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

[nolivdacom]

Hey Volker!
NO problem, I'm not in a hurry!

With reduced level sources the problem in the same.
It happens when there are strong transients (more obvious in lower frequency) and it is not "really" level dependent...
I mean you cannot play funk with this DI...?! only acoustic ballads  :'(
I also tried with same parameters (guitar, level, etc...) with preamps like G9, UA twinfinity, Phoenix audio DRS1 (remember? ;D) and I've got no problem...

 

[[silent:arts]]

Microphones are fine (with transients)?
Do you have a DI box?
Same Problem?

I'm very interested in this!

 

[nolivdacom]

I just tested with Guitar -> DI (radial pro D2 - passive) ->Jensamp MIC input (600ohms):
no problem, it works fine...

The Jensamp's DI create problems from Gain position 3 to higher position.

 

[Winetree]

Reported the D.I. problem over 1 year ago.
Post #112 and reply post #114
Replied Passive P-Bass pick-ups put out too hot of a signal.
I knew that wasn't true.
Never got them fixed.

 

[nolivdacom]

Is anybody had the same problem here? 

I understand that it can be a "too hot signal problem" but we should not hear "loud distortion squeal with a large volume spike", just saturation or something like that...

I used mine with active basses, Godin electrics and keys and never noticed something like that.

3nity, Are you sure it never happens? Even if you set gain to position 3 or higher? It is weird if it does not happens to every modules...

A solution to avoid this annoying problem could be to add input transformer to the DI input to limit transients, so we could use saturation that Jensamp brings with maximum gain settings...

 

[[silent:arts]]

The Designers explanation (in german language)

Replace C14 (3µ3F) with a smaller value, like 22nF.
I haven't tested this myself, but this should prevent overdriving the HiZ input with too low frequencies.

 

[nolivdacom]

Ok, thanks for the advice, I've got the same value (22nF) on my Gyraf G9...
Why did you choose 3µ3F for C14 on your design? Is this a common use?

 

[Apache5]

what is the advantage/disadvantage  in to put R18=100k and C13=68nF that is sugested too on the link versus only replace C13=22nF ??
Thanks 

 

[[silent:arts]]

what is the advantage/disadvantage  in to put R18=100k and C13=68nF that is sugested too on the link versus only replace C13=22nF ??
Thanks 

The load for the source will decrease.

 

[nolivdacom]

Hello,
I tried with 22nF caps for C14 (HiZ Input) and it doesn't really fix distortion problems.
I have to put my gain to minimum in order to use instrument input quietly.
Nothing to do so, just use it with minimum gain or connect instruments through a DI box and Mic input to be sure...
It was just to let you know.
Best

;D

 

[baadc0de]

Hello,
I tried with 22nF caps for C14 (HiZ Input) and it doesn't really fix distortion problems.
I have to put my gain to minimum in order to use instrument input quietly.
Nothing to do so, just use it with minimum gain or connect instruments through a DI box and Mic input to be sure...
It was just to let you know.
Best

;D

I must be lucky. I have them stock and we were using both a stingray and an original les paul. No problems, no farting, no distortion... gain was "enough" easily.

 

[nolivdacom]

Don't know what's wrong... I tried with an acoustic "art et lutherie" and an electric "PRS" guitars...
I don't have any problems with Universal Audio twin finity, Gyraf G9, Phoenix Audio DRS1 and metric halo preamps. When I use DI box (radial D2) with Jensamp mic input I don't have any problems.

 

[okgb]

Due to the nature of the design  [ older  ]  it does not have as much headroom as modern equivalents
the one I made will easily distort on loud  [ shouting ] type singing , totally craps out .
Doesn't take away from the soft fuzzy quality it has , but it's not for everything .

 

[baadc0de]

Due to the nature of the design  [ older  ]  it does not have as much headroom as modern equivalents
the one I made will easily distort on loud  [ shouting ] type singing , totally craps out .
Doesn't take away from the soft fuzzy quality it has , but it's not for everything .

An inline pad (I think 20dB) is used most of the time here with it. Gives us much more control, and we can record bass heavy things like kick drums with it then. Which is great, because it's the best outside kick drum micpre we have.

 

[[silent:arts]]

Toying around with the idea of a small new batch.
Would need to buy the RK240 brand new from haute this time.
Anybody interested?

 

[tzman]

Yes!!! Would like two!

 

[irfrench]

I'm definitely interested in pair! 

This is a horrible question to ask but given the time of year approaching - what sort of price is each unit likely to come in at?

 

[[silent:arts]]

This is a horrible question to ask but given the time of year approaching - what sort of price is each unit likely to come in at?

Legit question. I'm waiting for two major unknown prices: Haufe RK240/2M and ASY26.
Requested both today, but don't have an answer yet.

 

[[silent:arts]]

However, did the PCB work today. Changed the polarity bug of C7, and changed the HiZ input to the suggested 68nF / 100k.
Would be rev04 

 

[kvothe]

I would take 2, maybe 4 if some colleagues join in.