Choosing parts for BOSOZ

[pjpoes]

Ok so I have the boards for my project, and I have some of the parts laying around, but I want to check before I attempt to use things that will degrade performance or not work. I also would like to know about some of the parts Im looking to use.

First, I was planning on using Holco or Vishay resistors. I know that Mr. Pass feels that using better parts is uneccassary, but I wouldnt mind some other opinions. I wont waste the money if it truely doesnt matter, but are there some area's where a better part could make a difference.

I was gonna use the IRF610 mosfets he suggests, and they are cheap enough, and used in enough other projects, that I thought I would buy 30 of them, and attemp to match some sets for this project. Though he says there is no need, its only a little bit more time. I also thought I would use the 1n4739 zener diode he suggests. Just out of curiosity, are these parts as good as one should use, or are some better diodes available. I know so little about the different types, I just cant tell when looking at them.

As for the C1-2 spot, where is 10uf capacitor is recomended. What type is best here, what voltage should it have. Is using some sort of better quality such as teflon or something like a Hoviland or musicap. If not, what is a good choice.

In the C3-4 spot, what is the recomended type. It mentions an electrolytic 1000uf type, but no voltage is given. What is a good recomended voltage. I assumed, based on the rail voltage, that 100v's would be safe, but I could be reading this stuff wrong.

As for the potentiomiters, it says they are optional, and I understand people prefer using them. They are pricey, yet not enough so that I would think they are very transparent. A part of me would rather just use a resistor there, or run without them. I was gonna use a stepped attentuater in the P3-4 spot and a pot in P5, and that was it. Nothing in P1-2.

For the powersupply, any upgraded parts good here. Black Gate, Nichicon, or whatever a good choice in the powersupply. Are the ones he recomends good in the powersupply. I recall having trouble getting the 1000uf part he recomends for C101-102. The Diodes he uses in the Diode Bridge, are they as good as I would want to use. I often here people talk about using better diodes to upgrade powersupplies. I didnt look at the part he chose all that clearly, but it didnt look like anything special.

C107 in the powersupply was another I couldnt get through Digikey anymore. I tried, but it came up with some sort of warning, I think it said to call Digikey. I wasnt sure if that meant I was gonna have to order some. Does AC rated simply mean bipolar type. I have seen some refered to as AC rated, but wasnt sure what that meant, other than bipolar. Thanks.

My last issue is the transformer. I have 4 of those 28v toroidal transformers from Parts Express. I wasnt sure if this was going to be 28-0-28 or if its 14-0-14. If its the latter, I understand it wouldnt be appropriate to use, however a 28-0-28 would be ok right? Im trying to find out if I can use these transformers in this project or not. If not I will simply buy one such as the avel he recomends. Anyone know if the quality of the toirodal is real important, such as it is with his amplifiers. Thanks for any help.

[moe29]

The sound you get from using what's reccomended in the parts
list is fine... better than fine.

The 1000uF 100V caps are evidently not being carried by DigiKey
anymore. Maybe someone else can reccomend a part number for
a Panasonic cap that matches it.

You will need two of the transformers mentioned. If you are going
to use the artwork to make a PCB for the PSU you should stick
with the reccomended rectifier bridge.

mostly i would say, build stock and take a listen. If you feel you
need to add upgrades from there, go for it. Kind of gives you a
built in upgrade path.

Good Luck! : )

Here's a picture of my main board - BOSOZ - in this thread

BOSOZ assembly question

[pjpoes]

well I bought the boards already, so I am not making my own, simply using the ones I got. Easier for now I think.

My only thing with the parts is that in some cases, better thought of parts, are the same money. Well no I shouldnt say that, most of these parts I simply am not familiar with, they may be every bit as good. I also have a decent supply of Holco resistors, so if they are perfectly adequate, I may use those.

As for the 1000uf cap, that was one I just wasnt sure about. Since it simply wants an electrolytic, though Im sure the panasonics are fine, I was gonna place an order with Handmade Audio anyway, I thought maybe some Nichicon muse caps might be a good idea. Any thoughts on that. THanks.

[metalman]

In my BOSOZ variant, I used Holco resistors, Solen 10uF film caps, and Nichicon electrolytics throughout. It sounds pretty D*mn amazing to my ears. I think your choices will serve you better than you think.

[moe29]

Nothing wrong with using parts on hand - they meet spec, use 'em!



from the article:

Many do-it-yourselfers have called me up and explained the
wonders of various better parts, capacitors, resistors, wires,
and diodes, that I could have specified that would improve a
project. Some of you have been kind enough to send samples,
which I much appreciate. Oddly, nobody sends me better
transistors, and considering that gain devices account for most
of the distortion, this is what I would really prefer.

[wijx]

Can I use Audyn-cap MP 800v for C5 and C6 (dont know the part number on the pass Labs scheme).

If so what's better 1x10uf or 1x4,7 with 1x5,6 parrallel?

[wijx]

C5 and C6 from this PCB http://web.vip.hr/pcb-design.vip/xccs-bls.html

[hifimaker]

Here's another thread on the same topic.

Best BOSOZ preamp parts selection thoughts

[wijx]

I know, but also without an answer

[metalman]

[i]Originally posted by wijx[i]
Can I use Audyn-cap MP 800v for C5 and C6 (dont know the part number on the pass Labs scheme).

If so what's better 1x10uf or 1x4,7 with 1x5,6 parrallel?

On the voltage rating you can use anything ~100V rating or larger. In my opinion I would use a single 10uF, but the 1x4.7 + 1x5.6 would work too. For that matter, there is nothing that says you have to use 10uF, it all depends on where you want the low frequency roll-off to occur.