After today getting into trouble with my current design as the casing is simply too small I thought of the following:
It is audio so only interesting when there is a challenge and preferably a few challenges
I think I will use the obsolete and hard to find (so they must be good) AD815AYS to drive the transformers.
It is audio so only interesting when there is a challenge and preferably a few challenges
I think I will use the obsolete and hard to find (so they must be good) AD815AYS to drive the transformers.Do you have an I out Dac?After today getting into trouble with my current design as the casing is simply too small I thought of the following:
It is audio so only interesting when there is a challenge and preferably a few challenges
My Dac is really happy with those far east trannies.
I trusted Pavel Pogodin on that one. He said he could not detect a difference between Lundahl and the ones he picked from China. I had them on my DSC dac and was utterly satisfied. But in our hobby there is no ultimate solution. Something I love and hate at the same time. I will see how those AKM 3000 (Haufe) trannies work. I don't need I/V conversion so I use them nacked with no integrated circuit in front.
You could use something jfet based from Papa in front of your trannies.
You missed the picture of the pair I found One is already twice the size of the whole amplifier board. Also 1 kg a piece. Minimal a factor 100 better with regards to distortion compared to Neutrik NTL-1 that I used regularly.
Only Pass device I would consider is the B1 Rev 2. I have the 2SK170BL but no 2SJ74BL. I do have 2SJ74GR but no 2SK170GR. After having received a few fakes I think I won't try to find those.
Which Haufe transformers do you have? Good experiences with ST-7679-1.
One is already twice the size of the whole amplifier board. Also 1 kg a piece. Minimal a factor 100 better with regards to distortion compared to Neutrik NTL-1 that I used regularly.Only Pass device I would consider is the B1 Rev 2. I have the 2SK170BL but no 2SJ74BL. I do have 2SJ74GR but no 2SK170GR. After having received a few fakes I think I won't try to find those.
Which Haufe transformers do you have? Good experiences with ST-7679-1.
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I did not. Thanks for the suggestion. I got sidetracked by finishing up another project…
I‘ll look into yours and Yatsushiro’s suggestions tomorrow.
They are from a Verteilerverstärker 1 in 6 out On the casing it says AKM3000 I opend one up and under the former there is a little circuit board.
Attachments
Blessed with a lack of background knowledge I ran one of my TPA3116 with special output filters that where called voice coils. It was my best sounding amp at the time. I used coax satelite cable as speaker wires. There was no dicernable interference with any of the many devices we had in our Appartement. I am about to do the same with these amps and see what happens.
Then you can be assured that EMI will be emitted. This can be seen and noticed clearly with MA12070. It is a recurring items in reviews/measurements of devices that have inadequate or even no output filtering. The more or less cheapest solution with the
2 x BLE32PN300SN1L and 2 x 1 nF works quite OK as a minimum.
Infineon recommends a few things:
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d46264a8de7e0164b359d78016f6
@denbret: of course I have seen that picture but there are no beads or coils to be seen. Either they are at the bottom side or they are not there at all. When there is no filtering the device is not interesting, when it has output filtering is looks like a serious device.
2 x BLE32PN300SN1L and 2 x 1 nF works quite OK as a minimum.
Infineon recommends a few things:
https://www.infineon.com/dgdl/Infin...N.pdf?fileId=5546d46264a8de7e0164b359d78016f6
@denbret: of course I have seen that picture but there are no beads or coils to be seen. Either they are at the bottom side or they are not there at all. When there is no filtering the device is not interesting, when it has output filtering is looks like a serious device.
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It is not about us (well, also a little bit 😀) but the EMI entering other devices in the chain. You really don’t want that. Did you ever measure class D devices?
And eh… after the speaker terminals eh … then it is already outdoors…
Imagine the amplifier to be a transmitter with 2 long antennas.
And eh… after the speaker terminals eh … then it is already outdoors…
Imagine the amplifier to be a transmitter with 2 long antennas.
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Ok understand.
In my case though having the amps about 4 inches from the raw speakers inside the Box, it makes no sense to sweat over filters. I can use shielded wire to the chassis and line the inside of the box with shielding material. The speaker grills are already of the metal type.
With the price of these amps I see no reason to use passive speakers any longer. Hate them anyway.
In my case though having the amps about 4 inches from the raw speakers inside the Box, it makes no sense to sweat over filters. I can use shielded wire to the chassis and line the inside of the box with shielding material. The speaker grills are already of the metal type.
With the price of these amps I see no reason to use passive speakers any longer. Hate them anyway.
Yes it is a known model but you have a recent version with tiny coils. At least is has some filtering, many simply haven't any. The older ones have decent coils and a built in design error. If you remove the unbalanced to balanced operation opamps and solder wires to the inputs better twist those wires. Why? To prevent pickup of EMI from the outputs. Also route the wires as far away from the outputs as possible and check what you change with an oscilloscope. Some changes tend to become habits with predefined thought that it always are improvements. Not measuring = not knowing.
Those 1 nF after the coils can be replaced for 1 nF 100V MKT/MKS in small pitch with good results. Tip: remove debris/flux with isopropyl alcohol after reworking.
Those 1 nF after the coils can be replaced for 1 nF 100V MKT/MKS in small pitch with good results. Tip: remove debris/flux with isopropyl alcohol after reworking.
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