Gentlemen,
last December METAL and I made up our mind and did our own layout for Mihai's (Roender's) FC-100 AMP.
This is Mihai's original thread:
http://www.diyaudio.com/forums/solid-state/111756-rmi-fc100-single-stage-audio-power-amplifier.html
The reasons for our decision have been:
- the frontend of Mihai's FC-100 belongs to the best (!) designs I have ever seen in the AMP's world
- we had a couple of NJL - ThermalTrak - transistors at hand and wanted to use them on the backend
We offered our layout in a Group-Buy thread, but after some discussion have been asked to prototype
our PCB first before offering it to the community.
I ordered a couple of professionally etched prototype PCBs and ZSAUDIO and I built the prototypes.
http://www.abload.de/img/fc-100nduq1.jpg
The result:
An absolutely "rock-stable" amplifier playing at its best.
Two comments about its sound-quality:
by ZDR (who did his own layout):
"Well, I am done now. I just have one little problem - how do I stop those little hairs on the back of my neck from standing
up while this baby is playing?"
by ZSAUDIO:
"All of you guys who plan to build this amp just do it. The PCB what Rudi and Metal offer is an art."
I had a problem related to my own build though.
The typcial forward voltage drop of the integrated TT - diodes of my charge of NJL-transistors was higher than of Mihai's transistors,
and I was not able to activate 5 diodes in the TEMPCO - string.
Thanks to a sudden inspiration of FranzM. I bypassed one TT - diode by an external SCHOTTKY diode and fixed my own problem.
Since then I have been able to listen to the beautiful sound of the FC-100.
My "Prototype - Experiences" are documented in this thread:
http://www.diyaudio.com/forums/solid-state/202047-roenders-fc-100-prototype-builders-thread.html
I have incorporated ZSAUDIO's and my own experiences and your requests into the Revision 1 of the FC-100 PCB
and will offer you in this group-buy:
- the FC-100 Rev.1 PCB:
http://www.abload.de/img/fc_100_gerbv91ybk.png
The PCB includes the Frontend, the Backend and a complete, high-quality Backend - PSU.
Its size is 245 x 74 mm.
For those of you who plan to use your own PSU, reservoirs CAPs, etc..., I have inserted a pre-determined breaking line on the PCB.
The quality of this PCB is the best that you can imagine:
- 2 mm thick FR4 PCB, double-sided, 70µm copper traces covered with Gold immersion, soldermask, silkscreen, ...
Its price will be 15€.
- Mihai's FrontEnd Shunt-PSU:
http://www.abload.de/img/fc-shuntagytp.png
Its size is 76 x 74 mm; its price will be 8€.
- whatever you like to have to "make this group-buy complete", for example:
Futaba 0R1 / 5W emitter resistors, MKP 1839 / 1µF capacitor, input capacitor, Speaker Protect PCB, Soft-Power-On PCB, ...
One of the pre-requisites to make this AMP a real success is to match certain transistors: the input differential pair,
the output- and pre-output drivers, LEDs, ...
I am currently thinking about designing a "Transistor-Matching-PCB" (if you would like to have).
I will leave this group-buy open, until all of your questions have been answered (but will terminate it on April, 15th at least).
I feel a little bit sad, right now.
Mihai's FC-100 is beating my current favourite DIY - AMP, the TO3-SYMASYM.
This is the best-sounding DIY amplifier I have come across so far.
Will there be any AMP - PCB that I will be going to offer you in the future?
Find the current order list below.
Feel free (you would be a fool if not) and join this group-buy.
Best regards - Rudi_Ratlos
last December METAL and I made up our mind and did our own layout for Mihai's (Roender's) FC-100 AMP.
This is Mihai's original thread:
http://www.diyaudio.com/forums/solid-state/111756-rmi-fc100-single-stage-audio-power-amplifier.html
The reasons for our decision have been:
- the frontend of Mihai's FC-100 belongs to the best (!) designs I have ever seen in the AMP's world
- we had a couple of NJL - ThermalTrak - transistors at hand and wanted to use them on the backend
We offered our layout in a Group-Buy thread, but after some discussion have been asked to prototype
our PCB first before offering it to the community.
I ordered a couple of professionally etched prototype PCBs and ZSAUDIO and I built the prototypes.
http://www.abload.de/img/fc-100nduq1.jpg
The result:
An absolutely "rock-stable" amplifier playing at its best.
Two comments about its sound-quality:
by ZDR (who did his own layout):
"Well, I am done now. I just have one little problem - how do I stop those little hairs on the back of my neck from standing
up while this baby is playing?"
by ZSAUDIO:
"All of you guys who plan to build this amp just do it. The PCB what Rudi and Metal offer is an art."
I had a problem related to my own build though.
The typcial forward voltage drop of the integrated TT - diodes of my charge of NJL-transistors was higher than of Mihai's transistors,
and I was not able to activate 5 diodes in the TEMPCO - string.
Thanks to a sudden inspiration of FranzM. I bypassed one TT - diode by an external SCHOTTKY diode and fixed my own problem.
Since then I have been able to listen to the beautiful sound of the FC-100.
My "Prototype - Experiences" are documented in this thread:
http://www.diyaudio.com/forums/solid-state/202047-roenders-fc-100-prototype-builders-thread.html
I have incorporated ZSAUDIO's and my own experiences and your requests into the Revision 1 of the FC-100 PCB
and will offer you in this group-buy:
- the FC-100 Rev.1 PCB:
http://www.abload.de/img/fc_100_gerbv91ybk.png
The PCB includes the Frontend, the Backend and a complete, high-quality Backend - PSU.
Its size is 245 x 74 mm.
For those of you who plan to use your own PSU, reservoirs CAPs, etc..., I have inserted a pre-determined breaking line on the PCB.
The quality of this PCB is the best that you can imagine:
- 2 mm thick FR4 PCB, double-sided, 70µm copper traces covered with Gold immersion, soldermask, silkscreen, ...
Its price will be 15€.
- Mihai's FrontEnd Shunt-PSU:
http://www.abload.de/img/fc-shuntagytp.png
Its size is 76 x 74 mm; its price will be 8€.
- whatever you like to have to "make this group-buy complete", for example:
Futaba 0R1 / 5W emitter resistors, MKP 1839 / 1µF capacitor, input capacitor, Speaker Protect PCB, Soft-Power-On PCB, ...
One of the pre-requisites to make this AMP a real success is to match certain transistors: the input differential pair,
the output- and pre-output drivers, LEDs, ...
I am currently thinking about designing a "Transistor-Matching-PCB" (if you would like to have).
I will leave this group-buy open, until all of your questions have been answered (but will terminate it on April, 15th at least).
I feel a little bit sad, right now.
Mihai's FC-100 is beating my current favourite DIY - AMP, the TO3-SYMASYM.
This is the best-sounding DIY amplifier I have come across so far.
Will there be any AMP - PCB that I will be going to offer you in the future?
Find the current order list below.
Feel free (you would be a fool if not) and join this group-buy.
Best regards - Rudi_Ratlos
Attachments
Last edited:
Patrick,
the main differences are:
- 4 reservoir CAPs (instead of 2)
- filter and space for bigger heatsinks in the backend PSU - section
- bigger solder PADs for the emitter-resistors
- each TT - diode can be jumpered individually
I did not change anything regarding the frontend- or backend - section of the AMP.
Best regards - Rudi
the main differences are:
- 4 reservoir CAPs (instead of 2)
- filter and space for bigger heatsinks in the backend PSU - section
- bigger solder PADs for the emitter-resistors
- each TT - diode can be jumpered individually
I did not change anything regarding the frontend- or backend - section of the AMP.
Best regards - Rudi
Francis,
if you want to: I will order NJL0302DG / NJL0281DG from MOUSER or FARNELL or ...
In the original thread Mihai recommends to closely match the output-transistors (hFE and VBe).
I had a dozen of each of the transistors and the Hfe varied from 91 to 117 (for the NJL0281DG, f.e.).
But I found 2 closely matched triples of each.
I will contact ZSAUDIO and ask him for his experience.
Then I know what I can offer you.
Patrick: I have 4 0R22 resistors left.
Best regards - Rudi_Ratlos
if you want to: I will order NJL0302DG / NJL0281DG from MOUSER or FARNELL or ...
In the original thread Mihai recommends to closely match the output-transistors (hFE and VBe).
I had a dozen of each of the transistors and the Hfe varied from 91 to 117 (for the NJL0281DG, f.e.).
But I found 2 closely matched triples of each.
I will contact ZSAUDIO and ask him for his experience.
Then I know what I can offer you.
Patrick: I have 4 0R22 resistors left.
Best regards - Rudi_Ratlos
Attachments
Would someone be interested in doing a GB of transistors, match them and sell them matched.
Since this is lots of work, I'm 110% ok to pay more since there is time involved doing the matches.
I'm not getting lazy but I've been matching non-stop for Aleph X and JX and I'm getting tired...
That would be very sweet!
Ciao!
Do
Since this is lots of work, I'm 110% ok to pay more since there is time involved doing the matches.
I'm not getting lazy but I've been matching non-stop for Aleph X and JX and I'm getting tired...
That would be very sweet!
Ciao!
Do
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