[Arlekiin]

Hello,

So I got a new DIY amp which is loosely based on the Morgan Jones amplifier but uses Svetlana tubes and has several modifications to improve the Powersupply and completely kill any kind of buzz. It has been built by someone working who has been building tube-amps for few decades.

HeadWize - Project: The 6N1P OTL Headphone Amplifier by Bruce Bender

Supposedly its modified so hard it cant even be called this but this is all I can say rightnow, ill get deeper into it later on...

I will add pictures during the day but the main question I have is...

Is it normal for a brand new tube amp (~20h playtime) to sound glorious and terrible at the same time?

It sounds very rich but at times it seems it has hard time coping with the bass and it starts to tremble if it is a correct term.
But then again certain tracks sound clorious but "Smashing Pumpkins: Disarm" sounded terrible.
Jethro Tull Acres Wild sounded clorious in the other hand.
Wierd thing is in Massive Attacks: Angel the bass extends beyoyond belief.

Right now it seems that it has hart time if the song has complex structure which combines deep bass and high treble at the same time...but then again I have no Idea what it is I am talking about.

Got to listen more to understand....i read some amps take ~400h to burn in properly? I got it for a day to listen it and decide if im gonna buy it

 

[Arlekiin]

Also there is this wierd sensation of my ears humming and its not the amp humm (even at very low volumes) and being somewhat disoriented by the soundscape...
I wonder if he accidentally discovered a way to hack into human brain? Or maybe its deliberate :S

 

[audiowize]

That amp has 500uf of capacitance at the output, so you have to consider that you likely have a $2-3 electrolytic there.

As for the hum, try listening with one headphone driver off one ear, then the other. The schematic calls for a DC supply for the tubes, but there isn't a voltage reference. Also, there is one triode per channel sitting up at +175v on the cathodes. To build the best possible tube headphone amp, that triode and the same triode in the other channel should be in the same envelope, with a separate DC supply biased up at 200v. The other two triodes per channel should be on their own supply with no DC bias or a little bit of positive DC bias (40-70v). The effect of having high heater to cathode voltage in the positive direction can be noise that will come across as unusual hum.