I'm not taking any precaution handling usual Mos and JFets, at least not in my few usual environments, simply because time did show that I'm not zappy there
on the other hand, when hotter weather comes, each time I'm leaving my car, I get zapped on doors
that probably means that my car is zappier than I am
on the other hand, when hotter weather comes, each time I'm leaving my car, I get zapped on doors
that probably means that my car is zappier than I am
Thanks for the static reassurance all. I remember reading more about that a couple years ago but going forward the anti-static bag will be a reminder to ground first. Moment of absent-mindedness.
Well, now that I got my dumb question out of the way I can looking forward to nothing but insightful, thoughtful, and sophisticated questions in the future.
Well, now that I got my dumb question out of the way I can looking forward to nothing but insightful, thoughtful, and sophisticated questions in the future.
I did reach out to the diyaudio store and they said a month or so, but of course things were delayed. They are on the way!
I was asking because the transistors were available, and they said it would be a good idea to order the transistors now if you can in case they are going before the boards are available.
As i understand, it is a simple ampermeter used in such amps like XS 150 (https://www.passlabs.com/products/xs150/) which shows the fact when the amp is operating in class A or AB. I want to add such meter in Aleph J, but would someone explain to me when the amp starts to operate in class AB? As i suppose it's determined by source-drain current of output mosfets?
I'm not taking any precaution handling usual Mos and JFets, at least not in my few usual environments, simply because time did show that I'm not zappy there
on the other hand, when hotter weather comes, each time I'm leaving my car, I get zapped on doors
that probably means that my car is zappier than I am
i remember growing up, these gasoline tankers had a chain that is dragged along as the tankere moved, a sure way to avoid static build ups, strangely nowadays i do not see them anymore......
if you're mentioning it in that context, M2 can go to B, when driving tougher load
with 8R load it's A Class all to the voltage ceiling
i remember growing up, these gasoline tankers had a chain that is dragged along as the tankere moved, a sure way to avoid static build ups, strangely nowadays i do not see them anymore......
nowadays that's rubber stripe from chassis to asphalt, steel rope cored
so no clunking noises , just occasional fpzzzzt
Typical Aleph J Noise Levels?
Just finished my Aleph J last weekend and enjoying it very much. However, I've been trying to figure out why the noise levels vary so widely, inputs shorted vs. unshorted, when compared to other Pass DIY builds I have completed.
I measure around 70-80 microvolts of noise at the speaker outputs with the inputs shorted, putting this well under the spec of the FirstWatt commercial version. However, when I measure with open inputs I see around 3.5 millivolts! (I believe I saw similar reports somewhere in this thread, but can't find them right now.) When connected to a preamp, a Pass B1, noise is 200-300 microvolts which is not a problem.
Note that I dropped these boards into a chassis that housed my F5 which had less than 100 microvolts of AC noise with inputs either open or shorted. It also had low noise when connected to the B1 preamp. The general wiring approach for the Aleph J, generally remained the same using the existing wiring.
Just wondering if I'm missing something that I can correct or if this is the nature of this beast. Any ideas or pointers would be helpful.
Just finished my Aleph J last weekend and enjoying it very much. However, I've been trying to figure out why the noise levels vary so widely, inputs shorted vs. unshorted, when compared to other Pass DIY builds I have completed.
I measure around 70-80 microvolts of noise at the speaker outputs with the inputs shorted, putting this well under the spec of the FirstWatt commercial version. However, when I measure with open inputs I see around 3.5 millivolts! (I believe I saw similar reports somewhere in this thread, but can't find them right now.) When connected to a preamp, a Pass B1, noise is 200-300 microvolts which is not a problem.
Note that I dropped these boards into a chassis that housed my F5 which had less than 100 microvolts of AC noise with inputs either open or shorted. It also had low noise when connected to the B1 preamp. The general wiring approach for the Aleph J, generally remained the same using the existing wiring.
Just wondering if I'm missing something that I can correct or if this is the nature of this beast. Any ideas or pointers would be helpful.
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The popping sound still occurs - albeit randomly - and then disappears after a few seconds. I haven't done a thorough investigation of the RCA jacks yet. It's just odd - if it was a tube amp I would be replacing the input valve!
F5 is a single-ended input amplifier.
Aleph J is a differential input amplifier. When you short the RCA input, both transistors' bases will see the same potential (same ground potential); when you open the input, one base will see the ground potential (and whatever noise is there), and the other base will be floating. That ground noise will be amplified. Aleph J is a high input impedance, very wide bandwidth amplifier, which emphasises the "problem". It is a brilliant amplifier. It just needs a bit of attention to let all the virtues truly shine.
Thanks for the great explanation. Very helpful. Even though the amp excels in its musical abilities, I still want to explore methods of reducing the noise, possibly trying a hum-breaking resistor on the input ground as an easy experiment.