Balanced Zen Line Stage

[Mad_K]

Thank you Chris.

This preamp is also known as BOSOZ, for you searchers out there....

 

[ElectroNick]

Hi Mad K,

The wiring looks great. Seems like it took a lot of your precious time.
But hey, the result was worth it.
I'm building one myself also. Copied the original board and started etching in the kitchen. So far so good. All components have arrieved, except the balanced stereo output pot.

I noticed you used a dact. That was on my list too untill i saw the price : Euro 315,- Is that a price one has to pay in the Norway aswell ?

Any tips of shops in Europe that would sell 'm for less ?

Greetz,
Nick

 

[Mad_K]

"I noticed you used a dact. That was on my list too untill i saw the price : Euro 315,- Is that a price one has to pay in the Norway aswell ?"

-No we are lucky, because we can order from www.audiocomponents.nl , and that's 1/2 that price!!!!

Any tips of shops in Europe that would sell 'm for less ?"

-Sorry...

 

[tortello]

Mad K, only a doubt, since I'm going to build a Balzen too:
24 steps are too few for a confortable volume regulation, or this is not a great problem, in your opinion?
Thanks.
Marcello

 

[Mad_K]

The DACT CT2-10k-4 with 24 steps is just perfect IMO... It doesn't relly feel like a stepped att., because it is sooooooo smooth

 

[Mad_K]

Here's the "under construction" picture

 

[SvErD]

Hei Mads

Where did you get the chassis?

 

[Mad_K]

Hei!

I got it from http://www.elfa.se/no/

Do a search on "DS2480". Really cheap, and very nice!

I struggled a bit with the design to fit it into the box, but I really wanted this chassis so...

I have also bought another one which I'm housing my new phono pre in.

 

[moe29]

Mads,
What amplifier are you driving with the BoSOZ? Are you
using the BoSOZ as an unbalanced to balanced converter?

did you show us pictures of the Phone Pre?


moe29

 

[Mad_K]

I'm, driving my Aleph30, shown here:

http://diyaudio.com/forums/showthread.php?s=&threadid=6966&highlight=aleph30

As I have balanced out of my CD, soon-to-be balanced from my computer (new project: balanced cable driver for my SB Audigy), and unbalanced the rest; I'm doing both.

The phone pre are in for a redesign, as I didn't like the first circuit. It's coming up REAL soon. One can't listen to CD all the time you know


Here's the new phono-plan: http://diyaudio.com/forums/showthread.php?s=&threadid=9628&highlight=ultrasimple

 

[jh6you]

24 steps are too few

If I am a professional and have to think about the market demands, Yeah, I might use a 32-step attenuator. But, DIY is just for me, so it doesn’t matter even with a custom-built 12-step attenuator… Daily, I touch two or three or four steps and hardly more… --Only a thinking--

 

[Mad_K]

update

I've updated my bzls with a new (and improved) rectifier
Initially I just used what was laying around, but after reading so much about the sonic impact of rectifier diodes, I felt that I must give it a try.. So instead of the single 6A standard bridge, I went all out and made a discrete dual bridge of the new Hyperfast- Soft Recovery (Stealth™ Family) diodes from Fairchildsemi. The actual model are the ISL9R8120P2 8A, 1200V STEALTH DIODE, TO220 http://parametric.fairchildsemi.com/datasheet.asp?PN=ISL9R8120P2&FAM=Rectifier&P=35054

Contrary to my expectations it made a really big difference!!!
I haven't had much time to listen (and the diodes are not burned in yet), but it was like a window-washing! The sound cleared throughout the entire spectrum. More detalied, yet smoother. Soundstaging is better.

I didn't try other types, but I believe the stealth diodes from fairchild are some of the best. Anyone who hasn't read this thread http://www.diyaudio.com/forums/showthread.php?s=&threadid=12539&highlight=high+speed+diodes should do so...

So from now on I will not use ordinary rectifiers in my amps anymore

Here comes some pics of the update:

 

[Mad_K]

p2p

p2p is the way to go...

 

[JOE DIRT®]

good Job on the install!!!....and thanks for the tip..I`ll give them a go on my next project!!!!


Cheers!!The DIRT®

 

[Cobra2]

Re: Balanced...

BTW, Have anybody compared the linestage with Aleph P ?
And, what would be the better sounding???

ArneK

 

[Mad_K]

good Job on the install!!!

The DIRT®

Thanks!

I don't know if you noticed, but the board actually got a little too long ('cause I was listening to the amp while I made it), and I had to cut it. I also meant for the diodes to stand upright, but the standoffs in my box where so long, I had to bend them so they wouldn't short to the top cover

 

[Mad_K]

Re: Re: Balanced...

BTW, Have anybody compared the linestage with Aleph P ?
And, what would be the better sounding???

ArneK

I believe they don't sound much different, except if you use it as a unbal.->bal. converter and is driving a true diff. amp like the aleph-x. The P is a much better converter because of the activce current sources. But for me, I like the passive cs. I'm not planning to go X either, so... Regular aleph is just an amazing amp

 

[moe29]

Mads,
Thanks for keeping us updated on your BZLS.
I noticed in one of Peter Daniel's threads that he
uses shunting caps too on his Gain Klone bridges...
(is that correct terminology?) maybe something to try later?
or do Hyper-fast diodes not benefit from that mod?

I shouldn't even be thinking about mods until i get
my BOSOZ in a finished chasis!


keep up the good work



m.

 

[Mad_K]

Thanks moe!

I believe a well tuned rc-snubber might yield good results, but I don't bother. Using just c-snubbers can actually make matters worse...

 

[lgreen]

What caps

I am thinking of making one of these. What transistors did you use (IRF610?) and where did you get the transformer?