Which amp sounds better Balancing Act or Zana Deux?

They are both single ended. 

 

The question is whether you prefer global feedback or not. 

They are both single ended amplifiers.

 

The signal is handled by only 1 active device at any stage of the amp. You need at least 2 devices in a given stage to pass a balanced signal.

 

I have no doubt that there are differences in sound between these 2 but it has nothing to do with being balanced vs not. It has to do with the fact that basically everything about how the amps are built is different. Transformer coupled VS OTL, global feedback VS none, and the tubes are totally different. 

 

Amps with feedback are generally considered to have better control and a generally "tighter" presentation. Amps without global feedback are a little looser, less controlled, and layed back - although this trait is quite dependent on how much power you are using. From what I can gather the ZD uses global feedback tastefully, and the BA should have enough power overhead with almost any headphones that you should not be anywhere near the point where it will really obviously distort so I would GUESS that the differences are on the subtler side. 

 

There are not many inherent advantages to a "real" balanced amp VS a single ended one, and balanced amps come with their own funky broad generalized characteristics and some interesting problems to design around. Considering that tastes vary these advantages on paper may not even be seen as that by listeners. 

 

If you want to fairly compare the amps, ignore that one is balanced, or SE, or tube or SS, or whatever it is. Plug a pair of headphones into the amp, and listen to them.

 

 

 

 

 

I should note that I have not actually heard the BA, but want to. A lot. My comment above is meant only as a gross generalization of the sounds of amps with global feedback VS ones that run open loop. I dont think I actually said what the BA sounds like, please dont take it that way.

The ZDT is also OPT and also balanced output so... really should be asking ZD or ZDT at that price.  And at that price, there is also the WA6SE, WA2, WA22 and WA5.  Just on looks, the BA wouldn't enter my house.  The ZD and ZDT have that retro thing going without looking silly but the BA looks like amateur hour to me.  No way the wife lets it in the door

Almost none of them are actually balanced, so why would they have to have balanced I/O? You might as well ask that of the ZD.

 

 

 

Regarding balanced outputs:

This is not difficult to do with ANY transformer coupled amp. You simply float the secondary of the transformer and its balanced. Really, thats all there is to it. You very rarely see this done because if the insulation between the primary and secondary of the transformer breaks down you WILL have high voltage on the secondary. If you keep the secondary grounded and the insulation fails high voltage is shorted to ground. By grounding the secondary of the transformer the user is at a MUCH lower risk of being shocked by HV in the event of failure.

 

Can anyone prove that floating the secondary VS grounding it at one end creates an audible difference in the last stage of a typical 2-stage SET amp with no global feedback? No?

no different secondaries for SE and balanced... 1 secondary, switched between outputs.

 

Regarding balanced inputs:

Balanced inputs to an SE amp is very easy to accomplish with an input transformer. The BA has them. They offer other (IMO) much more compelling advantages than simply allowing the hookup of balanced lines to an SE amp. Input transformers basically make the amp ground-loop-proof. How cool is that? Pretty cool if you ask me. The problem with input transformers is that they cost money. People who are afraid of transformers will also point out that they are transformers.

 

 

Why dosnt the Woo5 have balanced ins and outs:

I dont know, ask jack.

If you want guesses:

Input transformers would have made the amp a few hundred dollars more expensive, people complained enough about how much it cost when it was new. If you really want them, you can buy nice transformers in a little box with an XLR on one side and an RCA on the other. Balanced inputs for your Woo5. Or any single ended amplifier for that matter.

Floating the output transformer is an unsafe or at best risky practice. There were no balanced SET amps to compete with when it was introduced, and as a transformer coupled multi-thousand dollar amp it was more or less alone in the pack of OTL's that were commonly seen on head-fi at the time. The fact that the Woo5 has multiple impedance taps on the secondary is several times cooler than a single secondary transformer. I guess the filament supplies that Craig uses are several times cooler than the filament supplies Woo uses.

 

On the note of a balanced Woo amp, Woo makes the Woo22, which is push-pull (balanced) from input to at least the primary of the transformer. (see the section on floated transformers) I'd listen to it before I bought it even though its actually balanced. Not everyone likes push pull amps, and quite a few people flat out hate them. The flip side is that quite a few people flat out hate SET amps and la-la-love push pull amps. Some people listen quite happily to both. Whatever the case is, the sound from a Push-pull amp is not the same as the sound from an SET amp. Personal tastes being a personal thing who can say whats better but you. Pay no attention to what is and isnt balanced and listen. just the music.

David- A Zana just turned up in the For Sale Forum. If you're curious about the sound, you might do well to pick it up and give it a listen. No wait for the next run and you could resell it for about the same if you wanted. (No affiliation with seller, just a fan of the Zana - especially with the HD-800.. )