Does anyone have interior photos of a completed Aleph J done in a 4U Deluxe, with the Universal PSU board, Antec transformer, and monolythic bridge rectifiers? Would be super-helpful to have a clear set of photos for where @alanhuth want to ultimately end up. Thanks!
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Thanks.
The AC wiring length is extremely short (around 10cm / 4 inches) and that includes the thermistor in series with the primary winding.
The secondary windings are fed underneath the power supply PCB, which in turn minimises the length of DC wiring between power supply PCB and amp PCBs.
I built mine into a pair of redundant LED heatsinks. Yes I used heavy cables but the length didn't really affect the preformance that much.
My choice of PSU components seems to have had a more dramatic affect.
The huge heatsinks also help
My choice of PSU components seems to have had a more dramatic affect.
The huge heatsinks also help
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Correct. That BOM for Aleph J boards is exactly that. The BOM for power supply will have that info concerning that board. I think I get your point, it could cause more orders I guess, but I've pretty well resigned myself to pretty much always having "extra" orders...
I really like the power supply boards I got from Teabag, very nice and heavy. Fits most any sized caps, like store PS board it has snap off pieces for rectification. very heavy boards...not the smallest in the world...
Not sure if anyone has mentioned this here yet, but spend 20-25 bucks on a Soldapult….I only recently got one. I've always used braid for solder removal after trying to use one of those gun/bulb deals. They never worked as well as braid for me. This new device is the bomb. Bought it on Nelson and 6l6 advice, it works beyond my expectations. Teflon tip doesn't burn, cram it in there along with iron and it will remove every trace. Plus once it has removed solder, you can squirt out the little "solder sculpture" that results. Recommended! Should have bought this a couple of decades ago.
Braid still has its place, and get the good stuff.
Russellc
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Correct. That BOM for Aleph J boards is exactly that. The BOM for power supply will have that info concerning that board. I think I get your point, it could cause more orders I guess, but I've pretty well resigned myself to pretty much always having "extra" orders...
Sorry that I wasn't clearer. The intimidating thing for me about putting together the actual Mouser/Digikey order is editing the BOMs (for example, which parts to omit from the PSU BOM if you're using bridge rectifiers, and then adding the bridge rectifiers, and then wondering whether you need hardware to mount those rectifiers to the baseplate) and then wondering what odds and ends aren't on either of the BOMs (like mounting hardware, since the back plate kit is out of stock). We'll get there, but it'll take some thinking. And you're right, we probably should resign ourselves to "extra orders"...
I was debating this myself, and you have persuaded me. @alanhuth already has one and was also singing its praises. Whether it ultimately stays in the "tools you should have" in the noobs guide will depend on whether we use it. Perhaps you will say, the question is not "whether" but "how often."
===== The Saga Continues ======
So, while the baby was sleeping (she got her vaccinations yesterday so she slept a lot today) I had a chance to "swap" power transformers between my Aleph J (in which the power transformer audibly hums) and my M2x (in which there is a little noise from the speakers but no transformer hum - I'm working on some mu metal shields for the M2x Edcor transformers as part of my "when baby sleeps and there are no other chores" projects). By way of comparison the M2x noise sounds like a tube amp, while the Aleph J hum is some pretty bad electrical hum you can hear across the room. As those following my posts with something between amusement and empathy may recall the Aleph J biases without an issue, which to me suggests that the power transformer hum is from a problem with the power supply and not on the amp boards. (Is this a reasonable assumption?) The AJ power transformer hums no matter which of its amp boards (or both) are attached, but no hum is present when there is no load (neither board is attached).
I ran some leads between the secondaries of the M2x power transformer and the bridge rectifiers of the AJ and flipped the power switch.There was no hum in the M2x power transformer, but the sound coming out of the speaker was a bit noisy. Not sure the cause of the noise..... On the other hand, when I ran some leads between the secondaries of the AJ and the bridge rectifiers of the M2x there was no hum in the power transformer, but the sound coming out to the speakers was much more noisy than with the M2x's own power transformer. Very confusing.
So here's my conundrum: I'm leaning toward some of the laminations of the AJ power transformer humming ,but the absence of power transformer hum when AJ power transformer is "hooked up" to the M2x confuses me. My only thought is that the AJ and M2x present different enough loads to the AJ power transformer that the AJ boards causes its transformer to hum while M2x boards are an easier load for the AJ power transformer and the hum is absent (but the noise coming out of the speakers is still bad). I'm too much of a neophyte to know if this makes sense (less than 10 builds and relatively little audio electronics knowledge). What I think I'd really need is another set of AJ boards to test the AJ power transformer against so the load the transformer sees is the same as in the present build (I'm not willing to build a whole other amp at this point to test this hypothesis).
So this is the point where I humbly ask for recommendations. I haven't tried swapping out the power or amp boards of the respective amps (mostly because I'm fairly happy with the M2x and don't want to break sh*t), but this is the only thing I can think to try that I haven't yet. I'm pretty sure I've tried every other recommendation offered on the forum (with a few possible exceptions that had to do with system noise as opposed to transformer hum). Should I just ask Antek to swap the transformer for me (or purchase another failing that)? Is it possible that a bad solder joint is causing all this grief? (Jim, I'm half looking at you to answer this since you've seen my soldering on the AJ amp boards, as well as tested them....). Is it possible that something is wrong with the AJ power supply board or bridge rectifiers? I'm struggling to imagine that this is the case (or that the safety cap or thermistors are bad) or else the amp board would measure poorly, which is not the case at all. In fact, the voltages coming out of each section of the power supply are in the expected range (I have these values in a previous post). Is there another test I can run on the power supply besides testing the voltages? (Please note: my test equipment is comprised almost entirely of a multimeter.)
Any thoughts, suggestions and prayers are greatly appreciated.
Thanks,
/d
So, while the baby was sleeping (she got her vaccinations yesterday so she slept a lot today) I had a chance to "swap" power transformers between my Aleph J (in which the power transformer audibly hums) and my M2x (in which there is a little noise from the speakers but no transformer hum - I'm working on some mu metal shields for the M2x Edcor transformers as part of my "when baby sleeps and there are no other chores" projects). By way of comparison the M2x noise sounds like a tube amp, while the Aleph J hum is some pretty bad electrical hum you can hear across the room. As those following my posts with something between amusement and empathy may recall the Aleph J biases without an issue, which to me suggests that the power transformer hum is from a problem with the power supply and not on the amp boards. (Is this a reasonable assumption?) The AJ power transformer hums no matter which of its amp boards (or both) are attached, but no hum is present when there is no load (neither board is attached).
I ran some leads between the secondaries of the M2x power transformer and the bridge rectifiers of the AJ and flipped the power switch.There was no hum in the M2x power transformer, but the sound coming out of the speaker was a bit noisy. Not sure the cause of the noise..... On the other hand, when I ran some leads between the secondaries of the AJ and the bridge rectifiers of the M2x there was no hum in the power transformer, but the sound coming out to the speakers was much more noisy than with the M2x's own power transformer. Very confusing.
So here's my conundrum: I'm leaning toward some of the laminations of the AJ power transformer humming ,but the absence of power transformer hum when AJ power transformer is "hooked up" to the M2x confuses me. My only thought is that the AJ and M2x present different enough loads to the AJ power transformer that the AJ boards causes its transformer to hum while M2x boards are an easier load for the AJ power transformer and the hum is absent (but the noise coming out of the speakers is still bad). I'm too much of a neophyte to know if this makes sense (less than 10 builds and relatively little audio electronics knowledge). What I think I'd really need is another set of AJ boards to test the AJ power transformer against so the load the transformer sees is the same as in the present build (I'm not willing to build a whole other amp at this point to test this hypothesis).
So this is the point where I humbly ask for recommendations. I haven't tried swapping out the power or amp boards of the respective amps (mostly because I'm fairly happy with the M2x and don't want to break sh*t), but this is the only thing I can think to try that I haven't yet. I'm pretty sure I've tried every other recommendation offered on the forum (with a few possible exceptions that had to do with system noise as opposed to transformer hum). Should I just ask Antek to swap the transformer for me (or purchase another failing that)? Is it possible that a bad solder joint is causing all this grief? (Jim, I'm half looking at you to answer this since you've seen my soldering on the AJ amp boards, as well as tested them....). Is it possible that something is wrong with the AJ power supply board or bridge rectifiers? I'm struggling to imagine that this is the case (or that the safety cap or thermistors are bad) or else the amp board would measure poorly, which is not the case at all. In fact, the voltages coming out of each section of the power supply are in the expected range (I have these values in a previous post). Is there another test I can run on the power supply besides testing the voltages? (Please note: my test equipment is comprised almost entirely of a multimeter.)
Any thoughts, suggestions and prayers are greatly appreciated.
Thanks,
/d
can't recall if youve tried tightening/loosening/slightly rotating the transformer?
do you have an input snubber across the secondaries?
it might also be worth considering getting a couple more rectifiers to swap in. I'm not sure what to make of your test with swapping leads between the two amps. maybe ground loops?
The one thing i noted is that the mechanical transformer hum went away on the AJ transformer when you hooked it up to the M2X. Gives me a little hope now that your transformer is fine and it's isolated to what's going on between that and the PSU board.
do you have an input snubber across the secondaries?
it might also be worth considering getting a couple more rectifiers to swap in. I'm not sure what to make of your test with swapping leads between the two amps. maybe ground loops?
The one thing i noted is that the mechanical transformer hum went away on the AJ transformer when you hooked it up to the M2X. Gives me a little hope now that your transformer is fine and it's isolated to what's going on between that and the PSU board.
Looking at one of the pictures of post #5144, the wires from the bridge rectifiers to the power supply board look quite light gauge. Perhaps that may be an issue, or not.
https://www.diyaudio.com/forums/att...37-aleph-illustrated-build-guide-img_0559-jpg
The power supply wires to the amp boards look small too.
https://www.diyaudio.com/forums/att...37-aleph-illustrated-build-guide-img_0559-jpg
The power supply wires to the amp boards look small too.
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