I am completing M2 production. The recently aquired Antek buzzed like a big dog. I could hear the hum getting to my speaker easily. I might have not noticed it with the top on from listening distance away, but, hey, one of the reasons for solid state is not to have to put up with hum.
Replaced with a lower VA Plitron - quiet as a mouse. It is not DC or hash in my Mains, just a terrible toroid. Too bad Plitron was purchased, and I can't find out if they are even selling to schmucks like me anymore.
Replaced with a lower VA Plitron - quiet as a mouse. It is not DC or hash in my Mains, just a terrible toroid. Too bad Plitron was purchased, and I can't find out if they are even selling to schmucks like me anymore.
Came to the conclusion it was just the way power cords and cables were situated. Putting things more in order, sound is in both speakers but at even less level. It was pretty tame to start with, having to put ear next to tweet to hear fizz, not able to hear hum unless putting ear next to woofer, then couldn't hear it from tweeter.
Not power amp in any event, which was my initial fear when starting all this inquiry.
Thanks to all for ideas and tips, particularly Dennis who suggested to do what I should have done from beginning, short inputs and listen.
Russellc
If the Antek is defective, return it. They are very affordable transformers, I have used them in every project I have, except one where I used what I had at hand. All performed perfectly. The transformer you are showing is an excellent one here according to many members of this forum.
Russellc
Parts express has a few Plitron as closeouts. They also have Avel-Lindberg, which used to be excellent back in the day. Really, return your Antek and get a replacement. Use it in another project. My Aleph J and M2 both use Antek 18/18 @ 500VA and are quiet. Or they would give a refund? I don't know as so far I have had very good luck with them.
My BA3 uses a SUMr 1000VA 24/24 transformer and it is a very well made heavy duty piece of gear. The BA3 is dead silent with nothing at the speakers even with head in cone of any kind. So quiet you have to look inside amp through vents to see the led on power supply.
Russellc
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I haven’t used an antek myself but I haven’t heard anything bad about them plus being in the states makes it easy to return. I’ve only used Toroidy transformers in all my builds and have been quite happy with them. Honestly I wish it was easier to try some other companies too one being Plitron. I definitely would have gotten on the group buy that was going on years ago.
Even though Plitron is in town, buying form them seems to no longer be an option.
A member here contacted them about a reasonable quantity purchase (50 units
of 300VA 2x18VAC) and they didn't even respond.
Maybe they'll respond for 100 units?
I just want to say that my Aleph J build uses an Antek 400VA transformer, so I know they can make good products.
Primrose quoted me for 300VA 2x18v (shielded and banded) at 120 USD + 60USD shipping. 2 toroids for 315USD (including PayPal charges)
Lead time = 8 weeks.
I’m going to just stick with the 225VA Plitrons for now. (one in each monoblock M2) (the 225 VA 2x18v were not custom back then, I did have to order a few smaller transformers to make the minimum order though)
Might have to order a set just to have ready for the next building bug.
Primrose quoted me for 300VA 2x18v (shielded and banded) at 120 USD + 60USD shipping. 2 toroids for 315USD (including PayPal charges)
Lead time = 8 weeks.
I’m going to just stick with the 225VA Plitrons for now. (one in each monoblock M2) (the 225 VA 2x18v were not custom back then, I did have to order a few smaller transformers to make the minimum order though)
Might have to order a set just to have ready for the next building bug.
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Patrick suggested that I reup the photos of my bad board so that anyone could offer suggestions as to potential errors. I cleaned the board of most of the flux to make things clearer so please forgive the blue lint from the shop towels that I used to dry the isopropanol. I didn't see it until after I took the photos. If anyone has any suggestions or sees any obvious errors please let me know. Greg was wildly generous and sent me some matched MOSFETs, which should arrive this week. An enormous thank you to him. I hope to be able to help someone else similarly in the future. Thanks for everyones input in advance,
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Keep at it, this amp is worth the trouble to go through. You will be so glad you did.
I really hope this thing straightens out in short order. You seem to have followed all the basic instructions with great care. Also you didn't introduce any "better ideas" or "improvements" like many with problems have done.
You read and take everyone's advice. I know I am stumped!
Russellc
R17 looks like it may have seen the heat of battle. That is most likely a result vs. cause. If upon closer inspection, it looks discolored - I'd consider replacing it before installing the new MOSFETs. There may be other things too. That's why I love posting pics to the forum.
Ggetzoff - Echoing Freejazz00 - what an awesome gesture!
Ggetzoff - Echoing Freejazz00 - what an awesome gesture!
This morning I turned on system this morning - and, after the first side of a record ended, noticed some strange popping noises coming from the left side; much like an input vacuum tube going bad. Intermittent and high in volume enough to be heard from the sofa.
Troubleshooting - swapping inputs, , etc - narrowed it down to the DIY Aleph. I removed the RCA connector and the popping still continued. I broke out the DMM and checked bias and DC offset. Everything looks good. Swapped speaker cables, and, no surprise, the sound followed the bad channel. With the amp still on, I carefully pushed on capacitors, pulled on wires, even poked at the input JFETs - all to no avail.
Now for the mystery: after swapping everything back to its proper place (with the amp still on!), the popping sound disappeared. An hour later and it isn't back. Needless to say I'm worried it will come back to annoy me.
I believe the Amplifier Gods are mad at me for recently selling the rest of my vacuum tubes and my backup Adcom
Troubleshooting - swapping inputs, , etc - narrowed it down to the DIY Aleph. I removed the RCA connector and the popping still continued. I broke out the DMM and checked bias and DC offset. Everything looks good. Swapped speaker cables, and, no surprise, the sound followed the bad channel. With the amp still on, I carefully pushed on capacitors, pulled on wires, even poked at the input JFETs - all to no avail.
Now for the mystery: after swapping everything back to its proper place (with the amp still on!), the popping sound disappeared. An hour later and it isn't back. Needless to say I'm worried it will come back to annoy me.
I believe the Amplifier Gods are mad at me for recently selling the rest of my vacuum tubes and my backup Adcom