Giantkiller moves forward into Full Heterodyning.

[giantkiller]

@GK, Is and All

Walls of solid noise... can be removed with resonance too.. as you know and have proven! It took me a while to figure out your guilty secret which even you do not yet know!

GK I strongly suspect that you build a time machine this weekend and go back to 1550BC to try a quick test of your Super-Bombastic Audio TPU by giving a bloke who needs an inconvenient wall demolished a hand... 

Oh and I do have documentary evidence! Albeit a drawing of the event by someone who heard it third-hand from a friend of a friend of a blind guy who witnessed it... pretty good evidence by any standard...

See below... Two guys can clearly be seen carrying an Audio TPU, behind a guy who takes all the credit with his silly rams horn (or is that Is pretending to be an innocent bystander).

Acerzw, correcting the errors in biblical history 

(Walls of Jericho, naughty GK (and Is?) ! Lucky you didn't leave any equipment behind, otherwise Jesus would have ended up doing a podcast which his followers would have dutifully downloaded onto their water/goat powered Joshua-Bose made iPods!  )

There truely is nothing new under the sun, eh brother?

--giantkiller. Basic instructions before leaving Earth...

[acerzw]

@GK,

You are saying you have discovered the sun has a preferred orientation too! Amazing, I have been looking for the top for ages! Please post details here... 

Acerzw

[bolt]

I don't know whats happened GK i think this should work fine.  Check the voltage out of the 5 volt reg. Note it doesn't sit directly on the supply but in the bias loop. The pot must make a difference if its working should draw least 1/2 amp quiescent at midrange and might go to 3 amps closed. This amp should run HOT within seconds of turning on thus good heat sink essential.

The op amp looks fine the gain set by the input ratio roughly a gain of 9 non inverting its really just a buffer an supply the symmetry.  See what voltage you have between the mosfets for the biasing. There is a chance something wasn't right and a mosfet has been killed. You can check the opamp independent of all the other biasing by lift the output leg and stick 1k back to the input then put a 1uf cap on it and scope it should work fine.

Such a simple circuit must be something really silly. If you get really stuck and cant fix it then you can buy a 4 channel car mosfet amp from ebay for about 25 bucks brand new which is cheaper then you can build these things for. Even the alu case and fittings will cost more then that to buy and make.  In hind site it may have been prudent to go that route instead. Some designs have 4 separate pcbs inside too makes a bargain you cant refuse to get access to four 25 watt RMS MOSFET amps for 6 bucks each dont matter even if you blow the crap of it of for that money. The standard config is 400 watt music power. So called 100 watt rip off music power per channel usually comes down to 25 watts RMS at 0.01% distortion.

They need small mods to lift the bandwidth like removing or decreasing input and output sig to ground caps that would normally roll off the top end to make them a bit more stable and save power where you cant hear it anyway but we need the bandwidth.  Some of the amps are spec at 35k with no mods. I cant see any reason why these wont go to 100k when "lifted" as most mosfets are spec much higher then that and should be ample for tpu testing and plenty of power. I'm confident this will make a good test bed.

Ebay is an excellent source for cheap parts including inverters. They are so cheap now for 500 watt inverter will give you access to ferrite rings, cores, chokes, resistors and caps and mos fets that would cost 3 or 4 times more to buy the parts alone.  Sometimes there are sold as faulty i seen 1000 watt inverter for like 5 bucks which are a tpu builder bargains for spare parts.

[innovation_station]

 

nice bolt
lol!!

i just happin to have a verry nice 4 channel amp right here  also here is a pic of a mono car audio amp 1 hom stable and all digital  i have 2 of thease  and the last pic  is an 150 w invertor taken apart there irf634b fets in this invertor and there just happins to be 3 of them in there

but i really liked the invertor part

ist

[giantkiller]

Well screw the shake and bake shit. Would have been nice to have built something. But when the opamps don't even respond then its time to move on. I went to ebay and found this little gem.

http://cgi.ebay.com/2400-WATT-W-4-Channel-CAR-MOSFET-AMP-AMPLIFIER-NEW_W0QQitemZ180163349708QQihZ008QQcategoryZ4950QQrdZ1QQssPageNameZWD2VQQcmdZViewItem

Any feedback would be great. I trust my judgement but secondary opinions are always welcome. Gonna go spend the day with my girlfriend. I need to get the hell away on break! This corner is just too dark for the length of time I have been at this.

Worked with opamps for years but nothing as stupid as this failure. This attempt doesn't even equate as geek time. I think the schematic is crap.