No reason to remove it.

No reason to hide anything.

Put it back if you wish.

No reason to remove it.

No reason to hide anything.

Put it back if you wish.

Cool, good news!

Yup, nothing to hide here. We will never post the original Stax T2 schematic but nothing wrong with this.

I'm also going to use that PSU for the milled from solid BH amps but with a delay circuit all on one board. That way I don't need to buy new transformers...

Here's the pics of the BH power supply based on the HV supply here:

Here's the pics of the BH power supply based on the HV supply here:

The only thing I could mention is something I'm a bit anal about. The capacitor charging current from the bridge diodes is pulse like. The current drawn from the capacitors is pretty smooth. So it is always a good idea to isolate them in the tracking - in other words that the diodes connect individually to the capacitor terminals, and the output connections also connect separately to the capacitor terminals. Otherwise the pulsing current flow from the diodes flows in part of the output tracks and can introduce unnecessary PSU noise. Similar things can be done on the ground side as well to prevent the same pulsed currents from getting into the output grounds - this used to be called the "Calrec rectangle" after its adoption by the microphone company.

Nice idea. Thanks for the input.

Nice idea. Thanks for the input.

I'm assuming blue is the bottom layer?

The top is blue. I've got the components mounted on top, but the rail transistors mount on the bottom along with the filament transformer. I needed it this way for how I wanted to mount it.

Ah, just wanted to make sure that big long trace past the pour didn't rely in the solder mask as insulation, but sounds like this isn't the case. Very nice, I really like it.

Look what the mailman dropped off today....

(click to enlarge)

[ATTACH=CONFIG]3987[/ATTACH]

Look what the mailman dropped off today....

(click to enlarge)

[ATTACH=CONFIG]3987[/ATTACH]

WOOF!

Nice!

It's coming alive!

Very cool

Cool! Build it quickly and tells us what you think!

Thanksgiving is over, but it's time for this turkey to start the stuffing.

And many thanks to Doctor Gilmore for making it possible!

Damn, that reminds me to get cracking on the gigantic version for Kevin and me. Bloody hell, too many projects, not enough time.

I should have my boards by the end of the week.

Its going to be a great december...

Damn, that reminds me to get cracking on the gigantic version for Kevin and me. Bloody hell, too many projects, not enough time.

You need to quit that dead-end day job of yours.

You need to quit that dead-end day job of yours.

Then who'd be the bread winner?

...I'll get my coat.

Then who'd be the bread winner?

...I'll get my coat.

Get me some bread, instead.

I've just skimmed pcx to see if I could find anything to take advantage of their 20% off. Just wondering if I could replace the ixys10m90s with this http://www.partsconnexion.com/product7566.html?

Also, how does this http://www.partsconnexion.com/product1290.html compare with the one on the BOM?

I've just skimmed pcx to see if I could find anything to take advantage of their 20% off. Just wondering if I could replace the ixys10m90s with this http://www.partsconnexion.com/product7566.html?

Also, how does this http://www.partsconnexion.com/product1290.html compare with the one on the BOM?

I've just skimmed pcx to see if I could find anything to take advantage of their 20% off. Just wondering if I could replace the ixys10m90s with this http://www.partsconnexion.com/product7566.html?

Also, how does this http://www.partsconnexion.com/product1290.html compare with the one on the BOM?

The 10m90s is a three terminal current regulator, used here as a protective current limiting device in series with each power supply rail. The parts you are suggesting as replacements are rectifier diodes.

There is no substitute to the 10m90s.

I'm picking up the boards from the post office in about 2 hours, so time to post the corrected parts list which need to be applied to the bom

Heat sink part numbers later.

Amplifier board first, There are 2, so double all of this

Resistors

---------

2 R1,R2 25

6 R3,R4,R13,R18, 1K

R44,R45

2 R5,R6 180

6 R7,R10,R11,R14, 175K

R29,R30

2 R8,R9 500

2 R12,R19 1200

4 R15,R16,R35,R37 100

1 R17 20K

1 R26 2k

2 R27,R28 5.1k

4 R31-R34 100K

1 R36 6.8K

2 R38,R39 200K

2 R40,R41 50K

2 R42,R51 10k

1 R43 3.3K

2 R46,R47 200

2 R48,R49 500k

1 R50 300

Transistors

-----------

6 Q1-Q4,Q9,Q10 2sc4686a

either 2 x 2sa1968, or 2 x ixtp01n100d

2 Q5,Q6 2sa1968

2 Q7,Q8 ixtp01n100d

2 Q11,Q12 2sc2705

2 Q13,Q14 2sc2240

2 Q15,Q16 2sa1486

2 Q17,Q18 2sa970

Q19 is a Linear systems lsk389 or a pair of 2sk170

1 Q19 k389

1 Q20 2SC1815

Diodes

------

4 D1,D2,D10,D13 LED

2 D11,D12 1N914

Miscellaneous

-------------

1 RV1 1k

1 RV2 2k

Standard current source is

Q6,Q5,R8,D2,R9,R10,R11

optional current source is

Q8,Q9,R12,R13,R18,R19

power supply board

QTY PART-REFS VALUE

--- --------- -----

Resistors

---------

3 R1,R9,R39 3000

4 R2,R3,R20,R21 15/2W

4 R4,R6,R22,R25 400k

4 R5,R10,R24,R29 300k

2 R7,R26 62k

8 R8,R11,R14,R16,R27, 820K

R30,R33,R35

2 R12,R31 20k

2 R13,R32 280K/1W

4 R15,R17,R34,R36 460k

4 R18,R19,R37,R38 100

4 R40-R42,R44 100k

2 R43,R45 5M

Capacitors

----------

4 C1,C3,C6,C8 680uf

6 C2,C4,C7,C9,C12,C14 100uF

2 C5,C10 .1uF

2 C11,C13 4700uF

4 C17-C20 .1uF/1000v

Integrated Circuits

-------------------

1 U3 7815

1 U4 7915

Transistors

-----------

4 Q1,Q2,Q9,Q10 fqpf8n80c

2 Q3,Q11 2sc4686a

8 Q4-Q7,Q12-Q15 2sa1486

2 Q8,Q16 10m90s

2 Q8A,B,Q16A,B 2sc3381

1 Q17 ixys10m90s

Diodes

------

2 D1,D3 24V or 30 volt zeners

4 D2,D4-D6 1N4007

3 D7,D8,D10 150v zener

1 D9 130v zener

Miscellaneous

-------------

2 BR1,BR3 BRIDGE made up of 4 high voltage diodes each

2 BR2

2 REF1,REF2 LM4040-10

2 RV1,RV2 2k

Edited December 3, 201015 yr by kevin gilmore

make that

2 BR2,BR3 BRIDGE made up of 4 high voltage diodes each

1 BR1