A break-in period is normal and expected for the Aleph J and other amplifiers. During this time the treble emphasis will diminish, and the imaging focus will normally improve. This can depend somewhat on the capacitors used on the amp boards as well as in the PSU.
I used Elna Silmics in the C3 position and Nichicon FG series in the C2 position. 220 uF, 35V in both cases. The PSU can also benefit by installing the snubber networks on the AC inputs from the power transformer. A close approximation for these is 10 nF for Cx and 20 Ohms + 150 nF for Rs & Cs. Further optimization may be done with the Quasimodo technique and a scope.
Stereo imaging is highly dependent on the quality of the power supply. A dual-mono supply will tend to perform the best if it is built properly. I have also found substantial improvements by using LT4320 based 'ideal' rectifiers, along with parallel high-quality caps of around 1000 uF on the output C bank of the PSU.
I used Elna Silmics in the C3 position and Nichicon FG series in the C2 position. 220 uF, 35V in both cases. The PSU can also benefit by installing the snubber networks on the AC inputs from the power transformer. A close approximation for these is 10 nF for Cx and 20 Ohms + 150 nF for Rs & Cs. Further optimization may be done with the Quasimodo technique and a scope.
Stereo imaging is highly dependent on the quality of the power supply. A dual-mono supply will tend to perform the best if it is built properly. I have also found substantial improvements by using LT4320 based 'ideal' rectifiers, along with parallel high-quality caps of around 1000 uF on the output C bank of the PSU.
1. Ops...ahem...yes - I was running out of cables when finishing amp. Will change with something more solid. Any recommendation for output wire?
2. No, thay are good, it must be light from camera playing tricks.
On the positive side:
I tried other speakers and single-ended input. Wow - what’s a difference. Less congested, more separation and soundstage. Still on the bright side though.
I would still say that my old HK 630 has more soundstage and separation and is definitely mellower. But:
- I may just need to adjust my brain to new sound signature.
- HK 630 is double-mono - it may indeed provide some magic here.
So most of my problems are somehow resolved.
The only outstanding thing is fatigue by high frequencies.
I would like to thank everyone who provided advises - this forum is the best, friendliest place on internet
I am going to try some more with hope of improving my Aleph even more.
The last photo of post 4066 shows two wires and a CL60 bolted to the chassis, and the safety ground wire connected to the other end of the CL60. This seems the wrong way round and looks like a safety issue to me. The safety ground wire has be bolted to the chassis. The idea of the CL60 is to provide some separation of the audio GND form the chassis / safety ground.
In post Aleph J illustrated build guide : #4066
The lighting as you mentioned earlier is no issue since there are 2-3 pictures showing the same issue:
+1 ZM
5 of your capacitors are partly blown (4 on the negative side of the supply and 1 on the positive)
Thanks, but as I mentioned already caps are not blown - it is just flash from camera playing tricks with light and shadows.
xbitwise,
Blown PSU capacitors would explain several of the unpleasant sound qualities that you have described. The 25V rating of those caps leaves no room for error in the supply voltage. I have to agree that some of those PSU caps look like the tops have popped up a small amount. It is too bad, because you used some nice Nichicon parts that were probably expensive. However, you have come here asking for help, and the good people of diyA have given you some. The FW amps are better equipped with 35V or even 50V caps in the PSU. I will trade a 50V rating for a 105 °C rating or vice versa.
Blown PSU capacitors would explain several of the unpleasant sound qualities that you have described. The 25V rating of those caps leaves no room for error in the supply voltage. I have to agree that some of those PSU caps look like the tops have popped up a small amount. It is too bad, because you used some nice Nichicon parts that were probably expensive. However, you have come here asking for help, and the good people of diyA have given you some. The FW amps are better equipped with 35V or even 50V caps in the PSU. I will trade a 50V rating for a 105 °C rating or vice versa.
I have got great help and already thanked for it. It is a great place and I appreciate any help. Having that said, I am able to recognize a blown capacitor - have seen more than enough of them. But I agree with your opinion about voltage. I cannot recall now why I have chosen 25v but it indeed seems to be a mistake. I will replace them with 50v one:
I just repeat what I have already written in answer to ZM - after changing to other speakers and single-ended input most of my problems are gone, except high frequency fatigue.
Thanks again!
Last edited:
Thank you Sir for your wisdom. You must be a real master if you can judge a condition of my capacitors on a low resolution smartphone camera with flash better than me with bare eyes. Point taken - they are swollen for you, no matter facts. Thank you, nothing more to see here.