singlepower supra replica

[fillemon]

that's true, there is no prob,

but what do you think of the remarks ?

[n_maher]

Here's my 2c.

1)i probably need to build the low impedance aikido (i thought i red somewhere the high is better although you have a low impedance headphone : is this correct)

I'd shoot for as low an output impedance as you can. I'm still trying to find output caps for my build.

2)the ouput cap should be 470uf, so scheme on the internet pop up with 47uf.

I'm not sure what you're asking here, perhaps you could link to the particluar schematic?

4)for resistors i would use holco/kiwame cause the dollar euro ratio is so low, and in absolute costs it is not that much

Sounds good, I went with all Kiwames.

5)i would use jj caps in the power supply

Again, that sounds fine to me but really depends on if they work in whatever power supply you're thinking of using.

6)how much difference is there on a tube or ss psu ? i have an old trannie of a el84pp, i could use it maybe.

Hard to say and really depends on what designs you're comparing. Most hard-core folks that I know favor tube-rectified designs as they allow for a gradual rise in B+. With solid state the minute you turn it on you're throwing full everything at a cold tube. If you're up for some learning track down Duncan's Power Supply Designer. That's what my friend used to design my Aikido PS.

7)if the cost price is not that much more, i dare to go for balanced, have to mod the new headphone, but that is not scary

I suggest single ended first. If you hate the sound it'd be a shame to have that much tied up in the amp.

[philodox]

With solid state the minute you turn it on you're throwing full everything at a cold tube.

Is that always the case? Peter is a pretty big tube nut, likes tubes for everything... but he actually prefers solid state rectification. I wonder why.

[JBLoudG20]

Is that always the case? Peter is a pretty big tube nut, likes tubes for everything... but he actually prefers solid state rectification. I wonder why.

Yeah pretty much. Solid state reacts very quickly. It's a complete other manner if throwing full B+ at a cold tube will do anything harmful, but I like tube rectifiers just because I like full tube gear. You can always put the heaters on a separate power switch, to heat the tubes up, then fire B+ when you are good and ready.

[aerius]

Is that always the case? Peter is a pretty big tube nut, likes tubes for everything... but he actually prefers solid state rectification. I wonder why.

Cheaper & easier to build. All you need is a simple CRC filter with big caps and you'll have practically no ripple in the DC.

Tube PSU's have limitations on the size of capacitors which can be used so you generally need to use chokes to get enough smoothing, but then you run into the problem of the damn things hitting resonance and ringing. Chokes also cost a hell of a lot more than resistors.

On the plus side, tube rectifiers give a nice delayed soft turn on, and don't generate as much switching noise as silicon diodes.

[philodox]

I think he does some sort of soft start, but I'm not sure. Practically no ripple sounds like a good thing. I'm pretty sure I cant hear my diodes.

But yeah, I'm sure the 'cheap & easy' part factors in.

[fillemon]

hello,

some remarks;

1) i have seen delay cicuits for the b+, so that after 30 seconds or so, the tube is hot, the b+ goes on, it was full SS. So that could be an option. I know that the advantage of tubes rectification is the slow upcoming b+. Still i thought that giving it a very fine psu would do the extra bit. still the price for that is quite big.

2)okee, we are on the hunt for big output caps, i'm gonna design it for 32 ohm, maybe i'll jump on the grado's, i have so many akg already; time for someting else maybe.

3)well i thought that kiwame didn't had all the values, i will get kiwame for those in the signal path

4)yes i have looked at ducans page lots of time, very nice software indeed.

5)very good remark on the balanced topic: wait and see how the non balanced sounds.

thanx people

oh again two posts while i was typing.

1)very true on the psu thing, you can't put a big cap after a tube in the psu, and indeed chokes are very expensive if you want decent ones.

2)hear your diodes, well that's what they should call: golden ears