Hi Stefan, bipolar=nonpolar, so the bottom (green) one is good.
Greetings from the Ruhr area 😉
Greetings from the Ruhr area 😉
Hallo Stefan,
both caps you posted are the correct ones. Just look for Nichicon UES. Mouser doesn't have the correct picture for the UES's, the ones I bought are actually green as well.
Second picture is from Darisus, I guess ? I bought a lot of Nichicons from them, didn't have a problem with any of them. Have one purchase in process with them right now for the smaller non-polars by Nichicon (UEP and UVP), because the UES don't fit on Mark's alternative VFET front end cards.
As they say, "Buy with confidence" 😀
Viele Grüße,
Claas
both caps you posted are the correct ones. Just look for Nichicon UES. Mouser doesn't have the correct picture for the UES's, the ones I bought are actually green as well.
Second picture is from Darisus, I guess ? I bought a lot of Nichicons from them, didn't have a problem with any of them. Have one purchase in process with them right now for the smaller non-polars by Nichicon (UEP and UVP), because the UES don't fit on Mark's alternative VFET front end cards.
As they say, "Buy with confidence" 😀
Viele Grüße,
Claas
The capacitor is not strictly necessary… the original M2 doesn't have it, so you could replace with a jumper.
I use the cap in all my input stages.
I use the cap in all my input stages.
For what its worth, I use the Ishikawa with C1 jumpered, also omitting the trim pot. For me, the Ishikawa is absolutely stunning in this form. Its my favorite input card hands down and I use it daily for the past 3 months, no issues. I'm not sure if anyone can describe the sonic impact of using the C1, but sometimes less is more. I think one member described the C1 as having a negative sonic signature impacting the base.
the reason why the C is there was the only thing I knew 🙂 just having been confused with the bi-and nonpolar labels, I read "bi" as "polar"
But to continue with C-trouble, what is the advantage of adding a motorrun cap to the PSU? Extrabang, speed? If someone has a link to an European Vendor would be nice.
tnx
stefan
If you add a motor run capacitor and you hook it up backwards, you may hear a bang, and because it would not be intended nor expected, you could think of it as an “extrabang.” This may make you run off in surprise with great speed.
Other than that, the addition of a motor run cap will certainly take up space in the chassis. Wether or not this is an advantage is for you to decide.
Other than that, the addition of a motor run cap will certainly take up space in the chassis. Wether or not this is an advantage is for you to decide.
Darr,
I think you may be confused about some things here.
RV1 on the main board of the M2X design is there to set the dc offset at the output of the amplifier.
RV1 on the Ishikawa daughter board (yes, it's the same label!) is there to adjust the phase of the 2nd harmonic distortion on the 2SK170/2SJ74 JFET input buffer circuit that is a hallmark in Nelson Pass designs. Without a spectrum or distortion analyzer, you cannot adjust this pot. This is clearly described in the instructions which is available for download from the 1st page of this thread. RV1 installation is optional. C1 is also optional but if a few mV offset of the Jfet inputs makes you concerned that the Edcor transformer core will be saturated, then install C1. In other words, the M2X design by virtue of including the option of installing C1, ALLOWS you to use somewhat mismatched Jfets. C1 will have a sonic effect though. Whether you like it or not, is up to you.
When Tea-Bag discusses minimizing the DC offset on his M2 boards, it was for the output stage. In his blog, he discusses adjusting R6, R7 and the pot P1 on his board to do so.
So the question I have for you is this. Where are you measuring your DC offset? At the output of the daughter board or at the output of the whole amplifier? Either way, a few mV isn't concerning.
If it is just a few mV at the output of the daughter board, and C1 is bypassed that will not likely energize the core of the Edcor transformer. However, it will be amplified 5 times by the transformer itself. In example, a 3 mV offset will become 15 mV. That being said remember capacitor C2 is there to squash that prior to the signal advancing to the output stage of the M2.
A few mV offset on the output of the M2 amplifier is nothing to worry about. I have seen numbers as high as 50mV to be honest and the sonic effects are not audible.
Best,
Anand.
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Nelson Pass's talk at the 2021 Burning Amp Festival included some experiments where he deliberately and intentionally set the offset voltage at the power amplifier output, to a gigantic number (not zero). It begins at the 13:00 timestamp of the video "Outside The Box", on the 2021 Burning Amp Video webpage (link)
I recommend you listen especially carefully to Nelson's cautions and disclaimers that start at 19:50 of the video. He warns you that you could damage equipment and injure yourself.
I recommend you listen especially carefully to Nelson's cautions and disclaimers that start at 19:50 of the video. He warns you that you could damage equipment and injure yourself.
Not sure where this is coming from.. Motor run caps are simply high voltage film, usually oil filled polypropylene. As such, they are not polar, and will not "go bang" because there is no way to hook them up backwards. They are physically large due to the high voltage capacity.
The intent of adding a large film capacitor to the output of a PSU is to lower the output impedance of the supply at high frequencies. The larger electrolytic caps (ca 15mF and up) are mainly inductive at higher frequencies. High quality 1000 uF to 2200 uF electrolytic caps instead of, or in addition to the motor run caps can also help.
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For more "bang for the buck" 😛, and for less space taken up, I nowadays more and more move to DC-Link (MKP) capacitors. They are available in large capacitance values, quite compact, and you can find them reasonably priced.
In industrial switch-mode supplys and solar inverters, they are replacing electrolytics, that's why they are more and more abundant in recent years.
And yes, to me also, a technical reason for using them (besides superstition
) is lowering the impedance of the PSU especially at higher frequencies.
When I think about a PSU, low impedance (best at all relevant frequencies) is always at the forefront of my mind, besides low ripple and high energy storage ... 🙂
Regards, Claas
In industrial switch-mode supplys and solar inverters, they are replacing electrolytics, that's why they are more and more abundant in recent years.
And yes, to me also, a technical reason for using them (besides superstition
) is lowering the impedance of the PSU especially at higher frequencies. When I think about a PSU, low impedance (best at all relevant frequencies) is always at the forefront of my mind, besides low ripple and high energy storage ... 🙂
Regards, Claas
Thanks for the answer Anand 🙂
My question is only for the Ishikawa card. The offset at the amplifier output is not affected here.
If I am imprecise, it is because my poor english. I am using the translator.
Sorry for that🙂
My jfets are matched from fetaudio. Knowing this, I skipped C1 capacitor by jumper, but I had 6mV at the input of Edcore.
I also don't have RV1 = 200R installed.
While reading the topic M2, I found this idea that I mentioned. On the teabag`s pcb, it easily mount a 20R pot instead of 10R resistors (on the Ishikawa card R1 and R2 ) and set the input offset to Edcore to 0V. The next step is to read the value on the pot, e.g. 8R and 12R and mount exactly such resistors.
So my question is, is it possible to use RV1 = 20R on Ishikawa card for this purpose? Next I'll measure the necessary values of R1 and R2 and this way I'll get 0V on the edcore input without the capacitor C1. It's good idea?
Hi, Going to try again and see if anyone has any suggestions. I was able to solve part of my issue from post #5717. The DC @ pin 4 is gone but channel still has the same issue. Vey low gain and muffled sound.
I have tried swapping a couple of daughter cards be channels and they are not the issue. both the Tucson and Ishikawa work just fine. I have recheck all the resistors and the voltage at them compared to the working channel.
How can I go about testing the Edcor without swapping it from side to side? I am really running out of ideas and skill with troubleshooting this.
I have tried swapping a couple of daughter cards be channels and they are not the issue. both the Tucson and Ishikawa work just fine. I have recheck all the resistors and the voltage at them compared to the working channel.
How can I go about testing the Edcor without swapping it from side to side? I am really running out of ideas and skill with troubleshooting this.
Installing Faston spade connectors on a PCB
Greetings fellow audionauts,
The M2X is my third build, and the first to use 1/4" in. spade connectors.
The AMP brand connectors I received seem to have thick 'legs', and will not easily press-fit into the holes on the motherboard (GND.0, GND.P, VNEG, VPOS, OUTPUT). So far, the tips just barely reach the back of the PCB, and I fear trying to push them harder, lest the PCB be damaged. At the same time, I feel like part of the reason for using them is the mechanical advantage gained from having the connectors pressed tightly into the holes.
Is this expected? Am I missing some esoteric insertion tool? I could file down the legs, I guess. Looking at the photos of several builds, it seems to me that the connectors are fully seated down to the board.
I spent about an hour searching various forums (Parts and Construction) for combinations of 'spade connector', 'faston', and 'PCB', and 'board', but I didn't find anything close.
Kind regards,
Drew
Greetings fellow audionauts,
The M2X is my third build, and the first to use 1/4" in. spade connectors.
The AMP brand connectors I received seem to have thick 'legs', and will not easily press-fit into the holes on the motherboard (GND.0, GND.P, VNEG, VPOS, OUTPUT). So far, the tips just barely reach the back of the PCB, and I fear trying to push them harder, lest the PCB be damaged. At the same time, I feel like part of the reason for using them is the mechanical advantage gained from having the connectors pressed tightly into the holes.
Is this expected? Am I missing some esoteric insertion tool? I could file down the legs, I guess. Looking at the photos of several builds, it seems to me that the connectors are fully seated down to the board.
I spent about an hour searching various forums (Parts and Construction) for combinations of 'spade connector', 'faston', and 'PCB', and 'board', but I didn't find anything close.
Kind regards,
Drew
Those look to be fine substitute.
Make sure the front side is going all the way in, if so it doesn’t matter how much extends through the back side
Make sure you apply enough solder to wick up through the holes and even up onto the connector slightly. That will provide plenty of support when cured.
Make sure the front side is going all the way in, if so it doesn’t matter how much extends through the back side
Make sure you apply enough solder to wick up through the holes and even up onto the connector slightly. That will provide plenty of support when cured.