Hi anhhct,
Connect the speaker grounds (not transformer "0") and connect the input signal ground of one channel to grounds of both RCA sockets. In this case both inputs will have the return path through a single wire. You can verify continuity from one input ground to another. Position the RCA sockets as close to eachother, connect their grounds together.
It is beneficial in this case to have two separate transformers or a transformer with four secondaries, two for each channel.
Good luck
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To all lovers of high-quality sound Hello! I've been listening to this amp for almost a year now and love it. There are, of course, comments (if you listen, in silence you can hear a small hum of Chinese transformers in the amplifier case). Do you think it makes sense to fill transformers with epoxy resin compound? I also ask the participants of the discussion to write what preamplifiers you use. I use this one:
https://aliexpress.ru/item/40009314...l.0.0.2e874aa6KZOkKX&sku_id=12000015939500752
https://aliexpress.ru/item/40009314...l.0.0.2e874aa6KZOkKX&sku_id=12000015939500752
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Now there was a desire to change the preamplifier to:
https://aliexpress.ru/item/32865370...s%21RUB%2125%C2%A0229%2C62%20%D1%80%D1%83%D0%
Or buy not a new Audiolab 8000Q / Audiolab 8200Q.
Will this further increase the sound quality and fully reveal the power amplifier from this discussion thread?
https://aliexpress.ru/item/32865370...s%21RUB%2125%C2%A0229%2C62%20%D1%80%D1%83%D0%
Or buy not a new Audiolab 8000Q / Audiolab 8200Q.
Will this further increase the sound quality and fully reveal the power amplifier from this discussion thread?
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My Accuphase A45. Perfect sound.
https://rpaudio.estranky.sk/fotoalbum/accuphase-a45/?photo=1
A year ago I bought an E210 from Aliexpress.Terrible sound. I threw it in the trash.
https://rpaudio.estranky.sk/fotoalbum/accuphase-a45/?photo=1
A year ago I bought an E210 from Aliexpress.Terrible sound. I threw it in the trash.
@platon.rado
You did an awesome work. Obviously, you have both tools and experience to make such an outstanding amplifier.
Please keep us informed about your progress and tell us more about your project.
... and I've been wondering: "What the hell happened to vmk2002. Where the hell he is?"
Regarding the transformer I suspect that electricity from your mains causes that sound. Sometimes we get electricity which isn't just sinusoidal but may have strange characteristics.
Quite often I also think about the changes, but my wife knows that she's better than the neighbours' spouse. So I keep what I have and love, if you know what I mean. 😉
Rather invest in a good DAC, if you ask me.
Hello everyone, and Happy New Year. Guys, a question. Does the A60 amplifier need an LR circuit at the output, if so, what parameters of the coil to wind and resistor data?🙄
Let's remember that there are no obstacles for God, he beats in the heart of every person and expects our willingness to show kindness, mercy and compassion. Let's take care of each other, pay attention to relatives, loved ones, friends and colleagues, help those in need, visit the sick and weak.
Hello Berlusconi. Have you ever had an idea to make balanced inputs to our A60 power amplifier?
No. It depends on the length of your connection to the source. Just make it short.
So no one answered which coil is better to make for the LR output in the A60.😞 Is it really such a secret?🙃 The first ones I did based on the Lynx PA 76 data(2mH). But I thought maybe someone could tell me the optimal data for this amplifier.🤔
Hello Berlusconi and all! It's not about the 230V power supply in the power network. I have a constant voltage filter. Also not that the earth loops inside the metal case affect. I checked it on a separate transformer (there is a spare one) and a separate power amplifier board. Everything is the same as in the case. Finally finished researching my preamplifier. I tested it in the NAD 372 amplifier system (instead of its regular preamplifier) and Quadral Ascent 90 acoustics. My preamplifier is too bright. I don't recommend buying it. Increasingly disappointed in Chinese products. As respected participants in the discussion think, does such a sound processor have a chance in stereo: https://www.globalmediapro.com/dp/A26XN7/Marantz-AV8003-Networking-AV-PreampProcessor/ You can buy it from us for 500 dollars, which is not expensive. Since it cost about 5000 dollars in our country, there is very little discussion of this device. And the A60 clone deserves a good preamp.
Good morning @vmk2002 !
I hope your problem is just transformer. But have you purchased "finished" board? Then there might be problem with low quality components. Not all, just one is enough to cause the problem, I have purchased a board without the rectifier capacitors and power transistors. I have used original ONsemi transistors and Vishay capacitors from reputable source. I also have started with bare PCB and have used all my own selected components. In the both cases measurements were great. Bandwidth and square wave response are impeccable. I have seen amplifiers with much better THD but A60 has THD values far below 0.1 and are dominated by the 2nd harmonics.
Regarding the preamp: price doesn't matter at all, all is marketing snake oil. There is snake oil for $500 and premium snake oil for $5.000. Even much more if you want Extra Luxury Snake oil.
I use preamp (Look here) which I have built from the scratch: Chinese PCB and selected components from reliable sources. It sounds great. Not cheap, but not expensive either, but I've built it and I know exactly what is in and how it measures.
Have a pleasant day dear friend.
I hope your problem is just transformer. But have you purchased "finished" board? Then there might be problem with low quality components. Not all, just one is enough to cause the problem, I have purchased a board without the rectifier capacitors and power transistors. I have used original ONsemi transistors and Vishay capacitors from reputable source. I also have started with bare PCB and have used all my own selected components. In the both cases measurements were great. Bandwidth and square wave response are impeccable. I have seen amplifiers with much better THD but A60 has THD values far below 0.1 and are dominated by the 2nd harmonics.
Regarding the preamp: price doesn't matter at all, all is marketing snake oil. There is snake oil for $500 and premium snake oil for $5.000. Even much more if you want Extra Luxury Snake oil.
I use preamp (Look here) which I have built from the scratch: Chinese PCB and selected components from reliable sources. It sounds great. Not cheap, but not expensive either, but I've built it and I know exactly what is in and how it measures.
Have a pleasant day dear friend.
I use a Krell Ksa-5 clone, it also has a switchable headphone output. I connected various branded and other preamps, but they were all far from it. I'm not going to change it for anything.😉
What is the thermal protection circuit that you implemented? My build is going slow. They sent me the wrong windings on my transformers and now waiting to get the correct ones sent and return these. Making a base plate for my case as well using pre drilled holes in the bottom plate. Should tidy up the wiring and help with noise. Taking my time on this. Might be awhile before I get everything mounted and wired up.
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Above I wrote that I have a temperature protection circuit complete with a relay volume control and a controller with a digital display. The kit includes a standby power supply (look in the center to the rear wall), there is also a soft start, a filter from direct voltage in the network, the main transformer is connected there. .The remote control is included. Here is a site where you can read with a translator, or in a personal message I will try to explain in detail if you are interested. There is no need to litter here. https://forum.vegalab.ru/showthread.php?t=48665
Hello Berlusconi. I have long wanted to explain the cause of the hum in the speakers, which was at the beginning of the assembly of my amplifier. Once you wrote that you have a stabilized voltage source for amplifier boards. I have a regular, diode bridge and capacitors. I observed on the oscilloscope the sawtooth supply voltage of 2sc2240 and 2sa970 transistors. That's why I heard the noise in the speakers. When I reduced the gain, the noise weakened.