My FO v1.4
Hello, here is my iteration of the 1.4. It uses two 550va EI transformers and is dual mono. I'm a relative newbie but the highs are clear and detailed. I can hear snapping where it used to be very faint. The mids are full and smooth and the bass is tight and impactful. It's been completed for two weeks now and I just wanted to let it break in. It is a very good amplifier considering everything cost me les than 500 dollars!
Hello, here is my iteration of the 1.4. It uses two 550va EI transformers and is dual mono. I'm a relative newbie but the highs are clear and detailed. I can hear snapping where it used to be very faint. The mids are full and smooth and the bass is tight and impactful. It's been completed for two weeks now and I just wanted to let it break in. It is a very good amplifier considering everything cost me les than 500 dollars!
Attachments
Last edited:
Err, tried this but got onto a forum and "Product" sends me back to the home page and from there I ran in loop and got nowhere.
Can't see the products and the prices, but Sami (Cresnet) has been nice enough to send me some info.
Would be nice to see prices, options (does it come with or without the 6800 caps...) and perhaps also performance with 30 and 50Hz delivery (the graphs I have are for higher frequencies).
Also, is it planned to send some of these smps to LC for evaluation to see how they perform vs the recommanded Hypex?
All very interesting, especialy as the Hypex SMPS are quite expensive IMHO, although clearly good performer, so would be nice to see how these perform with FO 1.4
Claude
Apologies. I forgot I contacted him directly. I think there was a poster that did evaluate them. It is a few pages back if I recall correctly.
Agree maxlorenz that is a very nice build and what a serious 😀 cascaded bank of batteries plus filters, also interesting to see the modules are mounted shielded, thanks sharing.
What is your DC voltage?
Perhaps LC could comment about minimum capacitance recommended per rail en per DCV when dealing with linear PSs ... 🙂
Regards,
M.
The rail voltages are +-51. I increased the bias to 330mA to compensate for the lower voltage. It seems to be working rather well and I cannot imagine how dual smps would make it sound any better.
Last edited:
I have a trick for linear PS that I use in all my best amps...but lets hear what LC recommends as a minimum capacitance for 50VDC...
Is it necessary to re calibrate the FO module? as its already calibrated?
Mine is showing something strange
Mine is showing something strange
Thank you M.
I tried mains wiring underneath the SMPS L shaped heatsinks as you recommended. Then the hum is almost gone.
I will re-wire all cables more carefully when I assemble in new chassis.
Cheers,
Sean
There are two LEDs on the FO, when I disconnet the power supply, the + LED goes off eariler than the - LED.
Thats why I asked if I have to re calibrate it or not, but I am now working on re calibration.
Regards
Great. Good luck.
To Cresnet,
It is remarkable that we still depend on caps' "quality", even with well designed PS. I have talked previously about my experience with connex SMPS: sub-par in stock way (thought, admittedly without burn-in) it performs without regrets sound-wise after paralleling output caps with big Wima 1uF film caps. I did not take measurements...
My preferred electrolytics are Rubycon ZL, followed by Panasonic FM, but I don't know if the are suitable 65VDC types.
Cheers,
M.