Hey all. The I omitted purchasing the CL60 for PSU->earth. A couple of reasons, mainly because I didn't see it in this build thread, only in the noob build which I'm going by. Also, the ceramic block used in the noob BOM wasn't in stock at either mouser or digikey, but I'm guessing I could avoid that using some point to point connections.
If I understand it correctly, thread searching CL60 I was able to garner the implementation is intended current limit faults, thus it's a component safety feature should first power up go sparktacular. Shouldn't the dim bulb tester effectively negate that need?
Need some advice, I'm almost ready to test the PSU without the boards. If I order a CL60 I think it would just go in series on the PSU chassis earth run, correct? I ordered a spare 4 terminal block and could use that, or would it melt in a fault? Did I see a a photo example of a PSU CL60 earth run just done on the chassis?
If I understand it correctly, thread searching CL60 I was able to garner the implementation is intended current limit faults, thus it's a component safety feature should first power up go sparktacular. Shouldn't the dim bulb tester effectively negate that need?
Need some advice, I'm almost ready to test the PSU without the boards. If I order a CL60 I think it would just go in series on the PSU chassis earth run, correct? I ordered a spare 4 terminal block and could use that, or would it melt in a fault? Did I see a a photo example of a PSU CL60 earth run just done on the chassis?
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The CL60 is used for two different things:
1/ as an inrush current limiter, which is quite important (indispensable if your PSU is oversized), it avoids stressing the PSU on startup. This (or these) CL60 are placed right behind the power-connector/switch and before the transformer, and this is a part that gets warm/hot.
2/ as a ground-lift, to have the signal ground kind of floating as long as everything is good. If the amp is working, this CL60 is basically standing idle afaik. Not indispensable but very good to have.
1/ as an inrush current limiter, which is quite important (indispensable if your PSU is oversized), it avoids stressing the PSU on startup. This (or these) CL60 are placed right behind the power-connector/switch and before the transformer, and this is a part that gets warm/hot.
2/ as a ground-lift, to have the signal ground kind of floating as long as everything is good. If the amp is working, this CL60 is basically standing idle afaik. Not indispensable but very good to have.
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NightFlight,
Take my suggestions for what they are worth, which is not much more than a noob! I did ask a lot of questions however about the CL60's as well. I was told that absent CL60s it would be ok to test my PSU as long as I used a dim bulb tester.. (I made the same error in not ordering them, nor the terminal block). As far as connecting the CL60 to earth, hopefully you can see below how I wired mine.. (I used an older version of the PSU board) Good luck!
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@NightFlight
I have a poop load of CL-60. PM me if you need some and aren’t placing a parts order anytime soon.
I have a poop load of CL-60. PM me if you need some and aren’t placing a parts order anytime soon.
CLs
Thanks everyone. I just opened my baggie and it looks like I did in fact order three CL60s. I can see how a ceramic block is just nice to have, and how you could just use the baseplate to run to earth from the PSU in series.
I see how some have earths across the baseplate. I see more folk pick a specific point, run a bolt and join everything there.
How hot does the CL60 get on the PSU earth side? Ok to use my spare 4 terminal block for earths? I would still connect it to the baseplate and back to the outlet.
Also, I found a KCC CL-90 in my college electronics kit. Never knew what the heck the thing was. I got a lot of extras for free from those dropping the course. Good times. 🙂
Thanks everyone. I just opened my baggie and it looks like I did in fact order three CL60s. I can see how a ceramic block is just nice to have, and how you could just use the baseplate to run to earth from the PSU in series.
I see how some have earths across the baseplate. I see more folk pick a specific point, run a bolt and join everything there.
How hot does the CL60 get on the PSU earth side? Ok to use my spare 4 terminal block for earths? I would still connect it to the baseplate and back to the outlet.
Also, I found a KCC CL-90 in my college electronics kit. Never knew what the heck the thing was. I got a lot of extras for free from those dropping the course. Good times. 🙂
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I can't open BOM revision D on diyaudio store. Has anyone have it and is willing to share.
Thank you.
Thank you.
I had trouble as well. Do you mean the PSU? P-PSU-1V30-BOM - Google Sheets
You can also export the mouser cart from here: Parts: the Rest of the BOM
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Make sure your browser is set properly.
This is the file from the store page.
Edited to add for clarity re: browser settings just in case that was too vague ... my wild guess is that you may be using Google Chrome or a similar browser that may block downloads from HTTP sites if the originating site is HTTPS. You can either use another browser, tweak some settings, or use a bit of a hack.
This is the file from the store page.
Edited to add for clarity re: browser settings just in case that was too vague ... my wild guess is that you may be using Google Chrome or a similar browser that may block downloads from HTTP sites if the originating site is HTTPS. You can either use another browser, tweak some settings, or use a bit of a hack.
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Well thanks. I never saw this BOM... now that I've built my boards its a bit too late, but the DigiKey references would have been nice!
LSJ74 vs 2SJ74
Regarding the LSJ74 vs 2SJ74 - I ordered the Aleph J Kit which include the LSJ74.
Would the Toshiba's make a difference? I come from a tube rolling background (I'm recently born again SS) so I enjoy those types of flavour changes and haven been known to overstate the differences as 'big'. Would this change be worth redoing the boards in the future? I realize these are going extinct, so I would like have 1 set on hand but also if they are not a big deal give them up to someone who wants them.
Then again if I don't buy them, down the road I may eventually die of unfulfilled curiosity restraint when they completely dry up. 😀
Regarding the LSJ74 vs 2SJ74 - I ordered the Aleph J Kit which include the LSJ74.
Would the Toshiba's make a difference? I come from a tube rolling background (I'm recently born again SS) so I enjoy those types of flavour changes and haven been known to overstate the differences as 'big'. Would this change be worth redoing the boards in the future? I realize these are going extinct, so I would like have 1 set on hand but also if they are not a big deal give them up to someone who wants them.
Then again if I don't buy them, down the road I may eventually die of unfulfilled curiosity restraint when they completely dry up. 😀
I have used both the Linear Systems and the Toshiba devices. I can't tell the difference. This is to say that the other circuit parameters have a greater affect than the transistors.
When it comes to solid state circuits, I prefer capacitor rolling 😉
When it comes to solid state circuits, I prefer capacitor rolling 😉
The Aleph J will benefit the most when built with the best dual-mono power supply that you can reasonably manage. I used a pair of Antek 300VA transformers and CRCRC boards. Bridge rectifiers were the LVB2560, which have low Vf. You could also use a pair of SLB power supplies. Either way, I would suggest 22V secondaries in the power transformers. Final rail voltage around +/– 25V, bias current 1.8A total per rail, or higher if you are comfortable with that.
Success!
Well she's done. 0.00V DC offset and 0.400V bias on each side which has remained stable. Ambient is 27C in the house and heatsinks are sitting at < 60C. I tossed in some rando hookup wire I had laying round for old digital projects - twisted this 20g copper with the power drill for input and output runs. Everything is silent. Running without top and bottom plates. I think it might be too hot in here. Needs some cable cleanup. Maybe a complete redo of the crimp connectors - I used my vice grips which was dumb.
Initially stumped by source ground loop which did horrible things. Measured 3.5VACpp between the two chassis, but a ground wire fixed that. My DAC has an IEC plug, but no ground connector at all. WTH?
I'm floored with the amp perfomance. I gotta get to bed, its almost 4am and I have to work in the morning...😴
Well she's done. 0.00V DC offset and 0.400V bias on each side which has remained stable. Ambient is 27C in the house and heatsinks are sitting at < 60C. I tossed in some rando hookup wire I had laying round for old digital projects - twisted this 20g copper with the power drill for input and output runs. Everything is silent. Running without top and bottom plates. I think it might be too hot in here. Needs some cable cleanup. Maybe a complete redo of the crimp connectors - I used my vice grips which was dumb.
Initially stumped by source ground loop which did horrible things. Measured 3.5VACpp between the two chassis, but a ground wire fixed that. My DAC has an IEC plug, but no ground connector at all. WTH?
I'm floored with the amp perfomance. I gotta get to bed, its almost 4am and I have to work in the morning...😴
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Very happy to report that the Aleph J is still fine, after changing the JFETs.
The Aleph J is really a special amplifier, even after a lifetime of very expensive (and good) amplifiers, both valves and solid-state. The Aleph J (at least with my Martin-Logan Montis) easily holds itself with anything I had in the past (from Jadis JA-80 monoblocks, to Dartzeel NHB-108, through several Audio Research).
It's true that the powered subwoofers of the Montis makes it easier for a 25W amplifier, but sound quality in the midband and treble is really, really good, on par with the best valve amps I had (and without some of their problems).
I've also been using it with some diy speakers, based on Markaudio 7MS and 11MS (again, really revealing, no crossover, single full range driver) and the Aleph J makes them really shine, at least on par with the Audion Sterling Plus (a lovely 13W single-ended-pentode amp).
As much as I enjoyed the sound of the F5, for my taste the Aleph J is even better.
I'm posting this to help people deciding wether to build the Aleph J. For me, the answer is "yes".