The all DHT SET Headphone Amp

[Wavebourn]

Originally Posted by ikoflexer

You can't get rid of the cap across the 4k3 resistor if you want the tube to properly amplify the signal. If you want to get rid of that cap you need a stacked supply. Then the 4k3 resistor also disappears. Which also makes the filament bias useless. So, if you want DC coupling then you either to the resistor plus cap, and the filament bias is useless IMHO, or you have a stacked supply, and the filament bias again brings nothing to the table.

Myself, not sure how much of a fan of DC coupling I am... is the effort and complications worth it?

It is exactly how I powered my last version of headphone amp, before the project had been postponed. Except the bottom PS was actually a shunt regulator, in series with upper 2 power supplies.

[iko]

I agree with Anatoliy, I would definitely do that for the bottom supply, make it a really good shunt regulator, to have outstanding low output impedance.

[stajo]

Originally Posted by Wavebourn

It is exactly how I powered my last version of headphone amp, before the project had been postponed. Except the bottom PS was actually a shunt regulator, in series with upper 2 power supplies.

Nicely folded aluplates there Anatoliy. I too is allergic to stupid smallish signal tubes sticking up for no reason and prevent decent stacking.

Nice looking toobs to be shown, the rest can rest.

Staffan

[Wavebourn]

Originally Posted by stajo

Nicely folded aluplates there Anatoliy. I too is allergic to stupid smallish signal tubes sticking up for no reason and prevent decent stacking.

Nice looking toobs to be shown, the rest can rest.

Thank you Stafan.

When I show tubes I always protect them somehow, like transformer box behind, cheeks on sides. Like here, for example:

[stajo]

Originally Posted by Wavebourn

Thank you Stafan.

When I show tubes I always protect them somehow, like transformer box behind, cheeks on sides. Like here, for example:

Well GU50s I would show, if not for the spectacular "pull-out-and-replace-hotties" arrangement. I beleave those were designed for cannons, werent they?

/S

[stajo]

Sorry for OT. I follow the thread. My half nickel is that I am most curious about designs that meets designgoals, not just show excellent figures in relation to nothing (1 Mohm resistor so). Preamps, especially anodefollowers, for example. Most data is useless unless you know what you load it with.

Keep up, interesting thread!
Staffan

[iko]

I think the people currently active in the thread are keen on building a good headphone amp, regardless of design goals. There's a good chance we lack any real engineers though.

[stajo]

Originally Posted by ikoflexer

I think the people currently active in the thread are keen on building a good headphone amp, regardless of design goals. There's a good chance we lack any real engineers though.

Just for the interest. How can you build something that is good if you dont know what good is and what its for?

/Staffan

[Wavebourn]

Originally Posted by stajo

Well GU50s I would show, if not for the spectacular "pull-out-and-replace-hotties" arrangement. I beleave those were designed for cannons, werent they?

For military radio amplifiers. Originally were designed by Telefunken for their army and police.

http://tubedata.milbert.com/sheets/043/l/LS50.pdf

[tinitus]

first time I'm here, and sorry to say, but I'm already totally confused