Uh oh. The caps came and they are indeed larger but perhaps not too large. I don't have the AJ PCBs yet so I can't check. Might these still work?
They aren't vastly different in size /spacing. I had one of the smaller ones; so it's the somewhat larger ones that are in question.
They aren't vastly different in size /spacing. I had one of the smaller ones; so it's the somewhat larger ones that are in question.
Attachments
Spec sheet says 35V is 12.5mm diameter and 50V is 16.0mm diameter, so an extra 1.75mm all around.
Looking at the pictures on page 1 of this thread, it may be a tight squeeze but if the adjacent components are moved slightly it may possibly fit.
Looking at the pictures on page 1 of this thread, it may be a tight squeeze but if the adjacent components are moved slightly it may possibly fit.
One stereo. Now playing🥰
400mV over R18. 21,8V on the rails.
50,1C on heatsinks After more than 48 hours warmup 🙂👍👍👍
Higest temp is 64,7C on the transformer. Pretty High temp but Not a serious problem as i understand it, is that correct??
Crankit up!!! 🙂
400mV over R18. 21,8V on the rails.
50,1C on heatsinks After more than 48 hours warmup 🙂👍👍👍
Higest temp is 64,7C on the transformer. Pretty High temp but Not a serious problem as i understand it, is that correct??
Crankit up!!! 🙂
Attachments
Last edited:
that bottom needs some ventilation
holes, slits, whatever you manage
same applies for top cover
holes, slits, whatever you manage
same applies for top cover
fugly! Very nice work.
How does it sound?
I have some mileage with slits, both top and bottom, and can recommend that solution.
Regards,
Andy
Yeah, i understand your forward thinking. But i am not going to close off the top and the front. The temps are not going to rise any thing at all. Is 64,7C on the transformer to high? I can drill as many and as big ventilation holes in the bottom plate that are needed. If it is needed. 🙂
But.
I have hexagonal aluminium mesh coming for the front and top, Because i like to see them dimmed leds and the overall design, cabling and electronics. When i am smiling, foot tapping and head bobbing deluxe. 🤗
And i like the free air ventilation. Yeah i am a true diy hifi nerd nerd😇
So sue me.
Andy: It sounds absolutely awsome. Stiff, transparent, clear and strong, yet warm, juicy, bassy and lush. Extraordinary present and deatalied sound imageing, without harchness, but with a jaw dropping dramatic dynamic BITE!
Next: Resume Building one more Aleph J and run them in Parallel mono. 🤗
Attachments
Last edited:
Tranny temp sounds a bit high, but I am not a transformer-temp expert. But I’d definately listen to Mighty ZM’s regommendations. Mine aren’t that hot, but I use two per amp.
Yea, ok. Well that seems sort of reasonable since my transformers are running two channels, while you are running one channel but with higher bias than stock i presume.
I am waiting for Mightys judgement 🙂
Well, i find it mindboggling that one Aleph J actually can beat Two ACA in parallel mono. Since they are sounding criminally good in my system 🥰
Crankit up!!!🙂
https://tidal.com/track/193686704
Last edited:
at least make wide slit at connection of bottom and back plate ....... even if you have front and top mesh, Donut is practically in non-vented corner, so if you make one decent airpath, it'll get chimney effect (hopefully)
recently we had one case of Toroidy Donut too hot, even if that one is potted in shiny drek
anyway, that one and your - enough from me to not even think of recommending Toroidy to anyone
65C is way too much, for 300VA, feeding stereo Aleph J
except in case that your measurement is way off - which can be case if you did measure with IR gun thingie - reflectivity can play games with those - been there, done that - and from then - I'm using just contact meters
now , you can sue me
As an additional remark:
It sounds just tight, so far. Just god damn right? 🙂Absolutely Crystal strong and clear but friendly biological, not nasal electrical scientific sounding.
Extremely detailed ”Soft dome sound”, not ”metal dome overly detailed” sound that diverts the focus and kills the musicality.
Not to dry bass. But strong and muscular, and just the right amount of fat.
And.
I would personally not be interested in building a more analytical amplifier than the Aleph J.
Lush, extremely powerful dynamic bassy juicyness, better than natural sounding and hands on shockingly present sound image is my kinda sound.
A little better than extremlely good, a little bit sweeter, a little bit closer and much stronger and bolder, a little bit more precise, a little bit larger and forgiving than life is not wrong. It is just right. Just A little bit MORE. For me🙂👍
I once upon a time lusted for the fluffy, airy, hifi- delicate and fragile sounding and mindboggingly deep and big sound. Not now.
🥰
But i am not ”right”. Not even close. It is just a personal, and over the years aquired taste of mine.
at least make wide slit at connection of bottom and back plate ....... even if you have front and top mesh, Donut is practically in non-vented corner, so if you make one decent airpath, it'll get chimney effect (hopefully)
recently we had one case of Toroidy Donut too hot, even if that one is potted in shiny drek
anyway, that one and your - enough from me to not even think of recommending Toroidy to anyone
65C is way too much, for 300VA, feeding stereo Aleph J
except in case that your measurement is way off - which can be case if you did measure with IR gun thingie - reflectivity can play games with those - been there, done that - and from then - I'm using just contact meters
now , you can sue me
Yeah, the cooling chimney effect sounds right. A circle of holes round the edge of the transformers. As is made around the tubes in a tube amplifier 🙂👍
I am talking IR-measurements. Going to do physical temperature measurments to verifiy. Will post if the temperatures are wrong.
❄️☃️❄️
this will help immensely
at least for temp adequate for method, and areas big enough for my clumsy thumbs, I'm not even thinking about opening the drawer for instruments
now- opening - circumferential holes - only if plenty of them
10mm wide slot anywhere is damn more effective
at least for temp adequate for method, and areas big enough for my clumsy thumbs, I'm not even thinking about opening the drawer for instruments
now- opening - circumferential holes - only if plenty of them
10mm wide slot anywhere is damn more effective
Just use your hands. Like Mighty and Nelson suggest. 65 degrees is something you will want to pull away from pretty quick 🙂 I don’t think it is that hot sitting there pretty much in the open.
A little bit more ”Real” measurement, still a little bit on the high side?🤔🔥
Oh yeah!!
Crank it up 😇🤘
Oh yeah!!
Crank it up 😇🤘
Attachments
Last edited:
now, if you're willing to conduct simple experiment, we'll know is it really utter drek, or we all are just disillusioned these days ( yeah, Corporations can't do wrong etc.) :
disconnect one channel from PSU, leave it for few hours on, then measure temperature
if with half of present load temperature is dramatically lower, then we know that you have two practical solutions:
it seems you did everything by the book; same scenario with previously mentioned shiny potted one - amp fully functional without burps, blurps and buzzess... but decent xformers are not behaving like that
illustration - I have supposedly 500VA Donut on my T-Bed 2, feeding 230VA of two Babelfish XA252 channels; made in 220Vac era, while now everywhere is 230Vac; two bridges config, nasty CRC (22mF hungry Sikorels with 0R1) , placed on not so heat releasing particle board base, taped with cotton Tesa (had to unwound some, so no original tape isolation) ......... and I can keep my palm on it all day long .......
I mean, I'm not so fetished about Donuts to keep my palm on them all day long, but I know that it is nicely warm even after 12h of being on ...... which is far away from hot
and 60C is damn hot
disconnect one channel from PSU, leave it for few hours on, then measure temperature
if with half of present load temperature is dramatically lower, then we know that you have two practical solutions:
- leave it as is, who cares how long it will last before going Dodo ( in most cases it'll go puff without harming rest of amp, except fuse)
- buy second one, make dual mono
it seems you did everything by the book; same scenario with previously mentioned shiny potted one - amp fully functional without burps, blurps and buzzess... but decent xformers are not behaving like that
illustration - I have supposedly 500VA Donut on my T-Bed 2, feeding 230VA of two Babelfish XA252 channels; made in 220Vac era, while now everywhere is 230Vac; two bridges config, nasty CRC (22mF hungry Sikorels with 0R1) , placed on not so heat releasing particle board base, taped with cotton Tesa (had to unwound some, so no original tape isolation) ......... and I can keep my palm on it all day long .......
I mean, I'm not so fetished about Donuts to keep my palm on them all day long, but I know that it is nicely warm even after 12h of being on ...... which is far away from hot
and 60C is damn hot
Yea, i will for sure do that temperature test. And post the result🙂
Next step in the build is to complete the other Aleph J and run them as 2 mono amplifiers. One channel per stereo amplifier absolutely disconnected from everything.
After that: the parallel mono test🤗
I will post the long term temperature measurements by configuration when they are up and rocking, souling, jazzing, bluesing, and playing teh funk!🙂👍
Last edited:
Just finished putting together an Aleph J. Not quite finished, with a few remaining things to sort out including wiring up the speaker turn on delay circuit and making a face plate for the front of the chassis.
Started out planning a dual mono configuration but ended up using this 650VA R-Core feeding dual PSU boards.
Listening to a DSD of Cannonball Adderly - Somethin’ Else playing through a tube output DAC into some Fostex Sigma full range drivers in large horns.
It sounds absolutely stunning! Thank you Papa, 6L6, Didiet78, Laverda and all the great knowledge offered throughout this thread!
Started out planning a dual mono configuration but ended up using this 650VA R-Core feeding dual PSU boards.
Listening to a DSD of Cannonball Adderly - Somethin’ Else playing through a tube output DAC into some Fostex Sigma full range drivers in large horns.
It sounds absolutely stunning! Thank you Papa, 6L6, Didiet78, Laverda and all the great knowledge offered throughout this thread!