Aleph J illustrated build guide

[Zen Mod]

try using solder iron this time, instead of chopstick

sometimes it's just matter who's more stubborn - amp or you

 

[Extreme_Boky]

Use a short burst of freeze spray while covering small areas, until you find where the cold solder joint (developing heat over time), a hot spot, or a failing part, is.

 

[andynor]

Back in post #6861, I discussed my issues with some noise in the right channel of my Aleph J.

Per everyone's recommendations, I opened it up and checked every solder joint on the affected channel and on the power supply with a chopstick, and didn't hear the noise at all. I did notice the bias and DC offset on that channel needed a few small tweaks (the left channel remained pretty close to perfect). I set the bias and the offset, measured everything again, and put it back in the chain. No noise for about a month.

Then the noise again. Repeated the whole process. This time bias and offset had not moved. Chop-sticked every solder joint again and no noise. Made final measurements, and closed it up. This time, I got about 2 months of perfect sound with no noise.

Now I hear it again. Any other suggestions as to what it might be? Go back and check my post listed above for details and to listen to a sample of the noise.

Thanks for any advice you can provide.

Brad

Didn’t see any pics of problem chan. Always helpful, maybe someone spots a possible prob area helping focusing your search. Also, measurements of key areas compared to properly working chan, focuses search.

Andy

 

[jholland18277]

Aleph J BOM

The BOM link isn't working anyone got a pdf?

 

[andynor]

What link? On Diyaudiostore.com or the link in the build guide page 1 from 2013? If the latter, it is eons ago. Check diyaudiostore.com.

Regards,
Andy

 

[Dennis Hui]

The link from the first post still works:

http://www.diyaudio.com/forums/atta...j-universal-mounting-spec-bom-aleph-j-ums.pdf

 

[peppennino]

Thanks. Yes, opt MOSFETs are different from the store boards, so Iq is bigger. A cap for stabilizing the meter?
Can I go up to say 1,7/1,8A with Dissipante 4U/400?

View attachment 964926

ZM's blog is precious, as always











Babelfish XJ , or JX …….. or whatever – Zen Mod Blog

I'm ordering two 50mm instruments. Hope I'll do a decent work for those holes in 10mm front panel...

 

[peppennino]

Well... It is not like a CNC hole, but I think it is good enough!



Trial with a SO-52 frame.
Slowly I carry on, lento pede...

 

[6L6]

try using solder iron this time, instead of chopstick

sometimes it's just matter who's more stubborn - amp or you

Somebody should use this in their signature line, is funny and quite true.

 

[Zen Mod]

I'm all like that .......... funny and quite true

Omnitrue ZM

 

[bpr]

Somebody should use this in their signature line, is funny and quite true.

If I can't find the source of this damn noise, I will add it to my signature, and add that the amp won.

 

[andynor]

If nothing else works, you might consider bringing the amps with you on vacation to a beach like the one in Dr. No. Nothing like a bit of nuclear waste to silence an amp

 

[andynor]

View attachment 987819

Well... It is not like a CNC hole, but I think it is good enough!

View attachment 987820

Trial with a SO-52 frame.
Slowly I carry on, lento pede...

Looking smooth, as always. Those for J’s or F3’s? Thought u used ‘talian chassises

 

[peppennino]

Always 'talian TELAI
For J

Nothing like a bit of nuclear waste to silence an amp

I was prevident with my PSU. If you need a Nuclear plant to feed yours, let me know

 

[tonistefanovski]

That heatsink is indeed quite small.
For the best results, you would have to place the fans underneath the heatsinks, blowing upwards. Maybe 4 or 6 fans in total, 2 - 3 per side...?
9Blades 12V 0.08A 50mm Cooling Computer Fan 5010 50x50x10mm DC 3D Printer 2-Pin | eBay

Finally finished.
Mounted total of 4 fans at the bottom of the heat sinks (thank you for suggestion).
I can hold my hand forever 😊 . Heatsinks are 400mm deep, 115mm high with 50mm fins.
Few words,
Before mounting I’ve measured every single component (as per building guide) …result is, after first power on, around 0.53V across source resistors and 30mv at the output.
For future builders please be patient and work carefully. You can’t go wrong!!!
Aleph J drives my Monitor Audio Silver 300 perfectly…sound is incredible…
Credits to Mr. Pass, credits to beautiful building guide and to every helpful person on this tread.
Tony,

 

[peppennino]

Also the second done

 

[Zen Mod]

now you have holes for two really big LEDs

it'll sound Big, if not divine

 

[Extreme_Boky]

Finally finished.
Mounted total of 4 fans at the bottom of the heat sinks (thank you for suggestion).
I can hold my hand forever �� . Heatsinks are 400mm deep, 115mm high with 50mm fins.
Few words,
Before mounting I’ve measured every single component (as per building guide) …result is, after first power on, around 0.53V across source resistors and 30mv at the output.
For future builders please be patient and work carefully. You can’t go wrong!!!
Aleph J drives my Monitor Audio Silver 300 perfectly…sound is incredible…
Credits to Mr. Pass, credits to beautiful building guide and to every helpful person on this tread.
Tony,

Nice build, inside and outside.

Is that the copper pins I see going into AMP PCB's, like these ones:

https://www.mouser.com/ProductDetai...9ygYZj8ieGw==&countrycode=AU&currencycode=AUD

I used them in my build - they are really good, made from soft pure copper, they fit the AMP PCB eyelets perfectly.

 

[peppennino]

now you have holes for two really big LEDs

it'll sound Big, if not divine

two 51mm LEDs



Completed

 

[tonistefanovski]

Nice build, inside and outside.

Is that the copper pins I see going into AMP PCB's, like these ones:

https://www.mouser.com/ProductDetai...9ygYZj8ieGw==&countrycode=AU&currencycode=AUD

I used them in my build - they are really good, made from soft pure copper, they fit the AMP PCB eyelets perfectly.

Sorry I can't open the link but I suppose that they are like at the picture!?