This is what i have also understood. Thank you for your help. I have no idea about trafos. I use smps's wherever i can. After i stabilize everything i will try a couple of connexelectronic smps300re to the AC inputs just for fun. I know that it will work . I just want to see if there is any sonic benefit. But since the topic is still on , what will happen if i connect the only secondary of each trafo to the two inputs of one channel ( so each trafo serves one circuit)?
If I understand you correctly, you would connect one trafo secondary to, for example, AC1 on the pcb. AC2 would be left open. If that is your intention, it won't work. AC1 supplies the positive rail for both the unregulated V+ and the regulated plus voltage for the op amp. In this example, there would be zero voltage on the negative rails and the amp won't function.
Jac
Jac
Connecting a transformer to a PSU is exactly the same as connecting an SMPS to a load.
Use a TWO WIRE connection.
If one has two SMPS (or a dual polarity version) then you use two sets of TWO WIRE connections. Same for a transformer with two secondaries. Use two sets of TWO WIRE connections.
Use a TWO WIRE connection.
If one has two SMPS (or a dual polarity version) then you use two sets of TWO WIRE connections. Same for a transformer with two secondaries. Use two sets of TWO WIRE connections.
Thanks! Also for the additional info. I did not know all that about the two power supplies.
Hi Andrew, thanks! What about the following image. This is for one channel. The power supplies are separated per channel:
https://picload.org/view/riiogpwl/diyaudio.png.html
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Thank you for your support with the power supply, i decided that it is easier to replace the transformers than go through experimenting with power supply configurations. There is no point.
So I completed the amplifier and the case yesterday. It was straightforward. I just followed the build instructions from Mario and my amp is now working. I only regret that i did not buy a good input capacitor for the build. So i ordered one yesterday. There is zero hum noise. I will post some pictures once the network here in ofice is restored. For jazz and instrumental music this amp is perfect. I am impressed. Instruments sound realistic. Also the stage is indeed huge. No further judgments untill i replace the input caps.
The amp started well with the mains connected for the first time. Then I connected the cables and the amp went crazy. I remained calmed and did some troubleshooting. I found that the hot glue (used for case insulation) from one of the rca connectors did not allow the signal ground to make contact with the rca plug. So the left channel had no signal ground. I was suprised that this thing created such havoc. I almost blown up the speaker.
Also could i replace the signal input cap with one with a bigger value? I happen to have some (2,2 and 4,7 uf)
So I completed the amplifier and the case yesterday. It was straightforward. I just followed the build instructions from Mario and my amp is now working. I only regret that i did not buy a good input capacitor for the build. So i ordered one yesterday. There is zero hum noise. I will post some pictures once the network here in ofice is restored. For jazz and instrumental music this amp is perfect. I am impressed. Instruments sound realistic. Also the stage is indeed huge. No further judgments untill i replace the input caps.
The amp started well with the mains connected for the first time. Then I connected the cables and the amp went crazy. I remained calmed and did some troubleshooting. I found that the hot glue (used for case insulation) from one of the rca connectors did not allow the signal ground to make contact with the rca plug. So the left channel had no signal ground. I was suprised that this thing created such havoc. I almost blown up the speaker.
Also could i replace the signal input cap with one with a bigger value? I happen to have some (2,2 and 4,7 uf)
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Attachments
What is this hot glue? Do you mean 63/37 solder?
The input is a two wire connection. The input NEEDS two wires to complete the circuit. Break one or other of these two wirea and the circuit is broken.
If the Flow/Hot connection is broken, the amplifier usually goes silent.
If the Return/Cold wire gets broken, the other wire becomes an aerial picking up interference from every EMI source around the home and from your neighbours.
That aerial injects wideband noise into the amplifier input to become a disaster at the speaker.
Fine
BTW my name is Dario
From what I can see you didn't use the official BOM, best results (soundwise) are achieved using it, it's the result of countless hours of listening, parts comparison and a huge amount of money.
It will make a difference.
Fine
BTW my name is Dario
From what I can see you didn't use the official BOM, best results (soundwise) are achieved using it, it's the result of countless hours of listening, parts comparison and a huge amount of money.
It will make a difference.
I have this thing with names! So thank you Dario for this offer and the excellent instructions. I am already enjoying the amp so much. It was one of the best spent money for my system.
I only changed the big caps because i had a big surplus of them. At least they have the same values and they are all audiophile grade. Almost all the rest is from the official bom.
I already changed the input cap to a zcap supreme and that already made tremendous difference. Thanks to Bob i learned that i could put a bigger value cap. I am tempted to do other changes already e.g put the caps you suggest at the bom.
Thanx! I think thats exactly what happened. Concerning the glue I mean normal hot glue , the one that comes in bars. I used such to shape an insulation ring between the rca plug and the case. Because i lost one. But while i did it in a hurry the glue insulated also the contact of the ground. **** happens! The only other glue i used is permatex cold welding glue, to connect the front panel, because it is realy not needed to put screws there. There is no mechanical stress and for me it works better. I was tempted to connect everything with that glue! It makes everything so easy.
Permatex® Cold Weld
Really sad news
Mauro Penasa, the designer of the original My_Ref died.
http://www.diyaudio.com/forums/memoriam/309127-mauro-penasa-tragically-passed-away.html
Thanks Mauro for your genius and your legacy.
Mauro Penasa, the designer of the original My_Ref died.
http://www.diyaudio.com/forums/memoriam/309127-mauro-penasa-tragically-passed-away.html
Thanks Mauro for your genius and your legacy.
