JLM Baby Animal

[Purusha]

Thanks Matt. God's speed :green:

BTW, this should be mentioned on the BA web page don't you think?

Will variable impedance option give me some tangible changes with all mics or just ribbons?

 

[mattmoogus]

Hmm Id be very surprised if it isnt mentioned there somewhere. Its certainly in this thread a few billion times.

Ive now got two pres with variable input Z, one with a JLM1:4 input and one with a Lundahl 1578. I find its much more useful on the 1:4, I was having a lot of fun with it this last week recording various types of vocals. It works really seamlessly and you can really use it like a subtle tone control.

On the 1578, because its 1:10, I can only increase the load on the transformer/mic so its not as useful and the transformer doesnt tend to sound as good when its being 'over'loaded. Actually I think Im yet to actually record with the pot anywhere but wide open.

Youll get a tonal change with all mics (and DI aswell) because even if the mic has super low output Z and doesnt care if its loaded or not, the input transformer still behaves differently depending on the load. With the 1:4 this varies from open and airey to smooth and tight, with useable sound everywhere in between. Like I said, with the 1578 it doesnt work so well. The OEP (set to 1:6) also seems to work pretty well though it gets a little toppy when its unloaded.
This is the reason why we change the secondary load resistor instead of simply loading the mic directly, as you also get the input transformer's sound changing.


M@

 

[Purusha]

Thanks Matt, you made my day. :thumb:

I guess I'll have to make a new line of dual mic pre cases with this option as well.

 

[craigmorris74]

While waiting for my XLR jacks to arrive, I decided to check the voltages of my 4 BA's. On all of them, I'm getting 0V at opamp pins -in and out. Is this because I don't have the jacks hooked up yet, or is this a problem?

Definite issues are:
On 2 of the BA's I'm getting 0V at -V and in+.
On one of them, when phantom power is engaged, the LED doesn't light and I hear a funny sound. I didn't leave it on long enough to figure out where the sound was coming from.

Any suggestions on where to look for problems. I'm checking my soldering as we speak.

Craig

 

[craigmorris74]

Addition to post above,

I reflowed the solder around all suspicious joints on the two boards with the real odd voltages, and now the read like the other 2, which is as posted on the JLM site, but with 0V at opamp pins -in and out.

I'm still hearing a ringing noise when I engage the phantom power on the one unit though.

Craig

 

[mattmoogus]

Visually compare the one with the phantom problem to the other working ones and you should see the problem pretty soon. Check all polarised parts for a start to make sure theyre in the right way.


M@

 

[JLM Audio]

I'm absolutelly sure the NEUTRAL preamp is excellent, do not misunderstand me. All your kits are great and very well designed.
I have lots of different preamps, so at this moment I'm for the most transparent mic preamp possible for audiophile classical orchestral recording. And for me that means no transformer and no capacitors if possible.

No that is fine :grin:. Just remember you are going to need a cap on the input to block phantom power even in a bipolar design.

While waiting for my XLR jacks to arrive, I decided to check the voltages of my 4 BA's. On all of them, I'm getting 0V at opamp pins -in and out. Is this because I don't have the jacks hooked up yet, or is this a problem?

With no opamp fitted -in and opamp out will be 0v. They will only be at the +24v (or half volts) with the opamp in and working correctly. Before powering up you can check you soldering by checking with a ohmmeter that none of the opamp pins are less than 300ohm to 0v. Almost all faults we have fixed here for others have been pads soldered to each other causing a short to 0v or another part of the circuit.

 

[misguided]

Hi, I'm attempting to assemble the BA2 for a friend of mine and was trying to find a wiring guide to hook up the JLM111DC. I don't deal with audio stuff much so have no idea which terminals to hook it up via.

Btw, I'm assembling the BA with JLM14 & JLM99v

I'd be very grateful if someone would enlighten me so i can finish this for my friend.

Thanks in advance.

 

[Schmilsson]

"For 1:1 use any winding for primary and any other winding for secondary.
For 1:2 you could use winding 1 for primary and wire +2 to -3 and take +3 & -2 as the secondary."

I went 1:2 and ran PCB +out to terminal 1+ and 0V to 1-. A jumper from 2+ to -3 and then 3+ to hot XLR pin and -2 to cold XLR pin.

 

[misguided]

Ah excellent. Thanks eskimo!
[quote author="eskimo"]"For 1:1 use any winding for primary and any other winding for secondary.
For 1:2 you could use winding 1 for primary and wire +2 to -3 and take +3 & -2 as the secondary."[/quote]
I saw that on the baby animal page, but i could'nt make much sense of it

 

[Jonkan]

My output transformers arent marked in any way...

How do i know what is what?

/J

 

[JLM Audio]

Hi, I'm attempting to assemble the BA2 for a friend of mine and was trying to find a wiring guide to hook up the JLM111DC. I don't deal with audio stuff much so have no idea which terminals to hook it up via.

Btw, I'm assembling the BA with JLM14 & JLM99v

I'd be very grateful if someone would enlighten me so i can finish this for my friend.

Thanks in advance.

My output transformers arent marked in any way...

How do i know what is what?

I was only saying to Matt yesterday that I thought we had accidentally sent out the couple of JLM111DC's that had turned up without there stickers in the crazy amount of parcels we had to do in the last couple of weeks. Anyone missing a sticker on there JLM111DC please just send me a email to [email protected] with your address and I will post the stickers to you. To wire your transformers up follow the above diagrams noting that the side with 3 red insulated wires is the positive side and is shown with that side up in the photo's.

 

[astrovic]

[quote author="JLM Audio"]in the crazy amount of parcels we had to do in the last couple of weeks. [/quote]

Well, that'll learn you to make excellent products :green:

Any hint on the release date of the new BA's? Please? Pretty please? [/grovel]

 

[JLM Audio]

I would think it would not be until early January by the time we fully test these and get the final run of PCB's. Remember the BA Dual will be almost twice the price of the Normal BA and the BA Neutral is a purepath pre which is only really suited to room recording and classical in my books but Amek and SSL lovers might think otherwise. So the normal Baby Animal will still be the one that will suit most peoples needs best.

 

[3nity]

Matt or Joe, i'm awaiting a pair of boards impatiently....Now i have 2 API output transformers by CJ could this work fine in the BA?
Thankyou

 

[craigmorris74]

Hey guys,

Thanks for answering all my previous questions. I've got proper voltages everywhere, so installed my opamps.

I'm getting a good signal through 3 channels, but no signal at all through one channel. I've got proper voltages at the opamp pins and high resistance between each pin and 0V. I've got conductivity between my xlr pins and the board. What other areas would you recommend me troubleshooting?

One other thing I had the trouble with this channel making the strange noise when I engaged phantom power earlier. It was audible without the xlr's being hooked up, as in the unit physically made a sound. Could I have messed up my input transformer?
Thanks,

Craig

 

[ChrioN]

[quote author="JLM Audio"]It can with a JLM14 and JLM111DC output transformer do 86dB of gain[/quote]

It can, or it will?

 

[mattmoogus]

[quote author="ChrioN"][quote author="JLM Audio"]It can with a JLM14 and JLM111DC output transformer do 86dB of gain[/quote]

It can, or it will?[/quote]


Both.


M@

 

[ChrioN]

cool

 

[3nity]

Hi Joe, i received my Baby Kits yesterday they are ready to be racked but still got one question as i have 2 API output transformers that i want to use with the BA. Is there anything i should know or should i dive?

One more thing.....i have a 10k resistor left by kit, is that cool??

For the record: i'm gonna put one 990c by JH and the other a 1731....again anything i should know before doing it??