[UntilThen]

Dracula might sound too real. So instead I’m listening to Bob Dylan sing Knocking on Heaven’s Door.

Guess what... that’s the best rendition of the song.

 

[leftside]

I guess the Oblivion doesn't sound as dark as this Oblivion

 

[baronbeehive]

Try watching a well mixed horror movie with Sonic's amp and headphones. It's a unique experience.

Not sure I want to... Zombies... aaghhh, thanks anyway! But here's another horror story, it has just dawned on me why your horizontal load lines look odd. Surely the 2 points to draw it from are from 0 V (18mA) which is the max desired bias current through the tube with the 500k load, and 0 I at B+ (300V). In which case the load line cannot be horizontal... devilish laughter.. ha.. ha.. ha...

Nice pics Sonic!

 

[MrCurwen]

The load in question is an active load, it not just resistive. So it can actively keep delivering current (the 18mA) even as Va approaches B+.

So it is drawn just as I did. That is also how it behaves in reality.

A passive component, be it a real resistor or a coil that is assumed / approximated as a resistive load, cannot do that.

 

[UntilThen]

I guess the Oblivion doesn't sound as dark as this Oblivion

I’ll try that when the broadband connection comes on. One moment bush fires, another day hail and thunderstorms, the weather here can be a challenge.

Fortunately I also have a hard drive of songs.

 

[baronbeehive]

I’ll try that when the broadband connection comes on. One moment bush fires, another day hail and thunderstorms, the weather here can be a challenge.

The fires there are a daily news item here, god knows what it's like there, record temperatures and such like. We seem to be having floods a lot more here, rain almost daily since autumn. I don't suppose that's what you want to hear though.

Maybe things will change for the better soon. There was a news item yesterday that in parts that have been devastated by the fires new green shoots are appearing!

 

[UntilThen]

Next I'll build @joseph69 Citadel. The chassis is supposed to be delivered next week.

Share pictures of the build along the way.

 

[wasupdog]

I have a system which is on the cool sounding side but I wouldn’t say it’s bright or warm. Tidal is streaming from my MacBook Pro into a Gumby A2 and a Citadel. It can veer towards bright or warm depending on the recording. The Citadel will give some kicking bass if it exists in the recording but it doesn’t exaggerate what’s not there.

The Citadel is on par with other near TOTL amps I’ve owned. There’s some give or take on all of them but if you’re looking at a specialty amp like this you probably have some idea of what you like and what sound you’re looking for.

My preference isn’t for tube amps in particular but if I was running one as my main rig it would be this one. You have all of the quickness, punch and speed of solid state amps but there’s some lushness to the sound to remind you there are tubes in the chain. It’s the best of both worlds implemented into a tube hybrid. I’m not detecting any perceivable loss at the frequency extremes which is my pet peeve with tube amps.

Denon AD-D9200
This is a great pairing although the headphones on their own are really good. This is one of the headphones out there that are tonally correct out of the box with no major spikes or dips throughout the range. Verum One is another. The tubes are a great in combination with the cellulose drivers. If I was demoing this blind I might believe it if you told me this was an open back planar.

The 9200 scale appropriately and are improved in all areas. Punchy sound. Imaging is impressive the way the Citadel improves transient sounds in space on the 9200. The 9200 is not quite pin prick the way Utopias can throw up tactile imaging but now it’s close without the treble spike.

I ran these on low impedance and can barely hear some low tube noise with no sound playing. The 9200 are quite sensitive, as in you can run them straight off of an iPhone and still sound good sensitive.

Abyss Phi CC
Excellent separation, soundstage and texture. It’s like you’re taking what Abyss already does well and adding on top of it. This is where sound starts to get real. On acoustic guitars you can hear the pick scratching against the strings. High transparency into the recording.

This pairing has a holographic sound that I only recall hearing before on setups like the Orpheus demo and WA-33/WA-33 Elite with Abyss Phi and Susvara demo.

The Citadel doesn’t break a sweat running this on low impedance mode but the Phi are more sensitive than the OG. Remember that the Citadel has more power than the Oblivion.

Cayin HA-300
This one has the classic 300B tube sound that imparts a big glowing sound to everything you listen to. As appealing and romantic as it is I don’t crave this sound for my main rig and find the Citadel superior in technicalities. Soundstage on the Citadel is more correct. The HA-300 is more ball shaped. A great amp with dynamic driver phones if you want the 300B sound.

XI Audio Formula S
I really like this amp and I don’t know of any other headphone amps that use an r-core transformer. Light, fast and airy sounding. The Citadel retains the speed of the Formula S but with a smoother feel on top. The harder feel I would characterize on solid state amps in general. I don’t think the sound signatures are quite the same but I suppose they could be similar if you took the Formula S and inserted a tube stage in the front end.

More to come later once I have more time and figure out the cable situation with some of my other headphones. My only regret with the amp is that I should have had Tomas build this with a 1/4” headphone jack on the side!

 

[wasupdog]

Pics or it didn't happen!

 

[SonicTrance]

The Citadel is on par with other near TOTL amps I’ve owned.

Thanks for the impressions! I'm very glad you like it!
I'm wondering if you use the RCA or XLR inputs? Citadel will sound cleaner with XLR inputs and also have more gain! Something to experiment with.

 

[UntilThen]

Even though the sonic differences between Citadel and Oblivion are described on the website, I wonder how immediately noticeable they are with the 2 amps side by side for a comparison. It does seem that both still have that tube tone but with varying degrees.

There will be many who will like this sound signature because it's a high fidelity sound. I know I do. When you go to a HiFi Show, high fidelity sound is what you expect to hear. I'm not particularly fond of a setup with over emphasised bass. The bass on Oblivion isn't light either. It's in the right proposition. There are times with certain songs, I marvel at the bass dished out from the HD800, a headphone that is not noted for it's bass. With a high quality recording of a song, it is immensely enjoyable. With these amps, you would want to try as many headphones as possible. I agree with the addition of the 1/4 inch headphone out together with the xlr balanced out, it would have been more convenient.

Back in Sydney for the 3 days long weekend for Australia Day, I am missing my main headphone rig even though I have my stereo here.

 

[UntilThen]

My picture on the following link is gathering more and more likes. They must be wondering what is that amp on the top of the rack. Looks like Starship Enterprise.

Post #24717

 

[joseph69]

Does anyone own either the Oblivion or Citadel as well as the GS-X mk2?
If so, do they share a good amount of similarities? I'm asking because I find more than a few some impressions reminding me of my GS-X mk2.

 

[cskippy]

I don't see the connection between Oblivion and GSX mk2. Maybe speed and technicalities but treble on GSX mk2 has an etched grating quality to it where there is said to be just beautiful smooth treble on Oblivion. They might share a general neutral to bright trend in sound although I bet GSX mk2 is brighter.

 

[joseph69]

I don't see the connection between Oblivion and GSX mk2. Maybe speed and technicalities but treble on GSX mk2 has an etched grating quality to it where there is said to be just beautiful smooth treble on Oblivion. although I bet GSX mk2 isThey might share a general neutral to bright trend in sound brighter.

The similarities you've mentioned above are what I'm referring too. As for the treble, this is dependent on your headphones and upstream gear.