555 timer class D amplifier and tape recorder experiments

[TheJaHa5]

You should come out with your own line of Cassette tape recorders! This video is very interesting!!!

[CoolDudeClem]

@raymond9987654321 Yes because my camera's audio is even worse, just sounds muffled and noisy.

[raymond9987654321]

@CoolDudeClem

Oh. Hmm, have you tried recording videos by putting your mic, preamp'd into your line-in on your PC, recording it, then sync'ing your audio recording with your video, and removing the camera audio? Just wondering (note: a clap at the beginning of the vid may help with sync'ing the audio easily)

[Vintagesoundz14]

Hi Clem, i would like tomasic a basic amplifier for my old computer in the Loft, do you have the Scchematic for this or could you make one, i am not good at making things like this but have a box of components form an old hi-fi and wouldlike to make a basic amp, this looks like a goodstarting point.

[MrStemkilla]

cant you just put the audio output and run that threw a petenchyomiter then to the gate of the transistor?

[CoolDudeClem]

@MrStemkilla Yes that is possible, but the transistor would have to be biased properly, typically what would be used to bias it is a 10k resistor from base to ground and a 100k from base to positive, but it can vary with different transistors and supply voltages.

[MrStemkilla]

@CoolDudeClem what is the 100k from base to positive for? i tried it out and it works grate! but i could not figure out why it would not work with out the 100k or some concretion between the two. can you exsplane?

[CoolDudeClem]

@MrStemkilla basically a transistor needs a little bit of voltage at the base if it is going to be used as a class A amplifier, so that's what the two resistors do, with enough voltage at the base, the output to the speaker (or whatever is connected) will be about half of what the supply voltage is. and a small change at the base from something connected will produce a big change at the output, you might want to look at youtube . com / user / SteelWheelsDown this explains a lot.

[MrStemkilla]

@CoolDudeClem what is the difference between amplifiers (class D class A)

[CoolDudeClem]

@MrStemkilla There are many types, class A, B, AB, C, D and even a class T, unfortunately there's too much here to explain in a comment, best to go and look it up on Wiki.

[MrStemkilla]

@CoolDudeClem i do not understand how the efficiency is lost on some amplifiers. when the efficiency is high then its giving out fractions what the full wave form of the signal coming in meaning its not giving off the same wave length as it is receiving. i can see where that may come in to be important in some devices but generally i find a class AB just as efficient as A since its not giving the full signal output if you get what im saying

[CoolDudeClem]

@MrStemkilla When it come to efficiency,it's all mainly about heat loss, Class A amplifiers, although give the cleanest output, they loose a lot of energy as heat, class D barely looses any energy as heat, and AB is somewhere in the middle.

[MrStemkilla]

@CoolDudeClem yes i am having problems with heat but then agen i was useing way too small transistors :) it was rated for .6 A i was pulling about 1 amp .. and when they are that small they do not have heat sink mounting holes.. ya i was just protoboarding and i need to order better

[TheMrmagnetophon]

I have a question about the schematic, what is q1 and q2 mean???

[CoolDudeClem]

@TheMrmagnetophon Q1 and Q2 are simply transistors, I dont know why but for some reason in schematics transistors are labled "Q" instead of "TR" or "T" or something like that whitch would have made a lot more sense.

[TheMrmagnetophon]

@CoolDudeClem oh right, thanks, hey what ones did you use?

[CoolDudeClem]

@TheMrmagnetophon I used a BD139 (npn) and a BD140 (pnp), but basically any macthed pair of transistors would do such as BC547 and BC 557 or TIP41 and TIP42.

[TheMrmagnetophon]

@CoolDudeClem The BD139 would be the q? amd BD140 would be q2? I am correct in that?

[CoolDudeClem]

@TheMrmagnetophon Yes that's right, I would have replied sooner, but I was doing something else.

[KRC1023]

Very nice circuit! i am building one for use as an amplifier, because i do NOT want to pay 40 dollars for parts to use in my FIRST experimental amplifier.

[SubwooferBox1000]

what were the songs included in this video?

[davesworld85100]

m8 we can see what you had for dinner on your top you scruff (24) sec

[CoolDudeClem]

@davesworld85100 And? You have a problem with that?

[davesworld85100]

@CoolDudeClem people will lath at you thats all

[CassetteMaster]

Very nice experiments!! Did you use the PWM audio to the head without external bias? Or did the 555 circuit just supply the bias each time?

I have had the idea of a 555 PWM audio to be used as a bias myself, and plan to do a recorder like that sometime.

[CoolDudeClem]

@CassetteMaster The 555 PWM was connected to the head with no external bias, in the second experiment I did in this video I was using it as a bias oscillator.

[CassetteMaster]

@CoolDudeClem Amazing. I will one day make a tape recorder using PWM bias/audio!

[BadEditPro]

What is the model number on that front loading Denon you're using. I want one! :) JC

[CoolDudeClem]

@BadEditPro It's a Denon DRS-810, I have done a video about it in one of my really early videos on YouTube. This in a box of cassette decks that were being thrown out, I asked if I could have them and he said it was Ok to take them.

[BadEditPro]

@CoolDudeClem Thanks! :) JC

[Vintagesoundz14]

is that a digilogic speaker? is that the one you had linked a s a par to pc or do you have more than 2

[CoolDudeClem]

@Vintagesoundz14 No, it's from a Durabrand home theater ''surround'' system, I had 5 of these, but two of them I parted out just for the actual speakers themselves, this is one of the ones I use with my PC cause I can't find the spare one.

[jrigvd]

connect a flyback transformer

[CoolDudeClem]

@jrigvd I've already done that! check out some of my singing arc videos.

[orbiter8]

You really need to get some more updated music Clem ;) j/k

[giammyzanna]

The tape on the reel to reel has a lot of dropouts :(

[CoolDudeClem]

@giammyzanna Rather that than the muffled sound with all that "murrrrrp" and other weird noises I get from my camera.

[Skumpaj]

Wheres the intro? It was nice!

[CoolDudeClem]

@Skumpaj This isn't a CoolDudeClem's electronic workshop episode, but I guess it could have been.

[Skumpaj]

@CoolDudeClem okay, but nice intro anyway, you ought to work for bbc.

[sk7ca]

No offense man, but i think Jeri Ellsworth is a bit cooler! ;P

[CoolDudeClem]

@sk7ca erm Who?  Never heard of him/her.

[sk7ca]

@CoolDudeClem Oh okey! well then you better look her up ;) her nicks on youtube are jeriellsworth and jeriellsworthjabber

[videolabguy]

Awesome. You ARE the coolest nerd I know of.

[thehugh100]

Lol, nice vid. I dont suppose you could make a vid of a 555 osiclator controlling another 555, so you would get wierd sounds XD

[starlite2991]

good vid Clem  thanks