An additional weigh in re: static straps / mats - particularly since I recommended them earlier.
One of the trickiest things for both the forum members and the new builder is to troubleshoot over the internet. The Aleph J (while having few parts that would likely get fried due to a ESD issue) does have some relatively expensive parts compared to non-Pass designs. In addition, when a transistor gets fried from ESD, it will involve troubleshooting, desoldering, parts selection (involving matching to replace it properly) and re-soldering the part or parts. If it happens, the frustration to the new builder goes up, and the likelihood of a successful completion goes down. For a purchase of usually less than a few bucks it's an easy recommendation on my part.
I see a lot of great suggestions re: keeping costs down for the new builder. I think it's awesome. However, ask anyone that's zapped a part if they wish they'd bought an ESD strap and learned to use it properly ... they'll likely say yes. They're usually less than a dollar or two.
You don't necessarily need a mat, but I like them. Building on a surface with some give and a slight "tack" is nice. However, decent soldering / ESD mats are a bit expensive relative to what a new builder could do with that money. Mats are a creature comfort. Straps are highly recommended (at least by me). I recommend starting off on the right foot by using good practices early. That way, they become common habit and it won't "get in the way" or be a hassle. My $0.02.
One of the trickiest things for both the forum members and the new builder is to troubleshoot over the internet. The Aleph J (while having few parts that would likely get fried due to a ESD issue) does have some relatively expensive parts compared to non-Pass designs. In addition, when a transistor gets fried from ESD, it will involve troubleshooting, desoldering, parts selection (involving matching to replace it properly) and re-soldering the part or parts. If it happens, the frustration to the new builder goes up, and the likelihood of a successful completion goes down. For a purchase of usually less than a few bucks it's an easy recommendation on my part.
I see a lot of great suggestions re: keeping costs down for the new builder. I think it's awesome. However, ask anyone that's zapped a part if they wish they'd bought an ESD strap and learned to use it properly ... they'll likely say yes. They're usually less than a dollar or two.
You don't necessarily need a mat, but I like them. Building on a surface with some give and a slight "tack" is nice. However, decent soldering / ESD mats are a bit expensive relative to what a new builder could do with that money. Mats are a creature comfort. Straps are highly recommended (at least by me). I recommend starting off on the right foot by using good practices early. That way, they become common habit and it won't "get in the way" or be a hassle. My $0.02.
I've just never had a static issue. I guess one could build only in the summer, I only have worried about my semisouths, when that day comes, all precaution will be taken...
I'm in the Midwest, have hardwood floors or tile, work on a wood table. I didnt even have a problem with Pearl 2....there is one critter ZVP 33 or something like that which is hyper sensitive to static.
I used to be a lot more paranoid about static, I think it was Zenmod that calmed me down with similar views on static risk.
Whatever works!
Russellc
I'm in the Midwest, have hardwood floors or tile, work on a wood table. I didnt even have a problem with Pearl 2....there is one critter ZVP 33 or something like that which is hyper sensitive to static.
I used to be a lot more paranoid about static, I think it was Zenmod that calmed me down with similar views on static risk.
Whatever works!
Russellc
+1 and agreed. I think I may have zapped a SMD BJT once, but never a larger package part.
I'd hate to have people look at my personal bench and some of my practices, even during the MN winters on carpet, but I figured for the (admittedly rare) times that an ESD issue could rear its ugly head... I'd recommend safe Static Elimination eXperimentation.
The cost of prevention...
To avoid any illusion of being a hypocrite, I can't say I've always used protection...
I'd hate to have people look at my personal bench and some of my practices, even during the MN winters on carpet, but I figured for the (admittedly rare) times that an ESD issue could rear its ugly head... I'd recommend safe Static Elimination eXperimentation.
The cost of prevention...
To avoid any illusion of being a hypocrite, I can't say I've always used protection...
Even if you don't use protection, you can still take some basic precautions. 😀😀😀
For example, you can keep the mosfets in their antistatic tubings except
when measuring/soldering and ground yourself before handling the parts.
For example, you can keep the mosfets in their antistatic tubings except
when measuring/soldering and ground yourself before handling the parts.
I never had a static issue either, I make sure I'm touching the ground plane of the board when I install any silicon.
When you say "ground yourself", you mean touching something metal that is also grounded to earth ground (e.g., like my soldering station)?
I don't think the builders of AJ does not have to be seriously cautious about static, because you guys will have to buy more than (8) IRFP240 if you want to match them, and even some of them are accidentally dead (rare), it would not be a big issue. Yes, touching some metal object is fine.
BTW, when you guys order IRFP240, you may want to consider to get 24 pieces, because they should come in a big factory plastic tube, it means they are from the same batch, more consistent. You guys can happily share 12 each (before or after matching) if you guys want to, and probably less expensive than just buying 8 due to bulk discount. Just my 2¢.
BTW, when you guys order IRFP240, you may want to consider to get 24 pieces, because they should come in a big factory plastic tube, it means they are from the same batch, more consistent. You guys can happily share 12 each (before or after matching) if you guys want to, and probably less expensive than just buying 8 due to bulk discount. Just my 2¢.
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Yep
Here is a tip: Place your order with Digikey and purchase 25.
Then ask the staff to ensure they send you manufacturer's tube containing mosfets all from the same batch number.
A Vishay manufacturer's tube has 25 mosfets.
Here is a tip: Place your order with Digikey and purchase 25.
Then ask the staff to ensure they send you manufacturer's tube containing mosfets all from the same batch number.
A Vishay manufacturer's tube has 25 mosfets.
I think for this project, we'll just tell folks to buy the matched transistor set from the DIYAudioStore.
From reading the 6L6 illustrated guide thread, I'm assuming that a dim bulb tester is really a required tool for building the Aleph J. Do you need the full array of bulbs (40w/60w/100w)? Incandescent bulbs are getting hard to source for many of us, so it would be nice to know if you could get away with just one for testing on this build.
I will probably get some flack for this, but I prefer to use variac for fire up. It requires a sharp eye and patience. Have as many multimeter s as needed, and slowly up power. If anything starts getting hot, resistor darkens, or voltages aren't as expected, power down
For beginners, dim bulb should be mandatory! If power supply checks out, inspect boards for errors post pics, then if good hook up and attempt fire up with dim bulb.
I used one in my tube days, but somewhere along line I just used variac. Takes close eye on voltages and parts, but I have developed a comfortable respect and it works for me.
Again, when Semisouth day comes, I will drag it out for duty.
Russellc
For beginners, dim bulb should be mandatory! If power supply checks out, inspect boards for errors post pics, then if good hook up and attempt fire up with dim bulb.
I used one in my tube days, but somewhere along line I just used variac. Takes close eye on voltages and parts, but I have developed a comfortable respect and it works for me.
Again, when Semisouth day comes, I will drag it out for duty.
Russellc
I prefer a variac for initial startup as well. This is usually without the channel boards connected. I’ll keep an eye on the DC voltage being produced as I crank up the AC. Repeat one channel at a time to set initial bias current and output offset. Remove variac for the next round of burn-in and confirmation of offset voltage.
Don’t have a dim bulb tester.
Don’t have a dim bulb tester.
Agreed. I haven't seen mine since moving from tubes to First Watt clones.
I did get a pair of fried mosfets on my 3rd BA3 build, ( the mosfets on the front end board, not the Jfets or outputs.) got a little over confident and ramped up too quickly with a mis wire to power supply. Should have had more patience. A dimbulb would have caught it.
Oh well, quick rewire and replace 2 mosfets so I got off cheap.
Russellc
I did get a pair of fried mosfets on my 3rd BA3 build, ( the mosfets on the front end board, not the Jfets or outputs.) got a little over confident and ramped up too quickly with a mis wire to power supply. Should have had more patience. A dimbulb would have caught it.
Oh well, quick rewire and replace 2 mosfets so I got off cheap.
Russellc
Aleph J, from the DIYAudioStore was my first Pass build. It works great, and is my most stable back up amplifier. I do love my M2x monoblocks.
This is a Great place to start.
This is a Great place to start.
OK, I've posted our next two blog installments:
Introduction: Tools You Will Need
Parts: Stuff to Get From the DIYAudioStore
As we've still not built our amps, I'm sure these will get revised. Comments and suggestions welcome!
Next task is figuring out how to best organize the list of parts we'll need from Mouser/DigiKey, since the official BOMs are really only the beginning...
Introduction: Tools You Will Need
Parts: Stuff to Get From the DIYAudioStore
As we've still not built our amps, I'm sure these will get revised. Comments and suggestions welcome!
Next task is figuring out how to best organize the list of parts we'll need from Mouser/DigiKey, since the official BOMs are really only the beginning...
Good stuff, I am stubborn and am dead set on building my own chassis, Can someone point me to heatsink sizing info? Also some PS questions, I feel like mono bridges are easier or more straightforward or maybe produce less heat?...is there a reason not to use them? Snubbers, I know the what can someone talk about why and how and are they needed/wanted/nice-to-have. If someone were considering dual mono using the diyaudio store pcb would there be any difference in joining/strapping the grounds on board or jointing everything with a star ground?