Aleph 30: project completed

[Andypairo]

I still don't see the speaker return.

If connected as adviced it should be OK, but since you said it works fine...

Ciao!

Andrea

 

[AndreaFx]

I still don't see the speaker return.

If connected as adviced it should be OK, but since you said it works fine...

Ciao!

Andrea

I modify the layout with the speaker connection

8,5 Ohm for the resistor it's ok or a I can increase/decrease the value? I use 8,5 because I had available, but i can try with 4, 6 or 10 Ohm if it's better.

thanks for support Andy........ I must offer you a beer

 

[Salas]

Great looking amp. Bravisimo! And how do you like the sound? What kind of speakers do you drive?

 

[AndreaFx]

Great looking amp. Bravisimo! And how do you like the sound? What kind of speakers do you drive?

Thanks salas

I haven't tried the ampli so good because first I want resolve the loop ground.

To date it played about 3 hours with a pair of DIY's speakers with morel component: model York
http://www.audiokit.it/ITAENG/KitDiffusori/2vie/MOREL/York.gif

Very good in my small room

 

[AndrewT]

Hi Andrea,
the value of the Power Resistor in the Safety Earth to Audio Ground connection is not important.


What is MUCH more important is that it survives longer than the mains fuse if mains were to touch the Audio Ground side.
Most recommend that a pair of Power Diodes wired in inverse parallel be added in parallel to the Power Resistor.

See ESP for a diagram of this.

 

[AndreaFx]

Hi Andrea,
the value of the Power Resistor in the Safety Earth to Audio Ground connection is not important.


What is MUCH more important is that it survives longer than the mains fuse if mains were to touch the Audio Ground side.
Most recommend that a pair of Power Diodes wired in inverse parallel be added in parallel to the Power Resistor.

See ESP for a diagram of this.

The power resistor is very big
http://www.audiokit.it/ITAENG/Resistenze/100_4555-1.jpg

Should survives mutch that mains fuse for me.

But.......you have an exemple of the circuit with diodes? What is ESP?

 

[AndrewT]

Andrea,
I think you may misunderstand the duty that this resistor may have to face if a mains wiring fault or transformer fault develops that connects Live to Audio Ground.

It may have to dissipate P=V^2/8.5ohms ~5.7kW until the fuse blows and the arc extinguishes.
How long will that 10W resistor last trying to dissipate 5.7kW?
I don't know, do you?

How long will a mains fuse last passing ~25A? Look up the tables for your chosen fuse manufacturer and value.

 

[Salas]

You will use 2pieces 5 Ampere diodes, or much bigger, or a diode bridge. One cathode goes to other's anode. This pair you wire in parallel to your 8.5R. So if big current must pass in some failure, it will go through one diode no matter the polarity.

 

[Salas]

Here is one example.

 

[AndrewT]

Salas,
ESP has asked that you refer enquirers to his site and not post extracts even if attributed. Your post isn't.

 

[AndreaFx]

Here is one example.

Good example salas....... and thank to Andrew, now i understand the problem

 

[AndrewT]

post21 to post51 before the message got through!!!!!
Dare we let you out alone?

 

[Salas]

Salas,
ESP has asked that you refer enquirers to his site and not post extracts even if attributed. Your post isn't.

Ah, ok. There is still the esp logo on top left of the pic, at least.