[BUILD] OV560 (Neumann OV60 in API500 format)

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Great work Richard 8)

- How do I know which way to orient the neumann OH100 DOAs on the PCB. It seems like they can fit in two different ways
have a look here

- How do I know which way to orient the 3 small ICs on the output board.
looking at the PCB like here the small dot on the ICs goes to the right

- How do I know which way to orient the 2 blue ICs on the main PCB. It seems like there is a line marked on one end of the IC that may indicate that it is the end that matches the + sign on the PCB. It looks like that in the photo on this thread, but it is just unclear enough that I can't be certain.
those blue parts are relays. they have a printed line at one end, this side goes where the + sign is on the PCB

- I am assuming that c*15 is a cap that is used with one of the DOA options. Is this the case? I take it that it is not needed.
absolutely right
 
Richard, maybe some pics are better:

OH100:
IMG_0418.jpg


Output ICs:
IMG_0414.jpg


Relays:
IMG_0417.jpg
 
Both 560 channels appear to work perfectly, both mic and hi-z inputs. Thanks V. for the help on the last bits. They sound great. Very nice definition and presence. I suspect the cost of the Haufe transformers is well justified. I will try to find some time this weekend to do some in-depth testing. I hope to do some comparisons with the v26 pre's and the apollo onboard pre's with guitar and vocals.

Great job with the design and implementation Volker - kudos.

- Richard
 
Some good news from Pier in the mail today, for all people afraid of used or NOS DOAs  :eek:

I have the OA10  (version with modern comp.) made.
I have just tested it (but I need other tests) ,
It has better performance that the original.


kind regards
Pier Paolo

he is also working on a OA12/20 replacement - we call it MO-6  8)
 
Regarding the MO6, I have designed the PCB and I am going to make a prototype.
I am waiting the PCB's from a PCB factory. I hope to have the prototype very soon.
I will keep you posted. 


kind regards
Pier Paolo
 
this is the image of the OA10 on 2520 socket  (prototype)

doa10dhfdhf.JPG



the components are changed with BC560C, BC556B and BC546B
the BC337 and BC337 are the same of the original schematic.
Performances are increased.


BTW the original BC212B is discontinued, BC182B is obsolete.


the compensation net is inside the DOA, I have modified it (a bit) for the "modern" transistors
 
Hi Silent,

Where abouts do these fall in regards to sound?

Transparent, clean, warm, neve or api like, etc.

Thanks
 
Just finished a pair of OV560.
What should I say - fits and works a treat - great work Volker.

Thanks a million
Bruno
 
...first session with OV560.
Sounds a little like a Chandler Germanium, thick and warm  ;D

thanks Volker!



 
Thank you Volker for uploading the files! Yesterday I had to do a quick recording within a project I am working on. What to say, I chose your baby and can´t say anything but "beautiful"!  ::)

I would not compare them to germanium style pre´s. They sound clearer, and less "colored" but still warm and open.

Just to let everybody know how I recorded the example Volker uploaded:

Nylon Akustik: MBH 603 with KA 100 / 1m distance

Snare: 13/7 Ash from "Snare Sound Designer" with MD 421.

I did not focus on best sound but to compare the Original and the replica Pre.

Cheers to all of you! Fredi
 
And this is where DIY meets!! Finished both Pre's under 6 hours, everything working but the LED's, but guess got those backwards again!!  ::)
I'm waiting for my 51x-rack, but thought about hooking a pre up together with Mnats' DBX900 PSU, works like a charm!!

They sound really good Volker, thanks!

EDIT:

I do have different sound on the two pre's, one sounds realy crisp, the I think it should sound, the other is less transparent, darker, as if there is missing a bit of high!, I'm sure there's something not right with the second one, because it's quite a difference... any idea's where to look?
I've switched the Hi-Z IC boards, but that didn't change anything.
There's less gain on the second pre too.
The difference is on both the Hi-Z input as the mic-input.
Could it be that the two OH100 sound so different?

EDIT: just to show he difference
Schermafbeelding%202013-04-19%20om%2008.07.10.jpg

First, and perfect sounding Pre...

Schermafbeelding%202013-04-19%20om%2008.05.52.jpg

Second, and missing something!  :eek:

EDIT: SOLVED!!!  In an error of my own!!!
 
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