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JLM Baby Animal Build

PostPosted: Wed Jun 29, 2016 3:59 pm
by waitup
Just finished these up for a friend of mine:

Image

Image

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Re: JLM Baby Animal Build

PostPosted: Wed Jun 29, 2016 7:01 pm
by Paul Maybury
Wow, nice lookin', aren't they? I love the compact form factor.
What transformers and opamps did you use?
Cheers,
Paul

Re: JLM Baby Animal Build

PostPosted: Sun Jul 03, 2016 10:33 am
by chrisp
Lookin at the pic I'd guess the input tranny to be the JLM1:4, the opamps OPA2604 and transformerless output by balancing using the second half of the opamp as a unity gain inverter (a neat JLM trick that adds 3db Gain, just like a 1:2 output transformer).

The BA gets most of its character from the input transformer and the gain stage (JLM99V, Hybrid or OPA2604), so the output tranny is largely optional so far as colouring is concerned - but useful if your recording environment is emissions unfriendly.

Nice build, and the vari-Z control option is very useful in practice so good move adding it in. Welcome to the JLM fan club.

Re: JLM Baby Animal Build

PostPosted: Sun Jul 03, 2016 3:07 pm
by Chinagraf
Vari Z is great, I built a 4 channel with 99v opamps.
I had one channel playing up wierd, sent Joe an email. He asked for some pics on the board and saw the smallest little solder I'd messed up on a resistor. Man's a genius.

Re: JLM Baby Animal Build

PostPosted: Mon Jul 04, 2016 11:24 am
by Paul Maybury
Hi, I have built these with JLM input trans and 99v op amps, they were super smooth but a little soft sounding for me.
I sold those on but subsequently built a couple more channels with Cinemag 1:3 input trans, 99v op amp, Cinemag steel core output trans wired 1:2 and the variable impedance.
These sound huge and very clear. Just what I was hoping for. It did make them expensive though.
I was curious as to the results Nick got using the most basic ingredients for his build.
Cheers, Paul

Re: JLM Baby Animal Build

PostPosted: Mon Jul 04, 2016 1:10 pm
by walding
they look very nice nick, may I ask what is cost to build them?

Re: JLM Baby Animal Build

PostPosted: Mon Jul 04, 2016 1:29 pm
by waitup
Paul Maybury wrote:Wow, nice lookin', aren't they? I love the compact form factor.
What transformers and opamps did you use?
Cheers,
Paul


Hi Paul,

Altronics microphone input transformers and OPA2604AP opamps. Client was on a budget so this was a compromise. They do still sound great though.

Re: JLM Baby Animal Build

PostPosted: Mon Jul 04, 2016 1:30 pm
by waitup
chrisp wrote:Lookin at the pic I'd guess the input tranny to be the JLM1:4, the opamps OPA2604 and transformerless output by balancing using the second half of the opamp as a unity gain inverter (a neat JLM trick that adds 3db Gain, just like a 1:2 output transformer).

The BA gets most of its character from the input transformer and the gain stage (JLM99V, Hybrid or OPA2604), so the output tranny is largely optional so far as colouring is concerned - but useful if your recording environment is emissions unfriendly.

Nice build, and the vari-Z control option is very useful in practice so good move adding it in. Welcome to the JLM fan club.


Correct all round.

Re: JLM Baby Animal Build

PostPosted: Mon Jul 04, 2016 1:30 pm
by waitup
Chinagraf wrote:Vari Z is great, I built a 4 channel with 99v opamps.
I had one channel playing up wierd, sent Joe an email. He asked for some pics on the board and saw the smallest little solder I'd messed up on a resistor. Man's a genius.


Yeah the variable impedance is really handy.

Re: JLM Baby Animal Build

PostPosted: Mon Jul 04, 2016 1:32 pm
by waitup
Price was a factor here, the client was pretty strapped. I think they sound good though.

Paul Maybury wrote:Hi, I have built these with JLM input trans and 99v op amps, they were super smooth but a little soft sounding for me.
I sold those on but subsequently built a couple more channels with Cinemag 1:3 input trans, 99v op amp, Cinemag steel core output trans wired 1:2 and the variable impedance.
These sound huge and very clear. Just what I was hoping for. It did make them expensive though.
I was curious as to the results Nick got using the most basic ingredients for his build.
Cheers, Paul

Re: JLM Baby Animal Build

PostPosted: Mon Jul 04, 2016 1:32 pm
by waitup
Hey mate,

I reckon it was about $350.00-$400.00, if that.

walding wrote:they look very nice nick, may I ask what is cost to build them?

Re: JLM Baby Animal Build

PostPosted: Mon Jul 04, 2016 7:53 pm
by Paul Maybury
Hi Nick, so those Altronics input trans sound good? That's great to hear, I've been curious about them.
I've been thinking about building an 8 channel unit with those trans and 5532 op amps for plenty of sweet sounding pres at bargain price.
Cheers, Paul

Re: JLM Baby Animal Build

PostPosted: Mon Jul 04, 2016 8:33 pm
by rowmat
Front panel legend looks nice.
How did you do it if you don't mind me asking?

I bought a couple of the JLM BA500 series preamp kits with the JLM input and output trannies and JLM99V opamp.
They are somewhat thickish and soft as Paul said but I wanted some tom pre's that rounded off the transients a little.

I used the DI input to record Steve Hadley's bass on a few tracks a while back and really liked the fat, warm tone.

Joe from JLM said the little JLM input transformer was designed to saturate and add some thickness to the low end.

I'll try a different i/p tranny in the other BA500 and do some comparisons.
Interesting about the Altronic's transformer.

Tried adding an image but the image uploader won't play nice. :-\

Re: JLM Baby Animal Build

PostPosted: Tue Jul 05, 2016 11:06 am
by waitup
Hey paul,

I guess they do. I mean I lived with them for all of about 5 minutes before the client took them!

NF.

Paul Maybury wrote:Hi Nick, so those Altronics input trans sound good? That's great to hear, I've been curious about them.
I've been thinking about building an 8 channel unit with those trans and 5532 op amps for plenty of sweet sounding pres at bargain price.
Cheers, Paul

Re: JLM Baby Animal Build

PostPosted: Tue Jul 05, 2016 11:09 am
by waitup
rowmat wrote:Front panel legend looks nice.
How did you do it if you don't mind me asking?


G'day mate,

Same way I do all my builds. A trophy shop engraves a product called Traffolyte (spelling?). I provide them with a .eps file exact size and they make it up for about $20.00. I glue it down and drill right through it.

NF.

Re: JLM Baby Animal Build

PostPosted: Tue Jul 05, 2016 12:43 pm
by Paul Maybury
Hi Nick, in the short time you had with them, would you say the Altronics trans was similar in performance to the JLM?
They are the same footprint and turns ratio, I believe.
Cheers, Paul

Re: JLM Baby Animal Build

PostPosted: Tue Jul 05, 2016 1:42 pm
by rowmat
waitup wrote:
rowmat wrote:Front panel legend looks nice.
How did you do it if you don't mind me asking?


G'day mate,

Same way I do all my builds. A trophy shop engraves a product called Traffolyte (spelling?). I provide them with a .eps file exact size and they make it up for about $20.00. I glue it down and drill right through it.

NF.


Cool.Thanks for that!

Re: JLM Baby Animal Build

PostPosted: Tue Jul 05, 2016 4:39 pm
by waitup
Hi Paul,

Sorry couldn't be sure!

NF.

Paul Maybury wrote:Hi Nick, in the short time you had with them, would you say the Altronics trans was similar in performance to the JLM?
They are the same footprint and turns ratio, I believe.
Cheers, Paul