Aleph J illustrated build guide

when speaking of amp's phase , it is strictly related to in-out phase relationship , of amplifier in question

so , normally taking in account one channel only , observed as black box

when two speakers in space are out of phase , that's just anomaly ...... of phase characteristic of entire system
 
My understanding of whether the amp inverts phase is when the speaker should move forward it moves backwards if both channels of out of phase. I did some very limited listening both ways and I frankly could not hear the difference. I guess I am not golden eared enough. If just one speaker is out of phase then the bass cancels each other and it is easy to hear the difference, more bass in phase. It is easy enough to try, just swap your speaker leads.

Same here. With the DAC and its inversion switch, on bass heavy or intense vocal passages, it seemed sometimes one sounded better, but I could NEVER be able to guess with any statistical significance in a blind test!

Russellc
 

Very nice build! I see that your input JFET pair have been strapped together, but I can also see an air gap between them in your image. One small suggestion might be to open your plastic tie, add a drop of thermal paste between your transistors and make sure they sit tightly together and then add new plastic tie.
 
Very nice build! I see that your input JFET pair have been strapped together, but I can also see an air gap between them in your image. One small suggestion might be to open your plastic tie, add a drop of thermal paste between your transistors and make sure they sit tightly together and then add new plastic tie.

Thanks for your help but, following ZenMod advice, I unsoldered the JFet so that is not gap anymore.😎
 
I have question on CL60 position on AC line 220V. i'm using talema transformer which only have 2 primary cable (dedicated to 220V), where should I put CL60? Just solder in one of AC line?
 

Attachments

  • Screenshot_2015-09-08-09-47-47.png
    Screenshot_2015-09-08-09-47-47.png
    255.2 KB · Views: 826
  • big_monosupply.png
    big_monosupply.png
    96.4 KB · Views: 814
I have question on CL60 position on AC line 220V. i'm using talema transformer which only
have 2 primary cable (dedicated to 220V), where should I put CL60? Just solder in one of AC line?

Yes, see the lower 240V wiring diagram that you posted. Whether it's two 120V windings in series
or just one 240V winding makes no difference.
 
Last edited:
finally after 2years (i got the pcb when it was still pre-order), my alephj is working. this is just 1 side monoblock completed, another one will be done next week.

* CRC supply, C is kendeil 68mF 50V, R panasonic 0.47R 3W. ripple measured 400mV, while my dmm is not true rms (R will be replaced by inductor later)
* 400mV on source resistor, dc offset is steady <1mV after 1hour.
* no thump during power on/off. i think that CL60 is working great here.
* deadly silence, no hiss no hum.
* 47°C on bottom heatsink at nearest irfp, 45°C on irfp plastic body, measured with laser temp meter. room temp is 28°C.

6L6 build guide is helping me so much, which make me trouble free untill now :cheers:
 

Attachments

  • IMG_20150920_214852_HDR.jpg
    IMG_20150920_214852_HDR.jpg
    888.9 KB · Views: 745
  • IMG_20150920_215055_HDR.jpg
    IMG_20150920_215055_HDR.jpg
    690.2 KB · Views: 752
Last edited:
measured my hand wound inductor at my friends, it only get 2.9mH where on calculation it should get around 4mH. Maybe because i did not wound it well. So i try to put a hammer inside the hole and inductance getting higher now.

As i read for inductor saturation, if i use this inductor on my CLC supply, which one is better? 2.9mH air core or 4mH ferrit core? if ferrit core saturates, what will inductance value, 2.9mH or become zero.H?
 

Attachments

  • IMG_20150919_115452_HDR.jpg
    IMG_20150919_115452_HDR.jpg
    420.4 KB · Views: 641
  • IMG_20150919_115842_HDR.jpg
    IMG_20150919_115842_HDR.jpg
    452 KB · Views: 347
finally after 2years (i got the pcb when it was still pre-order), my alephj is working. this is just 1 side monoblock completed, another one will be done next week.

* CRC supply, C is kendeil 68mF 50V, R panasonic 0.47R 3W. ripple measured 400mV, while my dmm is not true rms (R will be replaced by inductor later)
* 400mV on source resistor, dc offset is steady <1mV after 1hour.
* no thump during power on/off. i think that CL60 is working great here.
* deadly silence, no hiss no hum.
* 47°C on bottom heatsink at nearest irfp, 45°C on irfp plastic body, measured with laser temp meter. room temp is 28°C.

6L6 build guide is helping me so much, which make me trouble free untill now :cheers:

Nice work mate.