Same. Use ohms law. P=U*I (I=U/R). You have to check if you're voltage or current limited.
Pload_U=(U*U/R)/2=W RMS
Pload_I=(I*I*R)/2=W RMS
example SEWA:
Swings +/-10,5V@2A.
P8ohm_U=10,5*10,5/8/2=7W RMS
P4ohm_U=14W RMS
P4ohm_I=2*2*4/2=8 W RMS
We see that SEWA is voltage limited to 7W in 8 ohm and current limited to 8W in 4 ohm
Pload_U=(U*U/R)/2=W RMS
Pload_I=(I*I*R)/2=W RMS
example SEWA:
Swings +/-10,5V@2A.
P8ohm_U=10,5*10,5/8/2=7W RMS
P4ohm_U=14W RMS
P4ohm_I=2*2*4/2=8 W RMS
We see that SEWA is voltage limited to 7W in 8 ohm and current limited to 8W in 4 ohm
Professional BOZ PCBs?
I'm considering having really professional BOZ boards made. They will be in strong keeping with the original schematic, only with a little improved pre-reg filtering and a MOSFET regulator instead of the original hard-to-get bipolar. The pcb will be laid out for use with the original parts (usual PASS LABS industial quality). For the PCB spec I was thinking 35um, double sided (gndplane on topside), plated through holes and ENIG (Electroless Nicle/Immersion Gold) surface finish, black soldermask on both sides and white silkscreen on topside.
However, boards of this quality don't come cheap in very small quantities, so I am wondering if there are others that also want a board (or two). Price depeds on the total quantity. I've gotten some preliminary prices: 10pcbs:34USD/pcb 20:21USD 50:14 100:11. If I could get at least 10 people interested, I would order 20 boards and expect the rest to be spoken for over time. Attached is the schematic I'm proposing we use and the pcb silkscreen with PTH's. PCB size is 92x135mm.
I'm considering having really professional BOZ boards made. They will be in strong keeping with the original schematic, only with a little improved pre-reg filtering and a MOSFET regulator instead of the original hard-to-get bipolar. The pcb will be laid out for use with the original parts (usual PASS LABS industial quality). For the PCB spec I was thinking 35um, double sided (gndplane on topside), plated through holes and ENIG (Electroless Nicle/Immersion Gold) surface finish, black soldermask on both sides and white silkscreen on topside.
However, boards of this quality don't come cheap in very small quantities, so I am wondering if there are others that also want a board (or two
). Price depeds on the total quantity. I've gotten some preliminary prices: 10pcbs:34USD/pcb 20:21USD 50:14 100:11. If I could get at least 10 people interested, I would order 20 boards and expect the rest to be spoken for over time. Attached is the schematic I'm proposing we use and the pcb silkscreen with PTH's. PCB size is 92x135mm.
DIY version of BOZ layout
I have optimized the pads and holes (drill-guides) for a singlesided diy version of this layout. Since all routing is on the solderside, this is enterely possible. The only mod that has to be done is to solder a piece of wire between the "-" terminals of of C1 and C5 to make the ground connection since the groundplane is compromised. Enjoy
I have optimized the pads and holes (drill-guides) for a singlesided diy version of this layout. Since all routing is on the solderside, this is enterely possible. The only mod that has to be done is to solder a piece of wire between the "-" terminals of of C1 and C5 to make the ground connection since the groundplane is compromised. Enjoy
Mad_K's single sided PCB
Even a single sided PCB should be sufficent for a decent BOZ, by the way do you have any more SEWA PCB's. I'm planning a SEWA with 6C45 for the voltage amp in front of MOSFET's. The 6C45 will actually work well at 24V, should be a nice combination. I am presently using a CCS loaded 6C45 to drive a 300B and it sounds sweet.
Are you planning to drive the SEWA with BOZ, is BOZ good for a voltage gain of 20+
I am interested in a BOZ PCB mostly because I already have most of the parts in hand, and a curious about how it will sound.
Even a single sided PCB should be sufficent for a decent BOZ, by the way do you have any more SEWA PCB's. I'm planning a SEWA with 6C45 for the voltage amp in front of MOSFET's. The 6C45 will actually work well at 24V, should be a nice combination. I am presently using a CCS loaded 6C45 to drive a 300B and it sounds sweet.
Are you planning to drive the SEWA with BOZ, is BOZ good for a voltage gain of 20+
I am interested in a BOZ PCB mostly because I already have most of the parts in hand, and a curious about how it will sound.
Yes the BOZr0-SS PCB's turned out nice. Very compact. I still wish to get the real boards produced though, som much nicer... When ordering professional PCBs there is not much difference in price with single sided vs double sided though.
I have a couple of SEWA Rev.B boards left. I also have a small batch of Rev.C boards, which I think is a big improvement, at least mechanically. The Rev. C boards have 4 standoff mounts and the MOSFETs are mounted horizontally. Yes BOZ will happily give a +/-20V swing (distortion is proportional, but monotonic 2nd harmonic). Your interest in a BOZ board is noted, let's see if we can get some more people interested and I'll order the boards
I have a couple of SEWA Rev.B boards left. I also have a small batch of Rev.C boards, which I think is a big improvement, at least mechanically. The Rev. C boards have 4 standoff mounts and the MOSFETs are mounted horizontally. Yes BOZ will happily give a +/-20V swing (distortion is proportional, but monotonic 2nd harmonic). Your interest in a BOZ board is noted, let's see if we can get some more people interested and I'll order the boards
Hi,
I am interested for BOZ pcb but I would prefer if you made them dual mono, hope it is correct term for what I have on my mind. Two separated boards each with own PS.
And one optional feature on board so one can put additional pot at the input of BOZ because many people had a problem regarding distortion caused by too high signal from cd player, etc...You know what I mean.
I am interested for BOZ pcb but I would prefer if you made them dual mono, hope it is correct term for what I have on my mind. Two separated boards each with own PS.
And one optional feature on board so one can put additional pot at the input of BOZ because many people had a problem regarding distortion caused by too high signal from cd player, etc...You know what I mean.
If you want mono, you just use 2 boards and mount one channel on each pcb: The PSU takes more than half the board anyways. Input and output pots will not be included on board because this would make parts sourcing around the world difficult; it is best accomplished off-board anyways. If you look closer on my schematic you will notice I have included some extra resistors. I effectively have a voltage divider on the input, and you can scale down the input sensitivity by increasing R109/R209 and/or decreasing R107/207. So, you're up for 2 boards then?
PS: I'm going to use my 10K DACT CT-2 stepped attenuator on the input, and no pot on output.
PS: I'm going to use my 10K DACT CT-2 stepped attenuator on the input, and no pot on output.
:
Did I post here our "listening test" between SEWA and ZV9?
My friend has built the ZV9 and we listened both amps in different setups and homes like last time we did in the "monster 10 competitors test". This time it was much easier!
The preamps was BOZ, BOSOZ, REMUS tube pre, MF X10-D Buffer.
Result:
ZV9: very nice sounding amp!!! Silky, velvet super sweet sound! Nice resolutions, dynamic and bass. It is not true that the ZV9 has not enough bass to be use as wild band amp!! I think who said this He didn't operated the amp with a suitable loudspeaker!
SEWA:like every time it makes the music life!!!!!!!! It has a bit better resolutions in micro details, a bit better dynamic and basscontrol, but a bit rough sound compared to the ZV9.
Conclusion: (if there is?)
My friend want to build the SEWA and I don't want to build the ZV9!
I don't want just another good sounding amp......
But I would like to build a J-Fet SEWA!!!!!!!!!!!! Mads please help me!!!!!!!!!!!!!!!
I think, if we could combine the two amps, that would result probably the best amp in the world.
Greets:
Tyimo
My friend has built the ZV9 and we listened both amps in different setups and homes like last time we did in the "monster 10 competitors test". This time it was much easier!
The preamps was BOZ, BOSOZ, REMUS tube pre, MF X10-D Buffer.
Result:
ZV9: very nice sounding amp!!! Silky, velvet super sweet sound! Nice resolutions, dynamic and bass. It is not true that the ZV9 has not enough bass to be use as wild band amp!! I think who said this He didn't operated the amp with a suitable loudspeaker!
SEWA:like every time it makes the music life!!!!!!!! It has a bit better resolutions in micro details, a bit better dynamic and basscontrol, but a bit rough sound compared to the ZV9.
Conclusion: (if there is?)
My friend want to build the SEWA and I don't want to build the ZV9!
I don't want just another good sounding amp......
But I would like to build a J-Fet SEWA!!!!!!!!!!!! Mads please help me!!!!!!!!!!!!!!!
I think, if we could combine the two amps, that would result probably the best amp in the world.
Greets:
Tyimo
Wow! You guys blow me away! Nice report Tyimo!
The power jfets are not very suitable for the SEWA design, because of the tiny SMD package they come in. You would have to get smart and cascode etc like ZV9. I think you'd be better of just building a ZV9 if you want to use the JFETs. NP has this covered. Besides, the Lovoltechs isn't really availabe to the common diyer. I think it is better to design amps that you can use parts that are already in the thrash box, or you can source locally. Especially since the reported sound quality is not that far apart. I also think that for the pure musical enjoyment the SEWA design brings, it is very hard to beat. Like the BOZ.
edit: Zoltan, you're in.
edit 2: I've done some homework, and I think I'd better adjust the price on the BOZ pcb offer to 21 Euro to cover local taxes, paypal transaction and exchange fees etc. I actually lost money on the SEWArB boards
The power jfets are not very suitable for the SEWA design, because of the tiny SMD package they come in. You would have to get smart and cascode etc like ZV9. I think you'd be better of just building a ZV9 if you want to use the JFETs. NP has this covered. Besides, the Lovoltechs isn't really availabe to the common diyer. I think it is better to design amps that you can use parts that are already in the thrash box, or you can source locally. Especially since the reported sound quality is not that far apart. I also think that for the pure musical enjoyment the SEWA design brings, it is very hard to beat. Like the BOZ.
edit: Zoltan, you're in.
edit 2: I've done some homework, and I think I'd better adjust the price on the BOZ pcb offer to 21 Euro to cover local taxes, paypal transaction and exchange fees etc. I actually lost money on the SEWArB boards