[DefQon]

  Well, here goes, I have managed to gather together enough parts to start my first B22 build.
 
Actually, while I was at AMB's site I also ordered a y1 & y2 kit because I figured a B22 should be fed by something a little better that my Iphone5.
 
I will start with a 3 channel configuration, however i am second guessing that, I may end up doing a 4 channel even though i do not have a source to take full advantage of it, some day I might.
 
I know the  B22 was designed to be build with non " boutique" caps, however I happen to have a collection of Elna silmic II caps on hand that i could use, the larger power rail caps i have are 1000uf 50v rather than the
 
recommended 470uf, outside of PS issues, are there any reasons i shouldn't use these?
 
Waiting on a mouser order right now, but I am hoping to start populating the boards today if work schedule allows

.

 
I used 470uf 63v Elna Silmic II's I had lying around. The general rule is 10% tolerance on top of the values you're replacing. Voltage usually doesn't matter but resistance and capacitance does in some cases.

 

[jcx]

for power supply C you need good margin for V rating
 
you have to allow for peak of AC, high line V and the fact that smaller xfmr have poor regulation == larger V out when not loaded
 
and its good practice to allow 20% derating after all of the other factors are applied - 50 V rated caps are barely adequate for rectified 24 Vac transformer secondary

 

[Zashoomin]

I am looking to have a preamp output function on my B22.  How would I go about doing that?
Thanks in advance

 

[H22]

Digikey had some of the 470uf 63v Elna Silmic II's in stock, went ahead and ordered those. B22 boards are complete now except for those  power rail caps and the mosFets.
 
I am still waiting on some of the power supply components, mainly the triac, so build is on pause till I get the PS put together.
 
I decided to go with the standard 3 channel config with 8x gain, I can always change it up later if i feel the need to or just want to play with it. I have been doing this long enough i have become quite good at de-soldering components

.

 

[fishski13]

  I am looking to have a preamp output function on my B22.  How would I go about doing that?
Thanks in advance

 
look under the "Other Options":http://www.amb.org/audio/beta22/ . 

 

[H22]

little update just to bump the thread.
 
Work has kept me busy the last week,

hate when that happens.
 
I  received most of the parts to complete the s22, but I bodged 

  the quantity on a couple of the parts, so waiting on another digikey box to arrive.
 
The triac I was able to find at digikey was a 100va 24/24 unit, 237-1342-ND hoping this will be enough voltage to supply +-24.
 
I would like to have all the  finished and tested next week but i doubt that will happen. All I have left to do is assemble the s22 and mount a few remaining parts on the b22
 
boards, but this weeks schedule is going to be a killer and going on vacation after that.
 
Its killing me having the first stage of this build so close to finished and not having time to complete it....
 
Once i finally do get it done then building the case will be the next challenge.

 

[joeyjojo]

  Its killing me having the first stage of this build so close to finished and not having time to complete it....

 
I've got used to that feeling - it's been about 20 months since I ordered the first parts

 

[Zashoomin]

Well I know the feeling but that is because I keep forgetting to order parts and have to wait for them.  I am doing a 2 channel one and have all 3 boards done and just need to work on the enclosure.  20 months though is a long time.  It has only been about a month for mine.

 

[H22]

I was able to finish soldering up the s22 today after work, only took a few minuets, witch was nice as my work day started at 3am and ended at 9:30 pm !

Plugged it in and got just a hair over 48volts across v+ and v-.

There is a slight discrepancy, v+ to ground is 24.042 v
While v- to ground measures out at 24.073 v

So there would seem to be a .031 volt bias to the negative rail, I doubt this will be an issue and I'm guessing it's due to resistor tollerances.

I measured this with my new fluke 289 meter, with a 5 k resistor across v+ and v- to give a small ( 10 ma ( plus led )) load. The 289 is reportedly a very accurate meter.

So here is a quick pic I snapped after testing it, no burned parts

 

[DefQon]

What gain did you opt for with your b22?
 
Those ELNA Tonerex cap's look bit different to some of the ones I've been using, what uf/v rating are they, or even better source?

 

[Zashoomin]

I am trying to figure out the encryptions on the side of my transformer and cannot for the life of me figure out which wires go where and why.  It is an avel linberg one.  

 

[DefQon]

Picture's please.

 

[Zashoomin]

So there are 4 pads on the S22.  In order ~, G, G, ~.  I assume ~ is signal and G is ground.  also when I look at my IEC connector there is L, N and Ground.  I have no idea which wires should connect to what parts.  

Thanks in advance. 

 

[DefQon]

  So there are 4 pads on the S22.  In order ~, G, G, ~.  I assume ~ is signal and G is ground.  also when I look at my IEC connector there is L, N and Ground.  I have no idea which wires should connect to what parts.  
 
Thanks in advance. 

Two primarys binded together is 230v, you'll use I assume 1 one of them for your location, blue is pos, brown is neg/neutral and gry is ground. These hook up to your IEC connector. Two secondary windings two 30v each with it's own ground/neg but you know where that goes on the s22 board.

 

[joeyjojo]

DefQon is wrong in his assumption. Assuming you live somewhere with a 115 V mains supply you want to wire the primaries in parallel (BLU and VIO live, GRY and BRN neutral). Not 100% sure on the secondaries ...