Hi:
I am a recent proud owner of a lovely Aleph 5 which sounds incredibly wonderful, but there is a low-level buzzing in its output on both channels, either with no inputs or inputs shorted. Speakers are Gallo Reference 3.1's, 88db/W/m sensitivity. The sound is more of a buzz than a 60 Hz hum. It is not mechanical in the amp and disappears when I disconnect the speakers.
Can I assume buzz is Power Supply caps aging? If so, would you please recommend a good replacement cap with the correct physical dimensions? If not, do you suspect something else? I can open the amp and scope the ripple on the rails if that would help diagnose.
Thanks!
- Jack
I am a recent proud owner of a lovely Aleph 5 which sounds incredibly wonderful, but there is a low-level buzzing in its output on both channels, either with no inputs or inputs shorted. Speakers are Gallo Reference 3.1's, 88db/W/m sensitivity. The sound is more of a buzz than a 60 Hz hum. It is not mechanical in the amp and disappears when I disconnect the speakers.
Can I assume buzz is Power Supply caps aging? If so, would you please recommend a good replacement cap with the correct physical dimensions? If not, do you suspect something else? I can open the amp and scope the ripple on the rails if that would help diagnose.
Thanks!
- Jack
Caps would normally produce "Humming". Buzzing could be down to a failed or failing diode in the PSU.
Have you access to an oscilloscope ?
If not you could try the following:-
Disconnect both channel amplifiers from the PSU(s).
Make up a little test rig with a capacitor in series with a crystal earpiece. Then touch two test leads across each power supply, they should both be silent.
Now load each supply with lamps and repeat the experiment, you can do one at a time.
Finally load all four supplies (+/- L) and (+/- R) with lamps and test again.
It is UNLIKELY that both or either amplifier has developed a fault.
Have you access to an oscilloscope ?
If not you could try the following:-
Disconnect both channel amplifiers from the PSU(s).
Make up a little test rig with a capacitor in series with a crystal earpiece. Then touch two test leads across each power supply, they should both be silent.
Now load each supply with lamps and repeat the experiment, you can do one at a time.
Finally load all four supplies (+/- L) and (+/- R) with lamps and test again.
It is UNLIKELY that both or either amplifier has developed a fault.
I have an o-scope and will test the rails. I agree ripple would be a hum not a buzz. I'm now wondering if it's an induced noise from a nearby UPS. Will test that theory also. Buzz almost sounds like TV sweeps but there's no CRT's nearby to induce such a thing.
Turning off amp kills buzz and audio output (if any) almost instantly. One thing I really like about this amp is no turn on or off pops (unlike a certain amp I had that shall remain Naim-less).
Turning off amp kills buzz and audio output (if any) almost instantly. One thing I really like about this amp is no turn on or off pops (unlike a certain amp I had that shall remain Naim-less).
is it original or DIY? have it buzzed all the time?
it can be the caps. or diodes. or it can be a bad soldering. or ground issue.
At low volume it should take a good few seconds to quieten down and die.
Unless you have a DIY amp with PSU monitoring to prevent turn-off thumps.
that depends on the bleeder resistors. jenk them out and it will play for a looong time
put in a 500ohm 20W and it will go silent very fast.
my aleph2's played for about 2 sec after power down.
but they were DIY with with 408.000uF and 1K bleeder resistors.
SOLVED! - Aleph 5 Low Level Buzzing in Output - Radiation from UPS
I'm pleased to say the buzz was caused by too close proximity to a CyberPower UPS. The amp must have been picking up radiation from the UPS' switching power supply. I separated them by about three feet and no more buzz.
Problem solved. Thanks to everyone who offered help! I love my Aleph 5!!!
I'm pleased to say the buzz was caused by too close proximity to a CyberPower UPS. The amp must have been picking up radiation from the UPS' switching power supply. I separated them by about three feet and no more buzz.
Problem solved. Thanks to everyone who offered help! I love my Aleph 5!!!
that depends on the bleeder resistors. jenk them out and it will play for a looong time
put in a 500ohm 20W and it will go silent very fast.
Who? in the real World would use 500R 20W Bleeders ?
As a minimum I would use 1K as you did, but 10K will do the job without loading the PSU.
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one that dont care about power draw and want a fast PSU bleed
10K will take a very long time to bleed out. for my F5 i use 2.2K.
Update! True cause of low level Aleph 5 buzzing - Loose capacitor screws
I feel a bit silly but at the same time very relieved to report this. After I thought I had determined the buzz was external interference from a nearby UPS, I moved the amp into another room to test it with some new speakers, the buzz returned and would not go away.
I then opened the amp, scoped the rails and found the minus rail to have 4 times the ripple as on the plus rail. On a whim, I tightened the screws which connect each PS capacitor to the main PCB, the minus rail ripple dropped to match the plus rail, and the buzz at the outputs disappeared, this time for real.
Apologies to The Cyberpower UPS people whose product is NOT broadcasting interference into the Aleph.
And thanks to Mr. Nelson Pass for designing such a wonderful-sounding, beautifully built piece of classic machinery that thankfullly only needed some screws tightened to sound its best after many, many years of service.
This time I can say with certainty: Problem solved!
I feel a bit silly but at the same time very relieved to report this. After I thought I had determined the buzz was external interference from a nearby UPS, I moved the amp into another room to test it with some new speakers, the buzz returned and would not go away.
I then opened the amp, scoped the rails and found the minus rail to have 4 times the ripple as on the plus rail. On a whim, I tightened the screws which connect each PS capacitor to the main PCB, the minus rail ripple dropped to match the plus rail, and the buzz at the outputs disappeared, this time for real.
Apologies to The Cyberpower UPS people whose product is NOT broadcasting interference into the Aleph.
And thanks to Mr. Nelson Pass for designing such a wonderful-sounding, beautifully built piece of classic machinery that thankfullly only needed some screws tightened to sound its best after many, many years of service.
This time I can say with certainty: Problem solved!
Thanks, Mr. Pass. It doesn't have lockwashers now but I will add next time I open it (which may be a long time from now).
Your Aleph 5 makes my Gallo Reference 3.1's sing like no other amp, and added what sounds like almost a full, solid, slammin' octave to the bottom end compared to some other highly regarded amps. My wife heard the improvements across the entire range instantly the moment we turned Mr. Aleph on. I now drive it with a Primare SP31 in balanced mode and it all sounds AMAZING!!!
Your Aleph 5 makes my Gallo Reference 3.1's sing like no other amp, and added what sounds like almost a full, solid, slammin' octave to the bottom end compared to some other highly regarded amps. My wife heard the improvements across the entire range instantly the moment we turned Mr. Aleph on. I now drive it with a Primare SP31 in balanced mode and it all sounds AMAZING!!!
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