Zen Balanced Line Stage Balanced vs Unbalanced

[macka]

I have recently been trialing my new Balanced Line Stage in either balanced or unbalanced output to the Aleph 5.

Firstly, I have to say this is the best sounding pre I've heard for some time. Its quite a smart performer.

Why I did not build this ages ago is beyond me. Cheers Nelson.

Unbalanced in/out appears to sound a bit warmer, and unbalanced in/balanced output less warm and more crisp and clinical in comparison.

I maybe correct in assuming balanced output mode cancels some of the second harmonic disortion of SE operation?

I prefer a bit of 2nd harmonic maybe

As to my choice of parts its straight out of the article.

I'm using an Allen Bradley conductive plastic 25K dual gang pot on the input (unbalanced input mode) and the shunt attenuator (Aleph P) using (2) Lorlin 2 pole 6 position rotory switches with resisitors of 4.3K, 2K, 1K, 499R, 240R 120R.

This seems to work and does not appear to effect sound quality.

I intend to build Panos's relay version of the attenuator for 64 step multi stepped attenuation.

My output caps are Black Gate C series 10uf 50 volt, they are billiant!

regards

macka

[nar]

You're right,it's a wonderful sounding unit.
Why not try some SCR capacitors for the output?I realized 2 versions of the ZLS,one with SCR capacitors and one with Arcotronics film cap grey version.I much prefer the SCR version than the other...
Some Blackgate types are not for coupling use.But I guess the Silmic silk separator series is OK for the purpose,and we can find some special for coupling use Blackgates.I would use a small MKP decoupling cap parallel however.

Regards

[till]

is there any difference in sound between balanced line stage and aleph p first version? which?

[nar]

Might be some-I think logically,P should have better bottom bass control than ZLS-but should be a little more "smokey"in medium and treble region ...

Nelson would tell...

[Nelson Pass]

Depends. The early P used big devices, and was slightly
darker at the top compared to later product which used
smaller chip sizes. They don't sound identical, but it's
strictly a matter of taste, and I never did develop a preference.

[till]

so its not the question if balanced line stage OR aleph p to build, only a question of taste, or the kind of devices laying around on the bench?

[macka]

This is interesting but the BOSOZ is a much simpler design than the Aleph P and the extra complexity hardy seems warranted.

A quick question for Nelson.

The idea of the shunt relay driven volume network like the P is appealing for means of construction and precision rather than say two 5K dual gang pots.

Do you consider any performance penalities over the 5 K pot other than reduced voltage swing?

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I've since arranged proper cannon leads and terminations for the pre and power amp with the input - negative shorted on the input of the pre amps.

I trust this is the correct way to run the pre with unbalanced inputs.

To my ears the sound is quite clean and dynamic.

regards

macka

[Nelson Pass]

5K takes the maximum output down a decibel or so,
but there is plenty of swing available.

[Ian Macmillan]

I guess the obvious question is how different does the AlephP 1.7 sound given the added complexity and the addition of SuSy. For that matter, how does this differ both in implementation and sound from current X product? Okay, I know I am trying it on somewhat but I would genuinely like to know.

Ian.

[macka]

Ian,

This a good question so why not just ask for an A/B on the factory floor during lunch hour!

I suppose this is what diy is all about though, you have to make it to find out.

But from what I can see the P 1.7 is a commercial offering designed operate in either balanced/unbalance mode without any penalties referring to "optimal operation" in either mode according to the manual.

I think this refers to the additional components for best common mode rejection with unbalanced in/ and say balanced out.

However, the inherant SE operation appears in both designs so on paper one could only assume subjectively they would be slightly different but not major league, ie using fet current sources, input cap etc.

I'm still not sure why, but un bal in, unbal out sounds noticably different to unbal in , balanced out and would like to hear from the others if they have similar experience?.

The mids are cooler and recessed, the bass is much tighter and the top end is more agressive.

Perhaps I have a diy cremlin in there some where

regards

macka