JLM mic pre

[peter purpose]

Gentlemen,
I've just nailed this pcb together and am just waiting for a couple of parts to arrive before I fire it up, but if it should prove to be anything like what Dave (soundguy) has at his disposal, I'll be well chuffed.

peter

 

[Kev]

very interesting

hope it does what you want

 

[peter purpose]

Cheers guys.. :thumb:

Kev.... I want it to do what Soundguy says :wink:

PS.. Kev, where is your page with your JLM pre?

peter

 

[jrmintz]

Very nice, Peter. Please keep us informed. I've had thoughts running along similar lines, but I'm concerned my wife will throw me out if I build anything new for a while.

:green:

 

[peter purpose]

Just sneak out at night Seth.

 

[Flatpicker]

[quote author="peter purpose"]...but if it should prove to be anything like what Dave (soundguy) has at his disposal, I'll be well chuffed.[/quote]Hmmmm... I must've missed soundguy's post about it. :?

Why are you using 2 JLM99Vs? To split the gain chores?

 

[SonsOfThunder]

Nice job, PP!

Just curious as to why you chose not to use Joe's PCBs and what your actual choice of I/O iron is?

Can't wait to hear what you think about the sound. I am wanting to build this very pre myself, but I'm in the same company as Seth...

Peace!
Charlie

 

[peter purpose]

Tim... http://www.groupdiy.com/index.php?topic=755 for Daves comments.

Dual amps as per Joe's design.

Charlie... I have a warped need to make my own stuff..!! Input iron is a Sphere 7341 1:8, but I'm also going to try a Cinemag 8PCA too.

peter

 

[daArry]

very tidy PP! :thumb:

 

[SonsOfThunder]

PP... and the output trafo?

Thanks for the response. I think Joe's board is about as good as it gets. I haven't actually eyeballed them, but I figure as cheep as he sells them I can't "pay" myself for the difference.

:thumb:

 

[peter purpose]

Sorry Charlie... output is Profile 4804, same as API 2503.

I hear what you're saying on the board, but I really am anal about some of this stuff.

peter

 

[Bear]

Wow, looks like the boards were hand drawn, but perhaps tidier and more compact than the JLM. (Of course, no kitchen-sink options for the build.) Nice. :thumb:

Bear

 

[Flatpicker]

[quote author="peter purpose"]...Dual amps as per Joe's design...[/quote]Oh, I see now...

Thanks for the link.

 

[Flatpicker]

[quote author="Flatpicker"]Hmmmm... I must've missed soundguy's post about it. :?[/quote]Ha! I actually posted in it! I do remember it now. :green:

 

[peter purpose]

Pull yourself together Tim.. :green:

 

[Kev]

[quote author="peter purpose"]... Kev, where is your page with your JLM pre?[/quote]
not for general viewing yet

 

[JLM Audio]

I do like Peter's new improved 99v stickers he made.

They look great !

Joe

 

[Flatpicker]

Hey Joe,
Why does the schematic say not to mount the output transformer on the pcb?

Also, what would I sacrifice by just using one 99v in a standard 312 circuit - or should they even be run that way?

 

[tk@halmi]

I am not Joe, obviously (although I do wish to be as bright and as handsome he is). :grin:
There is no place for the output transformer on the JLM board simple as that.
The 99V has a low open loop gain compared to the 2520 or the JH990 and you run out of fedback at higher gain settings. Thus the recommendation to double them up in most cases.
I love the JLM boards though and find that mounting the transformer off board is a plus in my world. I have populated five of these boars so far in varioius configurations.
He even makes a very affordable 1:4 mic input transformer. The man is a DYNAMO!

Tamas

 

[peter purpose]

It's alive..!!

Writing about how something sounds is totally alien to this old boy, but here goes.....

IT'S LARGE, round, thick and juicy.

Only shoved my voice on a 57 in front of it so far, but it sounds great.

I'll test more over the next few and report back.

peter