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Amplifier Modules and PCBs For Sale

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Deleted member 148505

454Casull said:
Would be really interested to see if this enables ultra-low SINAD for future TPA325x amps where PFFB is maxed to the limit.
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Yes, you know where it's going to :).

Still waiting for Victor's osc, probably a month before it arrives.

After the buffer/pre and 800W power amp (ETA January 2024), next on queue is maxed out TPA3251 PFFB, won't say ETA anymore since it might get jinxed lol. It should get higher than 105dB SINAD (present Sylph-D100 P02 is 102dB to 103dB)

****
Fosi Audio reached to us and bought a 1pc Sylph-D400, actually courteous than just anonymously buy the module. They're probably testing it by now. 👌
 
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Deleted member 148505

Topping PA5-II Archimago measurements.
https://archimago.blogspot.com/2023/10/part-ii-topping-pa5-mk-ii-plus-pa5ii.html?lr=1&m=1

Not much of a difference with Sylph-D100, plus the D100 has a dominant 2nd harmonic.

1698783337697.png
 
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Deleted member 148505

zek said:
Or they are trying to copy your amplifier - maybe we will soon see a new model by Fosi Audio.
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They will be releasing a monoblock soon based on this guy's post.
If you are as good as gamerpaddy at reverse engineering, then you can copy any amp :LOL:. I hope he tears down LA90 one day lol.
Fosi Audio PBTL Deep PFFB with 2 ohms stable capability and replaceable opamp socket will be a hit to mass consumers I think.
 
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454Casull

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Joined 2004
JLesterP said:
Topping PA5-II Archimago measurements.
https://archimago.blogspot.com/2023/10/part-ii-topping-pa5-mk-ii-plus-pa5ii.html?lr=1&m=1

Not much of a difference with Sylph-D100, plus the D100 has a dominant 2nd harmonic.
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Yeah, but honestly, if we're just looking at 1 kHz performance any old TPA3251/TPA3255 will work, including TPA3255EVM and probably even the good old LM3886.

It's the 5 kHz, 10 kHz, IMD, and multi-tone performance in the highest octave that are important.

EDIT: Also, it looks like 3rd harmonic dominant (followed closely by 9th), not 2nd, although none would be audible at that level.
 
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rrobot

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JLesterP said:
0dB gain is the default. I added empty 0805 SMT pads (circled in yellow) so that the gain can be easily increased.
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This is looking like a fantastic product JLesterP 🙂 Would dip switches with several common gains be too expensive to implement? It'd be handy if the gain structure can be adjusted without removing the board for smt soldering. Great work in any case!
 
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Deleted member 148505

rrobot said:
This is looking like a fantastic product JLesterP 🙂 Would dip switches with several common gains be too expensive to implement?
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Thanks! Either the gain switches be placed on the bottom PCB which is more expensive due to double sided assembly, or the PCB area be enlarged to accommodate the resistors and DIP switches.

For this preamp / buffer I think I will shelve this design for the meantime since I have focused on creating -120dB 50W class-ab amp instead, since the costs are not that far from each other.

I have sent the SE800 to the assembly, 1 month before it arrives.
 
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rrobot

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JLesterP said:
Either the gain switches be placed on the bottom PCB which is more expensive due to double sided assembly, or the PCB area be enlarged to accommodate the resistors and DIP switches
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Yes, can imagine its more expensive. Swappable smt resistor for gain is not a problem really. It's certainly a product I'd be interested in if the prototype tests well. 😀
 
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vitopro

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Joined 2011
Hello,

usually i use Sylph-400 with opamp by-passed by 2 in/out jumpers drived by preamp.
Today i soldered 2 wires beetween input connector and decoupling caps.
Can be it sounds worse?
I turned in starting situation and sound is better? May anyone tell me wy it sounds worse?
If i well understud, with the wire i bypassed 3 resistors in series to signal?
 
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Deleted member 148505

rrobot said:
It's certainly a product I'd be interested in if the prototype tests well. 😀
Click to expand...
Yes, prototype showed promising results :)

zek said:
Some more detailed indication, please.
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Can't give the details until I create the final module. Still in design / simulation phase, not an open design.
Pricing around 323 USD per 140W/4R mono channel

vitopro said:
Hello,

usually i use Sylph-400 with opamp by-passed by 2 in/out jumpers drived by preamp.
Today i soldered 2 wires beetween input connector and decoupling caps.
Can be it sounds worse?
I turned in starting situation and sound is better? May anyone tell me wy it sounds worse?
If i well understud, with the wire i bypassed 3 resistors in series to signal?
Click to expand...
Do you have a picture of the connection? What kind of worse sound? lower bass/highs or garbled sound?
 
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Deleted member 148505

vitopro said:
Sound seems to be affected by input saturation. The sound is not distorcted but it is noticeably worse than with wiring broken and jumpers between input/output pin of opamp.
Click to expand...
If I understand your bypass correctly, there is series resistance between the preamp and the input coupling caps if you bypass and place jumpers on the opamp socket. If you directly wire your preamp to the input coupling cap, the sound will be inferior. Why is the input saturating and what is the preamp that you are using?
 
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vitopro

Member
Joined 2011
JLesterP said:
If I understand your bypass correctly, there is series resistance between the preamp and the input coupling caps if you bypass and place jumpers on the opamp socket. If you directly wire your preamp to the input coupling cap, the sound will be inferior. Why is the input saturating and what is the preamp that you are using?
Click to expand...
Pre is a tube preamp. Audioresearch Ls-22 clone.
 
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Deleted member 148505

rrobot said:
No buffer board for next year then ? 🙁😆 It's OK, I know you need to prioritise.
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Yes got no unlimited funds for prototyping :LOL:. I'll send it for manufacturing after the FBUltra* LM3886 amp, I'm aiming for -140dB distortion and lowest noise which will put it in the number 1 amplifier SINAD chart.

On the buffer-preamp I will use either OPA1656 or OPA2156 on the frontend. So that a volume control can be placed before it without much noise penalty. Also, based on my listening experience, using the same opamp all throughout is not as good sounding as when using different opamps on different stages.
 
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