advantage again?

 

[Sokel]

Based on what independent measurements and with what measurement settings?

Even going by that, you can add a power supply to the FB350 and be similar pricing. So what is the advantage again?

We have some early ones here:

ICEpower Conductor

Hmm, but where can you get them? I have an old 125ASX2 amp so the prospect of just getting a new board and have a nice upgrade is tempting.

www.audiosciencereview.com

Note that icepower measurements (althought honest in general based on previous models, the conditions are stated in the datasheet) use a 7th order 20kHz AP filter, so they seem a little better than would look with your usual BW.

The advantage, it depends.
Ease I guess, as one has fewer trouble to integrate PSU and safety features.
Plus, pre-certified for those who care.

 

[kyuu]

For a bare module without a power supply, no.
For 100 euro more one can get way better amp with integrated power supply module, certified, tested, etc. but a little less power.

Nice one though, thanks Amir!

I view an integrated power supply as a minus, actually. From what I've seen, it seems better to keep the power supply separate. I also don't see how it is "way better", although it does seem to be a stereo unit so pretty good value.

 

[daniboun]

Yes, exactly 100 euro more, as I wrote, with integrated power supply.

For 70€ your can get an amazing PSU for any TPA3255 module (2000W/ 48V)

Built using an LLC resonant circuit design with high-quality components. Excellent circuit design. Compact, modern (PFC+ LLC ). On the secondary side, A synchronous rectifier with 4 mosfets (150 v) instead of diodes. On the primary side, 2 transistors from magnachip: mdr60r037jf (37 mω, 70–80 a). The brain of the system is the kpe2592bsg chip—a specialized “2-in-1” combined controller that integrates control of the pfc (power factor corrector) and llc (resonant converter). The voltage range of 39–59.5 v is nice.

 

[Sokel]

I view an integrated power supply as a minus, actually. From what I've seen, it seems better to keep the power supply separate. I also don't see how it is "way better", although it does seem to be a stereo unit so pretty good value.

Oh, haven't realized that this Sylph is a mono kit.
Yes, ice is stereo.

The way better apart from measurements (I wait to see the power cube and the lows power ability of ice) comes from my personal way of view (mainly ease of any pre and post sale interactions, as ice is European (though they build in Malaysia I think) , so easy on warranty, etc.

 

[Sokel]

For 70€ your can get an amazing PSU for any TPA3255 module (2000W/ 48V)

Built using an LLC resonant circuit design with high-quality components. Excellent circuit design. Compact, modern (PFC+ LLC ). On the secondary side, A synchronous rectifier with 4 mosfets (150 v) instead of diodes. On the primary side, 2 transistors from magnachip: mdr60r037jf (37 mω, 70–80 a). The brain of the system is the kpe2592bsg chip—a specialized “2-in-1” combined controller that integrates control of the pfc (power factor corrector) and llc (resonant converter). The voltage range of 39–59.5 v is nice.

View attachment 545199
View attachment 545204

So about 500 euro for stereo all included (case, etc) as DIY.
Yes, good value, I agree.