Mic, Line, EQ... Preamps

TB7
 

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Location of Crossover

PCB size: 60x50mm

Hello Mr Mile, I am constructing your XL2 subwoofer crossover based on your given PCB and component layout. What is missing is the schematic.

I want to ask, whether this crossover is to be placed before the preamp or after the preamp. I would like to put the XL2 after my preamp, using a paralleled output from my preamp, as this would allow the main Volume control to adjust both the levels to my full range and subwoofers simultaneously.

Does the XL2 has any gain? I am concerned about overloading the crossover.

Thank you very much.
 

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First of all, thankful for the published schemes. Is it possible to use this preamp in conjunction with this tone control? I have an old chassis with 100k potentiometers, is it possible to use them here, if possible, what changes should be made?
Thankful
 

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  • APEX OP line preamp v0.21 Top.JPG
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  • Controle de tom estereo componentes.jpg
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Stereo tone control with +/-10dB bass and treble adjust.

Mr.Mile,
How to modify this board for more boost +/- 20dB? Will changing the pot from 22k to 47k or 100 k improves the boost? I have been using this tine control for many years,and i should say,this is one of the best tone control circuits. It has got no midrange modification when boosting treble.Also, its perfectly neutral when pots in mid position.I have some usb mp3 modules,which needs more bass and treble boost, Can you please suggest me how to use the board for increased boost?
Thanks in advance
 
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I would like to ad a Balance Pot to the P30zf. What is the best value and connections that you would suggest to follow your original design ?
Do we have also to change value of the volume pot and resistors around ?
Thanks
 

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  • APEX Schematic P30ZF Version 2.png
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  • APEX PCB P30ZF Version 2 .jpg
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  • APEX PCB P30ZF Version 2 .pdf
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  • APEX SCHEMATIC Version 2 P30ZF.pdf
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Hi Mile,

I changed out the resistors. No change in the oscillation. I checked and I see the oscillation at the line out so it is likely in the front end. One thing of note. I have +15.60v, -15.18v on the ICs. Can this me causing this?

hi mr terry and mr mile,

i finish guitar amp but i read +/-17.4v at tl072. is this problem for this amp?

my rail voltage 28vac.
 
its working. i dont connect JB3 and JB5 when i look on schematic i see signal going on that jacks. so i just short them and then amp singing. dc voltage at speaker out gone too cause of JB5 taking ground to speaker. i am soo happy for this :D:D

but tone controll is not enough bass i think and i dont think this giving 100 watt. any one know how can i calculate it withouth scope???
 
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