[skhan007]

OK, updates...

I've purchased the deoxit cleaner and will set aside time to clean my tube pins. Haven't had time to do that yet. In addition, based on recommendations in this thread, I purchased the iFi Ground Defender and new heavy duty IEC cable (much better quality than my thin IEC cables that I had sitting around). I'd say the hum is decreased 90% when on high impedance mode on the WA22. Very good progress.

 

[LegionofDoom]

OK, updates...

I've purchased the deoxit cleaner and will set aside time to clean my tube pins. Haven't had time to do that yet. In addition, based on recommendations in this thread, I purchased the iFi Ground Defender and new heavy duty IEC cable (much better quality than my thin IEC cables that I had sitting around). I'd say the hum is decreased 90% when on high impedance mode on the WA22. Very good progress.

How did you decide on the Defender vs. the Blocker?

I understand the Defender is for a hum problem you can hear thru your headphones (and usually gets worse as you turn up the volume). Principally from a ground loop issue somewhere?

And the blocker is more for mechanical hum from the amp itself that you hear without headphones just at idle. It’s from DC leaking into the amp somehow. And you hear it from the amp chasis directly.

Am I right about that?

 

[skhan007]

How did you decide on the Defender vs. the Blocker?

I understand the Defender is for a hum problem you can hear thru your headphones (and usually gets worse as you turn up the volume). Principally from a ground loop issue somewhere?

And the blocker is more for mechanical hum from the amp itself that you hear without headphones just at idle. It’s from DC leaking into the amp somehow. And you hear it from the amp chasis directly.

Am I right about that?

Good question. I just went with what was recommended by at least two other members on this thread. They had good results with the ground defender. I just went a head ordered the DC blocker from Amazon to try out. I figure, why not. One can be returned if it doesn't work as well as the other.

I'm listening to my HD800S right now as I type this, on hi-impedance mode. The audible hum is there between songs, but so much less than before. Regarding my particular hum (I believe it's the same as many others in this thread): Not audible during music play, but when the music stops, it's not a black background. Also, it doesn't change with the volume knob when the music is off. It's there even when no source is plugged in the back. I can't hear any hum without the headphones, so nothing on the outside of the amp, when on and idle.

 

[LegionofDoom]

Good question. I just went with what was recommended by at least two other members on this thread. They had good results with the ground defender. I just went a head ordered the DC blocker from Amazon to try out. I figure, why not. One can be returned if it doesn't work as well as the other.

I'm listening to my HD800S right now as I type this, on hi-impedance mode. The audible hum is there between songs, but so much less than before. Regarding my particular hum (I believe it's the same as many others in this thread): Not audible during music play, but when the music stops, it's not a black background. Also, it doesn't change with the volume knob when the music is off. It's there even when no source is plugged in the back. I can't hear any hum without the headphones, so nothing on the outside of the amp, when on and idle.

Ok your situation is basically the same as mine. The hum on Hi Z comes thru the ZMF VC headphones. I really do not hear chassis noise to the naked ear from my WA22 when right down near it---so it is a headphones phenomena. I hear some hum on Low Z, but more on Hi Z. In either case, it does not scale with volume. It's just there when no music is playing.

Going to try a Defender and see if I get your results.

 

[skhan007]

Ok your situation is basically the same as mine. The hum on Hi Z comes thru the ZMF VC headphones. I really do not hear chassis noise to the naked ear from my WA22 when right down near it---so it is a headphones phenomena. I hear some hum on Low Z, but more on Hi Z. In either case, it does not scale with volume. It's just there when no music is playing.

Going to try a Defender and see if I get your results.

Sounds good. I ordered my DC Blocker from Amazon and it'll arrive in a few days. I'll be sure to post findings. The iFi folks state you can daisy chain the Ground Defender and DC Blocker together, so I'll try that too.

I got an email response from Mike at Woo Audio:

Hope you had a great weekend.

Thank you for taking the time to write us. Congratulations! on your new WA22.

Some headphones that are high sensitivity rating (above 103db) are not suitable for the HI setting. We recommend using the LO setting for your setup.

We have a short video in our FAQ Series on this topic.



~ Mike
Office: 1 (917) 773-8645 (call or text)
www.WooAudio.com


That being said, I can certainly use the LO setting for my ZMF and Sennheiser headphones, as they're high sensitivity. My Abyss 1266 are really low sensitivity and thus, dead silent on the WA22. I was under the impression that the HI/LO setting would be necessary for matching impedance, but I guess not. I can use LO with my high impedance headphones and turn up the volume a bit more.

 

[LegionofDoom]

Sounds good. I ordered my DC Blocker from Amazon and it'll arrive in a few days. I'll be sure to post findings. The iFi folks state you can daisy chain the Ground Defender and DC Blocker together, so I'll try that too.

I got an email response from Mike at Woo Audio:

Hope you had a great weekend.

Thank you for taking the time to write us. Congratulations! on your new WA22.

Some headphones that are high sensitivity rating (above 103db) are not suitable for the HI setting. We recommend using the LO setting for your setup.

We have a short video in our FAQ Series on this topic.



~ Mike
Office: 1 (917) 773-8645 (call or text)
www.WooAudio.com


That being said, I can certainly use the LO setting for my ZMF and Sennheiser headphones, as they're high sensitivity. My Abyss 1266 are really low sensitivity and thus, dead silent on the WA22. I was under the impression that the HI/LO setting would be necessary for matching impedance, but I guess not. I can use LO with my high impedance headphones and turn up the volume a bit more.

I think Mike is right in sort of an "all else equal" fashion. In reality, the damping factor comes into play here and affects frequency response depending on your selection of low Z or high Z. This is much more of an issue for dynamic driver headphones than planars.

So yes...the volume level comments he makes stand to reason. But I think the sound quality (via frequency response) is another matter. My ZMF's are much more euphonic on high Z than low Z, especially in terms of bass response.

 

[skhan007]

OK- I was curious about that. I wasn't sure if a high-Z headphone played on the LO impedance setting would compromise frequency response and overall sound quality. Especially on dynamic driver headphones.

 

[synfinatic]

Another +1 for using high-Z with my ZMF VC and Atrium. Definitely sounds better than the low-Z setting on my WA-22. Generally speaking, most people from I've read here and elsewhere tend to prefer the high-Z output on an amp with 300ohm headphones like the ZMF dynamics and low-Z for things like Audeze and Focal which have much lower impedance values. Of course, if you like different, that's cool. I won't kink shame.

 

[thingwfeathers]

Just received my brand new WA22! Initial impressions are super positive. This is the first piece of equipment that made me tear up on first listen.

I did notice that the volume pot on my unit is a little scratchy. Definitely some metal on metal going on. Is this normal?

 

[skhan007]

Just received my brand new WA22! Initial impressions are super positive. This is the first piece of equipment that made me tear up on first listen.

I did notice that the volume pot on my unit is a little scratchy. Definitely some metal on metal going on. Is this normal?

Congrats and welcome to Club WA22!

If your volume knob is too close to the chassis, you can take an allen key, loosen the knob, slide it out a couple of mm, and tighten.

 

[VanHai]

Just received my brand new WA22! Initial impressions are super positive. This is the first piece of equipment that made me tear up on first listen.

I did notice that the volume pot on my unit is a little scratchy. Definitely some metal on metal going on. Is this normal?

Congrats, very versatile and great amp. The volume pot should be butter smooth. Since it is a BRAND NEW give the volume pot few turns everyday for a week. If it is still scratchy, contact Woo Audio.

 

[thingwfeathers]

Congrats and welcome to Club WA22!

If your volume knob is too close to the chassis, you can take an allen key, loosen the knob, slide it out a couple of mm, and tighten.

Thanks for the tip! Knob is nice and smoooooth now.

 

[skhan007]

OK, I have both the DC Blocker and Ground Defender in the house. Too early to tell, but they both definitely work in reducing the hum significantly. It might be splitting hairs trying to decide which one does the better job. They may actually be equivocal. I'll need more time to A/B, but these are both good at what they do.

 

[VanHai]

I tried to do a little bit of research but not much came out about the 12xx7 tubes with adapters to WA22. Finally ordered the adapters, they arrived this afternoon ( https://i.ebayimg.com/images/g/6Y0AAOSwnzJhJIfB/s-l1600.jpg).

I tried 3 pairs of tube, Sylvania 12AU7, Amperex 6201(12AT7) and TungsramECC81(12AT). The 12AU7 sounded as good as any 6SN7s, but to my surprise both 12AT7 pairs exceeded my expectation. With higher gain they produced more dynamics, deeper sound and the bass also hit harder than 6SN7s,

less volume. I hope someone will try this and give some feedback.

 

[skhan007]

Interesting. The 12au7 is typical in hi-fi with a µ= 20, while the 12at7 is typical in guitar amps and triple the gain with µ= 60. I'm glad to hear that it works and doesn't distort or throw off frequency response.