May 17, 201610 yr My progress I ordered a toroid with 360X2 @350mA but I don´t know what I can do. With this trafo, a 400 vol output is a overkill? I would like use a 20mA configuration on amp.
May 17, 201610 yr Author Nice work Jose. IIRC, the dropout voltage on this regulator is about 9 VDC for my 400 VDC setup. With a 360vac secondaries you should be able to get reliable 450 VDC regulated output without issue accounting for mains fluctuation. I believe Kerry has a related post on this matter here in this thread. Edited May 17, 201610 yr by mwl168
May 18, 201610 yr Thanks mwl168. I was wrong because I saw the pcb layout and ordered a 360 Volt trafo for 400VDC Well If I use 450 VDC PSU (All I need is change four resistors on de the PSU and it's easy), Need I change something on amp boards?
May 18, 201610 yr Author 45 minutes ago, jose said: Thanks mwl168. I was wrong because I saw the pcb layout and ordered a 360 Volt trafo for 400VDC Well If I use 450 VDC PSU (All I need is change four resistors on de the PSU and it's easy), Need I change something on amp boards? I cannot tell for sure from the photos you posted but make sure your pre and post regulation filter caps are up to spec. Looks like they are all 550VDC rated? I took a quick look at the Carbon amp board and I cannot think of anything you need to change going from 400 VDC rails to 450 VDC. Others might chime in if they spot someting. By the way, on my setup, I can barely feel a temperature on the PSU heatsinks after hours of running my Carbon with 20mA output setting (I think my trafo has 330 vac secondaries). The amp heatsinks are a different story, they run VERY HOT, much more so than the KGSSHV. That's another thing to keep an eye on. Edited May 18, 201610 yr by mwl168
May 18, 201610 yr 21 minutes ago, mwl168 said: I cannot tell for sure from the photos you posted but make sure your pre and post regulation filter caps are up to spec. Looks like they are all 550VDC rated? I took a quick look at the Carbon amp board and I cannot think of anything you need to change going from 400 VDC rails to 450 VDC. Others might chime in if they spot someting. By the way, on my setup, I can barely feel a temperature on the PSU heatsinks after hours of running my Carbon with 20mA output setting (I think my trafo has 330 vac secondaries). The amp heatsinks are a different story, they run VERY HOT, much more so than the KGSSHV. That's another thing to keep an eye on. Thanks. Yes, all caps are 680uF/550VDC.
May 21, 201610 yr Well done jose. I was going to post these images in the builds thread but it’s missing in action. Thanks to Kevin and Birgir for being awesome. Thanks to Michael (mw168) for all the work you’ve put in with the group buys and documenting etc it’s been very helpful. A couple KGSSHV Carbon amps running 400V @ 20ma, GRLV supplies, SUMR transformers.
May 21, 201610 yr What a lovely build you have there, and so very compact too. Those offset trimpot adjusters look interestingly positioned.
May 21, 201610 yr Thanks guys! As to the sound, I’ve had a fairly good listen now, I can confidently say It’s a good improvement in performance from the KGSSHV’s and BHSE I have on hand. I’ve always maintained the BHSE and KGSSHV were a similar calibre, with different signatures depending on your taste and music genre. Interestingly I find myself in the same scenario with the Carbon and the T2, I don’t prefer one over the other, both have slight contrasting differences. To be crude and simplistic, the Carbon has transparency and the T2 sweetness and tone, but both amps do everything exceptionally well. The Carbon is unquestionably the most stable amp in my arsenal, do we need servos on the next board runs?
May 22, 201610 yr The highest reading I‘ve had on start up is around 15V and this quickly settles, I will try the servos at some stage to see if how they perform.
May 22, 201610 yr Yeah, the servos really aren't needed from my experience as well - it is super stable from the get go and settles very quickly.
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