My_Ref Fremen Edition - Build thread and tutorial

so, as promised i report back. I have been enjoying this amp for quite a while and really liked it. As usual, after some time i had to try out some modifications and decided to try the "cost no object" bom. So far, I am really really impressed. It really does make a very audible and pleasant difference. Quite some more details to hear, sound is even more spacious. Everything sounds just very natural and beautiful :D
I am curious if/how the sound changes after some break in time.
Kudos to Dario for creating such an amazing amp. Makes me happy so much :)))

bk856: How is your bass problem going? Any changes?
 
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so, as promised i report back. I have been enjoying this amp for quite a while and really liked it. As usual, after some time i had to try out some modifications and decided to try the "cost no object" bom. So far, I am really really impressed. It really does make a very audible and pleasant difference. Quite some more details to hear, sound is even more spacious. Everything sounds just very natural and beautiful :D
I am curious if/how the sound changes after some break in time.
Kudos to Dario for creating such an amazing amp. Makes me happy so much :)))

bk856: How is your bass problem going? Any changes?

Lots more hours on the amp and I've been using it exclusively for quite a while. I think either it's better or I'm used to it. I need to cycle in some other amps for comparison. I'm not sure I'd characterize it as a "problem" more like a characteristic or personality, and maybe it's now toned down in that area. Such a nice an well-behaved amp!

BK
 
Kudos to Dario for creating such an amazing amp. Makes me happy so much :)))

I'm not sure I'd characterize it as a "problem" more like a characteristic or personality, and maybe it's now toned down in that area. Such a nice an well-behaved amp!

It's always a pleasure reading that FE's builders likes so much the amp! :)
 
Hi
I use Z-Foil resistors in R7-R10-R12 and R13.
Forgot to bay for R 37-3K3 ohms.
How will this affect the sound of the amplifier.
I also bought Cerafine 220 uf-100v for C9.
Cerafine 50V was not available at Hifi Collective.
Will this affect sound negative?
For C15 i got 22uf-50V instead of 25V ..- or +?
BOM says 2pcs TO 220 mounting kit, but amp has 3 heatsink and bolts are too long?
Are there any components that can withstand little heat when soldering so
One needs to be extra careful?
New opamp?
Something new from Tomchr? Looking forward to his test of My-ref amp.
He is a busy man, but he has very much knowledge about the LM3886 chip.
Hope he likes the sound of My-ref as well as in his Modulus-86.
Is My-ref really as good as you say?:)
Maybe my FE-amps are ready for Christmas?:xmastree:
Having trouble finding affordable chassis for amps.
But I can not save money now.
Maybe on Black Friday?
 
Forgot to bay for R 37-3K3 ohms.
How will this affect the sound of the amplifier.

It will sound good, you can eventually upgrade later to achieve even better transparence.

I also bought Cerafine 220 uf-100v for C9.
Cerafine 50V was not available at Hifi Collective.
Will this affect sound negative?

It will not affect sound but it will NOT fit, not perfectly at least...

For C15 i got 22uf-50V instead of 25V ..- or +?

Mmh, I would stick to 50V caps fot that position, they can possbly see more than 25V

BOM says 2pcs TO 220 mounting kit, but amp has 3 heatsink and bolts are too long?

The two mounting kits are for the LM317s

Are there any components that can withstand little heat when soldering so
One needs to be extra careful?

In general all semiconductors.

New opamp?

Someone is experimenting but so far nothing will change on the official and support BOM, the opamp remain the LM318.

Something new from Tomchr? Looking forward to his test of My-ref amp.
He is a busy man, but he has very much knowledge about the LM3886 chip.
Hope he likes the sound of My-ref as well as in his Modulus-86.

No news so far, apart he bought the BOM.

Is My-ref really as good as you say?:)

I'm not saying anything...usually builders say so ;)
 
Hi
Thanks for answering questions.
I have built 2 of 4 PCBs.
100v Cerafine in C9 fits 100%
but it is a bit close to the z-foil in R10.
I'm a little anxious to hook up toroid transformers.
The secondaries have 2 blue and 2 black wires.
What's Hot / phase and what is neutral?
Will I hear it if I connect the wrong way.
Shall ground wire from the toroid (mark "0"), mains earth and PGND on PCBs
hook in the same place on the chassis.
Do not understand this grounding point and My-ref PCB.
Can not see that you have hooked PGND to something in tutorial pictures?
Tried to read Rod Elliott ,ESP article about safety earth connector.
did not understand his use of 35amp bridge rectifier, power thermistor resistor and 100nF capacitor for safety earth.
Tried to read Decibel Dungeon, power supply for beginners (dummies).
Realized that I was a dummie and that maybe I should not touch mains power at all.
I need to read more and maybe then understand basic electronics theory.

Can someone explain this with earth and MY-ref.?
(For beginners, please.)
 
Dario may well give more detail but everything you ask about transformer connection/earthing etc has already been covered in this thread and the build manual.
The boards power ground tab should not need to be connected to anything. Your transformers should have come with a connection diagram, often on a label attached to it. You have two secondary's so a black and a blue wire for each. twist them into pairs. You now have 2 twisted cords comprising of 1 black & 1 blue wire each. These connect to the tabs on the boards. First pair blue to AC1, black to NAC1. Second pair blue to AC2, black to NAC2. That is MY understanding of how to connect your transformers but i would proceed with extreme cation if i were you. Do not forget to connect the chassis to mains earth. Also use a dim light bulb tester to limit the power on first power up, it's easy to make one, details are on this forum. Do not continue until you are certain about what you are doing. There is a power supply section in this forum.
 
Hi
Thanks for answering questions.
I have built 2 of 4 PCBs.
100v Cerafine in C9 fits 100%
but it is a bit close to the z-foil in R10.
I'm a little anxious to hook up toroid transformers.
The secondaries have 2 blue and 2 black wires.
You have to find which of the tapppings are on which winding. Measure with a continuity meter and label them.
What's Hot / phase and what is neutral?
Will I hear it if I connect the wrong way.
If you connect out of phase, you risk damaging your transformer.
Shall ground wire from the toroid (mark "0"), mains earth and PGND on PCBs
hook in the same place on the chassis.
NO !!!!
The Mains PE wire goes to Chassis via a permanent mechanaical connection at the input socket.
The transformer interwinding screen goes to Chassis at the point where the screen comes out from the insulation.
The Safety Connection from Main Audio Ground (MAG) to Chassis can be from any large wire route within the MAG that can pass Fault Current until the mains fuse ruptures.
Do not understand this grounding point and My-ref PCB.
Can not see that you have hooked PGND to something in tutorial pictures?
Tried to read Rod Elliott ,ESP article about safety earth connector.
did not understand his use of 35amp bridge rectifier, power thermistor resistor and 100nF capacitor for safety earth.
Some amplifiers, particularly multi-channel, need an indirect Safety connection from MAG to Chassis. ESP shows a Disconnecting Network as described in many Forum Posts to reduce the interference current flowing around the audio circuits. This Safety connection is not always required. Test your build.
Tried to read Decibel Dungeon, power supply for beginners (dummies).
Realized that I was a dummie and that maybe I should not touch mains power at all.
I need to read more and maybe then understand basic electronics theory.

Can someone explain this with earth and MY-ref.?
(For beginners, please.)
If you are unsure about your mains wiring ask an Electrician to check your work BEFORE you power ON.
You should use a Mains Bulb Tester to check your wiring for every new mains project and for every modified mains project.
 
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Hi
Thanks for the reply davym and AndrewT.
I think I understand better now.
Has also taught me to search the thread.
Searching PGND provides many answers and many opinions.:confused:
I will try different methods for grounding when I have
acquired chassis for amps.I understand that mains grounding
to the chassis is most important .I think I should make such
mains bulb tester also ,to be sure.
Dario is there any difference in the sound of
22uf 50v FG and 22uf 50V KZ.
I bought 22uf 50V KZ for C15 (not BOM)
and 100uF 25v FG C16 (BOM)
Not 100% fit on the PCB for C15 and C16.
Will I lose any of the good sound with KZ?
 
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Hello everyone, many thanks to @peterma for advice
I continue to fill my shopping cart on mouser .. but I have a doubt ...
The R11 should be 1 Ohm and the mouser code (found in the BOM) me from this article 100 KOhms 1 / 4W ... http: //www.mouser.it/ProductDetail/Vishay-Dale/RN65E1003BB14/? qs = sGAEpiMZZMu61qfTUdNhG1jRaYe8f2sLOeVG3rqNtxs% 3d.


P.S .: any of you could share with me his cart mouser?
 
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@Peterma
What measurements change when using the Z-Foil?
I seriously doubt you will be able to measure any difference in performance by substituting a Zfoil for a normal in spec metal film when both are working within their recommended voltage range.
A standard metal film resistor has so little distortion that it needs some pretty sophisticated equipment and clever methodology to measure any distortion.
Changing to a Zfoil will make distortion measurement just as difficult.

Now putting either of them into an amplifier will hide most of what that previous test may have found it nearly impossible to measure.