Quote from: J M Fahey on August 13, 2026, 10:58:56 PMMicrophone (vibration driven generator)

 

Yes sir thanks when you mentioned this I remembered reading this 

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Also btw wow you are really kicking some serious ass on MEF 

Quote from: Kaz Kylheku on August 12, 2026, 02:23:59 PMIn other words, in a wire, the fact that protons are not moving while electrons are de facto means that the protons are moving in the opposite direction. If you could ride on top of an electron, you would be leaving protons behind in the rear view mirror, and that's essentially your conventional current flow.

Yes sir thanks aka hole current 

This one is PR495  You cannot view this attachment.

Quote from: Chorch Cluni on August 14, 2026, 04:05:39 PMHi all.
For decades i thought the popular Fender Frontman 15G and 15R (silver cloth, angled panel) was just the same as my Fender Frontman Amp (15W, black metalic grill, square front).
But I recently came to realise they have different model ID's: Type 241 and Type 495.

The schematic I got with my Type 241, however says Frontman 15R.

Can anyone tell me if both circuits are the same?.
I saw some dudes on Youtube with those Type 495 getting a way better sound than my Type 241.
Maybe it's easy to achieve that with some mods...

Please post your schematic here, also try to find and post the other versions.
AFAIK 15G and 15R are the same basic amp, only "R" has reverb, plain "G" does not.

Sadly Johan Segeborn´s videos can be deceiving, ANYTHING he plays sounds killer.

There´s also his recording technique whose sound does not match what you hear with plain ears: he uses two very high quality microphones:

One is an AKG C414BXL2  a big diaphragm studio condenser type which when placed against the grill cloth almost "inside" the speaker enhances lows big time, that is called "proximity effect".
An 8 inch speaker sounds like a 10 or 12 inch one.
It also has a presence peak above 3 kHz which gives it "bite"
Recorded speaker sounds much bigger than real life.

A second room speaker, a few meters away, gives *natural* reverb from the room and makes speaker sound "bigger"
It is not a modding problem.

He may also be enhancing the recording in Protools or whatever he´s using.

Just watch this:

Schematics?

Hi all.
For decades i thought the popular Fender Frontman 15G and 15R (silver cloth, angled panel) was just the same as my Fender Frontman Amp (15W, black metalic grill, square front).
But I recently came to realise they have different model ID's: Type 241 and Type 495.

The schematic I got with my Type 241, however says Frontman 15R.

Can anyone tell me if both circuits are the same?.
I saw some dudes on Youtube with those Type 495 getting a way better sound than my Type 241.
Maybe it's easy to achieve that with some mods...

Regularly guys ask me for advice on how to learn Electronics.

My invariable answer is: "get a Physics book at your local library , the section dealing with Electricity and Magnetism, the older the better, 1900s to 1950s are perfect.

Modern ones get stuck with Calculus, which is not really necessary, old ones focus on THE CONCEPT and rely on EXPERIMENTS.

But... but ... I want to learn Electronics, I want to understand, repair and design Amplifiers!!!

Ok , such a book will teach you Volt Ampere conductor frequency transformer inductor insulator battery switch resistor capacitor potentiometer galvanometer power motor generator relay magnet electromagnet electromotive force dielectric, etc.

Using these building blocks you will understand:

Potentiometer (variable resistor)

Transistor (TRANSference resISTOR)

Valve/Tube (electrons "faucet" or valve)

Integrated circuit (lots of transistors working together)

FET (electrostatically controlled transistor)

Loudspeaker (electromagnetic motor driving a cone)

Microphone (vibration driven generator)

and everything else.
 

Quote from: rockman627 on August 13, 2026, 12:11:58 PMI soldered a thin 26 gauge wire to those points and got sound to the amp.Plugging into the fx return also produced sound.

Great job!

I have something useful in my background in that long before learning some electronics as a hobby, my senior year physics class in high school covered electricity.

We learned things like, oh, voltage being the electric potential of a charge: J/C (joules per coulomb).  And if we go in the most changing gradient of an electric field, the faster the voltage changes, the stronger the field is: strength is V/m (volts per meter). Electric field strength is also N/C (newtons per coulomb): how hard is the field exerting a force, per unit charge.

The two relate: if we start with V/m, and substitute the J/C units for voltage, we get J/Cm.  But energy J is force times distance: N・m.  Substitute that for J into J/Cm and we get Nm/Cm, where the m's cancel out to get N/C: newtons per coulomb field strength.

Space is permeated by electric fields. At any point in space, we can assign a voltage.  There is no absolute zero voltage: we must pick a point and call that zero, then express all other voltages relative to that: lower voltages negative, higher ones positive.

Say we have a charge sitting in a field. The electric force is acting on it. If we move the charge upfield against this force by some distance we do work on it (N・m), raising its potential energy. If we divide that potential energy by the amount of charge, we get the potential: voltage. We have raised the charge to a higher voltage. The greater the field strength (J/C) the harder we have to push, so the voltage change is higher. That's captured by the equivalent V/m units of field strength: the more volts we raise over a given distance, the stronger the field must be.

Also in that same high school course we covered how if we do a surface integral around some closed surface, of the electric field through that surface, if the result is nonzero, it means that the surface (e.g. sphere) contains a charge. That's what it means for there to be a charge somewhere: more electric field lines are coming out of a space than in, or vice versa. We can add them all up with a surface integral around the space. That was an advanced topic; all of us in that physics class were also in the calculus class, so it was okay to get into that sort of thing.

This stuff is good to know for being less mystified by certain aspects of circuits.

Here we go