[Junglebook3]

Where do you typically buy tubes?
Also, is there a list of recommended tubes that work with the WA7 3rd Gen?

 

[warrenpchi]

That is the reason, @warrenpchi that we buy backup tubes and backup to the backup tubes

Oh I definitely buy back-up tubes for sure! Just saying they last longer than most people think.

 

[Zachik]

Where do you typically buy tubes?

Best deals (with higher risk) - eBay.
Otherwise, check out the classifieds on Head-Fi. Several tube sellers have their own websites, but prices usually higher than eBay (but most would give you at least 30 days guarantee)...
I believe Woo Audio is also selling tubes. Won't be the cheapest place but again - you get some guarantee, so definitely worth it for some!

Also, is there a list of recommended tubes that work with the WA7 3rd Gen?

I believe it uses 12AU7 tubes. There are equivalent substitutes, but I would say for starts look for 12AU7 tubes. That tube type is very popular and plentiful.

 

[Junglebook3]

Sad news: something went bad with my new unit, both of the front connectors - the 4.4mm and 1/4 inch - no longer output audio to the left channel. I tried many different headphones, audio cables, USB cables, two different PCs, restarting everything… no bueno. I’ve contacted Woo Audio. If I partially pull the cable out, I can get it to output to (only) the left channel, but if I put it all the way in, it outputs only to the right. This is consistent across cables, and for both the 4.4mm and the 1/4 inch outputs. So, I don’t think it’s the tubes.

Edit: it was a tube. Woo Audio answered my support request the same day, and hand delivered a free replacement tube the next day. Can’t ask for better support!

Update: it was a tube. Woo Audio answered my support request the same day, and hand delivered a free replacement tube the next day. Can’t ask for better support!

 

[whatdidyoulearnabout]

ZMFs reach insane volumes at 12 o’clock for me on the WA7 3rd Gen, so that should be plenty of headroom for anyone

I’m curious which headphones CanJammers were referring to. This amp easily powers my entire collection, and per the Abyss folks the Diana Phi as well, that more or less only leaves the 1266, Susvara, HE6 class of power demand. Other than that this amp should be able to power any headphone on the planet.

Ah, thanks for that — encouraging (except for my wallet). I just pulled the trigger on the WA7 viiis.


Digression filled with noob questions: I'm getting a bit confused about the relationship between the quantitative metrics of (1) sensitivity and (2) impedance versus the qualitative property of being "difficult to drive."

I see here they mention that:

In terms of key technical specs, both the Vérité open and closed have an impedance of 300 Ohms. The open have a sensitivity of 97 dB/1mW, while the closed have a sensitivity of 99 dB/1mW. Both Vérité models require sufficient power to sound their best, and listeners who wish to compare the Vérité to something like the Utopia, with its 80 Ohm impedance and 104 dB sensitivity, would be advised to make sure levels are matched as close as possible.

which leads me to believe that the Vérités are relatively "difficult to drive" (= "requiring significant power"?) and that both impedance and sensitivity are relevant metrics of this?

But you mention that e.g. the Susvaras (which have only 65 Ω impedance) are harder to drive than the Vérités (which have 300Ω)? Maybe it's the sensitivity, then, that's the relevant metric (as Susvaras 80.6dB/1mW, less than the roughly 98dB/1mW of the Véritéss) ? How does impedance come into play at all, then?

 

[jonathan c]

Ah, thanks for that — encouraging (except for my wallet). I just pulled the trigger on the WA7 viiis.


Digression filled with noob questions: I'm getting a bit confused about the relationship between the quantitative metrics of (1) sensitivity and (2) impedance versus the qualitative property of being "difficult to drive."

I see here they mention that:

which leads me to believe that the Vérités are relatively "difficult to drive" (= "requiring significant power"?) and that both impedance and sensitivity are relevant metrics of this?

But you mention that e.g. the Susvaras (which have only 65 Ω impedance) are harder to drive than the Vérités (which have 300Ω)? Maybe it's the sensitivity, then, that's the relevant metric (as Susvaras 80.6dB/1mW, less than the roughly 98dB/1mW of the Véritéss) ? How does impedance come into play at all, then?

One way to look at the comparison is in terms of sensitivity by voltage, dB/V. This measure accounts for differences in ‘stated’ impedance across headphones. The relationship is:

dB/V = dB/mW - (10 x log(impedance/1000))

By this, the sensitivity of the Susvara is 92.5 dB/V. The sensitivity of the Verite is 103.2 dB/V. This is a dramatic difference!

And just for comparison, the sensitivity of the Focal Clear, an ‘efficient’ (easy to drive) headphone, is 110.6 dB/V.

 

[All Day Breakfast]

For those who have ordered the new Audeze LCD 5s and the new gen 3 Fireflies 7 and wonder if it will have enough power to drive the LCD 5, Woo Audio has just released a short video showing the gen 3 Fireflies being used with the LCD 5.

 

[Junglebook3]

For those who have ordered the new Audeze LCD 5s and the new gen 3 Fireflies 7 and wonder if it will have enough power to drive the LCD 5, Woo Audio has just released a short video showing the gen 3 Fireflies being used with the LCD 5.

Another bit of data is that the LCD-5 is 14 ohm and 90 dB/1mW, while the Abyss Diana v2 is 42 ohm and 91 dB/1mw - the latter is easily driven off the firefly (that's my personal experience, as well as what both Woo and Abyss are saying). That implies that the LCD-5 should be no problem for the firefly.

 

[bluestorm1992]

Another bit of data is that the LCD-5 is 14 ohm and 90 dB/1mW, while the Abyss Diana v2 is 42 ohm and 91 dB/1mw - the latter is easily driven off the firefly (that's my personal experience, as well as what both Woo and Abyss are saying). That implies that the LCD-5 should be no problem for the firefly.

I would second this. The WA7 Gen 3 drives my V2 very nicely.

 

[whatdidyoulearnabout]

One way to look at the comparison is in terms of sensitivity by voltage, dB/V. This measure accounts for differences in ‘stated’ impedance across headphones. The relationship is:

dB/V = dB/mW - (10 x log(impedance/1000))

By this, the sensitivity of the Susvara is 92.5 dB/V. The sensitivity of the Verite is 103.2 dB/V. This is a dramatic difference!

And just for comparison, the sensitivity of the Focal Clear, an ‘efficient’ (easy to drive) headphone, is 110.6 dB/V.

I love this — thanks! A unifying metric. And one that reveals dB/mW to be the much more important factor in determining driving difficulty than impedance (if dB/V is considered an accurate quantification thereof).

So we have now:

Headphone	dB/ V ("Ease of Driving")
Hifiman Susvara	92.5
Hifiman HE 6	96.5
Abyss Model AB-1266 Phi TC	101.3
---- "Hard to Drive" ↑, ""Easy to Drive"↓	----
ZMF Vérité Open	102.2
ZMF Vérité Closed	104.2
Abyss Diana v2	104.8
Audeze LCD-5	108.5

Looks like the Vérités just avoid the "difficult" to drive designation by a hair, although I should remember that dB is a log scale, which is probably relevant here.

 

[All Day Breakfast]

I love this — thanks! A unifying metric. And one that reveals dB/mW to be the much more important factor in determining driving difficulty than impedance (if dB/V is considered an accurate quantification thereof).

So we have now:

Headphone	dB/ V ("Ease of Driving")
Hifiman Susvara	92.5
Hifiman HE 6	96.5
Abyss Model AB-1266 Phi TC	101.3
---- "Hard to Drive" ↑, ""Easy to Drive"↓	----
ZMF Vérité Open	102.2
ZMF Vérité Closed	104.2
Abyss Diana v2	104.8
Audeze LCD-5	108.5

Looks like the Vérités just avoid the "difficult" to drive designation by a hair, although I should remember that dB is a log scale, which is probably relevant here.

jonathan c said "The sensitivity of the Verite is 103.2 dB/V.” Not sure if he was referring to open or closed but either way why the (small?) discrepancy or an I missing something obvious?

 

[whatdidyoulearnabout]

jonathan c said "The sensitivity of the Verite is 103.2 dB/V.” Not sure if he was referring to open or closed but either way why the (small?) discrepancy or an I missing something obvious?

Oh, just that above I lumped both Vérités' dB/1mW measurements together,

roughly 98dB/1mW of the Véritéss

, which I just got by averaging between the Vérité Open (97 dB/1mW) and Vérité Closed (99 dB/1mW).

jonathan c computed the 103.2 dB/V number based on that.

In the table in my most recent post, though, I listed (and computed) the closed and open dB/V separately.

 

[All Day Breakfast]

Oh, just that that above I lumped both Véritéss' dB/ 1mW measurements together,

, which I just got by averaging between the Vérité Open (97 dB/1mW) and Vérité Closed (99 dB/1mW).

jonathan c computed the 103.2 dB/V number based on that.

In the table in my most recent post, though, I listed (and computed) the closed and open dB/V separately.

Thanks!

 

[jonathan c]

I love this — thanks! A unifying metric. And one that reveals dB/mW to be the much more important factor in determining driving difficulty than impedance (if dB/V is considered an accurate quantification thereof).

So we have now:

Headphone	dB/ V ("Ease of Driving")
Hifiman Susvara	92.5
Hifiman HE 6	96.5
Abyss Model AB-1266 Phi TC	101.3
---- "Hard to Drive" ↑, ""Easy to Drive"↓	----
ZMF Vérité Open	102.2
ZMF Vérité Closed	104.2
Abyss Diana v2	104.8
Audeze LCD-5	108.5

Looks like the Vérités just avoid the "difficult" to drive designation by a hair, although I should remember that dB is a log scale, which is probably relevant here.

~ The logarithmic scale points to the Susvara being hellishly difficult to drive compared to the LCD-5.
~ One point about the ‘stated’ impedances to keep in mind. For dynamic hp, the impedance varies with the frequency being reproduced. Thus, across the spectrum, the ‘effective’ impedance will differ from the ‘stated’ impedance. For planar magnetic hp, which are more purely resistive, the difference between ‘effective’ impedance and ‘stated’ impedance will not be nearly as great.
~ Lastly, a moderately difficult to drive headphone may become quite difficult to drive if the headphone amplifier feeding it is underpowered. The above line of demarcation between ‘hard to drive’ and ‘easy to drive’ is not absolute.

 

[HiFiGuy528]

Snap new pics of 3rd gen as preamp to Focal powered monitors via 4.4mm balanced to dual 3-pin balanced XLR (male).