I know you love to do the math. All I did was physically measure the rail voltage at clipping while measuring the AC output with an RMS meter while looking at the scope.
Then you measured/recorded incorrectly.
You could not meaure 20Vac into your load when the supply voltage had sagged to 28Vdc ±xVripple.
You could not meaure 20Vac into your load when the supply voltage had sagged to 28Vdc ±xVripple.
Yes, checked the schematic at post #528 and the layout - they're consistent. Just auditioned one of these builds - the sonics are excellent and neutral, probably due to the simplicity of the signal path. Substitution of TL074 with an OPA4227 gives jaw-dropping transparency and detail, while still maintaining neutrality. I wouldn't use anything faster than the OPA4227 (8 Mhz GBW, 2.3V/usec SR, unity-gain stable), but YMMV.
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Hi Linusguru,
Thanks for the confirmation of schema. I too had built one based on the scheme. I had used TL074.
reg
Prasi
In this application, TL074 is OK but a bit veiled. The Excaliber-series TLE2074 and TLE2142 should be better if you can get them. OPA4134 and OPA4227 are much better for transparency and detail. I haven't tried LME49740 because it's too fast and likely to have stability issues with this layout. I'll try re-design the layout later to keep trace lengths shorter.
Do share the layout and component adjustments done. I have been struggling with tone control for a long long time.
HELLO ,
I built this prototype Preamp BJT, I have to test it, but without box, where to connect the "0"?
HELLO ,
I built this prototype Preamp BJT, I have to test it, but without box, where to connect the "0"?
... Sorry, I did not realize that these are dual-voltage ..... 24-0-24
link for downloads line apex ALL for sprint layout 6.0
donload on sprint layout 6.0
preamplifier and amplifiers :
https://mega.nz/#!zIQ1wCDS!8q0TiWmE3fCh_eOKa9URjCqYTf92FoWNe_H8OqotMQc
Sprint Layout 6.0 ISO Free Download
https://mega.nz/#!CMRQjKSR!nTSVAJ8S6J8x25EzMkLsIu66JAptT2j6gs2eFpiIzl0
https://mega.nz/#!OA4TAYBT!3owuNUWG7-gViEi4h5Yx8TuEwt8rmNTB22O-2--bhoc
https://mega.nz/#!KQg3BJoI!249M6D75L8oA6cjHOuvreKKHHT9X_xaCM6OvbBvWt9Q
https://mega.nz/#!XYhAzBDY!IkJWJCDPkAfKveAWnbn4gu0U61W4Ll3DaZUocqPV2rA
https://mega.nz/#!LRIx1baL!J8zei5duFMxQWtPAu8NLwz2BZKyWSPC8hdu9-wK5evo
https://mega.nz/#!qZw0AQQb!RAFesBJrRRrSrfFmX3fX4xQZYYgX1ZcD7jGf_Fp4XQc
https://mega.nz/#!7VADmKKJ!_soIbvMlIZbxrFc5QwJwMMjk9HVYQjAn7hDTv6oy86g
donload on sprint layout 6.0
preamplifier and amplifiers :
https://mega.nz/#!zIQ1wCDS!8q0TiWmE3fCh_eOKa9URjCqYTf92FoWNe_H8OqotMQc
Sprint Layout 6.0 ISO Free Download
https://mega.nz/#!CMRQjKSR!nTSVAJ8S6J8x25EzMkLsIu66JAptT2j6gs2eFpiIzl0
https://mega.nz/#!OA4TAYBT!3owuNUWG7-gViEi4h5Yx8TuEwt8rmNTB22O-2--bhoc
https://mega.nz/#!KQg3BJoI!249M6D75L8oA6cjHOuvreKKHHT9X_xaCM6OvbBvWt9Q
https://mega.nz/#!XYhAzBDY!IkJWJCDPkAfKveAWnbn4gu0U61W4Ll3DaZUocqPV2rA
https://mega.nz/#!LRIx1baL!J8zei5duFMxQWtPAu8NLwz2BZKyWSPC8hdu9-wK5evo
https://mega.nz/#!qZw0AQQb!RAFesBJrRRrSrfFmX3fX4xQZYYgX1ZcD7jGf_Fp4XQc
https://mega.nz/#!7VADmKKJ!_soIbvMlIZbxrFc5QwJwMMjk9HVYQjAn7hDTv6oy86g
You need to make sure the pinouts of your jfets are correct. A lot of them have more than one pinout for the same part number.
Hello Mr. Mile sir.... My amplifier based on your lm3886 and stereo tone control is working fine. But I feel that bass is lacking. And sound seems very harsh on ears. I have used all components as per the layout. Should I change any components to make it pleasing to the ears?
Reg
Prasi
Hi Prasi,
From your pictures , I see you have used a log pot 10 k for bass and treble.That may be one reason for a uneven sound. You have to use a Linear pot 10 k. I have a apex tone control and its extremely good.
Reg
Prasi
Hi Prasi,
From your pictures , I see you have used a log pot 10 k for bass and treble.That may be one reason for a uneven sound. You have to use a Linear pot 10 k. I have a apex tone control and its extremely good.
Replace 10k with 4k7 or 2k2, also you can replace 22k with 47k.
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