BAD PCB and kits Now Available

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Joe Malone
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BAD PCB and kits Now Available

Postby Joe Malone » Fri Feb 23, 2007 11:33 pm

The new BA type PCB's run on the same 48v to 62v power rail as the original BA and fit straight into the same position.

Image

I'm looking at the second board, the NEUTRAL, and it looks like it is a version of this http://www.forsselltech.com/JFETMP1.PDF but with single ended output (2x2SK289, OPA2604, JLM99V as out driver). Am I right? Did you use DC servo for the output circuit? (somewhere under the JLM99V a chip?)
I'm very interested because I started to design a board for something similar, but in this case I would preffer to buy from you.
Give me please more details about the NETRAL.

The BA Neutral (BAN) is for building several versions of the Graeme Cohen Mic pre topology like Amek/SSL/Forssell/Green mic pres use but redesigned to run on one 48v to 62volt power rail. The PCB can take LM394 dip or can, MAT02, 2 x 2SK389, 2 or 4 x BC550C etc as its discrete front end. Working around a OPA2604A, NE5532A dual dip etc. The output stage can be JLM99v, Hybrid, 990, 992, 993 etc with output transformer if you want fully floating balanced output or OPA2604A, NE5532A etc for electronically balanced output stage. Has input stage trim pot to better balance transistor/fet match which is adjusted simply with a multimeter held between the two TP1 and null for 0v. Also a output swing trim that centres the output of the output stage opamp to half volts to give best maximum +/- swing. This is another 0v null trim while holding the multimeter on the 2 TP2 points. There is no servo as there is always half the supply rail volts on the output so a output cap is always needed and the trim pots do the DC offset trimming.

Whats the difference between the dual 99v and the dual BA?

Difference is BA Dual (BAD) it designed to run on one 48v to 62v power rail and has no servo options on the PCB, no remote relay switching and no A and B output for switching between single and dual mode. Otherwise is it similar. It can with a JLM14 and JLM111DC output transformer do 86dB of gain which allows you to insert a passive EQ in the trim/fader/insert point on the BA dual and makeup the 16dB loss of the EQ and still have a 70dB mic pre. or same goes for inserting a opto comp etc.



Below is a small Power switch and LED PCB that comes in the full BA everything kits now to make that even simpler.

Image
Last edited by Joe Malone on Mon Mar 26, 2007 12:12 am, edited 1 time in total.

ChrioN
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Postby ChrioN » Wed Mar 07, 2007 11:33 pm

That BAD is going to be just that.. 86db gain! Can't wait :o

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Postby Joe Malone » Wed Mar 07, 2007 11:38 pm

BAD PCB's are due to arrive here on the 16th of March and full kits will start shipping on the 19th of March.
Joe :-)
JLM Audio
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ChrioN
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Postby ChrioN » Fri Mar 09, 2007 6:33 am

After I get done with the floor in my apartment, I'm down for 2 of those bad boys :P

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Postby ChrioN » Thu Mar 22, 2007 12:51 am

Is there a delay? Have looked every day at the website, but haven't seen BAD there yet :P

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Postby Joe Malone » Mon Mar 26, 2007 12:11 am

Finally BAD PCB and kits are now up on the JLM website on the Baby Animal Page here http://www.jlmaudio.com/Baby_Animal_Mic_Pre.htm

Image
Joe :-)

JLM Audio

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bantam
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Postby bantam » Tue Mar 27, 2007 4:58 am

hello joe,
can you describe the difference between say a BA with jlm 99v and a BAD with 2x jlm 99vs. is it just a gain increase for ribbons and such or is it sonically a much different pre.

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Postby chrisp » Tue Mar 27, 2007 8:18 am

Hey Bantam

As I understand it (and Joe will step in if I get it wrong), the difference between the BA and the BAD configured with the same input tranny and opamps is almost entirely one of gain rather than sound. The BA is fine for most applications, but you would choose the BAD in three applications:

(1) for low output mics like the older style ribbons,
(2) where you are running the signal through some passive dynamics like an eq or compressor that will suck some of the gain, or
(3) where you need lots and lots of gain (eg to overdrive a tube stage down the chain, or to better manage the overall gain structure because some units down chain don't do gain well!).
Chris P
---------------------------------------------------------
I do lots of things. I believe eclectic skills are best.

greenmanhumming
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BAN availability

Postby greenmanhumming » Tue Apr 10, 2007 6:59 pm

when will we see the neutral version BAN available?

I'm up for a couple of channels of that.

price?

do you need a beta tester or is it past that point?

ChrioN
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Postby ChrioN » Wed Apr 11, 2007 9:34 pm

As I understand it, the Baby Animal micpres are very neutral. No need for a special "BAN"-unit.

just.sounds
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Postby just.sounds » Sat Apr 28, 2007 6:46 pm

Are the BA's also compatible with the LM4562?

http://www.national.com/pf/LM/LM4562.html

I heard very good things about this opamp.

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discobeet
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Postby discobeet » Thu Feb 28, 2008 1:29 am

Hey. I'm interested in ordering some BAD PCBs and I'm wondering if the kinks have been worked out of the boards?

Thanks,

Mark

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Joe Malone
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Postby Joe Malone » Sat Aug 16, 2008 3:54 pm

The BAD PCB hasn't had any kinks in it at all. There is about 500 built and working out there in the real world with no known issues.
Joe :-)

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conleycd
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Re: BAD PCB and kits Now Available

Postby conleycd » Fri Apr 24, 2009 7:29 am

Is a BA kit - with an output transformer vastly different from a API 312?

See, I was thinking of doing an API 312 with a JLM 99V (kinda a APIish Neve thing) but rather than modifying an API 312 board slightly to accommodate the 99v I thought a BA with a 99v and output transformer might be similar - with the convenience of the 48v power supply and no need for the go between.

Am I off base here? I have vintage API 312 racked up but I don't really want to modify them.

Thanks.

CC

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Re: BAD PCB and kits Now Available

Postby Joe Malone » Fri Apr 24, 2009 8:07 am

The BA is a similair circuit to the API but with the power rails rearranged so only 48v is need to run the audio circuit and provide 48v phantom power. So if you used the right transformers and 2520 opamp you could make a 312 on the BA PCB easy.
Joe :-)

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