The BA-3 as preamp build guide

Thanks @cubicincher

I enjoy the sound,

the Toshiba version is slightly more calmer, warmer and shows more contours and has more details (texture) in the ultra high end.
Fairchild (are not matched hardly) are also very good and shows in the far back a very airy presentation.

I reduced gain to about 13,5dB on both

I have to mark that my GND of the circuit is not to PE earth connected......I hope my small hum in power amp is not cause of it --
--because in the past I saw my T+A P1200R with no EARTH connections to main, so I decide to have my Pre amps floating....not a good idea??

next step will be dual mono......

regards Harry

happy Christmas to ALL
 
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ResisterClone
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Well it only took me 12 years to build the BA3PRE but it is well worth it! Thanks to Mr Pass & all the FAB DIY’ers that came before me.

If you ever would like to build anything in this “club” all you have to do is read the threads…it’s all there.

I even found the Toshiba's!
Dual mono of course with Sigma 22’s. First time with Acadamy Audio VCX volume control…works wonderfully. I went with the VRDN supply for this.
I-Select for inputs.
Took a few hours to bias/offset adjust….but steadied at 1V/1.2mv…breathing was optional!
So far dead silent driving a pair of MOFO’s.
Now to “burn-in” for a few days…but it sounds good at the beginning…smooth with good bass.

You folks have a great Christmas!!!
Brian in Seattle
 

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Hello, thinking of going the balanced route but before eventually getting there I am wondering if the Toshiba MosFets are still available, I see on the DIY Audio Store there are some but dunno if they are the right ones (here) or if these 2sk170 are also suitable, harder to find the 2sj74 but I guess some patience might pay back, are the ones on the DIY store any good or what should I look out for to make sure they are the correct ones?

Grazie a buona domenica
 
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^ The parts you list are the JFETs, not the MOSFETs. They are correct. Both links (the Toshiba or The Linear Systems parts) are totally fine. Since the store has the Toshiba parts at what I'd consider a very fair price, and they are considered the gold standard, I would get those.

For Toshiba MOSFETs - post in the swap meet that you want to buy some. Alternatively, contact Prakit directly. He is a known seller of genuine parts.
 
Buongiorno @ItsAllInMyHead and grazie for your prompt reply, since I have to get an extra BA3 board I rather buy the FETs on the store too, which ones should I get, the 6-8ma (available) or the 8-11 (not available)?

Unfortunately in my first purchase as per the seller you suggest one of the FETs was damaged and the guy who put the BA3 together for me had to find a substitute.

At this moment in time I switched the tube amp (KT88 in push pull) for the F4, even tho there is not the same "juice" the sound is pretty pleasant and dead silent, no hums at all but I am driving it with the Audio Research SP9 whose 21db are on the edge to drive the F4. Since I removed the BA3 lid I wanna take the time and fun to check the voltages on the PSUs while I eventually wait for another BA3 board and the FETs and my guy approving the upgrade to balanced as I plan to upgrade my DAC with a better one (I laid my sight on a Denafrips R2R which also has balanced output) and if it all goes smooth I might ask him to turn the F4 to balanced and, maybe maybe, some day to build another F4 and run them in mono configuration to make my JBL L220 spread their voice to the neighbourhood :)

Very kind of you and all of the forum member to always be patient and kind with a total newbie like me, if any of you happens to get to here please let me know ahead of time, I won't promise anything but an espresso (I do really pity US people to drink that stuff they call coffee...) and/or some beer is gonna be onto me!!!

Giovanni

BA3-7920.jpg BA3-7919.jpg BA3-7918.jpg
 
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^ Always a pleasure. If it is within your budget, consider an octet of 8-11 and save the extras JFETs. You know you will do another project, and they will not be around forever. Plus... you save shipping cost over getting another set later for another project. :)

It would be lovely to see you in Italy. Excellent coffee and beer are always welcome.

Cheers!
 
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Espresso (/ɛˈsprɛsoʊ/ , Italian: [eˈsprɛsso]) is a coffee-brewing method in which a small amount of nearly boiling water is forced under pressure through finely ground coffee beans.

ZM, you should come to West Michigan sometime and I’ll take you to KIN coffee in Holland MI, I’ll treat you to a Caffè americano “coffee”.

Don’t know much about the Corvette as I can’t afford one so why bother.
 
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ZM, you should

just mocking, as usual, but that's it

my Buddy AR2 lead me to Starbucks saying "for your standards this is not a coffee but you must get that as experience"

While Pa said - "I didn't had proper coffee until I started brewing my own" ........ and believe me - his approach to making coffee is same as with amps - crank it, crank it baaad!

anyway, I'm in age when I'm more for Topolino than for Abarth ......... while my coffee is filter (Italian, btw.) and everyone around is, well, having customary Turkish coffee

needless to say, switching to filter was result of hangin' in your neck of wood ....... it helped suppressing my orthodoxy :clown:
 
I been to the US recently, not even the espresso machine by an Italian restaurant (Italian...) was a far reminiscence of what an Espresso is, I'd suggest to you guys to come to Napoli and have an espresso with a croissant along the waterfront, then a sfogliatella while wandering around, then a pizza with a Peroni and then again an espresso which, by the way, in Napoli is simply called "un caffé per favore"
First time I saw a coffee in the US I thought they forgot the sticks to pick the noodles from the cup...
 
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I been to the US recently, not even the espresso machine by an Italian restaurant (Italian...) was a far reminiscence of what an Espresso is, I'd suggest to you guys to come to Napoli and have an espresso with a croissant along the waterfront, then a sfogliatella while wandering around, then a pizza with a Peroni and then again an espresso which, by the way, in Napoli is simply called "un caffé per favore"
First time I saw a coffee in the US I thought they forgot the sticks to pick the noodles from the cup...
alternatively, one could walk into every bar/ristorante to have a caffè until you come across one that does not taste good… (the journey probably would end after the swiss/french/austrian border
 
I can't tell about past Napoli but here coffee is kind of like religion, an old detto goes like "coffee gotta have the three C" which is "Come Ca**o Cuoce" translated into "how the - I'll leave second word translation to your fantasy - hot"

I was born in Napoli, mum is from Napoli and dad was from the little island where I live, until a few years ago when going to visit one of my uncles we had to go to a specific bar to have the coffee he likes, it had to be ristretto (shorter than average) and no sugar, a glass of water before the coffee to clean the mouth before tasting it and that's it. Unfortunately with time flowing too fast now he won't go that far any longer but each and every coffee in Napoli, like pizza, is amazing for average Mr Joe/Zen Mod of course there are exceptions but it depends on what one is used to, average food quality in our area ranges from good to very good.