I enjoy reading long threads, taking notes, recording post numbers. I know just enough to be dangerous. Many of my errant thoughts are addressed by others, before I make magic smoke. I even can pick up improvements to an amp, before I start ordering parts, and building stuff. The later, add on, daughter boards that have been introduced, are icing on the cake. Of course MJ has his 3 additional sets, forum member XRK971 has several more, with different themes. The Black Forest Buffer by EUVL is the latest that I have seen.
XRK971 sells his boards on Etsy, all the others requires one to obtain the boards by either ordering the card fabrication from fab house, or obtaining some from a fellow board member who did order through a fab house, and has extras.
The M2x amp is not presented as a beginner project. There are too many nuggets throughout the thread to not read.
Cedarburg:
I am one 6.8k resistor away from completing it! Unfortunately, that got dropped from the BOM during the order process with Mouser. Now that the Vfet can be in service I can tend to my beloved M2x and make a few needed mods. The M2xx with the XRK971 Buttah' board is as quiet in my system as the VFET. I can't tell the difference, in quietness that is.
I am one 6.8k resistor away from completing it! Unfortunately, that got dropped from the BOM during the order process with Mouser. Now that the Vfet can be in service I can tend to my beloved M2x and make a few needed mods. The M2xx with the XRK971 Buttah' board is as quiet in my system as the VFET. I can't tell the difference, in quietness that is.
> all the others requires one to obtain the boards by either ordering the card fabrication from fab house,
> or obtaining some from a fellow board member who did order through a fab house, and has extras.
One can order 5 pcs at e.g. JLCPCB with lead free HASL for only 3.10USD (for 5 pcs).
Postage + VAT on top.
One can be used to test with unmatched parts to get everything working.
Then build a pair with matched devices for actial use.
And keep a pair as spare.
Which was why I published the Gerbers instead of offering a GB.
Part of DIY is to order your own boards.
It is for certain not difficult.
Patrick
> or obtaining some from a fellow board member who did order through a fab house, and has extras.
One can order 5 pcs at e.g. JLCPCB with lead free HASL for only 3.10USD (for 5 pcs).
Postage + VAT on top.
One can be used to test with unmatched parts to get everything working.
Then build a pair with matched devices for actial use.
And keep a pair as spare.
Which was why I published the Gerbers instead of offering a GB.
Part of DIY is to order your own boards.
It is for certain not difficult.
Patrick
You guys really like to twist things and feel ofenden where no offense was issued!
I mentioned I believe forum software / structure is not best to cover these scenarios. It also fails at capturing impressions of different op amps and possible alterations to resistor values, for example!
Did I say the 6L6 failed at moderating? Heck! I’m willing to bet that Jim and other DIY moderators / admins felt the forum software was lacking and they changed the cleverly designed guides for on the first two posts of a thread (with messages of “placeholder” to reserve the second post!) to the newly designed guides that are a lot easier to read.
So don’t put words in my mouth, I am sure the only person that thought I was complaining about mods work was you. And it’s not the first time you have created tension where non should exist.
My only comfort is that I am sure Jim took no offense in the comment. If you did Jim, you know my mind and my intentions better than anyone here.
Rafa.
I mentioned I believe forum software / structure is not best to cover these scenarios. It also fails at capturing impressions of different op amps and possible alterations to resistor values, for example!
Did I say the 6L6 failed at moderating? Heck! I’m willing to bet that Jim and other DIY moderators / admins felt the forum software was lacking and they changed the cleverly designed guides for on the first two posts of a thread (with messages of “placeholder” to reserve the second post!) to the newly designed guides that are a lot easier to read.
So don’t put words in my mouth, I am sure the only person that thought I was complaining about mods work was you. And it’s not the first time you have created tension where non should exist.
My only comfort is that I am sure Jim took no offense in the comment. If you did Jim, you know my mind and my intentions better than anyone here.
Rafa.
One area the Cedarburg particularly excels in my system is low level detail. What I mean by this is I find myself with the volume lower on my preamp and still getting a very clear and detailed sound. With the IPS7 I found myself pushing the volume higher to get the musical details I desired.
Regards,
Dan
Regards,
Dan
I can confirm that Cedarburg is a very nice input board. Think it is the best board so far to present the "room information" at the recordings and also the dynamics are "scary". It has no problems driving the Edcor.....it seems.
Then I think none should feel offended.....I have learned how different members express itself
Then I think none should feel offended.....I have learned how different members express itself
Don't you worry Rafa, just the inventor of The Scourge maintaining a certain image. He doesn't want you to know that he actually is a nice man.
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This is just a quick “Thanks” to all who contributed advice as I finished my M2x. I eliminated my transformer hum, hooked it up to my Korg B1 and have now added it to my Magnepan MMGWs and a subwoofer. People love to talk about how Maggies are hard to drive, but the M2x with Ishikawa front end (Toshiba JFETs) puts out plenty of juice to produce plenty of sound, and all of it luminous. It’s a great, pure sound, just what I was hoping for. And the biggest Thank You to Nelson Pass for generously sharing these wonderful circuits.
I reflowed some iffy solder joints on the diodes. I was getting some uneven measurements on positive and negative output on the power supply (the diyAudio Store universal PS board), and a couple of folks suggested that could be an issue. In any event, the hum disappeared, the voltages evened up and I was off and running. I tend to get nervous soldering small joints on transistors and underheat and don’t get a good flow through the joint.
to jfuquay #5130
Hello jfuquay,
not carefully soldered solderjoints seems a common problem.
If members are showing photos from their pcbs I often can see that the solder wasn't running through the solder hole - completely. The legs of the through-hole-parts are not covered with solder on the opposite side of the pcb. This is often a sign that it wasn't heated correct (temperature and time) or the flux wasn't doing a good job. Another issue is leadfree solder - often a pain to handsolder.
I often measure from the new solderjoint (leg of the electronic part) to the next
solderjoint for resistance. Then I know if my work was well done. If necessary - reflow.
Enjoy your M2X - it is a great amp!
I also drive my ESLs sometimes with the M2X and KORG B1 NUTUBE-pre -
great combo!
Greets
Dirk
Hello jfuquay,
not carefully soldered solderjoints seems a common problem.
If members are showing photos from their pcbs I often can see that the solder wasn't running through the solder hole - completely. The legs of the through-hole-parts are not covered with solder on the opposite side of the pcb. This is often a sign that it wasn't heated correct (temperature and time) or the flux wasn't doing a good job. Another issue is leadfree solder - often a pain to handsolder.
I often measure from the new solderjoint (leg of the electronic part) to the next
solderjoint for resistance. Then I know if my work was well done. If necessary - reflow.
Enjoy your M2X - it is a great amp!
I also drive my ESLs sometimes with the M2X and KORG B1 NUTUBE-pre -
great combo!
Greets
Dirk
A suggestion for a new, community-designed, M2x Input Stage
I've noticed that two of the IPS cards seem to elicit much fiercer loyalty and more passionate devotion, than all the others: IPS7 and Cedarburg.
If this is generally true, why not consider cross-breeding them? Take the most dominant thoroughbred filly of all time (Zenyatta) and mate her with the most dominant stallion of all time (Secretariat). The offspring might be unbeatable.
A look at the boards themselves suggests an idea.
>> Why not try a [stability enhanced AD797] follower, with bootstrapped power supply rails? <<
Viktor Fronkinschteen reacts to this idea: Youtube clip 17 seconds long
Perhaps M2x builders would enjoy developing an IPS card along these lines, and then subjecting it to critical listening evaluation. It definitely would be a lot of fun, and the result might, just might, be an unstoppable colossus.
You might be wondering, why didn't I include this among my portfolio of free IPS designs, given away in this thread? I left that one out so that you gentlemen and ladies would have something to put in.
And of course, the designer(s) get to name the new IPS board. Montevideo? Riga? Vilnius? Zagreb? Anything you want.
Please enjoy!
(click on the images to see them full size and undistorted)
_
I've noticed that two of the IPS cards seem to elicit much fiercer loyalty and more passionate devotion, than all the others: IPS7 and Cedarburg.
If this is generally true, why not consider cross-breeding them? Take the most dominant thoroughbred filly of all time (Zenyatta) and mate her with the most dominant stallion of all time (Secretariat). The offspring might be unbeatable.
A look at the boards themselves suggests an idea.
- Opamp follower (unity gain stage) with bootstrapped power supply rails
- Stability enhanced AD797 @ Unity Gain
Viktor Fronkinschteen reacts to this idea: Youtube clip 17 seconds long
Perhaps M2x builders would enjoy developing an IPS card along these lines, and then subjecting it to critical listening evaluation. It definitely would be a lot of fun, and the result might, just might, be an unstoppable colossus.
You might be wondering, why didn't I include this among my portfolio of free IPS designs, given away in this thread? I left that one out so that you gentlemen and ladies would have something to put in.
And of course, the designer(s) get to name the new IPS board. Montevideo? Riga? Vilnius? Zagreb? Anything you want.
Please enjoy!
(click on the images to see them full size and undistorted)
_
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Brief first impressions. The 1612A has a little more midrange depth and treble is a little clearer. The AD797 excels with better bass.
This test was done with my Martin Logans. In the next few days I'm going to hook up my line arrays with their ribbon tweeters and offer another review.
Regards,
Dan
This test was done with my Martin Logans. In the next few days I'm going to hook up my line arrays with their ribbon tweeters and offer another review.
Regards,
Dan
Right!
-What makes the cedar able to go dc coupled? Is it the 797 itself?
-how the rail modulated by the input signal affect the complex AD797 PS tuning? I would assume the whole RC network would be needed on the franken ips7-ad797 but what if alterations may be necessary?
The other way around seems more straight forward. Most opamps would do fine in the cedarburg, maybe. Would the output cap become necessary?
I am too old to mess around with such things.
