Hi Kaplaars
Oscillation can also be caused -as you noticed - by bad or marginal input signal grounding...Ensure you have good source output ground, good RCA cable ground, good RCA connector ground contact with RCA cable plug and good ground connection wire to amplifier pcb. It may seem trivial but it can happen too...😉
Also, have you tried using J2 to bypass R43 to see if it changes the result.
Additionally are you using J8 at output of inductor or J7 before the inductor for testing the output ?
Fab
Oscillation can also be caused -as you noticed - by bad or marginal input signal grounding...Ensure you have good source output ground, good RCA cable ground, good RCA connector ground contact with RCA cable plug and good ground connection wire to amplifier pcb. It may seem trivial but it can happen too...😉
Also, have you tried using J2 to bypass R43 to see if it changes the result.
Additionally are you using J8 at output of inductor or J7 before the inductor for testing the output ?
Fab
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Andrew,
Family plans have slowed me down quite a bit on my audio projects but June should be very productive. I looked over the NX documentation regarding your transformer source. I sent them an RFQ for 1 unit. I was quoted $180 (gulp! sticker shock!!) for all the bells and whistles, which was shield between primary and secondary coils, plus belly band. I will send an RFQ to Amgis. Maybe the fact that they are practically at my back door will help.
Family plans have slowed me down quite a bit on my audio projects but June should be very productive. I looked over the NX documentation regarding your transformer source. I sent them an RFQ for 1 unit. I was quoted $180 (gulp! sticker shock!!) for all the bells and whistles, which was shield between primary and secondary coils, plus belly band. I will send an RFQ to Amgis. Maybe the fact that they are practically at my back door will help.
Wow. Was that Tiger Toroids? I paid less than half that! I haven’t spoken to him for a while but seems crazy IMV. Better to go with Amgis but just make sure you specify tha5 it should be mechanically quiet and have a GOSS band. I think Anand has sourced a trafo from aUS supplier that is pretty good. The other one to look at is Toroidy in Poland who do stuff for audio.
Thimios - very nice! Enjoyed the video and look forward to having a working -nx this year. Watching it has made me want to get going on this one all the more.
Andrew - this is Power Star that I took from your -nx instructions. The person who responded to my RFQ is Yu Guan Jiun. I'll see if I can locate Tiger via Google as maybe Power Star is not the same. I did check Toroidy and the price is approximately $93 USD, but the site does not have an option to ship to the US, as far as I can tell. I plan to also contact them to see if they will be kind enough to ship to me. Thanks for the tips on ordering a trafo.
Andrew - this is Power Star that I took from your -nx instructions. The person who responded to my RFQ is Yu Guan Jiun. I'll see if I can locate Tiger via Google as maybe Power Star is not the same. I did check Toroidy and the price is approximately $93 USD, but the site does not have an option to ship to the US, as far as I can tell. I plan to also contact them to see if they will be kind enough to ship to me. Thanks for the tips on ordering a trafo.
Scratch Amgis off the list, they only want to deal with the commercial guys. Toroidy responded back and indicated they will ship to the US, so I will send them an RFQ for the bells and whistles. Hopefully at a more reasonable cost.
Javier - Power Star are a Taiwanese supplier. They may also now be pricing to send single order guys like us away.
Ricardo, I have heard Toroidy are very good.
The contact at Tiger Toroids is Stephen Foster - I’d just email him direct (email address at the bottom of the web page).
Tiger Toroids is a British company offering a fast and flexible solution for transformers and sinewave inverters.
Ricardo, I have heard Toroidy are very good.
The contact at Tiger Toroids is Stephen Foster - I’d just email him direct (email address at the bottom of the web page).
Tiger Toroids is a British company offering a fast and flexible solution for transformers and sinewave inverters.
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Andrew, yes, that price says "we'll do it, but we don't really want/need that business". I'll try Tiger Toroids as well. With this much effort, it will pay off soon.
I haven't received a response from Tiger, but Toroidy did work out a quote for me. Just shy of 180 USD and an additional 72 USD for shipping. So inline with the previous quote. Amgis recommended that I contact Bridgeport Magnetics here in the States, so I will send a RFQ later today. Pricey stuff these days!
I will just tell myself that they are using purer copper these days, thus justifying the cost increase. Hehe
Copper prices have soared the last year or so, but I don’t know that this accounts for all of the cost increases folks are seeing on transformers. The prices below will be well below those paid by industrial users if I understand this stuff correctly.
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As a comparison, he did quote their standard audio transformer and that was a more palatable 72 USD (excluding shipping). Metals have indeed shot up but that's a huge jump.
Is it the reason that other metal wire used in big transformers?
I see something like aluminium wire in transformers used in ups.
Have you tried Antek transformers I have used many of their transformers with great success.
AnTek Products Corp
AnTek Products Corp
The quality of Toroidy is not what it used to be. I have bought many transformers from them during the years. The Toroidy Audio Grade transformers used to be 100% free from hum. This is not the case anymore. My last two transformers from Toroidy hums badly, and they have refused to send me replacements.
These days I would order transformers from Sedlbauer or Amplimo. They have a more consistent quality.
These days I would order transformers from Sedlbauer or Amplimo. They have a more consistent quality.
still4given - I have used Antek in some projects and I've been very happy with them, but I wanted to go all the way with shield and GOSS band, which Antek has limited product range and doesn't seem to cover 500 VA.
HH - definitely gives me pause considering you had 2 of them not perform well.
HH - definitely gives me pause considering you had 2 of them not perform well.