| Sproggit |
All
Being an absolute electronics newbie. I've been awake for the lasr 24 hours playing with jh6you's XSOZ in SIMetrix, COOL toy!! (SIMetrix I mean ;-))
Well, in the course of playing I read up a bit on the original Zen, started playing with different component / values and generally just enjoyed the heck out simulating an analogue circuit.
I've tried for the best bandwidth possible, and since I intend to build this (if it isn't absolute rubbish after my modifications) I've gone and bought a bulk pack of 1/4w thin film resistors, so advice as to where I should parallel 2/more higher value units would be appreciated.
If better qualified brains than mine would take a squiz at this and tell me how badly I've mangled an excellent circuit I would be extremely grateful!
I have attached a zip file with emf's of the circuit with a frequency response plot (-3db lowpass 179.79 kHz, -3db highpass 2.444Hz 26v flat from 12Hz to 41kHz) aslo included is emf of schematic and SIMetrix schematic file)
Regards
Jan |
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| jh6you |
| quote: | Originally by Nelson Pass
... I recommend one transformer per channel with the secondaries running in parallel to provide 24 VAC @ 4 amps. This will give you about 32 volts, enough for the 10 watt Zen, and if you are running balanced, I think we can get you to 40 watts into 8 ohms. |
Hi Jan
The above short quate from another thread is to inform about the output power of 40 watts into 8 ohms. Referring to your simulation circuits, I just like to recommend you to build it. You will experience a different sound from Zen. Microphones come closer to each music performer so that the soundstage is getting wider, cleaner (reduced noise and distortion), detailed and cheerful. The stereo image and the soundstage depth are great too.
It might be even better than ZV5... :bigeyes:
The power amp runs on 1.32A bias. If possible, however, I would like to recommend a choice of power transformers and heat sinks large enough for 2A bias, just in case...
Enjoy.
JH
PS. I suppose Henrik will help you for about the simulation. |
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| Henrik |
Sproggit
Stay close to jh6you´s scematic.
You can´t use zvn3310A as replacement for IRFP240, here You want a powermosfet, and this one also need extensive heatsinking.
If You should do something, then change the sourceresistors of the diff. pair from 1.5 Ohm to about 4 to 5 Ohm, this would give You much more X.
The amount of X-feedback is related to the efficience of the diffrential stage. If You short the right input to ground, You will only find some 15% at the right output related to the left output. This means You only get 15% of the X-benefits. If You raise the resistance to about 5 Ohm, then You will get about 80% X-benefit. If You made a Constant Curren Source You would get it all, 100%. |
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| jh6you |
I have listened to BOSOZ and XSOZV2 everyday for 45 days. I think that the time has passed long enough for the electrons to break through the whole path and for me to be used to the nice sound.
Last night I picked up one of my favorite CDs, Bob Dylan, Time Out of Mind, and was listening to the songs of his long-experienced and honest voices. By the way while he was singing the song, Not Dark Yet, I thought, yeah... the output of BOSOZ are with 47uF electrolytic capacitors and how the sound would change if I parallel them with nice small film caps...
I stood up and opened a box containing Icel-160V-1.0uF-1% film capacitors. I grabbed four of them and soldered them to each end of the 47uF caps parallel.
I replayed the same CD from the beginning to experience any different sound with the additional film capacitors. ???... The long-experienced and honest voices were the same. I smelled the same feeling of the songs. The same taste. ???... I might need to wait time until I could realize any difference in sound...
Anyhow, you could see the photo about my work.
JH |
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| ralf |
| quote: | Originally posted by jh6you
I have listened to BOSOZ and XSOZV2
I replayed the same CD from the beginning to experience any different sound with the additional film capacitors. ???... The long-experienced and honest voices were the same. I smelled the same feeling of the songs. The same taste. ???... I might need to wait time until I could realize any difference in sound...
Anyhow, you could see the photo about my work.
JH |
jh6you,
that are the same experiences as i made.
the only thing to try is to change the 47uF`s to completeley other ones. As bypasses to the electrolytics i can also hear no difference.
in my Bosoz i replaced the signal path resistors to expensive exotic ones - too -without any differences in sound quality. only, when i turn one of the bypassed film caps other way round there is difference in sound, as described in former posts.
since i am building the X`s now in fine cases i am attempted to use best parts only, but i think it`s waste of money.
But i am curious about Henrik`s experiences when building x`s with audio note parts...
Ralf |
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| Henrik |
jh6you and ralf
I have almost finished my XBOSOZ, I hoped I could finish it this weekend, but I doubt it. |
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| jh6you |
| quote: | Originally by Ralf
since i am building the X`s now in fine cases i am attempted to use best parts only, but i think it`s waste of money. |
I happened to read audio advertisements claiming that they proudly use H resistors, J capacitors, S internal wires... And, I happened to see who believes such advertisements and try to blindly replace resistors, capacitors and wires for their audio equipments. I am afraid to say that I was one of them.
These days I have a different approach. The question is which electronic components are fit for the circuit. It could be exotic components or reasonably good ones or surprisingly cheap ones or all of them or any of them.
I want to see not only the “exotic” grade of components, but also the “right” grade. Of course, if the exotic grade covers up the right grade technically and I have good budget, I might buy only the exotic grade.
:)
JH |
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| halojoy |
| quote: | Originally posted by jh6you
I happened to read audio advertisements claiming that they proudly use H resistors, J capacitors, S internal wires... And, I happened to see who believes such advertisements and try to blindly replace resistors, capacitors and wires for their audio equipments. I am afraid to say that I was one of them.
These days I have a different approach. The question is which electronic components are fit for the circuit. It could be exotic components or reasonably good ones or surprisingly cheap ones or all of them or any of them.
I want to see not only the “exotic” grade of components, but also the “right” grade. Of course, if the exotic grade covers up the right grade technically and I have good budget, I might buy only the exotic grade.
:)
JH |
very well said, JH
halojoy is with you 100%
that is no little amount |
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| ralf |
hi,
i think the biggest challenge is to find the "right ones", with which the amp sounds best.
But i can be very expensive until you find the right ones.
last week i bought some siemens MKV capacitors for building in in my final version of X Bosoz.
i bought 8 pieces of 22uF, absolutely exotic ones. they are filled with oil, which you can hear, when you shake it.
each of them meassures 80mm in diameter and 200mm in height and weights about 2,4 pounds. Costs: 150$, each.:bawling:
they are nos types of 1985 and more expensiv than jensens.
that means, that my XBosoz will get bigger than many power amps on this world...
i have made experiences with siemens mkv in crossovers, and it`s revealing with jenesen paper in oil.
I hope they sound good, nevertheless -they look giant.
next days i will post a pic of them.
...projects by the fanatics, for the fanatics....:D
Ralf |
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| halojoy |
| quote: | Originally posted by ralf
hi,
i think the biggest challenge is to find the "right ones", with which the amp sounds best.
But i can be very expensive until you find the right ones.
...projects by the fanatics, for the fanatics....:D
Ralf |
thanks
it remains to do some thinkings
in the line of your statements |
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| jh6you |
| quote: | Originally posted by ralf
... But i can be very expensive until you find the right ones... |
Thanks, Ralf. I will learn the right components at the cost of your experiments.
;)
JH |
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| ralf |
..that`s it,
but it will not work, when everybody waits, until others have tested components. :smash:
my first attempts were with ero MKP 1840, 6,8uF`s - cascaded to 33uF .
then bypassed with MKP from intertechnik, germany - hard to hear differences.
then bypassed by Styroflexes, 40 year old nos - hard to hear diffrences
then substituted with siemens MKV 900 volt types - the same-
next i will substitute with my new monster caps...
i`ll tell you the results next time...
i also substituted signal pass resistors with nos- ones called "Kohleschicht- resistors" which are selled from stein hifi systems, germany - for tree or four euro/piece- same result
O.k i could say that i heared ´small differences. the sound got warmer and so on. but i doubt, that i would hear it in blind test.
it`s not so, that my hifi ears are bad, i hear differences in sound between original soz/bosoz and xsoz/xbosoz - but i want to close out the psychlogical phenomenes like: oh i bought capacitors and resistors for half the price of a used car and therefor they sound best in the world - (otherwise i am a crazy guy who spends that amounts of money for nothing...:xeye: )
Many High-enders i know hear that what they wish to hear...
Nevertheless i am very interested in Henriks results with his parts.
I`m waiting nervous
Ralf |
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| ralf |
| quote: | Originally posted by jh6you
I am afraid to say that I was one of them.
:)
JH |
youre not the only one
Ralf |
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| Peter Daniel |
Ralf,
What is the source component that you are using? |
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| ralf |
| quote: | Originally posted by Peter Daniel
Ralf,
What is the source component that you are using? |
.
source components are 1/4 watt metalfilm resistors.
and in caps (in signal path)- what i have laying around. that are older ero mkp`s, new glimmer`s
old styroflexes (just bought 1000 pcs), some mkp`s of different manufakturers, MKV`s of siemens, different types, jensen oil paper.
i`m playing around with them, to get sure to have the best parts build in.
these days the resistors and other standard parts of my first attempt of AlephX will arrive me. When the first listening impression will satisfy me, the game with changing parts will go on...
the bigest differences are, when they are tested in signalpath of crossover. Here i can hear differences between each cap.
regards,
Ralf |
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| Henrik |
Ralf
The questin on what parts to use is a hard one.
My first SOZ was build with standard parts, and my next with exotic parts. The difference was clearly audible, but not a revolution at all. I do think, that the sins committed by parts in the X-feedbackloop is significantly cancled by the X.
The change from no X to X was the greatest improvement I ever done. Construction is the most important issue.
My test-XSOZ, wich consists of my old SOZ with exotic parts and some new standard parts to add the X.
I did one test on this test-XSOZ, I compared 2*22000uF Panasonic HA with 1*4700uF Blackgate Standard (wich was totally new, BG claims that they have to "play" more than 300 hours to reach max.) in my powersupply after the regulator. The test was clearly in favour of the Black Gate in any acpect. But if I got value for money, I don´t know, hard to say. And may be I heard wat I expected, so I do need to do some more tests before I am shure. Some times You se what You want to se. |
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| jh6you |
Henrik
I believe in this. High probability of sound improvement comes more from the different circuit designs than from the different passive parts. If I had saved total cost spent so far to buy non-effective exotic parts, etc., I could have bought at least one Pass X-150. But, we are diyAudio fanatics, as Ralf says. We feel happy ourselves in changing parts, and we have budget for this as Casanova have his budget for changing partners. :)
I look forward to hearing from you about the result of your new X-amps, and about your conclusion.
JH |
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| Henrik |
jh6you
Soon I hope! |
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| Sproggit |
Henrick & yh6you
Thanks for all the amazing info!
I have a question....
What would I have to change on the x-soz to drive headphones (Sennheiser HD 570's)?
Thanks again for your help
Regards
Jan |
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| JDeV |
I am on the brink of building my pre-amp. Decided on BoSoZ, but now thinking about XBoSoZ.
I intend to use XBoSoZ with Aleph30:
(I did try to follow this thread from page 1, did get some answers, also got confused couple of times, so please excuse for recurring questions.)
Questions (All on XBoSoZ)
1a. Which will work better with Aleph30 - X'ed or normal BoSoZ?
1. R115 - is it just a plain jumper -short?
2. The sum of R103,104,105,106,117 = 772ohm, is this crucial, or can I fit just 1 x 750ohm instead of all of these?
3. Must R117 now be 3Watt as well?
4. C101,102 - must it be metallised polyester film caps.(non polarised) ?
5. C101,102 - must it be 33uf, will 10uf work?
6. Do you now use P101, 102 for volume control - or do you use volume control on output?
7. For unbalanced input - do I just take -In straight to ground, do I still need P102 here?
8. The most difficult question - or most laughable - what is V1, V3 (AC 270m 0 Sine...)
Obviously I know nothing about the operation of amplifiers, but are learning :scratch:
Thanx for all answers and what ever other comments. |
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| ralf |
welcome to x...
i hope i can answer few questions:
1a: dont know, i have not tested with aleph, but i think bosoz suites better to aleph
1: yes
2: yes you can take one
3:theoretical you should use the wattage of sum of the resistors, which you want to replace with one resistor
4:no -feel free to experiment (see postings before)
5:the bigger the cap, the better/lower the lower frequency range
6:theoreticaly there is lower noise, by using the pot at the output, but unfortunaly a stepped attenuator makes cracks on the speaker when switching. but there should be impedance problems when using in output as Henrik says. In future i will test it in the input
7:no
Ralf |
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| JDeV |
Thanx for answers Ralph, 1 last Q:
| quote: | Originally posted by ralf
"7. For unbalanced input - do I just take -In straight to ground, do I still need P102 here?"
7:no
Ralf |
I am not clear on question 7.
1. Do I only take -In to ground?
2. Do I still need to utilise P102 - can I leave it out?
Thanx again . |
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| ralf |
1. yes
2.you don`t need p101
if you use XBosoz as unbalanced- balanced converter (as i do) you need a mono pot when pot is connected to input or a stereo-pot, when pot is at output. (of course per channel)
at input you use a 10k pot, at output you need a 5k pot.
Ralf |
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| ralf |
sorry, i meant p102,
Ralf |
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| JDeV |
Now I understand, thanx again.
Another question which I am not sure about, in BoSoZ there are C3 and C4, it is not on the circuit for XBoSoZ - are they now discarded?
What about their origenal purpose for filtering supply voltage? |
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| ralf |
As i know Henrik forgot them to put in schematic.
c3 and c4 with 1000uF should be build in.
i build-in 2000uf`s which i had on hand,
Ralf |
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| Henrik |
JDev
Last thing first, as Ralf just wrote, C3 an C4 should still be there, my fault, sorry.
1a. "Which will work better with Aleph30 - X'ed or normal BoSoZ?"
Try it, it is not difficult to swich between X and no X. I would say it would be better with X. I haven´t tried it, so why don´t You and then tell us?
3. "Must R117 now be 3Watt as well?"
1/4 - 1W will do for R116/117.
5. "C101,102 - must it be 33uf, will 10uf work? "
For the Aleph You just need 10uF, but if You are driving a more heavy load as my XSOZ You need 33uF.
6. "Do you now use P101, 102 for volume control - or do you use volume control on output?"
I have only tried a pot at the input. If You are driving the Aleph You can have a 5K pot at the output to also attenuate noise. But as Ralf said, it mig give some cracks at the speaker, I can´t explain why.
7. "For unbalanced input - do I just take -In straight to ground, do I still need P102 here?"
Need is a strong word, but the more identical the + and - input the better cancellation of noice and distortion. I tend to short the -input to ground at the terminals at the preamp, thus I will get differential noise and distortion cancellation on the potmeters (this requires P102) and wires inside the preamp, an also, as an alternative to short -In to ground, connect it to ground through a resistor matchig the singleended outputimpedance at the signalsource connected to +input if it is > 10K or so, Nelson mentioned taht in an other thread.
8. "The most difficult question - or most laughable - what is V1, V3 (AC 270m 0 Sine...)"
V1 and V3 is the signalsource, wich produces a ac signal with magnitude at 270mV and a sine wave with peaks at 270mV, all this for measuring.
Sproggit
"What would I have to change on the x-soz to drive headphones (Sennheiser HD 570's)? "
My version of the XBOSOZ is a nice headphone amp, but You need to rewire Your headphone, because You can´t connect it with common ground, You need 4 separate wires, 2 per ear. Driving them singleended would properly give You too much distortion. |
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| JDeV |
Thank you very much, Henrik and Ralf, for your replies. I am going to build the Bride both ways and will report back on how she behaved. ;)
P.S:
I just discovered this comment by Mr. 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."
So since Aleph30 and Aleph5 are very similar in design I am not going to bother with the impedance matching part. |
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| ralf |
| quote: | Originally posted by JDeV
I am going to build the Bride both ways and will report back on how she behaved. ;)
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...that would be nice of you,
Ralf |
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| jh6you |
Waiting for some news from your various experiments, I have thought about my BOSOZ and its output gain and distortion. If we reduce the output voltage gain, we get the lower distortion. Therefore, if I manage to reduce the gain down to the rock bottom, I could get the best result for my audio system. Great...
I have started digging into. I have altered four different gain levels: 11dB, 6dB, 3.5dB and 0dB. With 11dB-gain, I played the soundtrack to The Lord of The Rings on my DVD player for about 203 minutes, and with 6dB-gain for another 203 minutes, and with 3.5dB-gain for another 203 minutes, and with 0dB-gain for another 203 minutes, and back to 3.5dB-gain... On the course, I have opened and cleaned up my ears to sense every bit of differentiation of the distortions.
Damn it! I have forgotten the fact that my horn speakers have 8ohm-97dB. I have forgotten that the sounds have been already too loud even before the reach to the 1V-output of BOSOZ, and it means that all tweaks and tests have been done inside the 1V-output signal level. I should have remembered that my ears have no ability to distinguish any difference of the distortion at less than 1V of output signals. Hearing the difference of the distortion could have been possible only when the sound really roars so that the speaker horns tremble like mad beasts.
Anyhow, I have had a fun by doing something, and I have fixed it at the 3dB-gain simply because with the 3dB-gain and at the indication of volume knob almost to the upper end, the sound is loud enough at the level just below my own boiling point.
Waiting for some news from your various experiments... |
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| Henrik |
jh6you, no more waiting for now!
Hi all, I have just changed my test-XBOSOZ into a new and better XBSOZ, made with better parts in the X-feedback, some new circiut layout and new type of wire.
The sound is verry different from my testsetup, and my problem is, I really don´t know if it´s the new parts, the layout or the new type of wires that causes this change, so this will not bring any "scientific" conclusions on what really makes the differences.
I will come back later with some description of my impressions from my listening, but since the Blackgate type N need more than 50 hours idleing, so I wil give the at least 100 hours before I will make the final jugement.
Meanwhile, I will send some pictures, darawings and the full scematic.
I have tried to attach pictures to this post, but my computer crasches every time, I will send the pictures separately. |
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| Bricolo |
Whao!
Awesome work! :bigeyes: |
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| Henrik |
| X-board bottomview: |
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| Bricolo |
| quote: | Originally posted by Henrik
X-board: |
so this is the only difference between BOSOZ and X-BOSOZ? |
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| Henrik |
Yes!
Nothing more. |
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| Bricolo |
I'm glad to see that I'm not the only one who still uses those boards :D 'what's theyr name in english?)
But I prefer using 'line connected' boards, for basic projects. |
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| Henrik |
| In Denmark they are called veroboards. |
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| Bricolo |
| quote: | Originally posted by Henrik
In Denmark they are called veroboards. |
both the ones with points, and the ones with lines?
PS: ouch, I've seen that I've activated mail notification without taking care. I'll rapidly uncheck this box before being mail bombed :D |
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| Henrik |
| Ves, everything with a lot of small holes for mounting electronic parts. |
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| Bricolo |
ok.
Has anyone compared the X-SOZ to a Aleph-X ?
I'm not decided wich one I'll build, the aleph will certainly sound better (tell me if i'm wrong)
But it's ps is frightening :D |
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| ralf |
| quote: | Originally posted by Bricolo
ok.
Has anyone compared the X-SOZ to a Aleph-X ?
I'm not decided wich one I'll build, the aleph will certainly sound better (tell me if i'm wrong)
But it's ps is frightening :D |
Bricolo,
i am building an aleph x soon. since my ordered parts didnot come this xmas, it will last a bit longer to build them.
Ralf |
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| ralf |
hi Henrik.
thanks for posting the pics of your new X Bosoz.
absolutely fine work !!!
i am curious about your final description of the diference between your old - and the new one.
please let your xbosoz connected to mains next 2 or three days to break in the new parts.
and the tell us "unbiased":D ....
Ralf |
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| Henrik |
It has ben turned on for about 80 hours, so a day or two more is suitable.
I will be back then. |
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| jh6you |
Henrik
Looking at the inner side layout, I believe that the construction is based on your advanced plan and technique. The layout looks very systematic. The works done with the veroboard (or breadboard or perfboard) are amazing. P2P soldering looks like an art and wire-wrap is impressive. And, ...
:wiz:
Only one thing... I can see RCA connectors only.
Do you have any special reason why no XLR connector?
JH |
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| JDeV |
Pretty nice job Henrik. See this is what I mean by "Guys like you and the others with the same abilitys ....",
http://diyaudio.com/forums/showthread.php?threadid=9067 , definately in a differant class.
Hope it brings you many pleasant music hour's. :up:
Couple of questions if I may:
1.)Why do you have 6 FETS / board? Using the CCS's ?
2.)Does your PSU FETS also become extremely hot, about 70°C on heatsink? |
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| Henrik |
Ralf, jh6you and JDeV
Thanx for the "roses"!
The wires at the boards and the interconnections is made with solid OFC cobber core without isolation, I stripped some old Tara Labs loudspeakercable.
I used some of it for about 6 Years ago, and even today they shines as the are new, except from where I touched them with my bare hands while mounting, here the looks terrible because of heavy oxidation. So I desided to use these wires in my new project, but this time without touching them with my hands, only with tongs.
I am using the silver solder from Monitor Cabel, it is the easiest and best solder I ever tried, and if You hit the right tempreture, the fluss-medium works perfect and without burning.
jh6you
I don´t use XLR because I dont like them, mostly for aesthetically reasons. It is easy to just put one more RCA besides the singleended RCA to obtain balanced operation. For commercial products XLR´s are more manageable to the consumer, but for DIYers this should not be a problem.
JDeV
I am shure this thing will bring me many pleasent houres, it already has.
I don´t use 6 fets, only two. What You se is 4 Holco resistors, it is those with only two pins.
I can tell, my fets is running hot, not only the fets at the PSU but also the other fets and also the power resistors, that is why I have mounted them on the bottomplate, wich is made of 3 mm aluminium. The bottom plate runs at 23 degere C above ambiet when box is closed, wich is absoloutely the max. temp. for my taste.
In my first BOSOZ I had to install some small fans to cool the preamp fets and som big heatsinks for the fets in the powersupplies. The problem is, that the total heatdissipation is about 25Watt, and if You uses a little box as mine without any airflow to the outside world only inside airflow by fans, then the air inside becomes a little ove 45 degree C with a roomtemp. at 20 degree C. In this case the smaller heatsinks like Yours becomes 50-55 degrees C or so.
Your fets at the powersupply dissipates 3W each, because You run both channels from the same supply. I f I were You, I would do something about that. 50 degree C at heatsings is max.
By the way, I have measured heatsinktemp. by using a modified roasting thermometer, I just drilled a 4mm hole, in wich I put the sensor and som heatsink greese in between. This works nice.
Happy New Year to all.:) |
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| Henrik |
The solid OFC cobber wire I used is 1mm in diameter.
Here is a pic of my thermometer. |
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| jh6you |
For your info, mine is with 6 FETs (+/- 30V).
All six are attached directly to the 1.5mm aluminium bottom plate of the chassis.
The temperature of the bottom plate is measured about 20 degC above ambient.
JH |
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| Henrik |
jh6you
Actually, when I saw that You had mounted Your fets to the bottomplate, I realised that this was the best way for me too, and it just turned out well, a little at the edge, but it´s ok.
Not many have talked about the heatdissipation from the BSOZ, it is somthing You need to deal with.
Yours is running at 2*30v and only 40mA pr. channel, even then You get as high as 20 degree C above ambient. What is Your Voltage before regulation?
I am running 70 mA per channel, this means 2*82v (before regulation) at 70mA per channel, wich is 25W total. This 25W gives me 23 degree C above ambient at the bottomplate. My box is made of metal, and therefore it don´t isolate as much as Yours made of plywood, I think that is the explanation of the close tempreture we are measuring, even Yours is running at < 12W total.
Do You have any airflow through Your box? |
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| Bricolo |
| jh6you, where's the shematic you used? (with 6 fets) |
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| Henrik |
| I think jh6You made a miscalculation, he uses four fets per cannel and two in the powersupply, that makes 8 total. |
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| Henrik |
| You see, even I can´t count to ten at first, but of cource 10 fets in total. Ups!!!:xeye: |
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| jh6you |
| quote: | Originally posted by Henrik
You see, even I can´t count to ten at first, but of cource 10 fets in total. Ups!!!:xeye: |
Woooooops!!! It is total ten. :xeye: :)
JH |
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| jh6you |
| quote: | Originally posted by Henrik
jh6you
What is Your Voltage before regulation?
Do You have any airflow through Your box? |
2 x 42V.
No forced air flow. I just made number of small holes in the top plate above the location of FETs.
JH |
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| jh6you |
| quote: | Originally posted by Henrik
jh6you
Yours is running at 2*30v and only 40mA pr. channel, ...
Yours is running at < 12W total. |
Yes, you are right.
;)
JH |
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| Bricolo |
for those who built a soz (classical one or X)
what's the output power?
is a "high power" version possible? |
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| Henrik |
Bricolo
My XSOZ produces about 8W.
If You want more than say 15 W or so You shoud consider the Aleph-X. A high power version is possible, but take a look at this one: http://www.passdiy.com/gallery/soz-p6.htm |
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| Bricolo |
8W, ok :(
how can you calculate the output power? |
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| Henrik |
| Short version, look at the graph that shows the output watt versus supplyvoltage in the soz-papers by Nelson. |
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| Bricolo |
| and for the long version, depending of the bias? ;) |
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| ralf |
| quote: | Originally posted by Henrik
jh6you, no more waiting for now!
Hi all, I have just changed my test-XBOSOZ into a new and better XBSOZ, made with better parts in the X-feedback, some new circiut layout and new type of wire.
The sound is verry different from my testsetup, and my problem is, I really don´t know if it´s the new parts, the layout or the new type of wires that causes this change, so this will not bring any "scientific" conclusions on what really makes the differences.
I will come back later with some description of my impressions from my listening, but since the Blackgate type N need more than 50 hours idleing, so I wil give the at least 100 hours before I will make the final jugement.
I have tried to attach pictures to this post, but my computer crasches every time, I will send the pictures separately. |
Henrik,
now your new xbosoz had broken in...?
How would you describe the sound?
Was it worth the (much more) money?
Ralf |
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| Henrik |
Ralf
It certainly has, all I need now is to stay sober through out the day and do some seriously unbiased listening tests.
I will be back soon. |
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| Henrik |
Hi all
Ralf, I replied to you yesterday, that my XBOSOZ was broken in.
But to day I am not so shure.
Scematic: http://www.diyaudio.com/forums/show...9&pagenumber=17
Difference between my testsetup and my final is:
1) Coupeling caps changed from BlackGate Standard 47uF/50V to BlackGate typ N 47uF/50V (non-polarized).
2) Input- feedback- and input to ground resistors changed from Beyslag 1 Watt (reasonable good sounding resistor) to Audionote Tantalum resistors 1 Watt.
The drain and source resistors is changed from Yaego 2W to Holco MP930 resistors.
The rest of the resistors is unchanged, Audionote Tantaluresistors 1Watt.
In the Powersupply I have some Beyslag 1W and some Panasonic 1W.
3) Wirering on varoboards, connections between veroboards, attenuater and RCA plugs (except fom short wiring on input veroboard) is changed from thin silverplated solid ofc cobber isolated with teflon called Stripline (product from LCAudio) to 1mm Ø solid ofc cobbercore without isolation, stripped some Tara Labs Loudspeaker cable.
4) The testsetup´s feedbackloop were shortend from 35 cm(14 inches) to nothing more than the parts length say 10 cm (4 inches).
5) Changed the psu from BJT to Mosfets and made it a "virtual battery" suppliy like the PSU from Andrea Ciuffoli´s Powerfollower99. (This almost remooved the turn on thump).| quote: | Post from Ralf:
Henrik,
now your new xbosoz had broken in...?
How would you describe the sound?
Was it worth the (much more) money?
|
Because the nature of the changes I have just described, it is hard to tell wich role the different changes played in the entire improvements.
The improvements here and now don´t comes near to those from the X feedback, not what so ever.
"Was it worth the (much more) money" it is hard to tell Ralf. For me I think it is, and since Nelson´s Idears are free (bless his soul) I feel good to pay some more for this, and if You compare the time spent on this project, it´s peanuts.
But on the other hand, build these constructions on surplus and reasonable parts and I am shure You will end op with some real good sound anyway.
The very day I finished my new and final setup, I wrote "Hi all, I have just changed my test-XBOSOZ into a new and better XBSOZ" and "The sound is verry different from my testsetup".
When I fired up my new XBOSOZ it certainly was different, not only for the better:
Tighter bottom but less deatail in mid and high frequensies.
The 3D quality: deapth, wideness, highth, focus and space in the soundstage was remarkable poorer.
The little hardness from the testsetup in the upper mid and higth dissapeered, the sound became smoother.
But since I know that the 47uF/50v BlackGate type N coupeling caps has an ideling time at 50 hours, I told my self to calm down.
After about 30 hours ideling I felt much better when listening to my cd´s and records.
After 50 hours of ideling the sound changed again, and again after 30 more hours.
The impact from the BG N´s under the ideling process has been outrages.
Yesterday, after 80 hours ideling, I listend to to the amp most of the day, and my conclusion is:
Still tighter bottom but now more detail in upper mid and hight. Specially acustic instruments and vocals is well defined. In my testsetup vocals like Leonard Choen and Tom Waits often tended to be a little too hard and tense, I had to move my listening position a little back to avoid their attack, now I have moved listeningposition back and they are now more relaxed and focused and they so to speak stayes inside the the more homogeneous soundstage where they belong.
The sound is more relaxed and detailed, wich makes some cymbals on "Talking Timbuktu" of Ali Farka Toure and Ry Cooder outstanding, almost as if they extended their vibrant form from the rap-center of the drumstick to fade out in a gracefull horizontal movement throughout the whole room, hanging there for a while and then dissapear without any traces or echoes. This is a very nice and detalied representation.
In general, the dynamic is also a little better all over the spectrum.
After these 80 hours of ideling, I have a feeling, that this process still might not be over, so it coud happen that the balance or all acpects may improove even more. Time will tell. |
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| Henrik |
| Here is some drawings. |
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| Henrik |
| I did a mistake, it was not the last opdated, it is here. |
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| ralf |
Henrik,
thank you very much for the description,
greets,
Ralf |
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| Henrik |
Ralf
I am looking forward to read about Your Aleph-X when You have finished it.
Happy New Year!:) |
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| Bricolo |
Henrik: I'm trying to understand the differences between SOZ and X-SOZ; but it's quite difficult, since many things have changed
Can you explain me the reason of every change made to the original SOZ shematic? (resistor add, value changed...)
Thanks a lot |
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| ralf |
| quote: | Originally posted by Bricolo
Henrik: I'm trying to understand the differences between SOZ and X-SOZ; but it's quite difficult, since many things have changed
Can you explain me the reason of every change made to the original SOZ shematic? (resistor add, value changed...)
Thanks a lot |
...years ago i was in the dome (Munster) of Strasbourg - very impressive..
Nice to comunicate with fanatics all around the world - internet life high..
Ralf |
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| ralf |
| quote: | Originally posted by Henrik
Ralf
I am looking forward to read about Your Aleph-X when You have finished it.
Happy New Year!:) |
Henrik,
i fear it will take a while with the aleph x. (it`s not as easy to build p2p as XSOZ). The parts have arrived me, but i build a CD Player in the moment, too, which also takes much time....
Ralf |
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| Henrik |
Bricolo
If You look at the original scematic of the SOZ and compare it with my version of XSOZ, then You will know the difference.
To fully understand the X thing is something else, You can read about it in Nelsons patent, but it can be hard to understand.
If I can explain it in other way than NP did in the patent I will post it, and then we will se if my understanding is correct. Funny, nobody has yet given the fully logical explanation in laymans word, if somebody has, let me know. |
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| Bricolo |
| quote: | Originally posted by ralf
...years ago i was in the dome (Munster) of Strasbourg - very impressive..
Nice to comunicate with fanatics all around the world - internet life high..
Ralf |
what is the dome? :confused:
Do you mean "La Cathedrale"? (the big church)? |
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| Bricolo |
| quote: | Originally posted by Henrik
Bricolo
If You look at the original scematic of the SOZ and compare it with my version of XSOZ, then You will know the difference.
To fully understand the X thing is something else, You can read about it in Nelsons patent, but it can be hard to understand.
If I can explain it in other way than NP did in the patent I will post it, and then we will se if my understanding is correct. Funny, nobody has yet given the fully logical explanation in laymans word, if somebody has, let me know. |
No, if I compare the SOZ shematic anr yours, I will see the differences, but not understand them ;)
For sure, I haven't understood X. When I look at Nelson's patent, I find it quite complicated, when I look the aleph X shematics, I find it very different from the patend, they haven't anything in common, IMHO (the aleph X has "crossed" feedback, the patent hasn't)
And when I check the X-SOZ shematic, I think that X is only a concept, telling that X is only a basical feedback, but on a balanced amp (a fully symetrical amp)
But that's not the problem.
The thing I was asking you, is to tell me "I've changed resistor ... value, because of ....", "I've added this resistor, to do this..."
Because for now, I only see the differences, and I don't have the knowledge to understant them.
And your explanations would really help me much :) |
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| ralf |
| quote: | Originally posted by Bricolo
what is the dome? :confused:
Do you mean "La Cathedrale"? (the big church)? |
..yes
Ralf |
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| Henrik |
I will try to explain the X in XSOZ.
To add X to the SOZ as I did it, all you need is to add C1, C2, R212, R 213, R214, 215, reduce R208/209 from 220 to 100 Ohm and a preamp that can feed a load at only 120 Ohm.
C1 and R212 form the feedback from drain to gate at Q201.
C2 and R213 form the feedback from drain to gate at Q202.
When we apply Negative Feed Back, the signal source will se this as a lower input impedance or higher load, since every time the signal source wants to deliver a certain voltage the NFB wants to lower that voltage. But if the signal source is ideal, witch means it will keep the voltage level regardless of the load, it will not be affected, and no NFB will be added. So in order to get NFB and X we need to add some impedance to the signal source so it can vary with the NFB presented to it, and that we will do by placing R214 and R215 between node 1 and node 2 in the circuit, so that is why they are in XSOZ and not in the original SOZ.
This is just normal feedback, but in case of the X this is not so important. The far more important thing is, that when placed in a differential (not only balanced) gain stage like the SOZ, this NFB also opens a path for the noise and distortion produced by the gain in Q201 to the drain of Q202, and it arrives here non-inverted, witch means it will be cancelled differentially.
This path goes from node 3 through C1, witch blocks the DC, and through R212 witch will, in cooperation with R214, adjust the NFB level at node 2. From node 2 it passes the gate resistor to the gate, and then leaves Q201 in Common Drain*) mode and arrives at Q202´s source pin as if it was coupled in Common Gate*) mode and then appears amplified at it’s drain.
All along this path the noise/distortion keeps the non-inverted mode. When the noise/distortion arrives in identical mode to the output it will be cancelled differential, the speaker will not see it, but measured single ended it’s still there.
Signal path hits the nodes: 1-2-3-4-5.
X path for Q201´s noise/distortion hits the nodes: 3-2-4-5.
I have just described what happens to a signal presented to +IN, but the same will happen for –IN, and XSOZ should not be driven unbalanced!
In the Aleph-X it is the input diff. pair witch realizes the X, but both feedback loops includes it’s own Aleph output stage. Thus the diff. pair don’t need to be biased within the high output current, witch saves a lot of heat.
Quoting Nelson:
The essence is still using a symmetric feedback arrangement
around a differential pair, which isolates error from signal
and uses it to make distortion on two halves identically
in phase and thus cancelled.
Can’t be said more precisely by the man himself who got this brilliant idea.
*) See Nelsons article “DIY Op Amps” fig.6.
BTW my XBOSOZ is getting slightly better for every 24 hours of idling. |
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| Bricolo |
great :) thanks a lot!
How did you calculate the values for C1 anr R212? Is there a "common" value for feedback?
R207 has been removed (bypassed), won't this degrade THD? |
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| Henrik |
Bricolo
How did you calculate the values for C1 anr R212?
I did it in the SIMEtrix simulator, there I could follow the amps behaviour under varying circumstances.
Is there a "common" value for feedback?
Almost, as long as you keep inside the normal impedance ranges, this was not possible here. The Aleph-X uses almost standard values I suppose.
R207 has been removed (bypassed), won't this degrade THD?
It should, but I think the X will cancel most of it. The X-feedback needs this extra gain. I haven´t measured THD, but as long as the sonical change is for the better it´s ok, and they are I can tell. |
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| jh6you |
Henrik
Thank you for your kind explanation. And, I am sure that you are satisfied with the sonic performance of your XSOZ. By the way, I have two questions with your circuit posted above.- From the circuit, I see that you have the feedback of the output signal into the input after changing the phase by C1 and C2. As far as I understand, however, the feedback is to be without changing the phase for the purpose of the X distortion cancellation. Don’t you think so?
- Since you have C1 and C2, your feedback becomes positive feedback to the input on the same side. That is why the resistor values of R212 and R213 are relatively small. Is it right?
JH |
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| Bricolo |
| why does a cap invert the phase? |
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| FYC |
Henrik,
I had a SOZ, and modified to X-SOZ using Ian Macmillan's configuration. I tried to test your configuration during Christmas time and found that it did not work.
The voltage swing from the differential output is extremely limited, clipping appeared, and the overall gain is less than 1. I checked several time but cannot find any assembly error. I immed switched back to Ian's configuration and it worked again perfectly. The only difference between your configuration and Ian's is that you block the DC in the NFB loop, and the gain control resistor pair is low (1k - 82 ohm). In Ian's circuit, the NFB is DC, so we need to put in blocking capacitor in the inputs, and the gain control resistors are (10k - 1k). Any idea why? |
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| Henrik |
JH
1)Caps don’t change the phase, they only blocks DC.
Without NFB node 2 would have +1V just like at node 1. The NFB is -0.5V at node 2 (-5V at node 3 is lowered by R212 at node 2) and the signal is +1, so total is +0.5V (1-0.5).
The non inverted noise and distortion will be lowered by a factor of 10, just like the signal, but since there this is not a part of the input signal, it will not be lowered but go direct to the gate and appear at the source pin at Q1. From here it will be amplified by Q2 as Common Gate amplification with output at the Drain, all in non inverted mode and the noise and distortion will appear in common mode at both output terminals and thus cancelled differentially.
2)The small values of R 212 and R214 are needed in order to obtain a high frequency roll at -3db at 100kHz.
Ian Macmillan’s and my first XSOZ made it only to 75kHz at -3db and more important only 25kHz at -2db. This was certainly audible.
The price paid for the low values of R212 and 214 is very very low input impedance; 120-Ohm single ended, normal standard is 10K to 47K Ohm. This requires a very special preamp to drive this lower load, BOSOZ and BOZ can’t.
FYC
Sure it works.
All you need is a proper preamp to drive it; your missing voltage swing would properly be caused by the low input impedance at the XSOZ, that almost shortens the output from your preamp and thus makes it clipping and producing a lot of distortion, and then sounding awful. That was why I had to make the XBOSOZ; even the BOSOZ can’t drive my version of the XSOZ.
If you have a proper preamp, the sound is so much better than the Ian Macmillan’s “Ian-X-SOZAlt” or my first XSOZ witch was based on Ian’s values for R212 (10K) and R214 (1K).
When the caps is inside the X-feedback loop, their noise and distortion will be cancelled as well, if they are outside the feedback this will not happen. |
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| jh6you |
Herik
I was totally wrong about the changing phase. I was in a condition out of order. :bawling:
You have done your best to get almost complete cancellation of the nonlinear distortion by introducing the X-tech, and particularly with a combination of low value of R212 and higher value of R210. It also explains me that you have been trying to sacrifice the signal gain somewhat and, by doing so, to maximize the distortion cancellation.
By the way, you have said, when the caps are inside the X-feedback loop, their noise and distortion will be cancelled as well. What kind of noise and distortion is produced by the caps?
Since the input impedance of your XSOZ is very low, the pre might be overloaded or, as you have said, the output of the pre might be considered almost shortened. In this respect, your only XBOSOZ will work properly. However, if I want to use other than your XBOSOZ, what factors are to be deeply considered as matching preamplifiers?
Your brief explanation would much appreciate.
JH |
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| Henrik |
JH
Velcome back in order!
R210 has the same value as suggested by NP in the SOZ.
I have sacrificed no gain, my XBOSOZ and XSOZ have exactly the same gain as NP´s original designs.
Any passive or active components produces some unlinearity witch causes more or less distortion and they also produces some noise, even wires, but not that much.
I have to leave now, I will try to ansewer your last question later today or tomorrow. |
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| Henrik |
JH| quote: | | Since the input impedance of your XSOZ is very low, the pre might be overloaded or, as you have said, the output of the pre might be considered almost shortened. In this respect, your only XBOSOZ will work properly. However, if I want to use other than your XBOSOZ, what factors are to be deeply considered as matching preamplifiers? |
If the preamp´s outputimpedance is 12K and the poweramp inputimpedance is 120 Ohm, then I woud say that the output it is almost shortend. But if the preamp´s outputimpedance is 12 Ohm, it is far from shorted when loaded with 120 Ohm.
The output impedance in my XBOSOZ is 10 Ohm as I recall.
The pramp for my XSOZ shoud have between 10 to say 100 Ohm outputimpedance.
The specific need is an output swing at around 1.5V at 15mA current, wich is more current than most preamps is capable of.
WWW.LCAudio.dk has a preamp called SideWinder, wich can do this, Lars Clausen even recommend to solder a 150 Ohm resistor at the interconnect at the poweramp from signal to gnd. You can read about this at his homepage. |
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| FYC |
Henrik
I do have a XBOSOZ as my pre-amp to drive the XSOZ, but still get the limited swing. The XBOSOZ is also based on your schematics. Something strange here. |
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| jh6you |
Henrik
Thanks to your explanation, now I have better understanding how to match pre amps with power amps having very low input impedance.
Regarding the noise and distortion generated by caps, I was thinking about how they are bad against the sound quality. It seemed that my thought and the question however went amiss. Anyhow, I agree that when the nonlinear distortion output voltages produced by the gain transistor and the DC-blocking cap are fed back as noninverting voltages to the inverting input, they will be calceled almost null at the output stage. At the same time, if I see your XSOZ, it has not only noninverting voltage feedback, but also inverting voltage feedback which would lower the input impedance--probably very low due to the low R212. I hope I am right...
Simply, I thought that your XSOZ and the original SOZ have similar or the same output power ratings, but different signal voltage gains...???
JH |
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| Henrik |
FYC
Simple test:
I presume that your system is working at this moment, with Ian Macmillan´s XSOZ.
If so, try to short the output of your XBSOZ to ground with a resistor at say 150 Ohm while stil connected to your poweramp. If this don´t give you any problems, then your XBOSOZ is ok, and then the failure has been in your build of the XSOZ in my version.
If you get the same problems as you did before, then it´s proberly a failure in the XBOSOZ.
JH
I will be back again. |
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| Bricolo |
| what can we do to make the bosoz less sensible to the load? (I mean: keep the peak to peak output voltage quite stable, with a low impedance load, or a high one) |
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| Henrik |
JH| quote: | | Simply, I thought that your XSOZ and the original SOZ have similar or the same output power ratings, but different signal voltage gains...??? |
But it isn’t like that.
I have reconsidered the question about the cancellation of noise and distortion from the caps inside the X-loop in the XBOSOZ, I am afraid this won’t happen, because it is not present at the output at node 3, it is more like a new signal source at the input node 2.
If you move it to the front of the input, you would need to increase the value significant in order to get the same low-end roll off, so it is still better to keep them inside the feedback loop. You also get a lower bias point for the fet´s which gives a little more voltage swing, but this could also be adjusted otherwise.
| quote: | | At the same time, if I see your XSOZ, it has not only noninverting voltage feedback, but also inverting voltage feedback, which would lower the input impedance--probably very low due to the low R212. I hope I am right... ...??? |
The signal is inverted in the feedback, but the noise and distortion is noninverted.
Bricolo
Lower the drain resistors and raise the gain by reducing R15.
More efficient, make it an XBOSOZ, the X-feedback alone will lower the output impedance dramatically and then you also get X |
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| jh6you |
| quote: | | I have reconsidered the question about the cancellation of noise and distortion from the caps inside the X-loop in the XBOSOZ, I am afraid this won’t happen, because it is not present at the output at node 3, it is more like a new signal source at the input node 2. |
As you have said earlier, I think that the distortion produced by the cap inside the feedback loop will be cancelled too. Anyhow, it does not matter whether it is actually cancelled or not, as the size of distortion is expected ignorable, IMHO. I will consider the caps with respect to the frequency bandwidth only.
| quote: | | The signal is inverted in the feedback, but the noise and distortion is noninverted. |
IMHO, both signal and the noise/distortion output voltages are fed back as noninverting voltages to the inverting input, with respect to the noninverting input of the signal. And the noise/distortion voltages are amplified and arrive at the output with inverted phase, cancelling the original noise/distortion. In addition, the input impedance is increased with this kind of feedback.
At the same time, both signal and the noise/distortion voltages are also fed back as inverting voltages to the noninverting input. The noise/distortion is decreased in this case too, but the input impedance is decreased in opposition to the above.
Don’t you think so?
JH |
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| Henrik |
JH
I am not shure I understand your explanation, and I still stick to my conseption on the X-feedback as I have described and illustrated earlier. |
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