Right channel noise
I've had my Aleph up and running for a few months now and it sounds lovely. Over the last few weeks, I've noticed occasional small pops, hisses, crackles and noise coming from the right channel. I spent a lot of time trying to figure out what was going on:
-it's not preamp related. I've tried two preamps, and no preamp and the noise is still there. It's the amp.
-not related to volume setting, the noise is just static at the same level no matter what volume the preamp is set at.
-it's not cable related. I've tried may types of interconnects and speaker cable and nothing changed.
-music still plays and sounds great, but the noise can be heard in addition to the music. Signal type doesn't seem to matter. Music doesn't change the noise level or profile at all. The noise level is low enough that music at greater volume drowns it out. Lower level listening is another story.
-I've switched speaker cables between speakers and the sound moves to the other speaker, so I know it's the right amp channel and not the speaker.
-once the amp has warmed up for about an hour, the noise stops.
-the noise is intermittent, not constant, and was not there until recently. No other changes to my system, save for moving around cables, etc.
I haven't yet pulled the amp from the shelf to measure anything, because I'm not sure where to start. I've attached an mp3 of the sound, recorded with my iPhone about 6 inches in front of the offending speaker. I've also read through this entire thread looking for similar issues, of which there were a few, but didn't seem to find how those got resolved. Any help would really be appreciated.
Thanks,
Brad
I've had my Aleph up and running for a few months now and it sounds lovely. Over the last few weeks, I've noticed occasional small pops, hisses, crackles and noise coming from the right channel. I spent a lot of time trying to figure out what was going on:
-it's not preamp related. I've tried two preamps, and no preamp and the noise is still there. It's the amp.
-not related to volume setting, the noise is just static at the same level no matter what volume the preamp is set at.
-it's not cable related. I've tried may types of interconnects and speaker cable and nothing changed.
-music still plays and sounds great, but the noise can be heard in addition to the music. Signal type doesn't seem to matter. Music doesn't change the noise level or profile at all. The noise level is low enough that music at greater volume drowns it out. Lower level listening is another story.
-I've switched speaker cables between speakers and the sound moves to the other speaker, so I know it's the right amp channel and not the speaker.
-once the amp has warmed up for about an hour, the noise stops.
-the noise is intermittent, not constant, and was not there until recently. No other changes to my system, save for moving around cables, etc.
I haven't yet pulled the amp from the shelf to measure anything, because I'm not sure where to start. I've attached an mp3 of the sound, recorded with my iPhone about 6 inches in front of the offending speaker. I've also read through this entire thread looking for similar issues, of which there were a few, but didn't seem to find how those got resolved. Any help would really be appreciated.
Thanks,
Brad
I’ve had sounds similar to that twice - once was a loose screw holding down a wire in the power supply. The other time was a bad solder joint. In both cases it was a bad connection. My suggestion is that you get a chop stick and start poking around all over and see if you can trigger anything.
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That sounds like a hot spot in its infancy.
Make sure that, in addition to what was already suggested, the lugs grip nice & tight on power rails. With a single power supply board & transformer, you'll be running those connections at around 4A (!)
Make sure that, in addition to what was already suggested, the lugs grip nice & tight on power rails. With a single power supply board & transformer, you'll be running those connections at around 4A (!)
Waiting for the arrival of some components to complete the aleph J boards, I am carrying out functional tests on the power supply unit, the transformer 500VA 230V primary and 2x18V secondary, on power rails I have 2 x 0 - 25.4, I think it should not create problems for the correct functioning of the amplifier cards.
Anyone confirm me? 😕
Anyone confirm me? 😕
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Absolutelly fine, @triksters. You do not need any exact voltage (like 24V), anything arround that is fine. And you will have a few volts less with the load (when the amplifier boards are connected). It will be arround 22-23V. It's fine. I usually have arroud 22V in my amps under the load.
The 25.4V unloaded is absolutely fine, but I hope it's +25.4V on one rail and -25.4V on the other rail, referenced to the shared / connected ground of your PSU.
Regards, Claas
Regards, Claas
Hi All,
Just a curiosity: what is the best way to implement a bias meter like in Papa's .8 series?
Just a curiosity: what is the best way to implement a bias meter like in Papa's .8 series?
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Pa is using sensitive instrument, measuring voltage sag across one wire in PSU
while steady - it's A Class
when it moves, it's A Classsssss
when it bounces, you're stone deaf - you didn't heard KlunK!
connect your meter across any of source resistors, put 10K ( or more if needed) trimpot inline, put 100uF across instrument
if you give me data for instrument, I'll be more precise about trimpot and ease of setting
while steady - it's A Class
when it moves, it's A Classsssss
when it bounces, you're stone deaf - you didn't heard KlunK!
connect your meter across any of source resistors, put 10K ( or more if needed) trimpot inline, put 100uF across instrument
if you give me data for instrument, I'll be more precise about trimpot and ease of setting
Thanks ZM
De Nada
I'm here to serve and protect, and to show than Mine is Biggest in the World
easier than you think
local surplus places/junkyards
obviously - any bigger Vendor
and of course - fleabay and Ali
do not expect to find PL knockout meter ( even if you can find them, together with case) ; if you want same look - you can't avoid CNC work
if you are content with any other style - plenty of meters to choose from - our Chinese brothers are making everything, and more
example of lucky find (persistent one is always given) , post #678 The Singing Bush
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you need to search for either mAmeter or Vmeter
in core, they're all the same , what's different is just printing on scale - so you need to choose what's available
nowadays is easy yo make your own scale ( whichever way - paper, Alu sheet, plastic) and print even ZM is Smartest of them all), if you want to
me - I'm happy with mA, maybe if V are printed that would bother me more ..... but frankly - I'm pass the stage of being nitpicky about anything I'm doing for my self - I just postpone it to time when I can do it exactly as I wish, without too much efforts
read wiki page about D'Arsonval meters, and you'll know basics Ammeter - Wikipedia
they're simple and surprisingly sturdy, considering how easy you can ruin them , with fingerpoking
usually important data is how many uA or mA is needed for full tilt, sometimes you'll also get Rdc of coil, sometimes V needed for full tilt
in praxis - 95% of meters you can stumble on can be used for your purpose
search, post links, plea for help
in core, they're all the same , what's different is just printing on scale - so you need to choose what's available
nowadays is easy yo make your own scale ( whichever way - paper, Alu sheet, plastic) and print even ZM is Smartest of them all), if you want to
me - I'm happy with mA, maybe if V are printed that would bother me more ..... but frankly - I'm pass the stage of being nitpicky about anything I'm doing for my self - I just postpone it to time when I can do it exactly as I wish, without too much efforts
read wiki page about D'Arsonval meters, and you'll know basics Ammeter - Wikipedia
they're simple and surprisingly sturdy, considering how easy you can ruin them , with fingerpoking
usually important data is how many uA or mA is needed for full tilt, sometimes you'll also get Rdc of coil, sometimes V needed for full tilt
in praxis - 95% of meters you can stumble on can be used for your purpose
search, post links, plea for help
😀
though - being Ameter, count on some fingerpoking inside, to remove internal shunt
remember - you already have source resistor in circuit, all you need is to sample some voltage across it
I need to fingerpoke also to place two LEDs inside 😀
Voltage reading is across 51K R23, right? Setting is @400mV, so do I need a 1V meter to match the center or something with a scale in Ampère that would display the real current (maybe better)? as standard current is 0,85A, I could pick a 2A full-scale, remove internal resistor and add a trimmer...
DC 0 - 2A ROUND analogico amperometro pannello corrente DIA. 66.4mm DH52 Direct Connect | eBay
Voltage reading is across 51K R23, right? Setting is @400mV, so do I need a 1V meter to match the center or something with a scale in Ampère that would display the real current (maybe better)? as standard current is 0,85A, I could pick a 2A full-scale, remove internal resistor and add a trimmer...
DC 0 - 2A ROUND analogico amperometro pannello corrente DIA. 66.4mm DH52 Direct Connect | eBay
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