Joseph
Yeah, zfoil everywhere 🙂
In the Evolution of friend of mine, I've put zfoil in the current pump too... expensive but they worth the money...will be next mod for my FE
I use chipquick for desoldering smd, but before working i will consult with Dario
Ciao
Marco
Yeah, zfoil everywhere 🙂
In the Evolution of friend of mine, I've put zfoil in the current pump too... expensive but they worth the money...will be next mod for my FE
I use chipquick for desoldering smd, but before working i will consult with Dario
Ciao
Marco
Ghiglie,
Not to worry. Just build it to the BOM and wait a bit for modifications. These topics come up from time to time and it's good to let these experimenters pave the way before changing anything. Besides, the standard FE sounds great. Even my old ones.
Jac
Hi all,
...i know that I should take into account the suggestion that Jac gave to Ghiglie, but...
- I have a couple of MyRef FE boards, last version, not yet populated
- already bought the EVO Rev A BOM (just to put in place)
- an open order to Mouser...
so I would like to add a couple of ADA4627 (OPA627 is too expensive to me).
Just to be sure, the right version for this application is the 1BRZ isn't it?
Any further advice/information is welcome.
Thank you.
Filippo
...i know that I should take into account the suggestion that Jac gave to Ghiglie, but...
- I have a couple of MyRef FE boards, last version, not yet populated
- already bought the EVO Rev A BOM (just to put in place)
- an open order to Mouser...
so I would like to add a couple of ADA4627 (OPA627 is too expensive to me).
Just to be sure, the right version for this application is the 1BRZ isn't it?
Any further advice/information is welcome.
Thank you.
Filippo
Dear Filippo,
Should be short, in a meeting right now.
While I do agree with Jac, in a general aspect, I would say that for people in the assembly phase right now - - going directly to the new configuration would simplify greatly the effort - you avoid the pain of taking out the chip.
I am confident to say that You can do that. And still, in case of not foreseen complcations, one can return to the original configuration, given that the changes are not destructive..
Ciao, George
Should be short, in a meeting right now.
While I do agree with Jac, in a general aspect, I would say that for people in the assembly phase right now - - going directly to the new configuration would simplify greatly the effort - you avoid the pain of taking out the chip.
I am confident to say that You can do that. And still, in case of not foreseen complcations, one can return to the original configuration, given that the changes are not destructive..
Ciao, George
ARZ and BRZ differ only for opamp's selection, B grade sounds WAY better, warmer and fuller.
But... But if you bought the new boards to evaluate the difference from older ones (along with different BOMs) I suggest you to build first the official version and only after JosephK's experimental version.
LM318 has a character of its own which is, somewhat, the My_Ref's characters.
A My_Ref with a different opamp could sound better but I don't know (yet) if it will mantain the same sound signature.
Going through the two steps you can give us you opinion 😉
Dario, in all honesty I was hoping that this comparison would be made by core people who know very well the original sound..
And maybe even have two versions, to be physically compared, like me..
And maybe even have two versions, to be physically compared, like me..
Am I missing something?
I will also make some opamp tests, as I've already said, probably this summer.
But other opinions are needed too, what's wrong with it?
Dario, you are right, for me it's OK in any way, too.
Filippo, I would say that the ADA chip is a good choice, for me it seems to be the better one. (respect to the OPA627, sonically) I agree with Dario about the grade.
In case You, or anybody else, would decide to vote for the OPA827, then I would repeat: the compensation cap, C32, 150pF should be changed to 100pF.
Ciao, George
And again, I do agree with Jac, nicely put:
Filippo, I would say that the ADA chip is a good choice, for me it seems to be the better one. (respect to the OPA627, sonically) I agree with Dario about the grade.
In case You, or anybody else, would decide to vote for the OPA827, then I would repeat: the compensation cap, C32, 150pF should be changed to 100pF.
Ciao, George
And again, I do agree with Jac, nicely put:
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See this pic from a previous version of boards:
You can see that markings are toward C1 and C2.
All 3 Amtrans should have markings toward C1 and C2.
Hello.
Sorry if not the topic ...
I am using an oscilloscope to scan small batch Amtrans AMCH. The audit showed that the outer foil all differently is attached to the leads (in relation to the logo on the body).
Therefore, only the orientation for printing on casing is not correct.
Don't you think so?
Regards, Sergey.
Hello Sergej,
maybe I've been lucky but the ones I've evaluated by ears (lets say 3-4 per value) were consistent.
Obvioulsy your method using an oscilloscope is a better one and, having one at hand, the only that can guarantee the correct orientation.
Bad news... 🙁
Unfortunately I found that all capacitors without special marks are oriented randomly. Tested WIMA, MultiCap, Evox Rifa? Amtrans, ERO, FT-1 (Teflon). Found some repeatable "directions", but not more 70-80%
Dario, tell me, please, on hearing from AMCH you have defined input (outer foil) to the left or right of the print?
Regards, Sergey.
Dario, tell me, please, on hearing from AMCH you have defined input (outer foil) to the left or right of the print?
Regards, Sergey.
Since I've did it 'by ears' I'm not sure it's the outer foil, I've simply selected the side that sound more similar to no cap at all.
In my case it was 'input' at the left of the markings.
Thank you!
That's right.
In most cases (on measurements) external foil is located exactly on the left of the markings.
Regsrds, Sergey.
That's right.
In most cases (on measurements) external foil is located exactly on the left of the markings.
Regsrds, Sergey.
That fits with how I imagine a box of capacitors/resistors delivered from one production phase to the next phase.
I have not followed Myref development for a while, where can I find the latest Freman Edition schematics to compare against the original RevC design?
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
In the opening post of the last GB you will find all relevant info and links:
http://www.diyaudio.com/forums/group-buys/300644-my_ref-fremen-edition-gb-10th-run.html
Not the ADA4627, IMHO...
Just to refresh memory today I've compared some of the opamps suggested as alternates for the LM318 in the My_Ref.
Since I don't have ready my My_Ref test bench I've did this comparison as LPf/Buffers in my DAC.
Yes, I know it's not the same thing but my experience tells me that sound signature and general behaviour remain similar.
IMHO the ADA4627 IS NOT A GENERAL IMPROVEMENT, it has better resolution/cleaniness on HF but at the same time sounds dry, it reduces the harmonic content of music.
B grade is better than A grade in this regard but still too much dry.
A grade, though, sounds more neutral while B grade is (too much) warmer.
IMHO harmonic richness is one of the best feature of the My_Ref Fremen Edition, so if those results remains valid for the My_Ref the ADA4627 will never be a suggested replacement.
What seems a general improvement is, instead, the OPA827 which mantains the same, if not better, harmonic content, sounds cleaner and more neutral but the My_Ref 'mojo' remains.
So far I would not suggest anyone to replace the LM318 but to experiment and OPA827 would be the next best fit.
Just to refresh memory today I've compared some of the opamps suggested as alternates for the LM318 in the My_Ref.
Since I don't have ready my My_Ref test bench I've did this comparison as LPf/Buffers in my DAC.
Yes, I know it's not the same thing but my experience tells me that sound signature and general behaviour remain similar.
IMHO the ADA4627 IS NOT A GENERAL IMPROVEMENT, it has better resolution/cleaniness on HF but at the same time sounds dry, it reduces the harmonic content of music.
B grade is better than A grade in this regard but still too much dry.
A grade, though, sounds more neutral while B grade is (too much) warmer.
IMHO harmonic richness is one of the best feature of the My_Ref Fremen Edition, so if those results remains valid for the My_Ref the ADA4627 will never be a suggested replacement.
What seems a general improvement is, instead, the OPA827 which mantains the same, if not better, harmonic content, sounds cleaner and more neutral but the My_Ref 'mojo' remains.
So far I would not suggest anyone to replace the LM318 but to experiment and OPA827 would be the next best fit.
Guys, I strongly recommend AD823.
Another thing to mention is that I have heard lme49710 do amazing things in a headphone amp and then sound pretty awful as the front end of an amp. Not sure if it was PSU or application but just because an opamp sounds good in one circuit is not a promise of success elsewhere. Of course this means my AD823 suggestion might be meaningless as it was not in the myRef circuit but the front end to a friend's amp. Grain of salt I guess.
Another thing to mention is that I have heard lme49710 do amazing things in a headphone amp and then sound pretty awful as the front end of an amp. Not sure if it was PSU or application but just because an opamp sounds good in one circuit is not a promise of success elsewhere. Of course this means my AD823 suggestion might be meaningless as it was not in the myRef circuit but the front end to a friend's amp. Grain of salt I guess.