Never mind, I already designed compact version of mine
I already built this amp 7 years ago, with home made single sided PCBs. Now I think it deserves something better
Comments welcome
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@ZDR:
I do not remember that I have shared my FC-100 frontend-PSU - shown below and being based on the LT3062 CPU - with Pinnocchio.
The reason, why I did not share: my eyes are growing old and I am not able to solder a LT3062 IC.
I believe that most of you are not able to solder either.
But: I have a young German DIY-friend, who has the eyes of an eagle and who soldered 2 of the LT3062 PCBs - one of them is shown below.
The LT3062 works perfectly for small current / "high voltage" frontend PSUs.
Best regards - Rudi_Ratlos
I do not remember that I have shared my FC-100 frontend-PSU - shown below and being based on the LT3062 CPU - with Pinnocchio.
The reason, why I did not share: my eyes are growing old and I am not able to solder a LT3062 IC.
I believe that most of you are not able to solder either.
But: I have a young German DIY-friend, who has the eyes of an eagle and who soldered 2 of the LT3062 PCBs - one of them is shown below.
The LT3062 works perfectly for small current / "high voltage" frontend PSUs.
Best regards - Rudi_Ratlos
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After soldering few AT32UC3A3256 with 0.5mm pitch, this 0.65mm is a piece of cake
My eyes do need glasses AND a magnifier though. It's the steady hand you cannot replace.I definitely plan to use LT3062, my PCBs are almost ready. It's a space and power saver.
Hi Rudi
,If you are still able to drink a very well filled glass of beer without loosing a drop of beer, you should be still able to solder : your hands are steady enough
.For your eyes, there are solutions : look at Andonstar ADSM302, ADSM201 : that's a solution to eyes problems, a not so pricey one (between 130€ and 200€ in Germany) ... That's my way with my old eyes
!Best regards
rephil
rephil: like pinnocchio I prefer a (a couple of) Whiskey(s) (my current favourite is Irish Jameson).
In case you want to prove / demonstrate your soldering skills, I will send you the PCB shown below.
The PCB contains a QFN-20 case (TPS7A4700 adjustable LDO voltage regulator, up to 20V, very low noise, can be jumpered as +/- voltage PSU)
and the MSOP-8 LT3062 adjustable (up to 40V) LDO voltage Regulator (which can be jumpered as +/- voltage PSU as well).
But I have one request / requirement: please solder one PCB for my own needs.
Best regards - Rudi
In case you want to prove / demonstrate your soldering skills, I will send you the PCB shown below.
The PCB contains a QFN-20 case (TPS7A4700 adjustable LDO voltage regulator, up to 20V, very low noise, can be jumpered as +/- voltage PSU)
and the MSOP-8 LT3062 adjustable (up to 40V) LDO voltage Regulator (which can be jumpered as +/- voltage PSU as well).
But I have one request / requirement: please solder one PCB for my own needs.
Best regards - Rudi
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Hi Rudi
,I am sorry, I will not solder your PCBs as I have problems with my hands : I can't play piano anymore
, and often too I can't solder as pain is too big (I can't hold devices in my hands when crisis is there). But I don't surrender : I continue diy-audio ... I am sure you could solder SM using good tools : e.g. member Tinitus wrote he did buy a new solder station (Ersa icon-pico). I did buy it too, and it is a better tool than my very old Weller. It is far easier to solder and much easier to use. A microscope like the Andonstar solves other problems too. There are many video on Youtube about tools like that. I am pretty sure you are still able to solder those PCBs
, well if you limit yourself to drink only very few Whiskeys ...Best regards
rephil
Rudi, I just noticed that LT3062 has rated Vin at +45V and absolute max Vin at +50V. Unloaded 30VAC transformer with filter cap will inject 53V. How did you solve this?
Well, my Gerth trafo is 2x30VAC, the one you had listed on your earlier pcbs. 2x28V is better, but it will still go over the rated 45V if there is no load, will it not?
Both LT3062 withstand 53V without load so far, I haven't loaded it yet nor left it powered on for extended periods of time.
Is there a reason no to use LM317 instead which is rated for 60V and easier on old eyes and hands?
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Hi Rudi, I have just finished this AMP and working well with wonderful sound image , especially at super high frequency . It is much crystal and extent non-limited.
However, I tried reconnect the speaker return from the attached image (in red circuit) SPK RET to the main DC power supply GND. I obtained a less high frequency , but feel H-M-L freq. would more balance.
Can you please share your experience and how should choose the proper SPK RET connection ?
However, I tried reconnect the speaker return from the attached image (in red circuit) SPK RET to the main DC power supply GND. I obtained a less high frequency , but feel H-M-L freq. would more balance.
Can you please share your experience and how should choose the proper SPK RET connection ?
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Same as Mihai (see attached image of Mihai's own prototype) I use the Speaker-Return-connectors position in the "red-circle".
I have connected the "red-circle connectors" position to the Backend Power Connector by means of two AWG12 wires.
To be honest: I do not hear a difference in sound between the "red-circle" position and the position near the Backend Power Connector.
Just use the position that you like more!
Have fun - Rudi_Ratlos
I have connected the "red-circle connectors" position to the Backend Power Connector by means of two AWG12 wires.
To be honest: I do not hear a difference in sound between the "red-circle" position and the position near the Backend Power Connector.
Just use the position that you like more!
Have fun - Rudi_Ratlos
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Hi Rudi
Any chance you can post a larger sized image - can't enlarge this one.
Thanks
Have a look at Mihai's FC-100 thread: RMI-FC100, a single stage audio power amplifier
The image shown above is on its 1st page.
Regards - Rudi_Ratlos
The image shown above is on its 1st page.
Regards - Rudi_Ratlos
Gentlemen, I have been asked by a DIY-friend to give him a pair of FC-100 amplifier PCBs.
I agreed and ordered 10 PCBs - the minimum amount to order.
Image 0 shows my own FC-100 (with an ADDON-PCB on top of the transformers); image 1 shows the topview of the current PCB.
The FC-100 is - at least in my ears - the "absolutely best-sounding DIY-amplifier" to build.
The chief-editor of a German audio magazine even took the FC-100 into his "hall-of-fame" and uses
it - among other amplifiers - to "evaluate" new audio components (image 2, on the right side: Endstufen : DIY FC-100)).
Compared to the previously offered PCBs: there are some "cosmetic track changes", but they do not concern.
The major changes of the current FC-100 revision concern the PSU.
The bridge rectifier - as shown - is a GBUx-type, being directly mounted on the heatsink.
You can easily change it ("But why?") to something like the KBPC1002 or even to a "boutigue LT4320" (LoL).
The second change concerning the PSU is: I will not offer you a PSU shunt as frontend-PSU, but will offer
a dual LT3062 - based frontend-PSU - PCB(see image 3 and 4).
My offer then includes 3 PCBs (2 x FC-100 PCB, 1 x LT3062 dual PSU), unregistered shipping and PAYPAL-fee.
Shipping within the EU-tax -union is 25€, worldwide shipping is 30€.
Please give me a PM, if you are interested to have the FC-100.
I will send you the schematics, BoM, drill-template, ... then .
Best regards - Rudi
I agreed and ordered 10 PCBs - the minimum amount to order.
Image 0 shows my own FC-100 (with an ADDON-PCB on top of the transformers); image 1 shows the topview of the current PCB.
The FC-100 is - at least in my ears - the "absolutely best-sounding DIY-amplifier" to build.
The chief-editor of a German audio magazine even took the FC-100 into his "hall-of-fame" and uses
it - among other amplifiers - to "evaluate" new audio components (image 2, on the right side: Endstufen : DIY FC-100)).
Compared to the previously offered PCBs: there are some "cosmetic track changes", but they do not concern.
The major changes of the current FC-100 revision concern the PSU.
The bridge rectifier - as shown - is a GBUx-type, being directly mounted on the heatsink.
You can easily change it ("But why?") to something like the KBPC1002 or even to a "boutigue LT4320" (LoL).
The second change concerning the PSU is: I will not offer you a PSU shunt as frontend-PSU, but will offer
a dual LT3062 - based frontend-PSU - PCB(see image 3 and 4).
My offer then includes 3 PCBs (2 x FC-100 PCB, 1 x LT3062 dual PSU), unregistered shipping and PAYPAL-fee.
Shipping within the EU-tax -union is 25€, worldwide shipping is 30€.
Please give me a PM, if you are interested to have the FC-100.
I will send you the schematics, BoM, drill-template, ... then .
Best regards - Rudi
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