DIY DUAL GERMANIUM MIC PRE-EQ BASED ON NEVE EARLY DESIGNS

[Whoops]

B101

 

[salomonander]

bumping this again as im wondering about the line inouts. the 1058 manual says this:
"600 ohms unbalanced selected at -20 dBm point on sensitivity switch. For use with external 10K ohms line input transformer."

im a bit of a dummy and im wondering if they are asking for a 10k:10: or a 10k:600. i have lots of marinair 10k:10k transformers laying around.....

 

[salomonander]

im also slighty confused about the transistores. are ac107, nkt216 and oc44 all the same and interchangable? cheers

i found a great source for mullard ac107. so im wondering if i can use them for nkt216 and oc44 as well?

 

[Whoops]

im also slighty confused about the transistores. are ac107, nkt216 and oc44 all the same and interchangable? cheers

i found a great source for mullard ac107. so im wondering if i can use them for nkt216 and oc44 as well?

I posted info on transistors and replacements in a past page of this thread. I think you have the info there

 

[salomonander]

i have seen that thanks. but it only suggests that ac107 and nkt216 are equivalents (if im reading it right). but looking at b100 for instance it sometimes mentions an ac107 (tekays drawing for instance) and other times an oc44. on the pics its  an oc44 as well. so im just wondering if all of these three are actually the same...

 

[Whoops]

i have seen that thanks. but it only suggests that ac107 and nkt216 are equivalents (if im reading it right). but looking at b100 for instance it sometimes mentions an ac107 (tekays drawing for instance) and other times an oc44. on the pics its  an oc44 as well. so im just wondering if all of these three are actually the same...

They're all different as the name suggests but they probably could be interchangeable in this circuit and work.
It's not that they are replacements of each other but more that in this circuit any of them would work.

 

[salomonander]

regarding the line input. it needs to be a 10k:10k type.
could anyone in possession of the real b100, b104 and b105 maybe be so kind as to make some measurements of the cards? im loking for their exact dimensions. cheers jakob

 

[API]

I will try to get the scans done tomorrow and measure them as well then.

About the line input i am pretty sure that it should be a 10k:600ohm transformer like the later 31267 used in the silicon modules.
I think the model used was the MU7526 but i can check tomorrow as well.

 

[salomonander]

I will try to get the scans done tomorrow and measure them as well then.

About the line input i am pretty sure that it should be a 10k:600ohm transformer like the later 31267 used in the silicon modules.
I think the model used was the MU7526 but i can check tomorrow as well.

thanks API,
thats awesome. cant wait

ps: could 10k:10k transformers work if one uses say a pad after them - or would it be a bad solution? they are 5k+5k:5k+5k marinair type 1448. does this thread apply to my case: http://groupdiy.com/index.php?topic=63299.0

 

[salomonander]

here are the scans provided by API (thanks a lot!)

 

[Whoops]

Nice,
thats great.

Thank you Salomonander and thank you API

Were you able to get the measurements of the cards?

thanks

 

[API]

Here is the B105 card as well.

Could not get a perfect scan since i did not want to remove all the components, but i think its clear enough.
All cards measure 57,4mm or 2 1/4” wide and 88,8 or 3 1/2” long with the golden fingers.
The finger part measures ca 43mm wide and 7mm high.

 

[Whoops]

All cards measure 57,4mm or 2 1/4” wide and 88,8 or 3 1/2” long with the golden fingers.
The finger part measures ca 43mm wide and 7mm high.

Thanks API

 

[salomonander]

thanks API, sorry for the late reply. just got back from holidays.

ps: anyone know what the b104/20 card is? its used in the 1059 preamp but i cant find any info on it

 

[API]

No problem!

Have not heard about a B104/20 card, possibly just a variation of components.

 

[Whoops]

thanks API, sorry for the late reply. just got back from holidays.

ps: anyone know what the b104/20 card is? its used in the 1059 preamp but i cant find any info on it

I have no info on any B104/20 card,  the only references I have found have B104 or B104A

Also the info I collected on the 1059 is that it uses  1x B100, 1x B104 and 2x B105 cards

 

[API]

I have still not seen a 1059 module or schematic so please post any info you have on that module.

 

[salomonander]

hey,
i will have to ask the "owner" of the 1059 schematic to give me permission to post. if he agrees ill upload it right away.

 

[API]

Sharing is caring..

 

[salomonander]

Sharing is caring..

im sure hes cool with it. just want to make certain and not piss him off.
btw - do you guys know what kind of switches were used? i assume shorting for the gain input? but do the frequency selection switches need to be shorting as well?

and one more question for api: can you maybe tell me, which of the resistors that sit in the frame (not the amp cards) are carbon ones? its impossible to tell from the schematic but i sure see some on the photos i found on the net. i know this asking for a lot...argh