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Posted (edited)

Ordering my own it is. one sigma22 board bould be enough to power two boards right? I already have a sigma22 wired for 30V. can the amp board be changed to use 30V input?

Edited by mahdi8
Posted (edited)

if you mess with the bias and change the opamp to opa445

you can get it to work.

 

the input chip can handle 36v, should just make it with 30v rails

all the transistors are rated at 80v, so should be ok.

 

caps would have to be at least 50v, 25v won't work

Edited by kevin gilmore
Posted

Is there a groupbuy for the dynalobal board at the moment?

 

 

There needs to be, I've never coordinated one, and I'm probably too unknown to be up and doing one , but someone out there, shut up and take my money, please. Like, yesterday.

Posted

i could do an off board version with flying output transistors,

then on big heatsinks, as much power as the transformer can supply

 

 looking forward to this one ::)

Posted

 looking forward to this one ::)

With big output transistors? But why would you need it if Susy dynahi exists? What's the major difference? I guess none.

 

AFAIK, it has always been like this: dynalo = w/o big output TO-220 transistors, dynahi = with big output TO-220 transistors.

Posted

not exactly.

 

dynahi has cascade on the input transistors because that was right at the limit of the fets.

the bipolar part has 6 more volts rated, so cascade technically not necessary. Also vas

stage has double transistors for more output current. otherwise identical.

dynahi was also +/-30 and the ssdynalo was +/-20 although you could raise it a bit.

 

boards have cleared customs should be here by Friday, and I have the parts to build

and test them.

 

once they are verified working (and I have checked the layout many times) people

could go ahead with a group buy.

 

birgir is getting me prices on the power supply.

  • Like 1
Posted

oops , seems some misread on me

I  thought that kevin is going to draw an off board version of goldrefrence regulator

 

it would be nice if using case with heatsink on bothsides or just case itself

Posted

i will be testing the new amp boards when i get them

will order the power supply board soon

i'm sure i can do a completely off board version of the

power supply board

Yes, please call Goldreference stable and final, and I will order PCBs.

Interested in on board version.

Posted

Yes, please call Goldreference stable and final, and I will order PCBs.

Interested in on board version.

I will chip in for the GoldenReference PSU board.

Posted (edited)

so 2 of the 3 simulators i use gave the same results for the power supply with the schematic shown.

But ltspice oscillates. Kerry made the following changes, until i build the real thing, will not know which

is right.

 

C3,C16   4.7nf

C4,C5  470pf

 

c9,c12,c8,c15  not used

 

no changes to the circuit board necessary for this i think

Edited by kevin gilmore
Posted

Sorry going to order for myself only, no experience to start GB if you meant it. Also, it's going to be rather expensive. The price of PCB house I've used to deal with is around 18-20USD per PCB of Goldenreference for the lot of 4 (180x110mm, double layer, FR-4, 1.5mm, 70um).

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