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

[daniboun]

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 the same output level at 5V with its volume set to maximum. Which should match perfectly.
I used a 38V/400W SMPS power supply for this project, set at 38V/10.5A with a ripple below 150mV and an active PFC. (Output can be set between from 33VDC to 38VDC)
As usual, I worked the front of the case from a wooden panel, I opted for Ash wood this time, just to change a little compared to my previous Bamboo projects

As I write this, Lester has probably sent a RTR amp to Amir for an upcoming ASR review. I know Lester aimed for a very good 108db SINAD @5W under ASR test conditions... let's wait for Amir here-)

About the FB100 Module : https://www.audiosciencereview.com/...ance-amplifier-modules-2024-and-beyond.50023/

In the same way as the 3E Audio modules, I am interested in the Sylph Audio modules because the two candidates play in the same high school) So I wanted to test this module out of curiosity and share my possible enthusiasm with the community)

I will share my opinion on this module after a good listening session and I will come back later on this same thread to tell you more)

@SylphAudio > Thank you in advance for your contribution and questions relating to the module

In the meantime, for those who are interested in this DIY project, here is the list of components used:
Count around $280 for this project

Sylph Audio FB100 module

Black aluminium case

Binding posts

IEC Switch ON/OFF

PSU : 38V/400W with active PFC

DC blocker (optional)

220V led

XLR plugs

XH 2.54MM shielded cables (for inputs)

Cables :
Any good quality copper cables, from 1.5mm2 to 2mm2, shielded if possible.
I make my own cables.

 

[SMen]

Hello daniboun. Just want to give you a big thumbs up for your inspiring efforts.

I can see that your power supply selection is on Ali Express. I have used Ali but also audiophonics. This looks excellent value. Did you select this on the basis that it is PFC, and on the <150 stated ripple which also seems good too?

I am thinking of building one of these so I await your listening findings. I am also interested in the previous D100 model. Do you miss the option of trying other op amps?

I suspect the designer's choice here is necessary to achieve the high SINAD and 'controlled and strong' PFFB.

One very newbie question though. The only concern I have is the larger balanced connector socket holes!! Do I just use a larger drill bit for these?

Great work, thank you!

 

[CamRector]

As always great job.
I used that same power supply in my first 3e build.
Waiting for your subjective comparison between the 3e and this.

 

[daniboun]

Hello daniboun. Just want to give you a big thumbs up for your inspiring efforts.

I can see that your power supply selection is on Ali Express. I have used Ali but also audiophonics. This looks excellent value. Did you select this on the basis that it is PFC, and on the <150 stated ripple which also seems good too?

I am thinking of building one of these so I await your listening findings. I am also interested in the previous D100 model. Do you miss the option of trying other op amps?

I suspect the designer's choice here is necessary to achieve the high SINAD and 'controlled and strong' PFFB.

One very newbie question though. The only concern I have is the larger balanced connector socket holes!! Do I just use a larger drill bit for these?

Great work, thank you!

Thanks

The Sylph Audio D100 seems a little outdated to me although it's still quite good. See the full review here:

D100 Review

On the latest generation of TPA325X modules, OP amps have very little impact on performance. The OPA1612 remains a sure value, which is why 3E Audio and Sylph Audio use this one. What has an impact on performance is the implementation of the PFFB, @SylphAudio > I guess you share my point of view)
I think that Lester wants to highlight with the FB100, that we can reach a good 110W / 4R with a 38V PSU, which allows you to have a good reserve without consuming too much and while preserving an excellent Sinad.

For balanced inputs, you must consider the size of the module... we are on small sized modules here, the JST XH 2.54 seem to be the right choice....

 

[SMen]

Thanks

The Sylph Audio D100 seems a little outdated to me although it's still quite good. See the full review here:

D100 Review

On the latest generation of TPA325X modules, OP amps have very little impact on performance. The OPA1612 remains a sure value, which is why 3E Audio and Sylph Audio use this one. What has an impact on performance is the implementation of the PFFB, @SylphAudio > I guess you share my point of view)
I think that Lester wants to highlight with the FB100, that we can reach a good 110W / 4R with a 38V PSU, which allows you to have a good reserve without consuming too much and while preserving an excellent Sinad.

For balanced inputs, you must consider the size of the module... we are on small sized modules here, the JST XH 2.54 seem to be the right choice....

Thank you

Sorry, I did not understand the JST XH 2.54 reference?

Yes, I think this is a very good summary regarding 110W / 4R with a 38V PSU. And a good point. Also regarding heat, and handling the heat. It is why I am attracted to this implementation. Looking forward to learning of your listening impressions.

 

[daniboun]

Thank you

Sorry, I did not understand the JST XH 2.54 reference?

Yes, I think this is a very good summary regarding 110W / 4R with a 38V PSU. And a good point. Also regarding heat, and handling the heat. It is why I am attracted to this implementation. Looking forward to learning of your subjective impressions.

My bad, I misunderstood, I saw that you were talking about holes to drill ))) "he only concern I have is the larger balanced connector socket holes!! Do I just use a larger drill bit for these" Drilling is easy with the right tools, I use this

Anyway, will share my impressions asap.I need some time, I'm working quite a bit at the moment

 

[SMen]

My bad, I misunderstood, I saw that you were talking about holes to drill ))) "he only concern I have is the larger balanced connector socket holes!! Do I just use a larger drill bit for these" Drilling is easy with the right tools, I use this

Anyway, will share my impressions asap.I need some time, I'm working quite a bit at the moment

Thank you! I know ... very basic question ... but duly answered! . Excellent.

 

[SylphAudio]

Thanks Danny for the purchase!
That was a fast build. My ASR sample amp is still in progress. Only the drilling holes for the smps and the amp module + wirings, then it will be good to go.

The Sylph Audio D100 seems a little outdated to me although it's still quite good. See the full review here:

D100 Review

I designed the D100 to have a higher 2nd harmonic through output inductor selection, it can measure 102dB 5W/4R if OPA1656 is being used. Do note that JRC4565 was used on that D100 review, and it is a random stock so you'll get more or less the same performance.

JRC4565 was selected to slightly lower the clarity / perceived highs and to have that old school amp (rich and thick) tone. (credits to AEDIO japan for the opamp rolling)

For FB100, it was designed to get the best SINAD out of a TPA3251 chip. It uses a different output inductor so the harmonics will be different compared with D100.

recommended power supply on link below. (adjust to 38V)

LOF350-20B36-C MORNSUN Guangzhou S& T | C5752296 - LCSC Electronics

LOF350-20B36-C MORNSUN Guangzhou S& T $42.5429 - - Power Modules ROHS datasheet, price, inventory C5752296

www.lcsc.com

 

[daniboun]

For FB100, it was designed to get the best SINAD out of a TPA3251 chip. It uses a different output inductor so the harmonics will be different compared with D100.

Thanks but what about advanced PFFB ? Would be nice to explain this point ?

 

[SylphAudio]

Thanks but what about advanced PFFB ? Would be nice to explain this point ?

Some modifications to achieve a higher feedback factor / deeper PFFB.

Also do note that since FB100 is very transparent, power supply selection can have a noticeable effect on the sound. I suggest comparing your power supply with a stock PA5 supply (create an adapter like on the pic below to be able to use it) to have a reference for comparison.

 

[daniboun]

Some modifications to achieve a higher feedback factor / deeper PFFB.

Also do note that since FB100 is very transparent, power supply selection can have a noticeable effect on the sound. I suggest comparing your power supply with a stock PA5 supply (create an adapter like on the pic below to be able to use it) to have a reference for comparison.

On one of my old projects I made a custom PSU for the PA5 and tried to compare but I noticed almost no difference between the stock PA5 PSU (144w) and the one I Diyed (300w)
The only way to compare it is to get reliable measurements....

A good basis for comparison will be for me to compare the FB100 to the 3E Audio coupled with my Micro-Audio PSU)

BTW I dismantled the PA5 psu and it seems to be a LLC type

 

[312elements]

Some modifications to achieve a higher feedback factor / deeper PFFB.

Also do note that since FB100 is very transparent, power supply selection can have a noticeable effect on the sound. I suggest comparing your power supply with a stock PA5 supply (create an adapter like on the pic below to be able to use it) to have a reference for comparison.

View attachment 348034

Thanks for sharing that. All of these little tidbits are super helpful.

 

[SMen]

Thanks Danny for the purchase!
That was a fast build. My ASR sample amp is still in progress. Only the drilling holes for the smps and the amp module + wirings, then it will be good to go.


I designed the D100 to have a higher 2nd harmonic through output inductor selection, it can measure 102dB 5W/4R if OPA1656 is being used. Do note that JRC4565 was used on that D100 review, and it is a random stock so you'll get more or less the same performance.

JRC4565 was selected to slightly lower the clarity and to have that old school amp tone. (credits to AEDIO japan for the opamp rolling)

For FB100, it was designed to get the best SINAD out of a TPA3251 chip. It uses a different output inductor so the harmonics will be different compared with D100.

recommended power supply on link below. (adjust to 38V)

LOF350-20B36-C MORNSUN Guangzhou S& T | C5752296 - LCSC Electronics

LOF350-20B36-C MORNSUN Guangzhou S& T $42.5429 - - Power Modules ROHS datasheet, price, inventory C5752296

www.lcsc.com

This is my impression regarding the FB100, that it has the design goal of ultimate SINAD so an "ASR ultimate" too. The D100 could still have some different qualities.

A good basis for comparison will be for me to compare the FB100 to the 3E Audio coupled with my Micro-Audio PSU)

I am not sure about this, because the power supply is so influential in the sound I have found.

 

[daniboun]

@SylphAudio > Question for you: knowing that the PA5 provides 83W/4R and 48W/8R with a 144W PSU, how much do you estimate the FB100 with a 400W PSU?

 

[SMen]

recommended power supply on link below. (adjust to 38V)

LOF350-20B36-C MORNSUN Guangzhou S& T | C5752296 - LCSC Electronics

LOF350-20B36-C MORNSUN Guangzhou S& T $42.5429 - - Power Modules ROHS datasheet, price, inventory C5752296

www.lcsc.com

I am wondering if this one is similar to your recommended? It is quite a lot more expensive but that might be partly due to importation and tax etc.

MORNSUN LOF550-20B36 SMPS Power Supply Module

This SMPS LOF550-20B36 switched-mode power supply delivers 36V and 15.3A for 550W of power. It incorporates a PFC (Power Factor Correction) ensuring 94% efficiency.

www.audiophonics.fr

It has higher amps. I am wondering what effect this has on output? All very interesting.

 

[daniboun]

I am not sure about this, because the power supply is so influential in the sound I have found.

That's precisely what makes things interesting) I'm not trying to understand the similarities but to distinguish the differences to help users make the right choices.

 

[daniboun]

I am wondering if this one is similar to your recommended? It is quite a lot more expensive but that might be partly due to importation and tax etc.

It has higher amps. I am wondering what effect this has on output? All very interesting.

The Morsun is the same as the 3E Audio amp reviewed here.... 350W version here

What could be relevant it is to get measurements between the suggested PSUs. LOF350-20B36-C or Mean Well LRS-200-36

Recommended Power Supply
(NOT INCLUDED)
- 36V to 38V DC Single supply SMPS 200W or higher.
- DO NOT use power supply with split rails.
- LOF350-20B36-C or Mean Well LRS-200-36
- Use 34V DC for unregulated linear supplies

My guess is : any good Smps with an acceptable ripple should do the job since the Sylph FB100 is supposed to have a good PSRR.

 

[SMen]

The Morsun is the same as the 3E Audio amp reviewed here.... 350W version here

What could be relevant it is to get measurements between the suggested PSUs. LOF350-20B36-C or Mean Well LRS-200-36

Recommended Power Supply
(NOT INCLUDED)
- 36V to 38V DC Single supply SMPS 200W or higher.
- DO NOT use power supply with split rails.
- LOF350-20B36-C or Mean Well LRS-200-36
- Use 34V DC for unregulated linear supplies

Yes, the Mean Well is here https://www.audiophonics.fr/en/smps-power-supply/mean-well-lrs-200-36-p-18662.html?search_query=Mean Well LRS-200-36&fast_search=fs
and much less expensive, but lower amps

I was reading what you wrote about the unregulated Micro-Audio PSU and I wondered if high "reserves" of amps might not have a similar effect? Interesting indeed.

I only have limited experience. I like the higher clipping point 'factor' that Sylphaudio has introduced to the 'equation' with regard to the 3251 vs 3255 when run at 36 - 38v.

Comparing 3e Audio to Sylph chipset implementation would surely need the same power supply though?

I'm going to give one of these a go definitely.

 

[daniboun]

was reading what you wrote about the unregulated Micro-Audio PSU and I wondered if high "reserves" of amps might not have a similar effect? Interesting indeed.

What initially motivated me to choose the Micro Audio PSU for the Micro Bamboo project was the conclusion of this article :

First One Build: Power Supply Selection

LC tested three First One amplifiers, each one equipped with different power supply [link]: Hypex SMPS1200A400 [link] AudioPower DPS-500/63 Connex SMPS2000R [link] AB comparison 1: Single Connex vs…

hifiduino.wordpress.com

 

[daniboun]

Hi amigos )

I was able to free up some time to do a more in-depth listen to my new project. So I took advantage of my teleworking to listen to my HD Playlist on my two amps: Micro-Bamboo and ASH-400.

Me Setup is composed of an SMSL D6S DAC which was measured by Amir and has the advantage of having an XLR output adjustable up to 5V. Note that at this output level, this super little dac almost reaches a Sinad of 124db!

SMSL D6S Review

As for my speakers, I did the test on my excellent Elac FS247.4 measured here. These are very linear speakers with great measurements considering their price.

The ASH-400 + DAC SMSL D6S combo allows me to use the FB-400 module in the best conditions since they have the same output level (as reminder: 14dB (5V/V for the FB100). My old living room is around 30m2 and let’s say it is poorly arranged, the listening conditions are not optimal in my case…..

Quite honestly, my HD Playlist covers almost all styles, from Jazz to Rock and including Pop and Classical) I would be lying to you if I told you that my 45 year old ears are capable of telling the difference between the two amps lol. The fact is that the 3E Audio and Sylph Audio modules are so good at a more than reasonable listening level that they are very difficult to distinguish on the audible audio band . However, I still found that the articulation and dynamism of the Micro-Bamboo at the bottom of the spectrum remains a bit higher and I imagine that this is really linked to the unregulated Micro-Audio PSU. But in all sincerity, I don't really like to comment without tangible measurements because our ears are very approximate measuring instruments). Now regarding power and available reserve, no doubt here : the Micro-Bamboo is really more powerful !

I think it would be fairer to compare the Sylph Audio FB100 to the Topping PA5 / PA5 II which use the same TPA3251 chip. What would be really interesting to understand: is the advantage that the FB100 could have compared to the PA5 which comes with a 144W PSU (126W for the PA5 II). I am impatiently waiting for Amir's measurements to corroborate this point, we will then see on the Power VS Distortion test what the FB100 brings us with a power supply of 350W or more. I'm also waiting to see if the FB100 can exceed 18 bits / 107db on the Multitone ASR test.

My ASH-400 project costs around $280, my Micro-Bamboo project is close to $400. That's a little more than 40% difference for around 70% more power under 4R and almost double under 8R in favor of the most expensive project.
My opinion is the following: if you need power and reserve opt for a project similar to my Micro-Bamboo, if your speakers have a good efficiency / sensitivity and you have a rather small or medium sized listening room, I think the ASH-400 will do the trick. In any case, the latest generation 3E Audio and Sylph Audio modules have an exceptional quality/price ratio. You will be able to adapt the PSU according to your needs with those DIYs projects to play on the price.