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Deleted member 148505
Here is the real problem.
"All inductors were placed inside a bubble wrap bag"
Bad very bad package for ferrite materials.
Yes ferrites should be individually wrapped, or better placed in a tray.
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Deleted member 148505
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Deleted member 148505
Of course 😀, I also tested it on my TPA3255.
Initial impressions, very detailed opamp for TPA3255, airy, has 'bloom' sound, smoother and less harsh than OPA1656.
But I like the OPA1692 better on my IRS2092.
I think I will go back with the LME49720 on my TPA3255 V1.1
I will test OPA1692 and OPA1656 again when my TPA3255 PFFB arrives. I did a better HF bypass there in the opamp section.
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Deleted member 148505
Hmm I think I will take back what I said, OPA1692 will stay in my TPA3255 V1.1 simply because it has better 'Sss' sound. Vocals are better.
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Deleted member 148505
After extensive listening, I enjoyed the LME49720 more on my TPA3255, it's more musical, even though OPA1692 has smoother highs. 😕
My sister said that TPA3255 is 'bassy' compared to IRS2092.
My sister said that TPA3255 is 'bassy' compared to IRS2092.
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Deleted member 148505
Tried NJM4580 on my TPA3255, the sound is 'dry' and midrange to highs are forward sounding. NE5532 is better.
Problem with NE5532 is the not so good 'CHhh' sound, and the instruments are synthetic sounding. Maybe someone can relate haha
Problem with NE5532 is the not so good 'CHhh' sound, and the instruments are synthetic sounding. Maybe someone can relate haha
So the LME49860 was the better choice for TPA3255... this sound like LME49720 but more musical.
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Deleted member 148505
I think the strength of LME49720 is in the mids, NE5532 has "crispier" bass compared to LME49720. I will try LM4562 and LME49860 in my next order.
Exactly the medium is the best i can hear with LME49860... the LT1364 is my other favorite for mid and musicality.
No need to order LM4562... you are already LME49720... try OPA1612 maybe
No need to order LM4562... you are already LME49720... try OPA1612 maybe
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Deleted member 148505
I might make the LM4562 DIP version the "default" chip for my PFFB (LM4562 is cheaper and some find it more airy and open VS LME49720) . I'll also try OPA1612.
Attached PFFB implementation on the bottom PCB. It is not 'hardwired', can be reversed to non-pffb by removing jumpers and RF1-RF4 and of course by changing back the parts.
PCB can handle 1D17A, 1D23A and VER2923 inductors.
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Deleted member 148505
Changed R442 to 35.7K ohms 0805 SMT
Credits to Piersma <link here>
Will use boost converter to get 12V that will power the chinese subwoofer filter kit that I've bought from shopee.ph
Aside from aux supplies, the output also requires small load current to operate correctly so if you will use it for TPA3255, you should put a resistor load on -V and ground.
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Deleted member 148505
Yes, it will be available before November.
Unfortunately when we measured the gross weight of the build with Coilcraft, it exceeded 500g which will double the shipping amount, so we only provided 3 options that weighs less than 500g.
Attached some pics.
Loopback THD+N of my QA400 setup is around 0.002% only, so with high-end measuring equipment, the result might be better.
Unfortunately when we measured the gross weight of the build with Coilcraft, it exceeded 500g which will double the shipping amount, so we only provided 3 options that weighs less than 500g.
Attached some pics.
Loopback THD+N of my QA400 setup is around 0.002% only, so with high-end measuring equipment, the result might be better.
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Deleted member 148505
"with high-end measuring equipment, the result might be better."
Hello
you forgot your daughter, who is a sophisticated instrument. 🙂
Good job
Roger
Hello
you forgot your daughter, who is a sophisticated instrument. 🙂
Good job
Roger
This is the Lester's sister the "instrument" Roger
How she find the TPA3255 PFFB Lester ?
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Good to hear that Lester... in wich way ? more warm ? more smooth ? more natural ? more detailed ?
Wwith 16dB of gain you know how many volt the preamp need to output for reach maximum power ?
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