Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Woo Wa22 balanced vs unbalanced input
New Posts  All Forums:Forum Nav:

Woo Wa22 balanced vs unbalanced input - Page 2

post #16 of 53

If anyone is still following this thread...

 

So, spending money on a balanced output to the headphone cable is wasting money???

 

A single ended output connection is the same as the balanced?

post #17 of 53
Quote:
Originally Posted by amham View Post

If anyone is still following this thread...

So, spending money on a balanced output to the headphone cable is wasting money???

A single ended output connection is the same as the balanced?

Basically yes. It is important to have balanced input since the the amplification is balanced, but after the output transformers it is single ended and the balanced outputs are for convenience.
post #18 of 53
Quote:
Originally Posted by ardilla View Post
 
Quote:
Originally Posted by amham View Post

If anyone is still following this thread...

So, spending money on a balanced output to the headphone cable is wasting money???

A single ended output connection is the same as the balanced?

Basically yes. It is important to have balanced input since the the amplification is balanced, but after the output transformers it is single ended and the balanced outputs are for convenience.


My understanding from Jack Woo is they are about to announce a modification of the WA22 to enhanced the SE input thus making the amp sound as good via SE input/output.  New builds will include this enhancement while older WA22's will need to go back to the factory for the update.  No understanding of when and how much.

post #19 of 53
Quote:
Originally Posted by amham View Post


My understanding from Jack Woo is they are about to announce a modification of the WA22 to enhanced the SE input thus making the amp sound as good via SE input/output.  New builds will include this enhancement while older WA22's will need to go back to the factory for the update.  No understanding of when and how much.

InterestingInteresting..

The modification must be a balanced to single ended conversion, and will never be quite as good as balanced input, but if implemented well it will probably be fine. Many amps does this, and it gives the amp the possibility to deliver the same wattage when fed unbalanced, which is good news :-)
Edited by ardilla - 4/25/14 at 11:33am
post #20 of 53

ah this thread again.

 

interesting, good for people who can't do balanced on the WA22.

post #21 of 53

The Woo Audio WA22 is a fully balanced amp with both balanced inputs and balanced outputs. The confusion regarding the WA22 stems from the confusion people have between the terms "balanced" and "differential".

 

For the purposes of this discussion:

 

A balanced circuit only means that you have two signal conductors, each with the same impedance to circuit ground.

 

A balanced, differential circuit means you have two balanced conductors, each with the same signal except on one conductor the signal is inverted (180 degrees out of phase).

 

Each channel of the WA22 has two signal inputs, + (in-phase signal) and - (inverted-phase signal) , (balanced and requiring a differential signal pair) and a ground. Each of the signal inputs feeds a separate drive circuit to either side of the transformer primary.

 

This creates a balanced, differential drive circuit that works by applying an amplified version of the original audio signal (+) to one side of the transformer primary while simultaneously applying an amplified inverted version of the original audio signal (-) to the other side of the transformer primary. Driving both sides of the transformer primary with a differential circuit doubles the slew rate (rise time) of the amplifier, and reduces noise induced from the external balanced cable run through the internal circuit. Actively controlling both sides of the transformer primary should also reduce distortion (grounds do float) but some may argue that it is negated by having dual drive circuits - each contributing distortion components.

 

While the WA22 will work fine with a single-ended input (rca), half of the drive circuit stays dormant at 0 Volts (or floats around a little) and the true audio performance of the WA22 remains underutilized.

 

The outputs of the WA22 transformers are balanced - all conductors (output signals and ground) have the same impedance to circuit ground. When I bought my WA22, I asked Jack Woo about the issue and he advised that while the XLR and 1/4" outputs share a common ground, the output ground is not connected to circuit ground - hence the output conductors are balanced.

 

There is definitely an advantage (audio performance) to using a balanced differential circuit to drive the transformer primary but it is unclear what advantages one would gain with a differential output from the transformer.

 

What comes out of the WA22 transformers is one left-channel signal, one right-channel signal, and a common ground. You can connect to the output via 1/4" TRS, dual 3-pin XLR, or single 4-pin XLR. It is unclear what advantage a balanced HP cable would make as the XLR outputs are electrically the same as the 1/4" TRS.

 

This is no slight against the WA22. It is a very elegant design. As I mentioned, it is unclear what audio advantage would be gained with a differential output. The WA22 is an ultra high-performance audio amplifier with balanced differential inputs, class A differential amplifier circuits, and balanced single-ended outputs.


Edited by tomlink - 10/2/14 at 9:08am
post #22 of 53

tomlink, thank you for your excellent description of operation. I also use the MyTek 192 to feed my WA22 / HD800 combo. I use the straight pass through mode. The WA22 input really comes alive with the higher voltage balanced output of the MyTek (higher than my previous setup).

I chose to use a balanced HP cable at the time of setup primarily because I needed a long cable and I thought why not go with XLR. I got mine from apuresound...great product quality I might add.


Edited by nututubes - 4/26/14 at 3:14am
post #23 of 53
Quote:
Originally Posted by nututubes View Post

tomlink, thank you for your excellent description of operation. I also use the MyTek 192 to feed my WA22 / HD800 combo. I use the straight pass through mode. The WA22 input really comes alive with the higher voltage balanced output of the MyTek (higher than my previous setup).
I chose to use a balanced HP cable at the time of setup primarily because I needed a long cable and I thought why not go with XLR. I got mine from apuresound...great product quality I might add.

How much voltage is that?
Edited by ardilla - 4/26/14 at 3:25am
post #24 of 53
Quote:
Originally Posted by ardilla View Post


How much voltage is that?

@ardilla, I pasted a quote from the mfg's posted design philosophy.

 

XLR output DEFAULT :
Average level (0 VU) = +4dBu= 1.228 VRMS on XLR (between pin 2 and 3)
Output trim (adjustable in menu) = -18dBFS
Max output (sinewave) 9.79V RMS or 13.84V Peak or 27.69 V Peak to peak
(Voltage swing)
This is the typical professional recording setting well handled by professional and
some hi-fi equipment typically powered by +/-15V power rails (or larger)
It's recommended for Hi-Fi systems with well designed high headroom preamps
and amps.

 

 This MyTek / WA22 / HD800 combo now gives me the sound volume I want, without driving the WA22 to max volume.

post #25 of 53
Quote:
Originally Posted by nututubes View Post
 

tomlink, thank you for your excellent description of operation. I also use the MyTek 192 to feed my WA22 / HD800 combo. I use the straight pass through mode. The WA22 input really comes alive with the higher voltage balanced output of the MyTek (higher than my previous setup).

I chose to use a balanced HP cable at the time of setup primarily because I needed a long cable and I thought why not go with XLR. I got mine from apuresound...great product quality I might add.

Nu,

 

I also bypass the volume on the Mytek 192. Mytek recommends it for best quality when you have volume control on the amp like the WA22. I have the 1/4" TRS cable that came with my HD800. I also wanted a custom balanced cable for amps with a differential pair output. It's convenient that I can use it on the WA22, and it looks great. I bought mine from JE Audio Designs. Justin builds some nice stuff and his prices are reasonable. Nice guy to do business with as well.

 

http://jeaudiodesigns.wix.com/jeaudiodesigns

post #26 of 53
I had same setup for a while mytek wa22 and hd 800

I have bypass with the jumpers to lower voltage
post #27 of 53
Quote:
Originally Posted by Dubstep Girl View Post

I had same setup for a while mytek wa22 and hd 800

I have bypass with the jumpers to lower voltage

Dsg, 

 

I left the output level at the default +4dBu pro level and bypass for volume. Seems to match well with the WA22.

 

Why did you drop the output level (I'm assuming to 0dBu)? Did you find that you were overdriving the WA22 inputs?

 

I found that driving the Mytek 192 from Pure Music AT 0VU gave me max output on the WA22 at 2-3 o'clock on the volume knob.

post #28 of 53

i didn't feel like I was overdriving, but I did want to keep it at a default level for non-pro equipment and though it would be better overall. Also, without the jumpers, I noticed a slightly more compressed and shout to the sound, it might have been just my imagination or the fact that it got louder faster, but I didn't feel comfortable with it. I haven't played with it since.

post #29 of 53
Quote:
Originally Posted by Dubstep Girl View Post
 

i didn't feel like I was overdriving, but I did want to keep it at a default level for non-pro equipment and though it would be better overall. Also, without the jumpers, I noticed a slightly more compressed and shout to the sound, it might have been just my imagination or the fact that it got louder faster, but I didn't feel comfortable with it. I haven't played with it since.

 

Interesting. I found that with the Mytek set at default +4dBu out, the WA22 didn't really come alive until I pushed Pure Music at 0VU. I'm thinking it might be the difference in tubes that we were using.

 

IAC, since 0dBu out s/n is not a big issue with a desktop application, you're probably better off picking up the extra 4dB of headroom.

 

BTW, I sold the WA22. I really, really liked the amp, but I needed to power speakers as well. I thought I might roll the uber-WA22 and buy a separate power amp, but I decided to look at a WA5 or Ragnarok to streamline my setup.


Edited by tomlink - 4/30/14 at 7:41am
post #30 of 53
Quote:
Originally Posted by tomlink View Post
 

 

Interesting. I found that with the Mytek set at default +4dBu out, the WA22 didn't really come alive until I pushed Pure Music at 0VU. I'm thinking it might be the difference in tubes that we were using.

 

IAC, since 0dBu out s/n is not a big issue with a desktop application, you're probably better off picking up the extra 4dB of headroom.

 

BTW, I sold the WA22. I really, really liked the amp, but I needed to power speakers as well. I thought I might roll the uber-WA22 and buy a separate power amp, but I decided to look at a WA5 or Ragnarok to streamline my setup.

 

im thinking of WA5 as well. 

 

originally i gave up on the idea of buying it since it uses double rectifiers and the idea of using 6sn7's, but many people are happy with it and Frank I holds it in really high regard, so i am considering trying it out, preferably a used one or hearing one at a meet. it would also work with HE-6 and be able to drive just about any headphone (in any specification according to Jack Wu lol....).

 

 

other considerations for me are the Glenn 300B amp (supposed to be about as good as 300B amps get) and the DNA Stratus 2A3.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Woo Wa22 balanced vs unbalanced input