| 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 |
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| 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 |
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| till |
| is there any difference in sound between balanced line stage and aleph p first version? which? |
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| 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... |
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| 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. |
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| 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? |
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| 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 |
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| Nelson Pass |
5K takes the maximum output down a decibel or so,
but there is plenty of swing available. |
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| 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. |
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| 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 |
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| macka |
Hey Guys,
DIY Boo boo.
Balanced mystery solved.
I found out why my Balanced operation was sounding so different..
I was in a hurry to commision the BOSOZ for balanced mode and recently discovered my balanced cable and XL connectors were wired incorrectly (I think I had hot and earth crossed at least).
I'm surprised it worked at all.
As to the sound now.. its magic!
regards
macka;) |
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| fcel |
Speaking of BOSOZ balanced output ....
Recently I have tried different set up of some of the stuff that I've built so far. I have mentioned a couple times in the other threads that my $500 Magneplanar MMG speakers sounds a little light in the bass region and I have always supplement the Maggies with a subwoofer.
Today, I hook up my BOSOZ (balanced out) to my Aleph 2 (balanced in) and I could not believe the amount of bass that I'm hearing from the $500 Maggies. I have used the Aleph 2 with some other pre-amps for the Maggies before but today is the first time I tried it with the BOSOZ. So, I'm very sure the much improved bass is due to BOSOZ. I'm beginning to wonder why BOSOZ makes such a big difference.
I was wondering if you guys have the same experience with your BOSOZ that are hooked up to "non-conventional" speakers.
And by the way, there isn't any turn on/off thump with this set up. |
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| macka |
Well,
My speaker are a dynamic piston range system but hardly conventional.
My previous pre out source was a Harman Kardan AV preamp model PT2500.
The BOSOZ slaughtered it, particularly in the bass clarity and dynamics, the sound is just so real.
By the way the Harman/Kardan uses NE5532 chips throughout, yuk says Nelson and rightfully so, they really suck compared the IRF610 Diff pair combo.
I have not A/B'd recently with the old preamp, but when the program material demands it , I can almost count the cycles on the bottom end.
PS I am waiting for Waynes remote passive volume control article which I hope I can incorporate into the BOSOZ. (For my Xmas stocking please)
These switched attenuators are way over the top, and there's no remote option. and my Lorlin 2 pole 6 position rotary switches just won't do.
cheers
macka |
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| macka |
Don't panic,
Disregard the Bass and Treble labels, its just an old box I "was" previously using for the Doug Self advanced preamp. (the boards of which are now in my audio museum)
Cheers
macka |
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| fcel |
| macka ... I'm glad to hear that your BOSOZ has definitive difference in the bass response too. |
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| martinschki |
sorry for the stupid question:
how can i use the advantage of the BOSOZ + Aleph5 connected balanced when my CD Player and my turntable has unbalanced Output (Cinch)??
Or should I build another Pre? (But everyone here praises the BOSOZ, so I also want to go for one!)
Regards,
Martin |
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| Mad_K |
| just plug them in man! :) |
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| BrianGT |
| quote: | Originally posted by martinschki
sorry for the stupid question:
how can i use the advantage of the BOSOZ + Aleph5 connected balanced when my CD Player and my turntable has unbalanced Output (Cinch)??
Or should I build another Pre? (But everyone here praises the BOSOZ, so I also want to go for one!)
Regards,
Martin |
Yes, you can take advantage of the BOSOZ and Aleph 5 connected balanced with an unbalanced input to the BOSOZ. It can essentially be used as a unbalanced to balanced convertor. Read the article...
http://www.passdiy.com/pdf/balzenpre.pdf
--
Brian |
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| macka |
Martin,
I assume you have not built the pre yet, if so would run with the BOSOZ as this is proven design with boards available or simple enough to make point to point wiring.
Here is a shot of my Aleph 5 with Hi Cap power supply, it runs very nicely and I may convert to the Aleph 60 or a small Alpeh X!
The Aleph 5 is still a great amp though and practical for most to contruct.
macka |
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| martinschki |
when you talk from point to point, do you think I could use
VERO WIRE? (at least for the Prototype?)
Unfortunately i donot know the diameter of the wire.
Regards
Martin |
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| martinschki |
Sorry, maybe my question was a little bit unprecise:
I HAVE that device at home and it is very easy to work with because the wire is insulated and while soldering the insulation melts automatically.
The only point could be, that the diameter of the wire is too small.
any suggestions? |
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| Mad_K |
| use it for the signal parts of the circuit, and double or triple it if you think it's not heavy enough for the power parts of the curcuit then. |
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| martinschki |
| quote: | Originally posted by Mad_K
just plug them in man! :) |
just for my understanding:
when i use an unbalanced CD Player I have to plug in the Cable on + and GND? What do I have to do with "-"?
Martin |
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| Mad_K |
| quote: | Originally posted by martinschki
just for my understanding:
when i use an unbalanced CD Player I have to plug in the Cable on + and GND? What do I have to do with "-"?
Martin |
That's correct. You ground the unused "-" input.
I strongly suggest that you read the http://www.passdiy.com/pdf/balzenpre.pdf
very carefully a few times. It's a lot of info, and it takes some read-throughs to get it all. Aslo do some searches on the forum with words like "zen linestage", BZLS, balzenpre etc. Most of the issues have been covered before.... |
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| Nelson Pass |
Keep in mind that with a single input if you want exactly
the same output level on both polarities with BOSOZ,
then you want to current source the transistors from
the negative voltage rail with a real current source,
not just resistors.
On the other hand, the Aleph 5 doesn't care at all, so it
is adequate to simply ground the (-) input.
This only gets imprtant when you are using BOSOZ balanced
output to bridge a pair of amplifiers. |
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| fcel |
| I have a CD player connected unbalanced to BOSOZ and then connected balanced to Aleph 2. I find that it doesn't make any difference whether the -ve input is grounded or not. What about you guys? |
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| jh6you |
BOSOZ is a diff amp having the transistor sources connected between two channels. Therefore, the unbalanced input might affect CMRR and the symmetry of output swings. Meanwhile, Aleph 2 is stereo amp of two mono blocks. The balanced input makes the higher input impedance while the unbalanced input the lower input impedance. This is all I know on surface. Anything else...? I dunno.
JH |
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| jh6you |
:boggled: Please re-read the above as follows:
BOSOZ is a diff amp having the transistor (gain device) sources connected between two sides. Therefore, the unbalanced input might affect CMRR and the symmetry of output swings. Meanwhile, Aleph 2 is stereo amp of two mono blocks. The balanced input makes the higher input impedance while the unbalanced input the lower input impedance. This is all I know on surface. Anything else...? I dunno.
JH |
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