100W Ultimate Fidelity Amplifier

[svinx]

Slew rate 20

v.s 7

. Different specification. 4570 not for audo applications. The best OPAMP for sound: OPA1641, OPA1611 (single) OPA1656, LME49710 (dual) IMHO.

Then why is it recommended to put jrc2068 in a17, if jrc2068 has a slew rate of 6.

 

[svinx]

Where did you see the slew rate of 20 ? all these chips for sound.

 

[Prohodimez]

Sorry, LM4562 (not NJM) Slew rate 20

. Good OPAMP for High-Fidelity Audio.
Then why is it recommended to put jrc2068 in a17... that's a good question! I think Mr. Apex will answer it.

 

[xrk971]

NJM2068 is a tried and true opamp that is used in many commercial designs. It is sufficiently good but is really meant for BOM conscious applications as it is $0.80ea. I think for DIY or high end audio, OPA1656 or OPA1642 sound better but cost about 3 to 4x as much. LM4562 is good, but a bit drier sounding than OPA1656 or OPA1642. Purely subjective on my part. I built three identical preamps and loaded one with OPA1656, another with OPA1642, and third with LM4562. Then listened to them and compared. NJM2068 is BJT based input and OPA1656 is FET input and OPA1642 is JFET input stage. The OPA1656 is capable of 100mA current so can drive almost any load and also has 24V/usec slew rate.

 

[svinx]

I have the original NEC 4570s, so I asked about their use in the ax9 and a17 amplifiers.

 

[Prohodimez]

I have the original NEC 4570s, so I asked about their use in the ax9 and a17 amplifiers.

Sorry, BRO, but these are already forgotten names...

 

[svinx]

what exactly is forgotten? apex ax9 and a17? or NEC 4570? I think it's worth waiting for an answer from knowledgeable people in this thread on the ax9 and a17 amplifiers.

 

[Prohodimez]

what exactly is forgotten? apex ax9 and a17? or NEC 4570? I think it's worth waiting for an answer from knowledgeable people in this thread on the ax9 and a17 amplifiers.

NEC 4570, is already history...

 

[svinx]

NEC 4570, is already history...

I asked whether it would fit into amplifiers or not, but the fact that for someone this is a story, to each his own ...

 

[VIPINSAINI20]

Hello everyone

FH9 FH11 is very interesting
But I'm facing problems
1.finding 4.7pF capacitors.
2. Lack of experience with biasing mosfet amplifier. (Little bit fear of losing the mosfet devices😑 ,Ionlyhave6pairs IRFP240/IRFP9240 left)
Otherwise I have no problem building my 6 channel amplifier with FH9 & FH11

Is there any BJT equivalent of FH9 FH11
I have NJW0281G NJW0302G and 2SC5200/2SA1943 in my personal bin.

I have assembled some p3a boards, A23,TDA7294 and LM3886TF and LM1875T.
But not a mosfet amplifier yet.

I can build my 6 channel amplifier with p3a but the pcb layout I have is bigger and takes unnecessary space, so I look all over the diyaudio and find Out, that Alex mm p3a layout is very compact and elegant, but sadly Alex mm didn't published the files for diy home etched pcbs, due to some reasons,

I look back at YouTube and get the Johnaudiotech, which I'm following for last 3 years and more, John have designed and developed a JAT-501 amplifier and published it for free diy purposes, but his pcbs are dual layer layout, although I don't have problems etching the dual layer pcbs at home as long as files are in black and white toner transfer method, it's due to lack of computer at home and lack of experience with Gerber files and their respective programs.

If someone have anything like FH9 FH11 but bjt equivalent. Please share your details.

Needed something compact like this

Or this but bjt equivalent

 

[IKOL1230]

Good day group, excuse me, who can pass me the P30 preamplifier, I want to assemble it and if someone already has it with files and can share it with me, thank you very much

 

[andrewlebon]

FH9

 

[DaveFred]

Here are the files for apex fx-12

Was there ever any consideration for making a two pair version of the APEX FX-12?

 

[Hennady Kovalsky]

Was there ever any consideration for making a two pair version of the APEX FX-12?

if you add a second pair of such output transistors, the driver will hardly work for such an increased input capacitance by a factor of two,

.

 

[semua26]

ВСІМ ПРИВІТ, ХОЧУ ПОКАЗАТИ СВОЇ ПРОЕКТИ, ЯКИМИ РОБИВ ЗА ПЕВНИЙ ПЕРІОД ЧАСУ ДО ПОЧАТКУ ВІЙНИ В УКРАЇНІ

HELLO EVERYONE, I WANT TO SHOW MY PROJECTS THAT I DID FOR A CERTAIN PERIOD OF TIME BEFORE THE START OF THE WAR IN UKRAINE!!!

APEX AX 14

 

[semua26]

ВСІМ ПРИВІТ, ХОЧУ ПОКАЗАТИ СВОЇ ПРОЕКТИ, ЯКИМИ РОБИВ ЗА ПЕВНИЙ ПЕРІОД ЧАСУ ДО ПОЧАТКУ ВІЙНИ В УКРАЇНІ

HELLO EVERYONE, I WANT TO SHOW MY PROJECTS THAT I DID FOR A CERTAIN PERIOD OF TIME BEFORE THE START OF THE WAR IN UKRAINE!!!

FH11

 

[semua26]

HELLO EVERYONE, I WANT TO SHOW MY PROJECTS THAT I DID FOR A CERTAIN PERIOD OF TIME BEFORE THE START OF THE WAR IN UKRAINE!!!

APEX AX20

 

[semua26]

HELLO EVERYONE, I WANT TO SHOW MY PROJECTS THAT I DID FOR A CERTAIN PERIOD OF TIME BEFORE THE START OF THE WAR IN UKRAINE!!!
APEX NX14

 

[andrewlebon]

Tone control from the internet works well with AX14
warm regards
Andrew

 

[Joel Wesseling]

Can anyone share the gerber files for Prasi capacitor bank? Mine are missing drill file.