It's finally done... well at least one channel anyway. And it works!!!! With one channel missing (hopefully to complete in the next couple of weeks) so it is difficult to run the amp through some serious tests. But intial listening is very promising
I have been quite for so long because the chassis was a real slog, cutting anodizing, assembling. It took far longer than I would have guest with a few detours along the way.
I will take some photographs of the interior once i assemble the second channel. As a taster i have posted some shots of the exterior.
The heatsinks do their job nicely and the VU meter adds some nice eye candy.
I really wanted to try something different for the design of this chassis. Tall, thin monoblocks to match my Zu's, and turning the fins to face outward.
A thousand thanks to all whom have inspired and helped along the way. I am beaming
I have been quite for so long because the chassis was a real slog, cutting anodizing, assembling. It took far longer than I would have guest with a few detours along the way.
I will take some photographs of the interior once i assemble the second channel. As a taster i have posted some shots of the exterior.
The heatsinks do their job nicely and the VU meter adds some nice eye candy.
I really wanted to try something different for the design of this chassis. Tall, thin monoblocks to match my Zu's, and turning the fins to face outward.
A thousand thanks to all whom have inspired and helped along the way. I am beaming
Attachments
Vix said:
Hi Vix,
this makes me think to the last suggestion by Nelson Pass for Zv9
Nelson Pass said:
I think there is general agreement that the Balanced Line
Stage in the Zen series is better, even for single-ended
applications, so I suggest that.
What does it mean? Just a balanced pre (bosoz) or some additional circuit to have balanced input inside Zv9 amp?
I've a balanced DAC as source, so I'd be very interested.
I also have a question, a bit out of topic (but I was embarrased to open a new thread only for that one).
Is it possible/beneficial, to cascode the mosfet at BOZ? Is there a appreciable sonic improvement? Anybody tried that? I've searched , but couldn't find it...
(Yes, I believe that BOSOZ is a better amp, and, if I want to upgrade, I should build that one. However, for the moment I am thinking about ways to squeze a little bit more out a BOZ, as long as it doesn't get too complicated).
Another thing: BOZ is biased by 1 K resistor at around 40 mA. Does it make sense to reduce this resistor to around 750 Ohm and get a little bit more current?
Thanks a lot
Is it possible/beneficial, to cascode the mosfet at BOZ? Is there a appreciable sonic improvement? Anybody tried that? I've searched , but couldn't find it...
(Yes, I believe that BOSOZ is a better amp, and, if I want to upgrade, I should build that one. However, for the moment I am thinking about ways to squeze a little bit more out a BOZ, as long as it doesn't get too complicated).
Another thing: BOZ is biased by 1 K resistor at around 40 mA. Does it make sense to reduce this resistor to around 750 Ohm and get a little bit more current?
Thanks a lot
Thanks Vix.
So next project must be a bosoz. What about this one?
http://www.twistedpearaudio.com/
We have just to wait for Neil to finish his ZV9, convince him about the need of a bosoz, then we can copy his chassis
So next project must be a bosoz. What about this one?
http://www.twistedpearaudio.com/
We have just to wait for Neil to finish his ZV9, convince him about the need of a bosoz, then we can copy his chassis
I am already convinced of the need for a Bosoz. When do we start javascript:smilie('')
Big Grin
Look closely at the second image. There are a series (8) small holes in the bottom third. Each one of these holes is a LED which measures voltage output. I will post better pictures and a full description once i finish up the second channel
')Big Grin
Look closely at the second image. There are a series (8) small holes in the bottom third. Each one of these holes is a LED which measures voltage output. I will post better pictures and a full description once i finish up the second channel
neil_kaye said:I am already convinced of the need for a Bosoz. When do we start
I'm at page 55 of 130 of the following thread
http://www.diyaudio.com/forums/showthread.php?s=&threadid=67448&perpage=10&pagenumber=1
when finished I'll understand everything about these
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
X-BosoZ for Zen V9
Finished reading the long thread.
In the while I ordered 2 mono X-BosoZ + 2 PS PCBs + Dale resistors from www.twistedpearaudio.com
I hope these are still avalaible, as I've wired money already through Paypal.
I also compiled a Digy-Key order for the parts based on the BOM at Twisted Pears
PREAMP
1 4 LM4040CIZ-10.0-ND IC VOLT REF PREC MICROPWR TO-92 0 1.15000 $4.60
2 12 IRF610PBF-ND MOSFET N-CH 200V 3.3A TO-220AB 0 0.67500 $8.10
3 2 1N4736ADICT-ND DIODE ZENER 6.8V 1W 5% DO-41 0 0.36000 $0.72
4 8 1N4739ADICT-ND DIODE ZENER 9.1V 1W 5% DO-41 0 0.36000 $2.88
5 8 P1.5KW-3BK-ND RES 1.5K OHM 3W 5% METAL OXIDE 0 0.47600 $3.81
6 2 P22W-2BK-ND RES 22 OHM 2W 5% METAL OXIDE 0 0.28000 $0.56
7 20 P220CACT-ND RES METAL FILM 220 OHM 1/4W 1% 0 0.17100 $3.42
8 10 P27.0CACT-ND RES METAL FILM 27.0 OHM 1/4W 1% 0 0.17100 $1.71
9 10 P51.0KCACT-ND RES METAL FILM 51.0K OHM 1/4W 1% 0 0.17100 $1.71
10 10 P10.0KCACT-ND RES METAL FILM 10.0K OHM 1/4W 1% 0 0.17100 $1.71
11 10 P100KCACT-ND RES METAL FILM 100K OHM 1/4W 1% 0 0.17100 $1.71
12 10 P39.0KCACT-ND RES METAL FILM 39.0K OHM 1/4W 1% 0 0.17100 $1.71
13 2 P1192-ND CAP ELECT 220UF 35V SU BI-POLAR 0 0.80000 $1.60
14 4 P6948-ND CAPACITOR 1000UF 100V ELECT TSUP 0 3.50000 $14.00
15 10 495-1278-ND CAP .22UF 160V METAL POLYPRO 0 0.34800 $3.48
16 40 A24742-ND CONN TAB FAST TIN PCB .250 0 0.08600 $3.44
17 20 1450CK-ND STANDOFF HEX 4-40THR .500" BRASS 0 0.52100 $10.42
PS
18 20 1N4004-E3/23GI-ND DIODE GP 1A 400V DO-41 0 0.04100 $0.82
19 2 1N4761ADICT-ND DIODE ZENER 75V 1W 5% DO-41 0 0.36000 $0.72
20 2 1N4749ADICT-ND DIODE ZENER 24V 1W 5% DO-41 0 0.36000 $0.72
21 4 P27W-3BK-ND RES 27 OHM 3W 5% METAL OXIDE 0 0.51000 $2.04
22 10 P1.50KCACT-ND RES METAL FILM 1.50K OHM 1/4W 1% 0 0.17100 $1.71
23 8 P6110-ND CAPACITOR 4700UF 100V ELECT TSUP 0 6.44000 $51.52
24 8 P10779-ND CAP 220UF 100V ELECT FC RADIAL 0 1.55000 $12.40
25 4 495-1375-ND CAP .10UF 160V METAL POLYPRO 0 0.54000 $2.16
26 2 IRF9610PBF-ND MOSFET P-CH 200V 1.8A TO-220AB 0 1.89000 $3.78
27 4 HS184-ND HEATSINK TO-220 W/PINS 1.5"TALL 0 1.11000 $4.44
(I shall not order 1/4W resistors, as I ordered Dale kit with the PCBs)
There are still some 1Uf and 22uF MKP caps that are to be ordered elsewhere.
Now what's left to do is to wait for a picture of both Neil's VU meters working
Finished reading the long thread.
In the while I ordered 2 mono X-BosoZ + 2 PS PCBs + Dale resistors from www.twistedpearaudio.com
I hope these are still avalaible, as I've wired money already through Paypal.
I also compiled a Digy-Key order for the parts based on the BOM at Twisted Pears
PREAMP
1 4 LM4040CIZ-10.0-ND IC VOLT REF PREC MICROPWR TO-92 0 1.15000 $4.60
2 12 IRF610PBF-ND MOSFET N-CH 200V 3.3A TO-220AB 0 0.67500 $8.10
3 2 1N4736ADICT-ND DIODE ZENER 6.8V 1W 5% DO-41 0 0.36000 $0.72
4 8 1N4739ADICT-ND DIODE ZENER 9.1V 1W 5% DO-41 0 0.36000 $2.88
5 8 P1.5KW-3BK-ND RES 1.5K OHM 3W 5% METAL OXIDE 0 0.47600 $3.81
6 2 P22W-2BK-ND RES 22 OHM 2W 5% METAL OXIDE 0 0.28000 $0.56
7 20 P220CACT-ND RES METAL FILM 220 OHM 1/4W 1% 0 0.17100 $3.42
8 10 P27.0CACT-ND RES METAL FILM 27.0 OHM 1/4W 1% 0 0.17100 $1.71
9 10 P51.0KCACT-ND RES METAL FILM 51.0K OHM 1/4W 1% 0 0.17100 $1.71
10 10 P10.0KCACT-ND RES METAL FILM 10.0K OHM 1/4W 1% 0 0.17100 $1.71
11 10 P100KCACT-ND RES METAL FILM 100K OHM 1/4W 1% 0 0.17100 $1.71
12 10 P39.0KCACT-ND RES METAL FILM 39.0K OHM 1/4W 1% 0 0.17100 $1.71
13 2 P1192-ND CAP ELECT 220UF 35V SU BI-POLAR 0 0.80000 $1.60
14 4 P6948-ND CAPACITOR 1000UF 100V ELECT TSUP 0 3.50000 $14.00
15 10 495-1278-ND CAP .22UF 160V METAL POLYPRO 0 0.34800 $3.48
16 40 A24742-ND CONN TAB FAST TIN PCB .250 0 0.08600 $3.44
17 20 1450CK-ND STANDOFF HEX 4-40THR .500" BRASS 0 0.52100 $10.42
PS
18 20 1N4004-E3/23GI-ND DIODE GP 1A 400V DO-41 0 0.04100 $0.82
19 2 1N4761ADICT-ND DIODE ZENER 75V 1W 5% DO-41 0 0.36000 $0.72
20 2 1N4749ADICT-ND DIODE ZENER 24V 1W 5% DO-41 0 0.36000 $0.72
21 4 P27W-3BK-ND RES 27 OHM 3W 5% METAL OXIDE 0 0.51000 $2.04
22 10 P1.50KCACT-ND RES METAL FILM 1.50K OHM 1/4W 1% 0 0.17100 $1.71
23 8 P6110-ND CAPACITOR 4700UF 100V ELECT TSUP 0 6.44000 $51.52
24 8 P10779-ND CAP 220UF 100V ELECT FC RADIAL 0 1.55000 $12.40
25 4 495-1375-ND CAP .10UF 160V METAL POLYPRO 0 0.54000 $2.16
26 2 IRF9610PBF-ND MOSFET P-CH 200V 1.8A TO-220AB 0 1.89000 $3.78
27 4 HS184-ND HEATSINK TO-220 W/PINS 1.5"TALL 0 1.11000 $4.44
(I shall not order 1/4W resistors, as I ordered Dale kit with the PCBs)
There are still some 1Uf and 22uF MKP caps that are to be ordered elsewhere.
Now what's left to do is to wait for a picture of both Neil's VU meters working
Thanks for taking the initiative on the parts list...
What did you have to learn about the Twisted X-bosoz and its synergy with the Zen V9?
I was thinking of adding a DAC circuit alongside the Pre-amp. I have not dug around much in terms of what DAC would work well with the diypass boards. I have built Peter Daniels NOSDAC and liked it a great deal so that is one option. I will drop Peter a note to see if he has any experience running his DAC with the Bosoz board.
I like the idea of providing one SPDIF (digital) in and one RCA (analog) in for the pre-amp and then a single RCA out
Just a general question then, does anyone have any suggestions regarding a DAC?
What did you have to learn about the Twisted X-bosoz and its synergy with the Zen V9?
I was thinking of adding a DAC circuit alongside the Pre-amp. I have not dug around much in terms of what DAC would work well with the diypass boards. I have built Peter Daniels NOSDAC and liked it a great deal so that is one option. I will drop Peter a note to see if he has any experience running his DAC with the Bosoz board.
I like the idea of providing one SPDIF (digital) in and one RCA (analog) in for the pre-amp and then a single RCA out
Just a general question then, does anyone have any suggestions regarding a DAC?
Neil,
in a previous post I quoted a Nelson Pass suggestion about the improvement of Zv9 with a balanced input stage. That's why the BosoZ, that has a sense only with balanced operations.
A DAC with the BosoZ would have a balanced output for cleaner and higher signal level (my Wolfson 8740 DAC has it already).
Good idea (if I understand well) to put the DAC into the preamp chassis. Anyway it would have balanced connections to BosoZ. So the preamp would have digital inputs (spdif, toslink, I2S and, why not, clock I/O) and an additional analog unbalanced input for a SACD/DVD player (these have not digital output for hi-res signals).
Outputs would be one unbalanced, for Zv9, and another balanced, for the next Zen project
in a previous post I quoted a Nelson Pass suggestion about the improvement of Zv9 with a balanced input stage. That's why the BosoZ, that has a sense only with balanced operations.
A DAC with the BosoZ would have a balanced output for cleaner and higher signal level (my Wolfson 8740 DAC has it already).
Good idea (if I understand well) to put the DAC into the preamp chassis. Anyway it would have balanced connections to BosoZ. So the preamp would have digital inputs (spdif, toslink, I2S and, why not, clock I/O) and an additional analog unbalanced input for a SACD/DVD player (these have not digital output for hi-res signals).
Outputs would be one unbalanced, for Zv9, and another balanced, for the next Zen project
Almost there...
The first channel worked out great... dead quite and no hum.
The second channel, before putting the two chassis parts together sounded great. After closing it up (one of my early posts illustrated that the chassis is made up of two equal parts that slide together) and running a signal a terrible hum appeared with no audio signal. The VU meter also indicates that no signal is getting to the output.
I quickly took the chassis apart and re-ran the test. This time the hum had disappeared and the Zen's beautiful sound was back, put the two chassis together and the problem reappeared.
How can i trouble shoot this. It is clearly a condition of two wires that were not in close proximity, that upon open closing the chassis introduce some interference. Who are the likely culprits?
1. DC wire
2. Output signal
3. Input signal.
4. Wires to fets
It seems peculiar and possibly telling that the VU meter indicates no signal to the output along with the hum
The first channel worked out great... dead quite and no hum.
The second channel, before putting the two chassis parts together sounded great. After closing it up (one of my early posts illustrated that the chassis is made up of two equal parts that slide together) and running a signal a terrible hum appeared with no audio signal. The VU meter also indicates that no signal is getting to the output.
I quickly took the chassis apart and re-ran the test. This time the hum had disappeared and the Zen's beautiful sound was back, put the two chassis together and the problem reappeared.
How can i trouble shoot this. It is clearly a condition of two wires that were not in close proximity, that upon open closing the chassis introduce some interference. Who are the likely culprits?
1. DC wire
2. Output signal
3. Input signal.
4. Wires to fets
It seems peculiar and possibly telling that the VU meter indicates no signal to the output along with the hum
After a night of tearing things apart I have not eliminated the problem but i have perhaps narrowed down what the possiblities are.
There is a volateg difference between the two chassis parts.... very bad.
The difference is minor in the millivolts and it is no stable.
I thought great, one of the FETS must be grounding out, i attached 2 FETS per side. One side of the chassis is attached to the main ground so i assume i could not be these two FETS as there would not have been any sound from the outset as they were already grounded.
So the voltage, i think is originating on the un grounded side and when i join the chassis together i complete the loop and the amp dies.
I pulled these two fets off and placed a nice new silicone pad between them and the chassis, checked everything else on this side of the board (i.e. i removed anything that was attached and just let it hang in space) but stillt eh problem persists.
What could be generating such a small voltage difference between the two chassis sides?
There is a volateg difference between the two chassis parts.... very bad.
The difference is minor in the millivolts and it is no stable.
I thought great, one of the FETS must be grounding out, i attached 2 FETS per side. One side of the chassis is attached to the main ground so i assume i could not be these two FETS as there would not have been any sound from the outset as they were already grounded.
So the voltage, i think is originating on the un grounded side and when i join the chassis together i complete the loop and the amp dies.
I pulled these two fets off and placed a nice new silicone pad between them and the chassis, checked everything else on this side of the board (i.e. i removed anything that was attached and just let it hang in space) but stillt eh problem persists.
What could be generating such a small voltage difference between the two chassis sides?
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