high power amp..

[Dirk]

Shouldn't those power supply caps be high voltage? The AC gets recitified into DC and 48v ac is gonna be 70 vDC or so...so shouldn't those supply caps be a higher voltage? I think DJ that you are stressing them. Hope they don't explode.

-Matthew K. Olson

Well, IF the drawing of the power supply is right, the caps are just in series, getting only about 35V each. However, the ground that is drawn, is plain useless. So IF the drawing is right, this is a single ended power supply, the total recified voltage is about 70 V DC and the max. power in 8 Ohms is around 60 Watt.

Dirk

 

[Dj BASS AMP]

if i add to the amp more 40000uF it make a different ?

 

[Jeff R]

if i add to the amp more 40000uF it make a different ?

No, it won't. 40,000 uF is more than plenty.

Can you tell us the dc voltage across the + supply and across the - supply?

 

[Dj BASS AMP]

68.9V DC

 

[moamps]

Hi, DJ.

Connection of power supply is unusual, ground is floating and you have risk to overvoltage caps. Your problem first of all here is to small voltage of power supply, you must change concept (putting in to bridge to biger power on 8E), and nothing will help (biger caps, more transistors etc...) I think that is time to abandon this idea. Sorry.

zzeenn

 

[Netlist]

PIC OF POWER SUPPLY OF THE AMP

DJ,
Are you shure this drawing is correct?
Take another look at the ground.

/Hugo - thinks this ground connection makes no sense at all.

 

[kevin gilmore]

without a center tap on the transformer connected to the
middle of the capacitors, you are lucky the thing works at
all. And with that transformer a center tap tied to ground
would give you power supply rails of +/-35 volts.

You will need another transformer and another diode
bridge and 4 more caps if you do it this way. Then and only
then will you get +/-67 volt rails.

Putting caps in series is a really bad idea.

 

[moamps]

You will need another transformer and another diode
bridge and 4 more caps if you do it this way. Then and only
then will you get +/-67 volt rails.

Hi,
one posibility to get +-67V exsist; half wave rectification with 2 diode, and doubling filtering caps (bigger ripple), but caps must be rated to 80V. Any way,.....I dont think that this amp itself (input stage) can menage this double power supply.

regards
zzeenn

 

[Dj BASS AMP]

so...
is i put a power supply of 48~0~48 VAC of 750VA and more 4 caps... it is will change something ??

 

[Dj BASS AMP]

I Have a pic... now if i connect to the amp power supply like the pic how much Watt on 8 ohm the amp will out?

 

[Dj BASS AMP]

if i build the new power supply..... the o/p Watt will be higher..?!
(i need to change the caps.... and the power resistor of the preamp...)

 

[Tazzy]

For the transistor stage of my zen v4 tube's I'm using the following design:

An externally hosted image should be here but it was not working when we last tested it.

It's a Nelson Pass / Kristjan Kljucaric crossover.

 

[moamps]

if i build the new power supply..... the o/p Watt will be higher..?!
(i need to change the caps.... and the power resistor of the preamp...)

HI,
my English isnt good, but I answerd this before. You are joking us. EOD

zzeenn:

 

[Netlist]

if i build the new power supply..... the o/p Watt will be higher..?!
(i need to change the caps.... and the power resistor of the preamp...)

DJ,
Post #10 (and others) of this thread explains in detail how much power you will get with a given power supply.
Try to make a few calculations and things will be clear.

/Hugo - Also finds it hard to calculate but can tell you it's worth the effort 😉

 

[Dj BASS AMP]

OK thanks for help to me... ! thanks all.
in the eng of the build i tell u how it is work...

 

[Dj BASS AMP]

36~0~36 900VA after rectification and caps...

+/- 50V.... it will change something ??

or to us in 48~0~48 1200VA after rectification and caps...

+/- 68V ....

i need the amp for 2 big loudspeaker...

ani one = 1800W Peak 2Ohm 900W RMS 2 Ohm...

 

[Dirk]

DJ,

If you only double the effective PS voltage without changing the ENTIRE amplifier design, you will probably launch your amplifier so high, that Saddam will think the war has begun

BTW, if you don't have a schematic, there is NO way you can ever make it a better amp.

Dirk

 

[Dj BASS AMP]

I understanding... Thanks...

 

[Dj BASS AMP]

i change the o/p and the medium transistors... and the power supply 45~0~45VAC 900VA... 2 rectifiers of 35A.... i change the caps and filter caps 6 of 10000uF.....

finally... in 8 ohm speakers.... the sound is stronger and clean...
but i dont now how much watt the amp out on 4/8 Ohm....

 

[peranders]

I understanding... Thanks...

i change the o/p and the medium transistors... and the power supply 45~0~45VAC 900VA... 2 rectifiers of 35A.... i change the caps and filter caps 6 of 10000uF.....
finally... in 8 ohm speakers.... the sound is stronger and clean...
but i dont now how much watt the amp out on 4/8 Ohm....

DJ, I think you have got some things wrong. You can't design an amp without knowing anything. If I would start a >500 watts amp project I would expect difficulties despite the fact that I work as an electronic designer.

Choosing the right parts is one thing, getting it working is another! It can even be hard to get the parts when you know what you want!

I have said it before, start with a 50-200 W amp first and take your experiencies with you when you start with the BIG amp.

When I read your questions and especially your answers I see a totally 😕 guy!