DSP Xover project (part 2)

Hello JC,
you made a lot of nice things round the Najda. Your Navigation Board looks high-profession. What i not understand in the thread, where do you pick up the Signal for your balanced output boards?

Best regards
Dieter

To be fully undo-able , I soldered shielded cable directly on the back of the RCA connectors and I put some hot glue for mechanical reason. Everything could be removed nicely and both unbalanced and balanced outputs are functional/
JC
 

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Hi JBS,
I did some additional sym input and output boards (see post 1356) but unfortunately I don't have any sym output pcb left. If there are enough demand I can re order some pcbs though.
JC

Well I must say, as did others, very nice work. Seeing that it's been about a year and a half sense you posted the pics would you change anything? specifically, anything pertaining to the output boards. I see also that you had a four channel board. :) very interesting. As always when it's hot it's hot, I guess I'm a little late for this party. I was hoping that sense Nick put the Nadja into production that more daughter boards would follow.
JBS
 
Seeing that it's been about a year and a half sense you posted the pics would you change anything? specifically, anything pertaining to the output boards. I see also that you had a four channel board. :) very interesting.
JBS

I selected That 12xx and 1646 IC for these boards (input/output) and designed them following datasheet recommendations. I use them in other projects and don't see any reason to change anything on the PCB.
JC
 
Opamp question

I would like to upgrade a couple of the LM833 opamps with the OPA627AP Opamp. I would like to bring in the Burr Brown sound.
The OPA627 are single opamps so i would need a browndog adapter to fit them in the dip socket. So far no problem, i guess that should fit and i am willing to do the investment.
Does anybody have experience with this setup?
Are there further changes i could make (or should make) on the surrounding 22uF caps to improve implementation?
 
I would like to upgrade a couple of the LM833 opamps with the OPA627AP Opamp. I would like to bring in the Burr Brown sound.
The OPA627 are single opamps so i would need a browndog adapter to fit them in the dip socket. So far no problem, i guess that should fit and i am willing to do the investment.
Does anybody have experience with this setup?
Are there further changes i could make (or should make) on the surrounding 22uF caps to improve implementation?

Hi,
I encourage you to read the posts 2449,2456 and 2511. Me and F2a11 ( please read his posts) have changed the LM 833 and also the 22uf capacitors.
Although the LM833 in our opinion sounds very good, the OPA627 improves the SQ specially in the highs. Also the replacement of the capacitors which are in the signal path is a big step forward in sound quality.
Regards
Sigi
 
Hi,
I encourage you to read the posts 2449,2456 and 2511. Me and F2a11 ( please read his posts) have changed the LM 833 and also the 22uf capacitors.
Although the LM833 in our opinion sounds very good, the OPA627 improves the SQ specially in the highs. Also the replacement of the capacitors which are in the signal path is a big step forward in sound quality.
Regards
Sigi
Hallo Signitz, Thxs for the reply.
Did see the posts, interesting...
Is the change of uF value for the caps only because of the size or also to provide better tuning for the OPA627?
I have bought OPA627 in the same DIP housing as the LM833, but only singe channel. So for dual channel i must use a browndog adapter. Do you know if i can swtch these with the LM833 chips without adapter? Will in that case 1 channel work? (there are enough channels on a Najda but i didn't try... afraid to damage anything)
 
Hallo Signitz, Thxs for the reply.
Did see the posts, interesting...
Is the change of uF value for the caps only because of the size or also to provide better tuning for the OPA627?
I have bought OPA627 in the same DIP housing as the LM833, but only singe channel. So for dual channel i must use a browndog adapter. Do you know if i can swtch these with the LM833 chips without adapter? Will in that case 1 channel work? (there are enough channels on a Najda but i didn't try... afraid to damage anything)
Hi,
yes, the change in capacitor value was because of the size of film capacitors. Whitebull posted at 2500 that he replaced with Wima 6,8 uF, size was very much smaller. We didn't see that capacitors, if we would have known about them, we would have installed them.
I think you will need the adapter for the OPA627, but am not sure.
Regards

Sigi
 
Hi,
yes, the change in capacitor value was because of the size of film capacitors. Whitebull posted at 2500 that he replaced with Wima 6,8 uF, size was very much smaller. We didn't see that capacitors, if we would have known about them, we would have installed them.
I think you will need the adapter for the OPA627, but am not sure.
Regards

Sigi
The Wima caps Whitebull used are indeed smaller and easy to get. Nice..
He says he used the MKS2 6,8uF for bass and 1uF MKS02 for mid and high. Is there a logical explanation for that? It seems that the MKS02 are of a lesser quality than the MKS2 caps.
 
Najda USB Driver not installs

I had moved to new PC with Win 7 and with Najda installation USB driver is not installed correctly, driver installation was performed with Najda Uder control installation but Najda device is still in Device manager as unknown USB device. When I connect Najda USB to PC message "USB device not recognized" is displayed.
Had anyone meet similar and solved the problem? On my old, also Win 7 PC, I had no problem with driver, new PC had USB v.3 ports, can this be problem?
 
The Wima caps Whitebull used are indeed smaller and easy to get. Nice..
He says he used the MKS2 6,8uF for bass and 1uF MKS02 for mid and high. Is there a logical explanation for that? It seems that the MKS02 are of a lesser quality than the MKS2 caps.

Hi,
the reason for the lower capacity for mids and highs is, that normally you don't need such a low frequency cut of for mids and highs.
Regards

Sigi
 
Here are suggestions for the front and rear panels (1U):

View attachment 424468

View attachment 424469

I'll prototype these panels, further to what I'll make the files available - so you could modify them to your taste and have your own panels manufactured.

Nick
hi nick,
I have one of your control boards and constructed as your instructions ( 2 nuts as spacers between pcb and display ).do you have 3d or .fpd files for the front panel as pictured #2203 .

thanks