F4 running on two SMPS300RAh -/+23V from connexelectronic (soft start already built in). One unit per channel.
200mV bias. None of the electronic components (both smps nor transistors) exceeding 50 degrees (celcius) in 5U/300mm chassis.
I will compare it to traditional transformer + caps sometime soon ... but so far I have no motivation, because it sounds amazing! The sound integration and continuity is just phenomenal. Especially different bass layers and top end!
It is driven by 2xad1865 dac (transformer I/V out) directly. No additional gain needed for my needs on TQWT MKIII speakers.
200mV bias. None of the electronic components (both smps nor transistors) exceeding 50 degrees (celcius) in 5U/300mm chassis.
I will compare it to traditional transformer + caps sometime soon ... but so far I have no motivation, because it sounds amazing! The sound integration and continuity is just phenomenal. Especially different bass layers and top end!
It is driven by 2xad1865 dac (transformer I/V out) directly. No additional gain needed for my needs on TQWT MKIII speakers.
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Great work! IMHO, it just doesn't get better than this with SS amplification.
Really nice build! Congrats!
Mpc74 resistors are also very nice, I wonder whether it has been a challenge to measure the bias of individual mosfets as the reaiators sit very close to pcb?
Bad news
Although those SMPS were designed for continuous current of Class A amps, after couple of days of playback one of the SMPS failed
Fortunately they are -/+, so both rails at the same time. Nothing happened to F4 Module nor to my speakers.No I got my motivation to go with traditional approach: transformer and caps
On the other hand those units are very good. I used them with success and no issue with many Class AB amps. Either I had bad luck and received faulty one this time or F4 is simply too power demanding for them, especially @ 200mV bias.
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why these
May I ask what the differences are between the MPC71 and, say, vishay dale RN / CMF resistor?
I already got that they're metal plate compared to metal film, but what could I conclude from that?
Thank you
david
May I ask what the differences are between the MPC71 and, say, vishay dale RN / CMF resistor?
I already got that they're metal plate compared to metal film, but what could I conclude from that?
Thank you
david
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I got my f4 up n running this evening. So, again, thanks to all who chipped in. Many thanks.
I got my diodes changed. Jim, you were right, no other damage.
I'm running at 175mv and it sounds breathtaking. I mean, like, whaaaaaat!
Plàyed 2 LP's. An acoustic guitar and single voice and DSOTM.
S#@T MAN, this thing is nuts, a big leap in imaging compared to the F5. Just fantastic. I'm going to bed, I feel like a kid at Christmas. I can't wait to get up and play records all day.
I got my diodes changed. Jim, you were right, no other damage.
I'm running at 175mv and it sounds breathtaking. I mean, like, whaaaaaat!
Plàyed 2 LP's. An acoustic guitar and single voice and DSOTM.
S#@T MAN, this thing is nuts, a big leap in imaging compared to the F5. Just fantastic. I'm going to bed, I feel like a kid at Christmas. I can't wait to get up and play records all day.