[AllanS]

Any thoughts on Woo Audio WA-22 2nd Gen HP Amp as a speaker amp pre?
I've had an eye out for a proper tube pre amp for a couple of years but nothing has moved me.  At the same time I've been leaning into HP use that I'm finding relaxing and enjoyable on a different level than the speaker system.
In either speaker or HP use I'm looking for solid bass, full mid range and easy on the ears top end.
The current system includes Eversolo DMP A8 => Schiit Lokius => Schiit Lyr+ => Schiit Aegir 1 => Spatial M4 Sapphires.  HP are Grado SR325.  The Schiit stack into either the M4 or SR325 sounds pretty good already so I've not been in too much of a hurry. 
TMR has a WA-22 Gen 2 that would fit in the budget.  I'm not sure it would be considered a proper pre any more than the Lyr+ but would get the preferred point to point-ish full tube complement and presumably more of that tube goodness.
I'd have to add a second Aegir but would more likely get a differential stereo amp to mate to the WA-22 balanced out.  I'm also intrigued by planar HP like the Dan Clark Expanse.
Thanks much for your thoughts!
Edit: HF to HP

[SteveFord]

I have not heard one but I can say that Woo Audio makes really good gear.
I've always found Jack Wu to be really accessible, I dealt with him when I was trying to run down old Stax Sigma parts.

[FullRangeMan]

Woo amps always impress me by the small transformers, but looks great.

[AllanS]

Thanks guys.  If I think about it long enough somebody will buy the thing and make a decision for me.

[brooklyn]

I did have an older Woo Audio WA 2 that I purchase used many years ago which had the pre-outs in the rear.. I did try it for a short time as a preamp with I think a Bel Canto amp to see how it sounded. I don’t remember being impressed so I sold it. I would think a modern day WA22 would sound so much better.. I would imagine Woo Audio stopped making the WA2 with a pre-out for a reason.

About 2 years ago I purchased a brand new WA2 headphone amp and teamed it up with a pair of Sennheiser HD800S headphones which I use on occasion. That is an amp and headphone combo that are made for each other.. I’m very happy with the pairing..

[AllanS]

Thanks brooklyn.  There is a lot that I don’t hear so I’m not willing to sacrifice details or imaging and soundstage depth / layering for either HP or speaker systems.  I’ll stick to what pres and HP amps are each is good at.

Your experience and Freo-1’s Sennheiser thread have me thinking. 

[FullRangeMan]

The biggest soundstage there is, are the Senn HD800 line with PTRF Distance 22 to 24dB, but they are not cheap and have a light bass, follow by the out of the line HifiMan Edition X(2016) = PTRF 18dB.
https://www.rtings.com/headphones/reviews/hifiman/edition-x

[AllanS]

The biggest soundstage there is, are the Senn HD800 line with PTRF Distance 22 to 24dB, but they are not cheap and have a light bass, follow by the out of the line HifiMan Edition X(2016) = PTRF 18dB.
https://www.rtings.com/headphones/reviews/hifiman/edition-x

Thank you FRM.  A new to me acronym / audio term PTRF distance. I wonder what else I have to learn about HP.

[FullRangeMan]

Thank you FRM.  A new to me acronym / audio term PTRF distance. I wonder what else I have to learn about HP.

The Soundstage graphic have an useful tutorial at (?):
PTRF  Accuracy.  Good value:  <2.5
What it is:The standard deviation of the PRTF (Pinna-related transfer function) of the headphones compared to a reference loudspeaker's PRTF at 30°. This quality is monaural and can be perceived even with one ear. This test does not apply to in-ears and earbuds, due to the lack of pinna interaction.

When it matters:An accurate pinna activation is mainly responsible for how natural and speaker-like the soundstage is perceived to be. The less error in the shape of the PRTF, the more natrual and speaker-like the perception of the soundstage will be. High amounts of error may indicate a soundstage that is unnatural or odd.


PTRF Size.  Good value:  >3.7
What it is:The average amplitude of the PRTF (Pinna-related transfer function) of the headphones compared to that of a reference loudspeaker's PRTF at 30°. This quality is monaural and can be perceived even with one ear. This test does not apply to in-ears and earbuds, due to the lack of pinna interaction.

When it matters: This value is responsible for the perceived size of the soundstage. The higher the value, the larger the perceived size of the soundstage. However, values above the reference (5.0dB) could result in a soundstage that is perceived as unnatural or odd.

PTRF Distance.  Good value:  >13
What it is:The depth of the "10KHz notch" of the headphone's PRTF, which is caused by phase cancellations at the concha. This quality is monaural and can be perceived even with one ear. This test does not apply to in-ears and earbuds, due to the lack of pinna interaction.

When it matters: This value is mainly responsible for the perceived distance and elevation of the soundstage. A small distance value may result in a soundstage that is perceived to be located inside the head. Larger values may help pull the soundstage out from inside of the head and bring it to the front.

[AllanS]

Many thanks FRM!