SIMPLE AMP

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Detex Audio 741 ic based low component count NICE SOUND
warm regards
andrew lebon
 

Attachments

  • 3f233fbdc9751150.jpg
    3f233fbdc9751150.jpg
    104.6 KB · Views: 2,665
Nice toy, i have made one alike few years ago

My daugther still use it playing guitar.

35 watts RMS at 8 ohms..... aprox. ... and almost 20W at 8 ohms.

Sounds good... stérile as chip amplifiers...but it is compact and simple.

I really do not remember if i have made modifications.... this is simulator..sometime real life we have to adjust something..for instance, the zener current not to overheat.... these details.

Nice toy to build in a weekend.

regards,

Carlos
 

Attachments

  • 35 Watts - 4 ohms Dx Toy.jpg
    35 Watts - 4 ohms Dx Toy.jpg
    310 KB · Views: 2,545
I think you must have made something else, because this amp, as is, is terrible.
It has +/-35V rails but the Op Amp can not swing more than 12V peak each way.
You are wasting 20V each side.
It's also overbiased and not compensated, so it will self destroy thermally.
Plus other small details.
 
if its the original 741 op amp, this is not suitable for audio, there are much better ones, for little money. Makes one wonder how any designer could use a 741 for audio these days.

Can't see how its a nice sound, have you listened to it?

The advantage of a 741 is that can be swapped by a 5534 that will greatly improve the sound audibly speaking , i guess
that the eventual customer will at least experiment a valuable
and encouraging upgrade that will actualy work.

The nice sound may come from the complete amp or topology, not from the opamp used. CFP amps tend to sound nice, and they are not so stable. You cannot drive an existing CFP with the fastest opamp hoping to get improvement.

Indeed, there is a classic CFP design using a very slow uA741, and it sounds nice. Well, why not show me your favorite simple CFP driven by 5534 or better opamp?
 
Detex Audio 741 ic based low component count NICE SOUND
warm regards
andrew lebon
Well, YOU say so.
No schematic, just a picture.
No specs, no PCB, ZERO info.
Do we have to take your WORD for it? Why?
if its the original 741 op amp, this is not suitable for audio, there are much better ones, for little money. Makes one wonder how any designer could use a 741 for audio these days.

Can't see how its a nice sound, have you listened to it?
Agree. No way to confirm what Andrew Lebon says.
pictures dont LIE hottest selling kit now
Yes, pictures don't lie.
You are showing another kit, not the one we are talking about.
So, who's lying?
Trying to finish 2sc5200 version with enitter resistors
warm regards
andrew lebon
So we are talking about a "simple" amplifier with 2 ( two) output transistors, and you show a 24 output transistor, fan cooled example? :eek:
Tell me this is a joke.:p
Dear andrewlobon,
Are the range of Detex Audio products available in India? Can you provide an address or Tel No?
--gannaji
Of course he will, he's trying to sell them ;)
Yup, this topology amplifier needs that speaker protector :)
How do you know?
We have not seen a schematic yet :eek:
Andy are you part time salesman of Detex ?
I guess you are right.
 
Yes, yes, I'm interested with the CFP one. :wave2s:

Please mention if it has been tested in real life. If not, I will still try it anyway.


The version i have has a double EF but a CFP is adaptable
and this should lower THD 1Khz to a few ppm at 10W ,
i do some sims and redraw a clean schematic for the purpose
and post it in a relevant thread.

Notice , that is low power since the 5534 will limit the max
supply voltage such that power output is barely 15W/8R but
with very low THD.
 
Notice , that is low power since the 5534 will limit the max supply voltage such that power output is barely 15W/8R but
with very low THD.
You are right.
That's exactly the design concept error I pointed at in the schematic shown in post #5 .
The output can't swing more than what the Op Amp can (in fact, even a couple volts less each way) and the Op Amp itself is limited to around +/-15V .
So no use for a +/-35V supply.
 
Actualy the output can swing the full voltage provided the output stage
is a CFP with a gain of about 2 to 3 , i ll propose the option in the 5534
based amp , although i m not a fan of these kind of topology but i got it
to work in the simulator at the expense of a little more THD given the output
stage is less linear if it has voltage gain.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.