[ColSaulTigh]

Voltage sag isn't really a thing in class A amplifiers. The B+ voltage will be lower due to the higher voltage drop of the rectifier, so the operating points of the tubes will change, but this is not significantly detrimental, you might see a marginally higher output impedance. Using a higher Vdrop rectifier will add more resistance to the power supply, which is really only a problem in amplifiers that have a variable DC current draw, i.e., class AB amplifiers. In class A, the current draw is constant, so the voltage drop is constant, so the operating points are steady state as opposed to being variable. This variable operating point in class AB amplifiers is what is referred to as "sag". In these types of amplifiers, it is a design goal to have a relatively "stiff" power supply, meaning a low resistance supply such that the voltage drop across it will not significantly change with variable DC current draw. But again, not an issue in single ended class A tube headphone amps where the current draw is constant.

I explained it in more detail here: https://www.head-fi.org/threads/hea...t-for-all-300b-tube-amps.962932/post-17193287

Thank you @L0rdGwyn ! As always, we can count on your vast knowledge of application that far exceeds mine. I appreciate your chiming on on this.

 

[TheMiddleSky]

I'm hardly an expert on the Caldera. I had a loaner and had finished burning it in when medical issues started messing with my hearing, so I didn't fully explore its sound. But I do own and love my silkwood VO and did compare the two, however briefly.

I don't hear anything in the upper mids/lower treble of the VO that sounds piercing or has a metallic feel (have heard it on 2-3 different DACs and at least a dozen amps). I also don't hear the "midrange recession" that has been mentioned many times in connection with the VO.

From day-1 I found the VO to be unusually expressive and musical tonally/timbrally, IMO its greatest strength. I just don't hear significant deviations from sonic reality with this headphone. In fact, I keep coming back to it to tell me the "absolute truth" about any amp or recording I'm getting to know.

One of these days I'll do more Caldera listening and finish comparing it to not just the VO, but also the Final D8000 (that was the comparison I most looked forward to). But I just had to put in my 2 cents on the VO...

Well, I do still love my VO too. The metallic feel I explained before not always apparent in every songs, but sometime they appear (usually in cymbal area). Fortunately, it's not offensive or create fatigue/pressure. It's there when I do critical listening, but only in "slight" amount. While in Caldera, these area for me is very liquid smooth. YMMV of course, depend on the set up, songs, and our ears anatomy.

Agree that "Expressive" is a total correct word to describe Verite!

 

[betula]

I will have an opportunity to audition both the Atrium and Caldera in January. I am very excited to find out how my expectations will meet reality. I developed a rather strong idea about their sound based on the many impressions and references in this thread. From ZMF I only heard the Atticus, Eikon, Aeolus and Verité open so far.

 

[Since1991]

I hope everybody is having a great day, because I definitely am.

 

[aloki]

I hope everybody is having a great day, because I definitely am.

I certainly am as well! Caldera Kingwoods arrived yesterday.

I am so blown away by how comfortable the suede headband is. They feel so well distributed on my head. They aren’t light enough to ever feel like “they are not there,” but certainly enough to wear for hours.

With listening thus far, I am so blown away by how far the bass extends and how effortless the music sounds. I haven’t compared to Atrium or Verites yet, but I am already in love with these. I can definitely see why people are saying the Verite is the in between of the Atrium and the Caldera.

 

[robo24]

I hope everybody is having a great day, because I definitely am.

Congrats! I hope you'll be able to share impressions compared to the other planar big boys like the Susvara and TC, and if you find a Glenn tube combo which works well with the Caldera. I have the TC coming in a few weeks myself.

 

[cdanguyen08]

And if you prefer your whiskey with an “e” (i.e., American made):



This isn’t a great pic, but the Calderas are killer on my solid state setup. I’m amazed every single time I put them on.

As someone getting into Bourbon myself, I absolutely love this photo.

 

[cdanguyen08]

Before i post my initial impression of the Caldera, I would like to ask if anyone here powers their caldera with a GSX mini? This amp gave me a completely unexpected sound signature with the caldera. Please share any info regarding this setup.

I'm running it off a gsx mini and so far have been very pleased. I have nothing to compare it to though as I'm still waiting on my custom SET amp from Mischa.

 

[dfiled]

I’ve A/B’d my calderas off my ovation v2 and GS-X mini. Surprisingly the difference is not dramatic to my ears. I don’t have golden ears.

 

[WillieB]

Lol. I'm wondering if the Elrogs will have a more SS sound in the HA-300mkii. I'm trying triangulate the sound based on what people have said. The Gold Lions sound great with the Caldera and HA-300. Lots of heft and detail. Western Electric vs Elrogs? Anyone done an high roller, tube roller comparison?

Caldera loves the HA-300 tho. Big thumbs up on that.

There is a thread here, and yes, there are tons of comparison and a lot of discussion about the Elrog. The Elrog doesn't show up until quite a few pages in, I think, but you can search around in there.

https://www.head-fi.org/threads/headphone-tube-amps-the-hunt-for-all-300b-tube-amps.962932/page-118

PS - sorry if someone already answered and this is redundant. I've been away from the thread and playing catch-up.

 

[WillieB]

I’ve A/B’d my calderas off my ovation v2 and GS-X mini. Surprisingly the difference is not dramatic to my ears. I don’t have golden ears.

Interesting that the Ovation does so well with the Caldera, but can't say that I'm surprised. A&S amps always seem to exceed expectations. The Ovation is a tone monster from what I hear.

 

[dfiled]

Interesting that the Ovation does so well with the Caldera, but can't say that I'm surprised. A&S amps always seem to exceed expectations. The Ovation is a tone monster from what I hear.

Yeah, I was concerned it would be underpowered for the caldera, but I needn’t have worried.

 

[jlbrach]

As someone getting into Bourbon myself, I absolutely love this photo.

I can attest to the fact that all HP's sound better after a couple of glasses of bourbon

 

[shafat777]

I have a GSX MK ii and it really seemed to turn the Caldera into a very neutral, fast and technical headphone. A bit higher impedance and/or other solid states like the Wells make them more girthy and beefy.

I agree completely zach. Whenever i get a new headphone (zmf or other) I try them on my GSX mini first just to get a feel for their actual sound. Tube amps tend to add color to the sound signature and although i prefer it like that, I still crave the uncolored sound from time to time. I did exactly that when my got the caldera. Using XLR balanced input/output of my Yggdrasil dac and the GSX mini, I tried listening to my caldera and the sound signature was not what i was expecting. The caldera sounded dynamic, fast, extremely music, but it lacked thickness in the notes. Bass was there but it lacked any weight behind it. Male vocal sounded crisp and clean but it was not very deep. Overall presentation was great and it provided a fairly decent sound stage but the low end was something that needed an adjustment.

It was not until later when i plugged in my caldera to my HA6A, that i realized just how sterile sounding the gsx minim was. Plz dont get me wrong, the mini is a great amp, it powers and plays great with just about every headphone is my collection (planar or dynamics alike). I was almost convinced that the caldera lacked bass and low end punch had i not tried it with my tube amp. I even hooked i up to my Elise OTL and although it sounded much warmer than the mini, the low end slam was all there. Not sure if breaking in the caldera will help it find synergy with the mini but for now, i will be using the HA6A exclusively with my caldera.

 

[zach915m]

I agree completely zach. Whenever i get a new headphone (zmf or other) I try them on my GSX mini first just to get a feel for their actual sound. Tube amps tend to add color to the sound signature and although i prefer it like that, I still crave the uncolored sound from time to time. I did exactly that when my got the caldera. Using XLR balanced input/output of my Yggdrasil dac and the GSX mini, I tried listening to my caldera and the sound signature was not what i was expecting. The caldera sounded dynamic, fast, extremely music, but it lacked thickness in the notes. Bass was there but it lacked any weight behind it. Male vocal sounded crisp and clean but it was not very deep. Overall presentation was great and it provided a fairly decent sound stage but the low end was something that needed an adjustment.

It was not until later when i plugged in my caldera to my HA6A, that i realized just how sterile sounding the gsx minim was. Plz dont get me wrong, the mini is a great amp, it powers and plays great with just about every headphone is my collection (planar or dynamics alike). I was almost convinced that the caldera lacked bass and low end punch had i not tried it with my tube amp. I even hooked i up to my Elise OTL and although it sounded much warmer than the mini, the low end slam was all there. Not sure if breaking in the caldera will help it find synergy with the mini but for now, i will be using the HA6A exclusively with my caldera.

Out of all the solid states I have the two most dry and zesty with Caldera are the GSX and the Schiit Asgaard. Ones that have more heft and liquidity are the a Cayin iha, wells milo, Ecp Ravenswood and JDS Element. It's probably partially the damping factor and the design of the amps, but the Caldera will vary quite a bit within solid state amps not just with tubes.