JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)

[[silent:arts]]

finished and working!

Alex, how does it sound?

 

[ultra-alex]

so far i made a little hi-z input shootout between some of my preamps with a fretless bass as source. compared with a millennia td-1, tube tech pm1a, rnd 517, sh monogama, ss mp73, ss mp12, ss mp32 and amek console pre with a radial jdi. i liked the tube tech most, followed by the jensamp and the shadow hills. although i have to say that the differences/impression were subtle/subjective and all the used amps performed very good as expected.
i like the jensamp a lot and will build a second unit.
cheers, alex

 

[Matthew Jacobs]

For those of use building this baby in a rack... Would a 9K PSU stuffed with +24/-24 components and the correct power TX do?

Another option would be two +24V PSU using 1 toroid, right? As it's good to keep the relays off the audio power, right? plus +48V for the phantom.

Looks like the 9K is the easiest solution for me as I have loads of them kicking around.

 

[[silent:arts]]

the 9K PSU should work fine

 

[nashkato]

i think there´s a mistake on the BOM .
R19, R24 reads 5k81 , should be 6k81 as on the PCB , i guess ?

 

[[silent:arts]]

i think there´s a mistake on the BOM .
R19, R24 reads 5k81 , should be 6k81 as on the PCB , i guess ?

yes - thanks for the hint - corrected the parts list 

 

[zmgwg]

silent:arts, how about using EA neve transformer as input, what do you think?

 

[[silent:arts]]

why not?
lower gain, interesting to see how you fit it at the PCB.
try it and give us feedback!

 

[okgb]

I'm presuming , please correct me if i'm wrong , that the germainium xistors don't pop easily
and that sockets are not necessary ?

 

[[silent:arts]]

with rev01 Darius killed a few while trouble shooting

however, the rev02 and rev03 I have here still have their first and only ASY26 working since their birth.
(and they have been abused a few times)
no need for sockets

 

[Tajmoben]

I finished mine up and they sound great!!! I do have one question though. When I switch from XLR to Hi-Z there's a small pop, is this normal?

 

[wowi]

I finished mine up and they sound great!!! I do have one question though. When I switch from XLR to Hi-Z there's a small pop, is this normal?

I just checked mine and yes, i also have a clear pop when switching. It's no big problem though, but maybe Kubi and Volker have an idea, how to avoid this. 

Wolfgang

 

[[silent:arts]]

I finished mine up and they sound great!!! I do have one question though. When I switch from XLR to Hi-Z there's a small pop, is this normal?

I just checked mine and yes, i also have a clear pop when switching. It's no big problem though, but maybe Kubi and Volker have an idea, how to avoid this. 

well, I don't know how to avoid this. like with relays I'm not aware of shorting versions, they are all break before make (while relays are switching so fast you nearly never notice this).

Looking at the schematic, next possible cause could be a DC voltage difference between both inputs.
We could try some (high, something like 4M7) resistance between pin 1 and 3 of the switch?
But HiZ and MicIn wouldn't be 100% isolated anymore

mhm, no time to try it this weekend, may be Sir Kubi has a better idea.

 

[okgb]

In case anyone is interested , the Marshall style " cliff ' [ the brand  ] jacks seem to
just fit , i didn't have a pc mount to check , so a couple of wires should do it .
had to trim the rounded part slightly  but the nut fit into the panel hole
looks same also as the jack t.c. electronics use [ brand ? ]

yeah , that's my '73 marshall 1987 head that someone else put a master volume in before i got it back
[ but I did ! , get it back ]

 

[[silent:arts]]

looks cool!

 

[[silent:arts]]

ok, I want to show you my D-ASY26 ;D ;D ;D

these are rev02 PCBs, converted to +24 / +48V. I did one further trace cut and wire to change the POL and LOAD switch position.

the PSU and PSU transformer is way overkill, I just used what I have had handy.
thanks Frank from NRGrecording for the perfectly engraved front panel!

 

[baadc0de]

It's a beauty, you should be very proud. How does she sound?

 

[3nity]

Volker looks great clean build.
Are the relays under the board???
I dont see them!

Thanks...

 

[[silent:arts]]

It's a beauty, you should be very proud. How does she sound?

exactly like the 51X version ;D

Are the relays under the board???
I dont see them!

yes. this is part of the positive (voltage) only mod

 

[3nity]

oh!