Burning Amp BA-3

[Zen Mod]

why not

 

[flocchini]

Returned to sanity

Maybe 6 pairs at 400-500mA to start - then increase if sinks can handle it

PSU will be driven by 2 500VA 2x 22V windings transformers

Best

Bob

 

[Zen Mod]

what are you going to drive , with it ?

 

[flocchini]

what are you going to drive , with it ?

My bass speaker is a SEAS W26

( The Madisound Speaker Store)

in a 2.3ft3 sealed box. Sensitivity is 87dB (2.87V,1m)

It is crossed over at 275 Hz with 2nd order crossover and currently driven by Aleph 30. On some music the output is slightly low to my ears 🙂🙂

The other two speakers in my system are PHL1120 at 95dB driven with F6 and Raven 2 at 96dB driven by F3

Thank you

 

[flocchini]

I should add pre is XP-10 and room is 28x22 ft with peaked ceiling at 12ft

 

[Zen Mod]

you'll have plenty of grunt , even with plain F5 augmented to 2 pairs of outputs

in case you don't need a room heater , it's wise to start smaller , then build up , but only if needed

 

[flocchini]

Thanks ZM

I have to learn patience and remember to move step by step 🙂🙂

 

[danielutzu]

Does anyone know where I can get a BA-3 PCB? The diyaudio store is out of them...

thanks,
Daniel

 

[Mr. dB]

Does anyone know where I can get a BA-3 PCB? The diyaudio store is out of them...

They're the only source, but if they're out they'll restock.

 

[Tea-Bag]

Does anyone know where I can get a BA-3 PCB? The diyaudio store is out of them...

thanks,
Daniel

I have one I dont intend to use. PM me your address and I will send it to you.

 

[Jason]

Does anyone know where I can get a BA-3 PCB? The diyaudio store is out of them...

thanks,
Daniel

There is actually a bunch en-route. They will be in the US store within a week or two I think.

 

[noSmoking]

Hi all,
I know there is a thread running for this so If it needs moved,Mods Please do,Thanks!
I read a post about Fake parts in particular the sk 170 and bj 74,well my curiosity got me and I start taking that info and looking at a few parts I have,It seems to be the truth that there is a small amount of copper showing on the pins at the trans body,I have some from know good suppliers and ah well some other suppliers,I have recieved good ones from major US suppliers and I have ordered from 2 overseas suppliers that are good,I have ordered from Spencer and Alweit on ebay,got 'em here fast and the real McCoy's,I didn't get a reply from Zoufang,maybe someone can call that ball,
I am waiting on heatsinks and then I can fire up my B-3,LOL.
Just my 2 cents,
NS

 

[ivan2000]

there are some possibly better alternatives , but even more unobtanium

2SK213/2SJ76
2SK214/2SJ77

for instance

Hi ZM
1. can i use 2sk216/2sj79?

2. 2sj76/77/78/79 and 2sk213/214/215/216
it seem to be one series parts. Can i use mixed pair? ex. 2sj77/2sk216

3. All of these parts are old, but i see some brand new in my local.
Is there a simple way to test the fake part?

 

[Zen Mod]

same parts , different voltage grades ;

without looking at datasheets , I'm expecting somewhat higher parasitic capacitances for higher voltage ones , but - if you don't have other choice - mix them

no big deal

those are nice parts

testing - Mosfet testing - pdf - Pa's site

see in datasheets what values you can expect

 

[ivan2000]

ZM, thanks a lot.

After seeing your resp, goto the local immediately.
my two pair of 2sk216/2sj79 was flying away.
it is so pitty really.

 

[generg]

Why not order from alweit?

alweit | eBay

🙂

 

[ivan2000]

Hi generg, thanks for offer the source. if i can't find on the local then i will order it.

Today, i got two pair of 2sk214/2sj77. Finally i can try to build the BA-3.🙂

 

[ivan2000]

Great, yesterday i had finsihed BA3 FE, with a green one (j77)and a black one(k214).
ps +-17.1v, the bias is 66ma.

Take it as a pre to my little tube amp, it sounds good.

Next will build BA1 output stage, can't wait to hear the voice of BA3+BA1.

Or try BA3+F4 first, to see what happen.
😉

 

[Zen Mod]

 

[rolandong]

Can diode trick work with BA-3 PP output like implemented in F5T?