Thank you for sharing.Three Cheers for FLOHMANN!
This “Aleph J Build Guide for Noobs” grew out of a “modest proposal” posting I made, asking for something exactly like what we now have with the Noob Guide. Here is that posting: A modest proposal for all the selfless volunteers helping us build Pass amps
If you recall, the response to that post was not encouraging. The general attitude was that a noob guide is not necessary, stop being a chicken, just dive in, we will help you. My repeated point was that sure, some people will emerge from the gauntlet in fine shape, but many others will a) never try, or b) get discouraged and choose to do something else.
Fred (FLOHMANN) replied differently. He agreed with the idea of a Noob guide to get people over the hump from ACA to a high-level Pass amp. And he put a challenge back to me: let’s make this noob guide together. i agreed. And here we are, six months later with a fantastic Noob Guide that many people have praised and thanked and claimed it was the key to their deciding to build an Aleph J, and it was integral to the success of their effort. I feel proud and vindicated for coming up with the suggestion. But here’s the thing:
I DID NOTHING to create the Noob Build Guide. I totally abandoned Fred, after committing to doing half the work with him. No excuses. I let him down. He did the whole effin thing all by himself. He deserves all the credit, and praise, not only for seeing the value in this pursuit, but in following through in an honorable manner and producing, what anybody can see is a first-class result.
Fred, the DIY community owes you a huge thanks, and I do in particular. I finally used the guide that you created and built my own Aleph in 2 days. Thank you! Of course, you were standing on the shoulders of giants like 6L6, but you did a ton of original work, and you did it without the help you were promised. I salute you!
This “Aleph J Build Guide for Noobs” grew out of a “modest proposal” posting I made, asking for something exactly like what we now have with the Noob Guide. Here is that posting: A modest proposal for all the selfless volunteers helping us build Pass amps
If you recall, the response to that post was not encouraging. The general attitude was that a noob guide is not necessary, stop being a chicken, just dive in, we will help you. My repeated point was that sure, some people will emerge from the gauntlet in fine shape, but many others will a) never try, or b) get discouraged and choose to do something else.
Fred (FLOHMANN) replied differently. He agreed with the idea of a Noob guide to get people over the hump from ACA to a high-level Pass amp. And he put a challenge back to me: let’s make this noob guide together. i agreed. And here we are, six months later with a fantastic Noob Guide that many people have praised and thanked and claimed it was the key to their deciding to build an Aleph J, and it was integral to the success of their effort. I feel proud and vindicated for coming up with the suggestion. But here’s the thing:
I DID NOTHING to create the Noob Build Guide. I totally abandoned Fred, after committing to doing half the work with him. No excuses. I let him down. He did the whole effin thing all by himself. He deserves all the credit, and praise, not only for seeing the value in this pursuit, but in following through in an honorable manner and producing, what anybody can see is a first-class result.
Fred, the DIY community owes you a huge thanks, and I do in particular. I finally used the guide that you created and built my own Aleph in 2 days. Thank you! Of course, you were standing on the shoulders of giants like 6L6, but you did a ton of original work, and you did it without the help you were promised. I salute you!
I'm with you 100%! It's a valuable asset to the community! The thing I appreciate about it is everything is to-the-point and you don't have to fish for answers to anything. While the build guide thread is full of great information, it's also a bajillion pages long now and it can be a challenge to find useful information (although there is an index of useful tips -- thanks!). The n00b guide made things super easy. Three more cheers for FLOHMANN!
I completely agree. I perused and lurked on this forum for months- maybe longer, and it was the noob guide that pushed me over into action. I think having a BOM for the PSU is very helpful. If you're logging onto Mouser for the first time, I think most people will agree it's completely overwhelming.
The other thing that the guide helped with is to know what's important, and what's nice to have. For me, one of the big questions was the bridge rectifiers- wondering what a snubber is, etc. etc. etc. Another was something as simple sounding as wire gauge, and connectors. There are these so-called best practices (do we solder a wire directly onto the PCB or not, and why?) which is hard to come by. As many have mentioned, once you actually go through the exercise of actually building these, a lot of it makes sense and becomes far less daunting.
As for impact, I find that I'm listening to music a lot more through this amp. The woodiness of cellos in chamber music, depending on the quality of recording, comes through really nicely, for example. This to me is the ultimate measure of success- do you want to listen to music more? I'm finding I'm looking for "audiophile" recordings etc. to listen to- almost more important than what the music is itself, which has led to some nice, unexpected discoveries.
So hats off to all the many, many people here in this community, who have spent countless hours helping, and to Fred for putting together the newbie guide. I saw mention of it on Reddit after it came out, and so I'm certain it's helped with a good number of "conversions" of lurkers into builders, which I think is what we all want ;-)
The other thing that the guide helped with is to know what's important, and what's nice to have. For me, one of the big questions was the bridge rectifiers- wondering what a snubber is, etc. etc. etc. Another was something as simple sounding as wire gauge, and connectors. There are these so-called best practices (do we solder a wire directly onto the PCB or not, and why?) which is hard to come by. As many have mentioned, once you actually go through the exercise of actually building these, a lot of it makes sense and becomes far less daunting.
As for impact, I find that I'm listening to music a lot more through this amp. The woodiness of cellos in chamber music, depending on the quality of recording, comes through really nicely, for example. This to me is the ultimate measure of success- do you want to listen to music more? I'm finding I'm looking for "audiophile" recordings etc. to listen to- almost more important than what the music is itself, which has led to some nice, unexpected discoveries.
So hats off to all the many, many people here in this community, who have spent countless hours helping, and to Fred for putting together the newbie guide. I saw mention of it on Reddit after it came out, and so I'm certain it's helped with a good number of "conversions" of lurkers into builders, which I think is what we all want ;-)
Awesome guide.
I just open and found an interesting tool for trimmers:
Vishay / Spectrol ACCTRITOB308-T000
ACCTRITOB308-T000 Vishay / Spectrol | Mouser
Bourns make them too.
Bourns H-90
H-90 Bourns | Mouser
My screwdriver sliped many times when I adjust DC output at my DAC.
And I was really scared to short something.
I will try one or both. Thanks!
I just open and found an interesting tool for trimmers:
Vishay / Spectrol ACCTRITOB308-T000
ACCTRITOB308-T000 Vishay / Spectrol | Mouser
Bourns make them too.
Bourns H-90
H-90 Bourns | Mouser
My screwdriver sliped many times when I adjust DC output at my DAC.
And I was really scared to short something.
I will try one or both. Thanks!
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Amp Board Dim Bulb Test Failure Question
Fellow builders,
I need some suggestions on diagnosing a problem.
I have searched the Aleph J threads to address my issue with finding a result.
I am testing the second amp board and the dim bulb test light brightens and then goes out. This is not according to the instructions. LED 3 does not light (LED 2 does and stays on for some time after the power is off, as expected). I have done a visual inspection of the PCB mounted on the heat sink and nothing appears out of line. The power test and the first amp test went as expected and all of the values are within spec.
I readjust the trim pots, checked the mounting of the capacitors and diode, and the values of Q2 and Q3/Q4. No grounding of the MOSFETS. I have not taken the shrink wrap off of Q1A and Q1B to check those yet.
I am looking for a place to start before tearing thing apart.
Thanks
Fellow builders,
I need some suggestions on diagnosing a problem.
I have searched the Aleph J threads to address my issue with finding a result.
I am testing the second amp board and the dim bulb test light brightens and then goes out. This is not according to the instructions. LED 3 does not light (LED 2 does and stays on for some time after the power is off, as expected). I have done a visual inspection of the PCB mounted on the heat sink and nothing appears out of line. The power test and the first amp test went as expected and all of the values are within spec.
I readjust the trim pots, checked the mounting of the capacitors and diode, and the values of Q2 and Q3/Q4. No grounding of the MOSFETS. I have not taken the shrink wrap off of Q1A and Q1B to check those yet.
I am looking for a place to start before tearing thing apart.
Thanks
Two questions: Does the dim bulb (incandescent, 100watt) go out completely? If not, it’s probably doing what it’s supposed to do. And, are your LEDs the same color on both sides? When I fired up mine, with the green LED on one side, I thought it was out, but it was fine, just very low output compared to the other colors I had.
RE: Amp Board Dim Bulb Test Failure Question-Partial answerr
Thanks for the suggestions. Root cause was the ground from rectifier was not seated firmly in the quick disconnect. Traced my steps and repeated the testing on the good amp right board to confirm before checking the bad ground connection. Same issue with the LED. Reconnected the ground and now all lights are on.
Now I need to determine why I am getting negative values on the left board. I was fiddling with the trim pots. Can trim pots be turned too far and fail? I am letting the amp sit and discharge before remeasuring the trim pots before for the initial settings (R27 at 68K and R7 at 1K).
Thanks for the suggestions. Root cause was the ground from rectifier was not seated firmly in the quick disconnect. Traced my steps and repeated the testing on the good amp right board to confirm before checking the bad ground connection. Same issue with the LED. Reconnected the ground and now all lights are on.
Now I need to determine why I am getting negative values on the left board. I was fiddling with the trim pots. Can trim pots be turned too far and fail? I am letting the amp sit and discharge before remeasuring the trim pots before for the initial settings (R27 at 68K and R7 at 1K).
Chris, thanks for the photos. Something like this. My current questions is related to the Trimpots. I cannot set the initial resistances for the Trimpots. I think I may have over turned them in my attempts to diagnose the Dim Bulb issue. Can the Trimpots been “over cranked”? One is now clicking. Is it time to get new ones? Thanks
As Andy described, they click at their limit. When it starts clicking, stop, you’re at the end of its adjustment (nothing is broken, it’s by design). Then start turning it the other way and counting how many turns it takes. When it starts clicking again, you’re at the other end. Should be about 25 turns. Presuming this is the 100K trimming pot, it should start out adjusted to about 68K when it’s installed. The starting bias should be 350mA during burn in, but the 68K setting yielded over 500mA for me to begin with which took a fair amount of turning to tweak out. So as a rough starting point, count back 12-1/2 turns to get it near the middle of the range. Should get you close to a point where you can make adjustments, I suspect.
Anyone else, feel free to suggest otherwise. It’s been a week or so since I did this myself.
Anyone else, feel free to suggest otherwise. It’s been a week or so since I did this myself.
So the diystore just last week sold me everything I needed for my Aleph J except the match set of lsj74 no big deal I thought until I emailed the store and they said they would be out for ‘several months’ again WARNING do not buy Aleph J parts from the diystore expecting you can complete your amplifier...since the noob guide doesn’t cover sourcing and matching lsj74 I guess it will just be on the shelf until parts are available, I could not be more disappointed.