you are using fine parts, Nichicon Gold capacitors in inputstage?
Looking forward to hear about your setup when you are finish
I am still working on Kypton C + Slewmaster two🙂
Kim
I'm a little embarrased about the Nichicon audio grades because I don't believe in audiophile components. They cost about the same as the regular Nichicon and the gold color gives me the warm fuzzy feeling inside. 😛
That is quite an experienced answer !
60 V is best for <4R , 70-75v for >4R. SOA can be even better with
typical musical material than a continuous test tone.
I've even paralleled 8R speakers on a channel with no issues @ 72V.
OS
Thanks Os, as I say, the secondary output wires of the 600VA transformers looks much thinner than the 400 Va trannies, about 2.5 mmsq against about 1mmsq. I suppose the voltage will will drop under more than normal load. I will give it a go for a complete dual mono setup.
I doubt you will see a voltage drop from thinner wires. The main thing to watch for is the wires over heating if there is too much current demand. Thinner wires may indicate that the VA rating is exaggerated. If that is the case you may see voltage drop due to low current handling.
Actually I read from somewhere that strip off those caps will sound better, 47Lab did that on their famous Gaincard
As we speak my 5 pair Njw1302/3281 +-79vdc are driving a 4ohm load...have been for months with no problems. I do have large heatsinks. The outputs run about 40c normal listening....never checked the temp when they are working hard.
When choosing electrolytic caps I definitely consider life expectancy and temperature rating.
Thanks guy's , I think I'm going to stick with the 50V trannies. One last question. Is a dual mono power supply really so much better than single transformer supplying two boards soundwise ?
I built mine as dual mono using two 625va 55v trannies and two 88kuF cap banks. I believe that the stereo separation is better (wider soundstage) then with the Honey Badger with a single 800va transformer for both channels. This might just be in my head expecting better separations with dual psu or maybe the slew has better separation then the HB with both single and dual psu.
Anyway, dual mono looks cool and give me peace of mind. The downside is that the psu take up extra space and that moving the amp kills my back.
Anyway, dual mono looks cool and give me peace of mind. The downside is that the psu take up extra space and that moving the amp kills my back.
Dual supplies make it easier to eliminate ground lòops. If you use 2 loop breakers and keep both channels isolated there won't be any possibility of a loop if signal grounds are connected in other equipment connected to your amp.
hellow
I am compiling parts availability status for the o/p board .
1. Can Q107 and 108 (MJE15032/33) be replaced with MJE15034/35 ?
Only difference I see is the Ic is lower (4 A vs 8A). Voltage is higher (350 Vs 250), HFE (100 VS 50).
2. Also for 5P, can MJE15034/35 combo work or we have go for NJW's?
3. Upto what voltage or pairs, I can use Onsemi MJE15030/31 for Q107/108 or cant be used at all.
I am compiling parts availability status for the o/p board .
1. Can Q107 and 108 (MJE15032/33) be replaced with MJE15034/35 ?
Only difference I see is the Ic is lower (4 A vs 8A). Voltage is higher (350 Vs 250), HFE (100 VS 50).
2. Also for 5P, can MJE15034/35 combo work or we have go for NJW's?
3. Upto what voltage or pairs, I can use Onsemi MJE15030/31 for Q107/108 or cant be used at all.
Hello! maybe someone to design MiniOPS on two pairs of output transistors 2SJ162 and 2SK1058 Regards
There is a 'Mini' version already using one pair LMOSFET. The reason I went with only one pair was to avoid matching devices that would be needed to use multiple pairs.
Other solution is to use Double die transistors as alfet alf16N/alf16P or Exicon equivalent. But they have wider package (To264) and need biasing revision as they have 2 die in one package. Advantage : they only need one package place on pcb per rail and there is no matching process needed.
Marc
