Thanks!
Yes I know. May be it will be good for some another kind of amp. (A5, Zen Lite etc.)
See you later!
Tyimo
Yes I know. May be it will be good for some another kind of amp. (A5, Zen Lite etc.)
See you later!
Tyimo
Hi Mads!
What do you think, when will you be ready with the BOSEWA PCB for standard parts?
Next week I will order some another PCB from my workshop and I could make yours too.
Greets:
Tyimo
What do you think, when will you be ready with the BOSEWA PCB for standard parts?
Next week I will order some another PCB from my workshop and I could make yours too.
Greets:
Tyimo
BOSEWA vs BOZ
I have decided not to pursue the BOSEWA beacause it is really a copy of the Aleph L 1.2. I have decided not to make pcb offerings of Nelson's commercial designs (discontinued or not), as there are just as good (if not better) projects that are open source. Right now I am working on a industrial quality BOZ board that will be my main preamp for the next decade or so. It is really the one preamp to beat IMHO. Earlier this summer I made a prototype of the BOZ circuit proposed in the SEWA thread today, and I found it to be better than the X2 and (from my memory) the BZLS as well. The Aleph L/BOSEWA can not possibly be better than the BOZ. The only advantage as I see it is the lower output impedance and the fact that it is non-inverting. However, it introduces an extra transistor in the signal path, and I am of the sincere opinion that LESS IS MORE when it comes listening to music. This means (single ended) class A, no (or very little) feedback, highly sensitive speakers and normal listeing levels.
As a side note; the SEWA/OTA designs do not require a low impedance source becase of the common drain configuration of the MOSFET. As far as I have been able to measure it has an input capacitance in the range of a couple of hunded pF.
😉
I have decided not to pursue the BOSEWA beacause it is really a copy of the Aleph L 1.2. I have decided not to make pcb offerings of Nelson's commercial designs (discontinued or not), as there are just as good (if not better) projects that are open source. Right now I am working on a industrial quality BOZ board that will be my main preamp for the next decade or so. It is really the one preamp to beat IMHO. Earlier this summer I made a prototype of the BOZ circuit proposed in the SEWA thread today, and I found it to be better than the X2 and (from my memory) the BZLS as well. The Aleph L/BOSEWA can not possibly be better than the BOZ. The only advantage as I see it is the lower output impedance and the fact that it is non-inverting. However, it introduces an extra transistor in the signal path, and I am of the sincere opinion that LESS IS MORE when it comes listening to music. This means (single ended) class A, no (or very little) feedback, highly sensitive speakers and normal listeing levels.
As a side note; the SEWA/OTA designs do not require a low impedance source becase of the common drain configuration of the MOSFET. As far as I have been able to measure it has an input capacitance in the range of a couple of hunded pF.
😉
O.K. I see. I understand.
Thanks for the infos about the sound quality.
You know me, I am a fan of the BOZ too!😉
See you later!
Tyimo
Thanks for the infos about the sound quality.
You know me, I am a fan of the BOZ too!😉
See you later!
Tyimo
Hy guys ,
I just read all the posts about the OTA , and I think I will try to build one .
Before I start , can you tell me the difference between the IRF150 and the IRFP150 ?
I have got 6 x IRF150 ( TO3 ) .
Best wishes !
@ + Philippe.
I just read all the posts about the OTA , and I think I will try to build one .
Before I start , can you tell me the difference between the IRF150 and the IRFP150 ?
I have got 6 x IRF150 ( TO3 ) .
Best wishes !
@ + Philippe.
Thanks a lot Mad_K ,
Wich is finally the most updated schematic using the IRF150 for this amplifier ?
I will build it without a PCB .
@ + Philippe.
Wich is finally the most updated schematic using the IRF150 for this amplifier ?
I will build it without a PCB .
@ + Philippe.
It looks nice , and with a very few part of components !
Can I also ask you about the according power supply schematic ?
@ + Philippe.
Can I also ask you about the according power supply schematic ?
@ + Philippe.
Like this:
http://www.diyaudio.com/forums/attachment.php?s=&postid=840640&stamp=1139436029
Only you need a 2x30VAC for 40VDC, again use what you have 😉
http://www.diyaudio.com/forums/attachment.php?s=&postid=840640&stamp=1139436029
Only you need a 2x30VAC for 40VDC, again use what you have 😉
Thanks a lot Mad_K ,
I am going to build it as soon as possible , in order to listen it with my Fostex FE208 Backhorns .
@ + Philippe.
I am going to build it as soon as possible , in order to listen it with my Fostex FE208 Backhorns .
@ + Philippe.
I've got several preamps I can use : a passive one , one other using OP amps and a third one using 5775 tubes .
Which one would be the better one ? I think the one with the highest gain in order to drive the IRF150 .
@ + Philippe.
Which one would be the better one ? I think the one with the highest gain in order to drive the IRF150 .
@ + Philippe.
I' ve got to find one that can provide 40 V DC with 300 VA or more power .
I don't know if there is such one on my shelves , if not I will buy 2 , to make 2 MONOral OTAs .
@ + Philippe.
I don't know if there is such one on my shelves , if not I will buy 2 , to make 2 MONOral OTAs .
@ + Philippe.
If you're out shopping, might I humbly suggest to get 2 300-600VA 2x18VAC transformers and series the secondaries. This will give you rails in the 45V region and is very flexible for future use. You don't actually need this big transformers, but they sound much better and runs cooler. I bought 2 600VA 2x18VAC transformers for my first project (SOZ) and I have made countless amps recycling these in various configurations 😉 Right now I am listening to a minimalist GC on steroids (wirth one of the transformers mentioned) and it is a lot of fun. 
Hy Mad_K ,
Thanks for your transformers suggests , I think I will buy something like that !
I olso realised erlier a GC with LM3875 . It is svisible here :
http://idefixes.phpnet.org/sections.php?op=viewarticle&artid=36
It's in french .
@ + Philippe.
Thanks for your transformers suggests , I think I will buy something like that !
I olso realised erlier a GC with LM3875 . It is svisible here :
http://idefixes.phpnet.org/sections.php?op=viewarticle&artid=36
It's in french .
@ + Philippe.
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