Mic, Line, EQ... Preamps

[ravpreet420]

Hi apexaudio
Plz post schematic of
Balanced line input with low cut 12dB/oct at 35Hz

 

[Ivchikx]

On ML3 these tone control pots (bass, middle, treble), can I use pots with center point? With all tone pots turned to center position, sound should be unchanged, e.g. same as from source?

 

[Ivchikx]

UPDATE: Just finished one pair of ML3 for TDA7294 amp and works like a charm. Big thanks, Apex.

 

[formula 22]

Schematic for preamplifier for sabwufer

Hi
I need a diagram and PCB for an active filter for the subwoofer amplifier: "Quasi amplifier for beginners" (of APEX Audio).
Regulated frequency of 40...120 Hz with a slope of 12...18dB.
This preamplifier that can directly to be connected to output to my stereo amplifier.

Thanks for your help

 

[irwanks]

Hi apex. I have made apex ml3 pcb. This is the result. Quality is good enough. But i had a little hum, but when i touched the casing of my amp, hum was disappear. Can you give me any advice for it. How to wiring apex ml3 correctly? I just used simple regulated power supply. Thank you very much.

 

[apexaudio]

Hi apex. I have made apex ml3 pcb. This is the result. Quality is good enough. But i had a little hum, but when i touched the casing of my amp, hum was disappear. Can you give me any advice for it. How to wiring apex ml3 correctly? I just used simple regulated power supply. Thank you very much.

You must grounded your case (gnd from regulated psu connect to amp case)

 

[irwanks]

You must grounded your case (gnd from regulated psu connect to amp case)

Thank you very much for your quick reply

 

[Endik]

In this thread I will post preamps, EQ, active x-overs, VU...
ML3 is Mic/Line XLR preamp with three band EQ +/-20dB
PCB size 100x40mm
Regards

Mr Mile,

Can you share pcb lay out in pdf format?

How to make this preamp to 4 adjustable potensio (high, mid, freq and low)?

regards
Endik

 

[engel dela pena]

apex,
please help how to put balance pot ,
i will use ML3 as multiple input maybe 4 or up ML3 and feed it to MX1,
i just hope your help of adding a balance pot to assign left/right to MX1 as master and ML3 as multiple input,
hope you help

 

[Endik]

Thank you Mr. Mile,
This is my ml3 sound ok but i will add 1 potensio for mid low freq,
can some one help me?
Thank you
ImageShack® - Online Photo and Video Hosting

An externally hosted image should be here but it was not working when we last tested it.

 

[irwanks]

Thank you Mr. Mile,
This is my ml3 sound ok but i will add 1 potensio for mid low freq,
can some one help me?
Thank you
ImageShack® - Online Photo and Video Hosting

An externally hosted image should be here but it was not working when we last tested it.

Nice work sir

 

[gooseneck]

Sir Apex...do you have diagram of 3-way active cross-over....?...please post...thankz in advance...

 

[engel dela pena]

sir mile,
any standard linkwitz riley,is much appreciated 3-way/2way x-0ver,active,
with variable frequency,please sir
please share something for bi amping

 

[sudhir kumar]

Sir Apex,
I have made your stereo tone control.Working very good,But when i turn the bass pot full(100%) it supress the treble,I have used 50k pots.Is there something wrong with this??

 

[sudhir kumar]

I want a 2 way active crossover circuit (12bd/octave) which can work on single supply of 12volt for use in car stereo.I any body have ,please help.

 

[QQ12e5k1]

Apex BJT Pre Amp

Dear Mile,
Is this correct Sir??
How much current it needs??

Regards

 

[apexaudio]

Dear Mile,
Is this correct Sir??
How much current it needs??

Regards

No, there is several mistakes.
Regards

 

[mikeltuaz]

Mr. Mile, been reading most of your post. Thanks for your time and effort.

Do you have design for echo?? with volume and intensity?? for addition to ML3.

Thank you.

 

[QQ12e5k1]

Mixer

Dear Mile...
I was make a new layout of Your tone control with add a XLR con for mic input...I got a plan to make 4 ch mixer with 2 mono input and 1 stereo input but I don't know how to add effect and another block like master and balanced output...
Can You help me to make my simple mixer??

Regards

 

[PHOENIXJAZZ]

Portable version

Mile,
Thanks for this thread!
I'm looking at this for use as a belt pack unit for a friend who plays accordion.
Two channels with all controls. Balanced input and output.

Is there a way to get this functionality with only a 9volt battery? I'm also curious how long it will work if I use two 9 volts?

Many thanks for sharing your knowledge with us.

Chris