DPA HV Microphone (discrete) Power Supply

Hi guys. I need to build a power supply for some DPA high voltage mics. I found the post where Mark Fuksman (Marik) made a power supply for Marco (sunflute).

I tried contacting these guys, and DPA, so far no response. I'm trying to find a schematic or some help building a 130V power supply. Also, it would be great if someone knew about the PCC4000 - that is the converter that allows these HV mics to be powered by standard 48V.

I figure the power supply couldn't be too hard, 115-115 power transformer, full wave rectifier, some (220u?) 160V or higher caps, and a rectifier.

Any help is EXTREMELY appreciated

Thanks,
Rob

I would use four or five sections of CR.
I use 22 mfd 450V caps.
From the bridge rectifier a 22 mfd cap followed by R then another 22 mfd cap and so on.
This gives much better noise attenuation than one big 220 mfd cap.

Sorr

[quote author="Handcrafted Tone"]Hi guys. I need to build a power supply for some DPA high voltage mics. I found the post where Mark Fuksman (Marik) made a power supply for Marco (sunflute).

I tried contacting these guys, and DPA, so far no response. [/quote]

Yeah I know,
sorry, I am putting new floors in our new house today was whole day of sanding :shock: ...
PM me with your email and I'll send you original DPA schematics.
Just remember, you get half B+ voltage on the signal output pin from the mic, so you will need to block it out. I used Black Gates there.

Best, Mark

THANKS GUYS!

btw, my email address is in my profile.

Hey Mark

Please, can you send me the DPA or B&K schematics you have?
My email is under my signature.
Thank you.

chrissugar

Thanks a lot Mark!

Heres what I have so far. Power supply is based on DPA schematic. Problem is, I don't know much about discrete regulators, and I'm having trouble sourcing 2 parts. If someone wants to collaborate on this project, I don't mind releasing a board layout to anyone thats interested.



Replacement parts:
* This supply was built with SMD and I'm having trouble sourcing a BF721 through hole equivalent.

* I cant find BZT03C130 124V Zener Diode (D3)

* I've replaced D1 and D2 with 1N5341B. The original called for BZV55C6V2 (I cant find it anywhere)


In an earlier thread, drpat mentioned he was getting 121V on his Millennia HV-3 preamp. This opens up a few options for IC regulators. How much better or worse is this topology compared to a standard IC?
I like the idea of using the STR3130 (NTE1742) as mediatechnology mentioned, but I'm not yet sure how to implement it in this circuit.

Thanks,

Rob

You are kidding right?

It is a series regulater

It is only a zener

Yes harsh but you have a web site offering PCB design and you are asking about a textbook circuit

without the web site I might have answered

yeah, I'm learning as I go. I never said I was EE, and I never went to school for this stuff. I asked Keith (ssltech) if I could offer some of his power supplies (actually it is a pretty standard PS, there are countless versions of it on the web).

I don't push that PS on anyone, if some one wants it, great. If not, cool. I thought there should be an alternative to the JLM, and for what it's worth, I like mine more.

So... Point me to the text book your referring too, because so far I have not read it.

thanks

btw, thanks for telling me it is a series regulator, that is exactly the term I needed, so I can go look it up myself.

You can make a very simple series regulator with a pass transistor, a resistor and a zener. Then you can add another transistor as an error amplifier. And another as a foldback current-limiter. And... :green:

BTW, any of yuz know of a 150V fixed regulator? I looked around a little while back and couldn't find one.

PERFECT, thanks a lot Wayne. This will greatly simplify the circuit. I may buy some THAT 1646 drivers from you when I build the preamp section.

[quote author="mediatechnology"]Rob; Double-check something. At the junction of R7 and R8 is there just C5? It doesn't look quite right to me. Are you sure D2's anode doesn't connect there? [/quote]

Thats what my DPA schem says... I'd like to try it in the future, but for now I want to get something working. I'll drop the STR3130 in there.

THANKS

[quote author="Handcrafted Tone"]
[quote author="mediatechnology"]Rob; Double-check something. At the junction of R7 and R8 is there just C5? It doesn't look quite right to me. Are you sure D2's anode doesn't connect there? [/quote]

Thats what my DPA schem says... I'd like to try it in the future, but for now I want to get something working. I'll drop the STR3130 in there.

[/quote]

If you look at the DPA schemo this part is a divider for +65V part. You don't need those components.

I'm just going with the STR3130 for now, unless I can source a 124V Zener.

thanks

[quote author="Handcrafted Tone"]
unless I can source a 124V Zener.
[/quote]

Add a stack of zeners in series, e.g. 4pcs 31V (or any other types that adds up to the needed voltage)

BTW, look at the G9 psu for a simple, IC-regulated high-voltage supply.

Jakob E.

i´m currently working on a psu for a neumann mv 101 (mk 102 capsule), which uses a tube as cf and has unbalanced output.
i wonder if you place a output transformer into the psu for gefell/dpa/b&k measurement mics for studio work?
-max

Why would you want to use an IC?

The posted series pass circuit is nice circuit. (Q1,R3,D2) (D1,R1,Q2,R2,D3,Q1)

simple and well designed and low cost. Look close at the design.

Knowing Ohms Law and Power calculations goes a long way

[quote author="mediatechnology"]

Marik wrote:

If you look at the DPA schemo this part is a divider for +65V part. You don't need those components.

Click to expand...

Thanks for that. I couldn't see that in the "simple and well-designed" 130V circuit they were doing anything. What do they use the 65V for?[/quote]

The DPA is a universal PSU for both tube and SS mics, so there the 65V is to raise heaters in CF.

Thanks everyone for your help, and to gyraph for the stacking zener voltage hint. I think I'll go ahead with the discrete version, maybe I'll learn something along the way.

Updated schematic



Last opsticale in the way, I'm having trouble finding a substitute for Q2 (BF721)
Mouser gives me the FZTA92 as a cross reference, but it's surface mount. Can I use any high voltage PNP transistor here, like maybe a MJE350?

BF721:
http://www.ortodoxism.ro/datasheets/zetexsemiconductors/bf721.pdf
MJE350:
http://www.onsemi.com/pub/Collateral/MJE350-D.PDF

Thanks

Thanks a ton Wayne.

I'm going to put a board together with a simple preamp based on the AD797 chip, and THAT balanced line driver. I have no intentions on selling it, but if others are interested I don't mind sharing the design.