nolivdacom

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #180 on: December 30, 2012, 01:35:17 PM »
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]

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #181 on: December 30, 2012, 01:43:30 PM »
Microphones are fine (with transients)?
Do you have a DI box?
Same Problem?

I'm very interested in this!

nolivdacom

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #182 on: December 30, 2012, 02:10:11 PM »
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.
« Last Edit: January 05, 2013, 06:50:51 AM by nolivdacom »

Winetree

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #183 on: December 31, 2012, 12:32:01 AM »
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

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #184 on: December 31, 2012, 04:08:39 AM »
Is anybody had the same problem here?  :o

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...

Quote
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]

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #185 on: January 05, 2013, 04:02:17 AM »
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

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #186 on: January 05, 2013, 07:04:33 AM »
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

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #187 on: January 05, 2013, 08:02:29 AM »
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]

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #188 on: January 05, 2013, 08:27:40 AM »
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

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #189 on: January 30, 2013, 09:39:42 AM »
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

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #190 on: January 30, 2013, 10:02:56 AM »
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

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #191 on: January 30, 2013, 10:23:39 AM »
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

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #192 on: February 02, 2013, 12:00:43 PM »

 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 .
GKB Audio / Greg Boboski

baadc0de

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #193 on: February 03, 2013, 07:24:07 AM »

 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]

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #194 on: November 11, 2013, 05:30:07 AM »
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

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #195 on: November 11, 2013, 09:19:24 AM »
Yes!!! Would like two!

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #196 on: November 11, 2013, 09:23:38 AM »
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]

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #197 on: November 11, 2013, 09:44:12 AM »
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]

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #198 on: November 11, 2013, 09:46:40 AM »
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  :o

Re: [BUILD] JENSAMP-51X (Germanium Mic-Pre by Darius Kubarth)
« Reply #199 on: November 11, 2013, 06:57:56 PM »
I would take 2, maybe 4 if some colleagues join in.


 

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