1. Stas06

    Effect of 10x Capacitor on Amplifier circuit

    Hi all, I bought capacitors of 22kµ instead of 2.2kµ. I was wondering whetther this circuit could still work with the 22kµ and what the effect is on the circuit. I'm not a electrical engineer so my knowledge is rather limited in this field. My best guess would be that these are used for the...
  2. A

    Determining Amplifier Input Power

    Hi All, I am trying to setup my Sony N500 Xplod Car Amplifier in home environment. I have presently a 20A fuse placed in a 25A socket of the Amplifier. Its input is 12V. So I believe a SMPS of 25A 12V will suffice its working. I am intending to change the 20A fuse to 25A as well to support...
  3. O

    Need help with modding hackrf one RTL-SDR card with right amp

    I'm trying to modding HackRF one rtl-sdr card, regarding this articles card have problem with tx bellow 100 MHz, lots of user complains about burning card, precisely MGA-81563 chip, I already burn once MGA-81563, and I replaces two of them. Someone suggest LVA-123+, but pins construction are not...
  4. K

    Amplifier 50 Hz hum

    I'm trying to detect the source of the problem and hope you can help me to where should i look for it. So when I'm raising the volume on the amplifier the hum gets more quiet then if its 0 volume.(Without any input, just the speaker connected) It's not ground loop probably. Already checked.
  5. Lavin.devil83

    Changing pwm Amper

    Hello I really need your help I need a circuit to change amp of Pwm Input : pwm 12V 5Amp Output: pwm 12V amp between 15-50 amp I have to say I don't know programming or program any type of IC I know I have to pay money for design a circuit like thus, but I live in Iran we can't and don't let...
  6. M

    Amplifier turns on and off

    Hi! I have bought a headphone amplifier which I have made small changes to. The two things I've done is: - disconnect the on-off button by soldering a cable between the poles - adding longer wires to the diode so that the led could be attached a bit from the amplifier What have happend...
  7. A

    Localization of first and second poles in this circuit

    Is the second pole in the node marked in red? I am not sure
  8. A

    Finding the gain expression for this CMOS operational transconductance amplifier

    So here's the circuit: I think M2 is a common source amplifier and M4 a common gate amplifier, so they form a cascode amplifier where the gain is given by : Av = -gm2 * r0, r0 is the impedance at the node where the drain of the common gate amplifier is at (Vop). r0 = ( [rds8 // (rds2a * (...
  9. J

    How to trigger a relay when the signal voltage slowly rises from 0v to 12v?

    Hi all, My requirement is to connect an additional light in parallel to my car's interior cabin light. My car supports upto 10w and I already have a 2W LED bulb inside, and the additional light is about 25W, so connecting it directly is not an option. So I connected a 12v relay with the signal...
  10. E

    Amplifier Noise Reduction

    How can I reduce Noise in this circuit?
  11. A

    AD630 Lock-in Module Resistor Experiment Troubleshooting

    Hello everyone, I'm trying to use this board as an analog lock-in amplifier; however, I'm running into some difficulties due to a lack of any documentation on the use of this device in lock-in experiments, save for PhysicsOpenLab blog post that performs the experiment I'm trying to replicate...
  12. C

    Summing Amplifier - Revisited

    Hello Everyone again, I have a continuation from my previous problem from my adjustments and testing that I was hoping to get help on. I am doing a multi channel mixer that pipes audio signals to different channels to go to different speakers. My previous post have pointed me to fixing the...
  13. Jisan0077

    Panasonic su ch 7 stuck on standby

    My amplifier panasonic su ch 7 stuck on standby. Why this problem and how can i solved it
  14. L

    Balanced Audio Preamp Circuit

    I tried to make a preamp circuit but I'm not getting any output at all. The simulation on LTSpice seems to work well. The Op Amp I'm using is LMV821 datasheet I'm using a balanced dynamic microphone Zener Diode is 5V1. I don't mind if its noisy as long as I get a some sort of amplification from...
  15. Alex_Khan

    Designing Differential amplifier with differential output

    Hello! I have done calculations for designing a differential amplifier (DA) with differential output. I simulate (using cadence ) the DA with the calculated values and perform the DC analysis of the circuit to inquire all the transistors are operating in saturation. However, I did not get all...
  16. cikalekli

    Input and Output Impedance of the Common Emitter Amplifier

    Hi, I just have solved one of the bjt common emitter question below. However, I'm curious that how can I additionally find those things below: 1) Input and Output Impedance 2) AC Gain Here is the example and my hand draw solution. However, the question only asked to find Vout/Vin... Also, my...
  17. Ivan Badal

    compute gclosed as a function ??

    I have this inverter and do not know how to compute gain gclosed as a function of R1,R2,R3,R4,R5 and R6?? V out = closed * Vin. Circuit is in attach file!!
  18. Pashgen

    How to find a mistake. Sound amplifier circuit board. Need help with troubleshooting

    Hi, I bought DIY amplifier board. And now I am trying to find what I did wrong. It can work for about 2 seconds and then sound dissappear. But power stays on, and LED is glowing I connected 24 volt toroid to start the board. In description it says that circuit is designed for 12 to 36 AC...
  19. A

    Type 807 Tube RF amplifier with transistor a pre amp

    Hi all, I have a 807 vacuum tube and I want to make a CW RF amplifier with it. I am thinking of using transistors in pre amplifier and 807 as final power amp. I have only one tube so I cannot make push pull amp. First of all I need to know if it will be possible to make such RF amplifier. If...
  20. A

    Peavey Centurion Mark III head with high DC voltage output

    Hello, I have a 1980 Peavey Centurion Mark III head that was buried in my garage unused for 15 years. I knew it had problems (it's not mine, i got it from a friend who was throwing it) so before doing something i checked all the components and everything looked great. Once done I plugged it to...
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