x soz

[Henrik]

Hi moe29

Glad you like the xsoz.
But if you are driving it with standard bsoz two diffrent things happens.
1) Too much (IMO) x-feedback because of the higher outputimpedance in the standard bsoz.
2) If you have 10 uF at the output of your bsoz, you will be down -3db at 18Hz. You need at least 100uF, then you will be down -3db at 1.5 Hz.

If this is the case you still haven´t got the full potential from the xsoz. I have been there.

 

[gnomus]

It's a waste to to build a 20w SOZ or XSOZ. The most you should go for is 12 watts. Beyond that all you get is a lot more heat but all most no increase in volume at your speaker.

 

[moe29]

Henrik,

Thanks for bringing that up again. I will make the modification and
report back. Maybe my initial listening impressions were biased
because it's something i built? Is there a specific capacitor you
are using for that part? Thanks again for all your hard work in
this area!


Paul,

You are right - there is a steep curve of diminishing returns when
you are dealing with the SOZ and output power. It's easy to be
seduced by the power of the watt

 

[Henrik]

Moe29

I am using Black Gate type N at 47uF at 50V, but they need to bracke in for many hours.
But Panasonic FC with an say 1uF coupling cap should be nice too.
And then X it.
I would like to read about your expierience.

Henrik.

 

[tomchaoda]

x-bosoz gain

The gain at the original BSOZ an SOZ was controlled by R115 and R207, now it is by R120, R121, R122, R123, and R212, R213, R214, R215, all resistors in the X-feedbackloop.
I have kept the original gainlevel, and also this gave the best frequency responce.

Henrik:

I know the formula for original bosoz's gain is 20*log(R1+R2/R15). Is the gain for x-bosoz's gain calculated in this way:

gain=20*log[R1+R2/(R120+R121)//(R122+R123)] ?

Thanks,

Thomas

 

[Adams_Leo]

Hi Henrik,
I have built soz and want to upgrade to your version xsoz and xbosoz with CCS 03 which you have posted in this thread page 18.
Here I have one question,My current SOZ work voltage at +-25V,but you post sch show 19V.Do I need change some components value to match at +-25V.


http://www.diyaudio.com/forums/showthread.php?s=&threadid=3949&perpage=25&pagenumber=10


Thanks
Leo

 

[ralf]

x-SOZ

Dear All,

since many years have passed:
are the sonic progresses last years so big, that you cannot any longer recommend building a X-SOZ X-BOSOZ combi?
or arent there so big diferences to later designed amps like F5?

best

 

[MEGA_amp]

Hi Ralf,

I recently finished a 15W SOZ, with intentions of X-ing it at some point, and its absoultely one of finest amplifiers i've listened to. According to comments by NP in the ZV6 article, there isn't a seismic shift in subjective performance between SOZ vs XSOZ, or SOX as he calls it, but it is worth the effort if you've already built a SOZ.... "I certainly recommend that you run out and buy about 10 dollars worth of parts and upgrade it". I think a great amp is a great amp, no matter what era we're in. Toplogies aside between an amp like F5 and SOZ/XSOZ, the biggest difference in the last 10 years or so is the use of Jfets, either in the input or output stage, the latter being more difficult to obtain. A lot of the DIY efforts around here lately are of the First Watt types and typically in the ~25W range, and you can drive a wider range of speakers. The SOZ/XSOZ are more relegated to full range/horns. Don't forget the fact that a SOZ/XSOZ at 25W would be a major undertaking in power supply and chassis building i.e. Monoblock. With most of the FW offerings, you can buy chassis/PCB's/Fets at the diyAudio store, and have an amp built in hours, and you'd be quite happy. If it's a choice between F5 and SOZ/XSOZ...if you have sensitive drivers, SOZ/XSOZ would be my choice without a doubt. Hope that helps.

Regards,
John

 

[ralf]

Thanks, John

20 years ago i build SOX /BSOX, but while time passed i build may amps and speakers. best of them were Hiragas and many Class D amps.
now, i am back in Class A with Hiraga 30w and Hiraga Le Monstre and very pleased of them. somehow i stumbled over all the newer Pass amps and wonder if its worth to build one or some of them. especially the older SOX/BSOX, due to its aesthetic simplicity.
yes i have sensitive speakers.
i am thinking about it...

 

[ralf]

Hi Ralf,

I recently finished a 15W SOZ, with intentions of X-ing it at some point, and its absoultely one of finest amplifiers i've listened to. According to comments by NP in the ZV6 article, there isn't a seismic shift in subjective performance between SOZ vs XSOZ, or SOX as he calls it, but it is worth the effort if you've already built a SOZ.... "I certainly recommend that you run out and buy about 10 dollars worth of parts and upgrade it". I think a great amp is a great amp, no matter what era we're in. Toplogies aside between an amp like F5 and SOZ/XSOZ, the biggest difference in the last 10 years or so is the use of Jfets, either in the input or output stage, the latter being more difficult to obtain. A lot of the DIY efforts around here lately are of the First Watt types and typically in the ~25W range, and you can drive a wider range of speakers. The SOZ/XSOZ are more relegated to full range/horns. Don't forget the fact that a SOZ/XSOZ at 25W would be a major undertaking in power supply and chassis building i.e. Monoblock. With most of the FW offerings, you can buy chassis/PCB's/Fets at the diyAudio store, and have an amp built in hours, and you'd be quite happy. If it's a choice between F5 and SOZ/XSOZ...if you have sensitive drivers, SOZ/XSOZ would be my choice without a doubt. Hope that helps.

Regards,
John

thanks!
i am still thinking about...
for which woud you decide between X-SOZ/ X-BOSOZ combo and Aleph2 with Aleph P1.7?

 

[MEGA_amp]

I'm actually in the (sort of) middle of building an XSOZ/X-BOSOZ and a monster Aleph. I even bought a Dact CT2-10k-4 attenuator for my X-BOSOZ that I've been tryin to build for years. If NP would just take a break from churning out projects for us, I'd actually finish something . I have Aleph P1.7 pcbs, but they've been collecting dust. I had a custom 3000VA 35V toroid made for just the occasion, to be able to build both Aleph and XSOZ, which will be driven by the X-BOSOZ. I'd probably go with the XSOZ/XBOSOZ first. I listened to a 15W SOZ for a few months, it's excellent. But I feel I haven't listened to it properly with a proper preamp, was using a DRV134 to convert to balanced, being driven by a NAD 1155. Build it, and build it big!

-john

 

[ralf]

hi John,

there seem to be further fanatics on this planet

similar, as you, i too have lots of big transformers and about 70kg of heatsinks, waiting for beeing installed in amplifiers.

do you have experiences with other amps than your 15W X SOZ?
why do want to drive alephs and X-SOZ with X-BOSOZ and not with Aleph P 1.7?
Do you know the gain of aleph x?

i hesitate a bit, because i wonder if its worth to build sooo big amps, which consume sooo much amperes and heat...

here is one of two of my tiny Hiraga Monoblocks, with "only" 2 amperes current per side. its about 1 meter length.
it really sounds very good, but i need to build further amps in boring Corona times.

 

[Jeffreyjuice]

Holy capacitors! Did I count right 660 electrolytic's per channel? Wow that's impressive. Are they 100uf each or more? And are there more pictures of these wonderful amps I can look at for further inspiration?

@MEGAamp I am starting to get an idea of where your screen name came from, I guess it's better than "Dude with tons of GIANT heatsinks" I am eagerly awaiting your Aleph X progress.

Jeffrey

 

[MEPER]

Is it to get a low profile amp that so many small caps are used?
I am not sure it is a technical advantage to get let us say lower ESR / inductance compared to use the "big bottles"?

 

[Zen Mod]

if nothing else, good Zen practice

so, 158% justified

 

[MEPER]

To reach 200% we need a 100nF parallel "dry cap" for each "wet cap"?

 

[Zen Mod]

naah

more like resistor+ green LED across each of them

 

[MEPER]

Ok.....blue LEDs will probably generate too much noise.

 

[Zen Mod]

blue LEDs are Papa's secret ingredient

 

[MEPER]

Wayne like the red LEDs.....so we can't say that red LEDs are for sissies?
Green are probably a good compromise.