If it measures okay, does it sound okay as well...??? Don't know... very subjective indeed.... or is it objective (measures nicely) vs. subjective thing?
I started playing with snubbers long time ago (decades).... every time I implemented a "correct" snubbing circuit, the sound DID change.... but not necessarily for better, especially if I gave it a lot of time to listen to differences before/after
In the end, I settled on 0.1uf / 50V NP Black Gate, type NX (a pair goes for $80 these days). That one (and nothing else/no other parts) was giving me the best sound, one that suits my personal taste and the rest of my system really nicely.
...see here:
Rubycon Black Gate Capacitors NX 0.1uF 50V NOS lot of 2 | eBay
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I have been eager to try this amp so I gutted my M2. Biased to 400mV and connected to sensitive speakers I got a slight hum, like I had with M2. That I can live since It sounded so nice. Then I got a sparkle in one channel and a short loud whistling discharge in same channel when power off.
Guessing I have to replace some capacitors? Ideas?
Guessing I have to replace some capacitors? Ideas?
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Looks like you've fixed the PCB to the heatsink at 2 points only. The board has 8 attachment points. I used them all. It's a long board. Not sure how important board flex is but I know mine is solid.
To track down your issue, you might need to post some photos of the board's underside - that's a pain I know but the topside view can only get you so far. Maybe someone can spot an issue?
Regarding the hum, maybe a pic of how the connecting power supply does its thing might help? My Aleph J has the transformer inside the case with star ground and ground loop breaker included. No obvious hum. You should have less hum issues with the transformer out of the chassis - so that one's intriguing.
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Sparkle in speaker is irregular like vinyl noise. I’m going to inspect solder joints on back of psu. I’m more concerned about the loud whisteling thud when powering of.
Regarding ground noise, the hum, I might found where it can be loops. The motor runs have a bleeder resistor on cap so can it be loop there? My F4 is absolutely quiet with the same psu but there I let the psu bleeder be the only one. Images soonish.
Regarding ground noise, the hum, I might found where it can be loops. The motor runs have a bleeder resistor on cap so can it be loop there? My F4 is absolutely quiet with the same psu but there I let the psu bleeder be the only one. Images soonish.
I see that I must put more solder on the power cables. They seem OK on front side. Any Ideas? Perhaps replace the output mosfets? I think it where on that side I heard a breaking noise.
What causes a loud whistling thud discharge when powering of?
I have a ground cable from PSU star chassi ground to AlephJ chassis.
What causes a loud whistling thud discharge when powering of?
I have a ground cable from PSU star chassi ground to AlephJ chassis.
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Definitely need more solder (and heat) on the power connections. The source and drain pins of the MOSFETs could use re-flowing as well.
Whistling would be high-frequency. Does that suggest oscillation? Any chance sov is getting some sort of parasitics between the main cap bank and the motor-runs in the amp chassis?
Whistling would be high-frequency. Does that suggest oscillation? Any chance sov is getting some sort of parasitics between the main cap bank and the motor-runs in the amp chassis?
First amp build!
After tackling a B1 and loving the outcome, I got the itch to keep building. Decided to tackle the Aleph J after recently parting with a beloved Aleph 30. Power supply and boards all testing good so far! Keeping any eye on bias and offset for the next hour, then it’ll be time to take it for a spin...
After tackling a B1 and loving the outcome, I got the itch to keep building. Decided to tackle the Aleph J after recently parting with a beloved Aleph 30. Power supply and boards all testing good so far! Keeping any eye on bias and offset for the next hour, then it’ll be time to take it for a spin...
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Thanks!! Literally no way I could have done this without your build guide! I went with a 400va transformer and was worried for a minute that the 4Ux300mm was the wrong choice. Worked out perfectly though.
Using Kef Q100’s right now. I have a full range speaker project that’s next on my list. That said, the J (and the Aleph 30 I had before it) both handle the 86db Kef’s perfectly. And My only voltage gain is coming from the phone pre (50db I think.) B1 is the only other device in the chain.
Using Kef Q100’s right now. I have a full range speaker project that’s next on my list. That said, the J (and the Aleph 30 I had before it) both handle the 86db Kef’s perfectly. And My only voltage gain is coming from the phone pre (50db I think.) B1 is the only other device in the chain.
Thanks Dennis! Vinyl is all I play at home - I save digital for the headphones at work. My table is a Thorens td160 BC mkII with a Grace 707 tonearm. Funny story - I bought the table from the original owner a while back, and was excited to take off the Grace F9 cartridge and put on a nice MC I had at the time. I took a listen with the F9 and was blown away! Easily the best MM cart I’ve heard, and ranks up there with most any cartridge I’ve listened to. I had Peter at Soundsmith make me a ruby replacement styli, and I couldn’t be happier with it. And it’s about as old as I am!
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I've got a similar issue with my Aleph-J that I need to track down. I've built it so both channels share the same PSU and when I power down, I get a very brief, high pitched whistle or "chirp" in both channels.
I figured I was some anomaly in the specifics of how I wired the shared PSU. Just about to dig into this now that I'm looking to switch back to using the Aleph-J as the winter is coming. I've been using a lower power consumption amp during the summer air conditioning months...