[Junglebook3]

9000 hours at 3 hours a day is over 8 years

 

[All Day Breakfast]

9000 hours at 3 hours a day is over 8 years

12AU7 tubes run from cheap and widely available to rare and expensive. New old stock (NOS) manufactured in the hayday of tube amplifiers and never used run the gamut. There are many variations in the 12AU series which affect current output, headroom and other parameters. These 12AU7 tubes are still widely used in guitar and other instrument amplifiers so there's lots of dealers you can find through search and a few reliable dealers on eBay. This site gives an overview of the 12AU7 and its alternatives. http://www.audiotubes.com/12au7.htm

 

[All Day Breakfast]

12AU7 tubes run from cheap and widely available to rare and expensive. New old stock (NOS) manufactured in the hayday of tube amplifiers and never used run the gamut. There are many variations in the 12AU series which affect current output, headroom and other parameters. These 12AU7 tubes are still widely used in guitar and other instrument amplifiers so there's lots of dealers you can find through search and a few reliable dealers on eBay. This site gives an overview of the 12AU7 and its alternatives. http://www.audiotubes.com/12au7.htm

Also you may see mentioned tube matching. On old stock tubes in demand which may have been used for a few hundred hours and then sold to tube resellers, the reseller has an instrument to tell how “used” the tube is. Used tubes should be fine if the seller has checked them out and found them to still have a lot of life left but you don’t want to put tubes in your amp which have different life times left. Thus the reseller will sell tubes he/she has checked which have similar use and similar remaining lifetimes on them as matched sets. This is desireable.

 

[whatdidyoulearnabout]

I'd also be happy to take requests - I have a ZMF VC, Aeolus, Auteur, Eikon, an HD 800s, as well as the aforementioned Diana v2, VO, and Focal Radiance. If you want me to do a comparison using your test track / headphones that I have on hand I'd be happy to.

Oo yes. I'm concerned about their ability to drive the high-impedance ZMFs, since Strayngs said he sold his WA7 v2 due to not being powerful enough. How are they with the VCs? (While we're at it, how are the VCs in general compared to the VOs?)

 

[Levanter]

Oo yes. I'm concerned about their ability to drive the high-impedance ZMFs, since Strayngs said he sold his WA7 v2 due to not being powerful enough. How are they with the VCs? (While we're at it, how are the VCs in general compared to the VOs?)

ZMFs are not difficult to drive, even newer DAPs e.g. DX300, M8 etc can drive them well.
Though according to can jam reviews a few mentioned the they felt the v3 was underpowered with more demanding headphones.

 

[Junglebook3]

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.

 

[Khitzi]

Thanks for your impressions on the WA7. By the way, what's the headphone stand with the wooden base you're using in this photo?

 

[bluestorm1992]

Thanks for your impressions on the WA7. By the way, what's the headphone stand with the wooden base you're using in this photo?

Here you go.

https://www.etsy.com/listing/605415466/headphone-stand-wood-steel-and-wood?ref=yr_purchases

 

[warrenpchi]

9000 hours at 3 hours a day is over 8 years

Or, to put it another way…

The typical American work week for a full-time position is 40 hours per week, or 2,000 hours per year. At that rate, if listening to the WA7 was your full-time job, you be doing that job, on one set of tubes, for four and a half years, before having to replace them.

Plus, as a Head-Fier, you know full well that you're going to tire of the amp and upgrade well before 9,000 hours.

 

[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!

 

[warrenpchi]

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.

Oh shoot, would be so ironic if it was a tube... KIDDING!

Also @HiFiGuy528, I summon you to help!

 

[Zachik]

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.

Edit: 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.

Swap the 2 tubes (when amp is OFF).
Still same behavior, or now the dead channel swapped sides?

 

[Zachik]

Or, to put it another way…

The typical American work week for a full-time position is 40 hours per week, or 2,000 hours per year. At that rate, if listening to the WA7 was your full-time job, you be doing that job, on one set of tubes, for four and a half years, before having to replace them.

Plus, as a Head-Fier, you know full well that you're going to tire of the amp and upgrade well before 9,000 hours.

NOW you tell me?!

 

[Junglebook3]

Swap the 2 tubes (when amp is OFF).
Still same behavior, or now the dead channel swapped sides?

Oh, yeah, looks like it's a bad tube - swapping tubes also swapped the dead channel. I'm in communication with Woo Audio, I assume they'll send me a new tube. I'm really unsure how a tube would go bad so quickly though?

 

[Zachik]

Oh, yeah, looks like it's a bad tube - swapping tubes also swapped the dead channel.

Good! Much easier and faster than shipping the amp round-trip for repair

I'm in communication with Woo Audio, I assume they'll send me a new tube.

You're in good hands - Woo guys are great.

I'm really unsure how a tube would go bad so quickly though?

Think of tubes like light bulbs - sometimes you get a defective one that burns up after 5 days, but 99% of the time they would work for years (as spec'd).
Also, if the tubes are NOS (New Old Stock) - well, now add into the equation tubes that were manufactured 50-70 years ago...

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