braeden

Re: [Teaser / Feeler] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #20 on: February 03, 2013, 04:52:39 PM »




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

Big knobs = big gain.

I actually have a set of these lying around somewhere, I think they're a little bit smaller but I want to get rid of them (hint hint, anyone interested?)



[silent:arts]

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #22 on: March 12, 2013, 01:11:57 PM »
Changed the title to [BUILD] and added documents in the first post 8)

100WChris

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #23 on: March 21, 2013, 08:04:26 AM »
Hi!
I did it!  :)
First test with the K13117. Everything is working, no smoke, only good sound and really deep low end!
Thanks to Volker and Kubi for this great project.

[silent:arts]

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #24 on: March 21, 2013, 01:36:25 PM »
First test with the K13117. Everything is working, no smoke, only good sound and really deep low end!

 8) 8) 8)

now a nice enclosure, gain switch and you are done.
keep us updated!

Dr_J

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #25 on: April 06, 2013, 06:37:16 AM »
Hi Volker,

package arrived well, as i already mailed you.
Short question, is there a plan/way to add 48V phantom power?

ROCK-ON!

[silent:arts]

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #26 on: April 06, 2013, 08:53:17 AM »
Sure. Your PSU already has the 48V.

Connect it to a switch, and to 6K8 resistore to the XLR Input and you are done.
A Cap to ground might be another good idea to have some "slow start".

Or use MIO PCBs,
the added PAD and polarity reverse won't hurt in a Mic Pre.

Dr_J

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #27 on: April 08, 2013, 05:19:10 PM »
Hi volker!

Cool, i missed that (just don't have the psu pcb handy to me).

An other short one, is there a recommendation / source for the gain switch / pot?
At NRG I read something about an 2x24 ELMA switch!?

Currently gathering things together.

ROCK-ON!

100WChris

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #28 on: April 12, 2013, 01:01:06 PM »
Hi!
The K13117-Switch is a 2 deck, 2 pole, 24 step switch. The only one i have found is the Elma Switch 04-2133 (https://www.distrelec.de/ishopWebFront/search/luceneSearch.do?dispatch=find&keywordPhrase=211283)
if you don´t need 24 [email protected] i guess you can use a 12 step switch, but again it has to be 2 decks and 2 poles.
if you find a cheaper solution let me know :-)
Chris

Dr_J

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #29 on: April 12, 2013, 05:47:11 PM »
Thanks a lot Chris for the link!
But hell... this one is expensive!!  :o  :o  :o Shocking!!!
There must be another way....!?

ROCK-ON!


[silent:arts]

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #30 on: April 13, 2013, 04:30:20 AM »
yes, Elma Series 4 is a very good switch (but expensive).

others will work too, if you want 35 steps  8)
http://www.ebay.de/itm/PP36-21-Russian-military-Rotary-switch-35-steps-2-plates-2pcs-/251195107080?pt=LH_DefaultDomain_0&hash=item3a7c652708#ht_904wt_964


Dr_J

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #32 on: April 17, 2013, 04:52:45 PM »
Hi Volker,

thanks for the links! I guess i have to improve my ebay search skills  :D

The Russian switch looks great and would fit perfect the subline of the project "Big knobs, big gain!"  ;D
But I will go for a one unit case...

I've ordered 2 of the switches of your second link, we will see...

ROCK-ON!

Dr_J

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #33 on: April 21, 2013, 09:20:29 AM »
Hi Volker,

I'm missing the power transformer on the BOM, any recommendations on that?

And I'm just looking at the Gain-Resistor-sheet.
If i'm taking 1db steps up to 23 positions, it leads to  gain range of +20 to +44db.
In this case Rb is constant 47k, so a simple 1 row 23 step could do the job, couldn't it?


ROCK-ON!
« Last Edit: April 21, 2013, 10:19:38 AM by Dr_J »

[silent:arts]

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #34 on: April 22, 2013, 12:02:26 PM »
I use this one - might be a little bit oversized:
https://www.distrelec.de/ringkern-transformator-80-va-25-vac/noratel/ti-044218-me-ec/353317

Don't have the gain resistor sheet upfront right now,
but yes, sounds legit (if you install the 47k resistor fixed)

100WChris

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #35 on: April 22, 2013, 12:37:45 PM »
Hi Dr_J!
I used a 2x30V/80VA trafo to power my test-build. Also oversized i guess, but i had i laying around...
Kubarth pointed out in the german forum, that he used this switch for his build:
http://uraltone.com/kauppa/product_info.php?info=p1077_Rotary-switch--2x24.html&XTCsid=jb7dm7trbdnbhjgj3umi7dihq6
it´s cheap, so no need to lose 30dB of gain just because of the switch... i´ll order two of these
best regards
Chris


Dr_J

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #36 on: April 22, 2013, 05:57:43 PM »
Hi Volker,

thanks for the link and the included  technical data of the power transformer (backwards calculations are a bit sketchy).

@110WChris:
I have read it and if i compare the pictures following the link that Volker posted above... to me they both look similar...
Whatever, i ordered 2 of the Chinese ones according to the Link of Volker, we will see...
Maybe we could make a comparison here...

The Gain resistor value of [Rb] could be fixed @47k in case of +1db steps up to +44db gain, it was just a question
of understanding and maybe interesting for some other builders...

Next is to figure out the front panel design, that I would like to have... knobs, switches, lights... some fun here  ;D

ROCK-ON!

Dr_J

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #37 on: April 24, 2013, 01:48:41 PM »
Hi,

i'm currently thinking about adding a JLM GoBetween, any thoughts on that?
Especially for the PAD switch? Is a PAD switch worse thinking about here?

ROCK-ON!

Dr_J

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #38 on: May 13, 2013, 05:33:02 PM »
Hi every one,

I have ordered the Chinese 24pos switch, they've arrived some days ago and look real fine!!!
This was a great hint!!
To me, i'm happy not ordered the Elma ones.... (mybe in a 100 years i'll regret it :) )

ROCK-ON!

100WChris

Re: [BUILD] K13117 (ClassA MicPre by Darius Kubarth / Kubi)
« Reply #39 on: May 14, 2013, 05:32:15 AM »
Hi Dr_J!
i ordered mine in Suomi :) they look like this:


How is it going with your build?
Chris


 

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