Aleph J illustrated build guide

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Extreme_Boky

Extreme_Boky

Member
Joined 2003
I know it's not easy to remove the PCB's from an amp, cut the trace, insert the 10-20ohm resistor, mount everything back... so, I remembered what I did to TEST if my suggestion is going to work first, before doing all the hard work. So, here it is:):):

Check the attached photos. Quickly scroll between "Before" and "After"... and you'll get what I mean...

1. Unsolder both GND wires (one coming from the PS, the other coming from the speaker's negative binding post)
2. Tie them (solder them) together.
3. Leave them "floating in the air"
4. Solder the 10-ohm resistor to the end of these two wires.
5. Solder the other end of the resistor to GND on the PCB

Turn the amp on. The buzz will be gone (hopefully).

If it is not gone, look elsewhere for the root cause... remove the resistor, unsolder the wires, and then solder them back to the PCB.

Nick
 

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Extreme_Boky

Extreme_Boky

Member
Joined 2003
Of course, if the buzz is gone.... you can then choose between these two options:

Leave everything as-is and enjoy life.
or
Do it properly (remove amp PCB's, cut trace, place the resistor on the underside, put everything back...)

The side NOTE: Looking at the "After" photo.... isn't it obvious that the speaker return should NOT go to amp PCB??

Just sayin'...
 
mbrennwa

mbrennwa

Member
Joined 2005
audioroot.net
Paid Member
Extreme_Boky said:
I know it's not easy to remove the PCB's from an amp, cut the trace, insert the 10-20ohm resistor, mount everything back... so, I remembered what I did to TEST if my suggestion is going to work first, before doing all the hard work. So, here it is:):):

Check the attached photos. Quickly scroll between "Before" and "After"... and you'll get what I mean...

1. Unsolder both GND wires (one coming from the PS, the other coming from the speaker's negative binding post)
2. Tie them (solder them) together.
3. Leave them "floating in the air"
4. Solder the 10-ohm resistor to the end of these two wires.
5. Solder the other end of the resistor to GND on the PCB

Turn the amp on. The buzz will be gone (hopefully).

If it is not gone, look elsewhere for the root cause... remove the resistor, unsolder the wires, and then solder them back to the PCB.

Nick
Click to expand...

I still don't understand the idea of splitting GND into speaker-GND and input-GND (see my earlier post).

I totally agree with your suggestion of looking for the root cause of the hum. However, blindly inserting resistors without understanding what's going on does not seem right.

So, I ask again: what is the background idea of splitting GND into two different GNDs with a resistor???
 
mbrennwa

mbrennwa

Member
Joined 2005
audioroot.net
Paid Member
quackers said:
It would be real helpful to those that are new to the game, if those who really understand the Aleph J design were to post an "official" diagram of the end-to-end grounding scheme for the Aleph J. Or if one does exist, please point in that direction.

Thanks!
Click to expand...

I have not used the diyAudio boards for my Alephs, so I don't know the details of the diyAudio boards. However, I don't think the Aleph J is different than other amps in terms of grounding.
 
ghzgary

ghzgary

Member
Joined 2017
quackers said:
It would be real helpful to those that are new to the game, if those who really understand the Aleph J design were to post an "official" diagram of the end-to-end grounding scheme for the Aleph J. Or if one does exist, please point in that direction.

Thanks!
Click to expand...

Hi, JSA1971, yes RIP Neil Peart, one of my heroes who had such a positive influence on me and many others. He was so much more than a great drummer.

Hi quackers, I was exactly in your place, looking for the definitive best grounding scheme, but unfortunately, there is no such thing.

There are many different opinions about how to best ground an amplifier, with pluses and minuses for each, so no perfect right answer. See for example this thread.

How to wire up an Amplifier

I am following, for the most part, the sources I posted earlier today, mainly because they make sense to me. Other things that make sense to me about grounding and wiring in general for audio frequencies.

1. Use star grounding to minimize common impedance coupling.

2. Source and return current should be balanced (same but opposite) on a set of wires. Don't have one wire sharing two or more different currents. For example, I plan to use (still building my amp) two ground wires from the star point to the amp boards, one for each voltage leg (so 4 power wires total to each board).

3. Twist any balanced sets of wires together so the currents cancel best, and keep them away from other wires and metal to the best possible. Capacitive and/or magnetic coupling can occur if they are close to metal so there could be currents running through something unintended. I see pictures of units wired to look clean and pretty, which means wires are tucked under the chassis bottom, or strapped along the heat sink or zip-tied together. That all looks pretty no doubt, but electric fields don't care about prettiness. I expect my unit will be somewhat of an ugly duckling. Obviously people are happy with the way their "pretty" units sound so this is undoubtedly a second-order effect.

As I build my amp, I'll try to take detailed photos of how the wiring is done at each step as I progress. Looking at pictures of other built units on this thread it's often hard to see exactly where the wires are going.
 
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