[BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)

[[silent:arts]]

K13117 PreView

K13117 Schematic
K13117 PCB
K13117 BOM
K13117 Gain Switch Values

N13117 Schematic
N13117 PCB
N13117 BOM

 

[kante1603]

Now why does that look familiar to me....... ;D

Udo.

 

[[silent:arts]]

You might visit a german Forum or Fratzenbuch? ;D

 

[[silent:arts]]

HOT!

 

[3nity]

Is this hot like really cool or hot like transistors really got hot?? lol
Tell us a bit more about it.
Thanks

 

[okgb]

you Germans and your wacky K's ! Lean meat  ?  low fat ? pyramid power ?
I see xfmr goodness and allot of caps , hmmmm , curious drizzeled with fat ?
not copping pier's pre eh ?

 

[[silent:arts]]

Tell us a bit more about it.

Transformer balanced input and output (designed for the specific transformers, no options)
pure classA running on +/- 30V

 

[[silent:arts]]

not copping pier's pre eh ?

not copping anything  8)

 

[[silent:arts]]

not copping pier's pre eh ?

Greg, since I have been asked: what do you mean exactly?

 

[okgb]

Since I didn't know , I was referring to Pier's ma-1 germanium pre , because I couldn't see & your's
didn't seem to be a 2520 type as his was not , was trying to figure it out , just a little friendly kidding .
class A Iron goodness ?

 

[desol]

To tell you guys the truth...i haven't been able to get that chicken out of my mind for that last two days.
Mmm...looks like garlic hot sauce maybe? Anyway...i just picked up a family pack of thighs.

 

[grantlack]

let me guess... the red wire is the NFB feed from the nuclear reactor's gas turbines?  ;D

 

[[silent:arts]]

Schematic without component values.

We will limit this project to 60 / 30 PCBs (= 30 Stereo Sets)
PCBs will be ordered next week.

Darius made some listening tests, description in german only:
http://www.nrgrecording.de/nrg/viewtopic.php?t=2364&start=98

 

[dmp]

Rg1 / Rg2 control the gain? What is the max gain?
FYI for others: there are some nice pictures on page 5 of the German forum.

 

[[silent:arts]]

Rg1 / Rg2 control the gain? What is the max gain?

correct. the value table Darius calculated did either go from 20 to 64 dB, or 25 to 69 dB.
this was done for Pikatron a output transformers, we now decided to go for a Haufe which needs some adjustment. I'm sure Darius is already calculating  8)

 

[dmp]

I see two MAT02s in the pictures... cool. Makes me think this might be like a 990 with class A throughout. 
Have you compared the Haufe to a Jensen 16b?

 

[[silent:arts]]

Have you compared the Haufe to a Jensen 16b?

no. and to make support etc easier transformers are fixed (input = E-1420, output = RK494), no options.

 

[[silent:arts]]

Preliminary documents (values may change):

K13117 Schematic
K13117 PCB


N13117 Schematic
N13117 PCB

One unit is on the road for listening tests to finalize some component values  8)

 

[[silent:arts]]

some Pics of the first K13117 (copyright by Darius Kubarth)

 

[strangeandbouncy]

. . . I am not sure your gain knobs are big enough. . . .