a Dual LA2A - the [silent:arts] version

[[silent:arts]]

Gentlemen, may I present you the [silent:arts] D-LA2A:

it was not easy to fit the two channels in a 2U rack, but with a little care it worked:

it was my first self designed double sided PCB, and my first Tube project.
I'm glad everything is working :grin:

I have had problems with gain over "7" (may be this grid stopper thing), but I changed the gain pot to a 22K log in series with a 75K resistor to get an easier to adjust gain range (still 26dB gain - enough for a compressor / limiter).

hope you like it (since this LA2A is NOT ptp) :twisted: :green:  :green:  :green:

 

[radiance]

As always, a very pro looking job :thumb:
Love the blue PCB's in there.....and the sub panels to mount the pots on so you will not have bolds on your main frontpanel. I guess it can't get much better than this!

 

[Purusha]

I see those racks finally arrived :grin:

HOWEVER, VERY IMPRESSIVE WORK VOLKER :thumb: :thumb: :thumb:

 

[3nity]

Awesome! I see on the PCB's you marked left and right that means the unit is a Stereo? or dual mono?
Really cool!

 

[fum]

Nice!

How did you do the pot pcbs mounted to the back side of the front panel (what kind of hardware).

Is it a short screw sunk into the front panel, or...?

Regards

ju

 

[Stagefright13]

HOLY SMOKES! That's just awesome. Congrats!!

John

 

[[silent:arts]]

[quote author="3nity"]Awesome! I see on the PCB's you marked left and right that means the unit is a Stereo? or dual mono?
Really cool![/quote]
it is dual mono or stereo - just press the button in the middle.

[quote author="fum"]How did you do the pot pcbs mounted to the back side of the front panel (what kind of hardware).[/quote]
there is no pot pcb, only the pots and the switchs. they are mounted to 2mm Alu panels, connected to 8mm threaded bushes.

thanks for the kind words everyone :grin:

 

[hejsan]

Very nice work :thumb:
I'm also in the process of making a dual mono/stereo unit.

Is this some standard power transformer you are using?
I actually bought the one from edcor, it is not a donut though.

Have you checked if the matching is satisfactory? Did you somehow match the t4b's?

Coolness,
hejsan

 

[matta]

Volker,

VERY cool looking, amazing you got it into the 2U rack. You now have more space for other gear!!!! As always you never cease to amaze and I'm impressed :thumb:

I love the choice of colour as well, black panels are far to safe :green:

Matt

 

[Lowfreq]

OK, STOP IT!!!

I'm constantly trying to convince myself I don't need an LA2A, and you and matta aren't helping at all :wink: .............. ha ha

Sheesh, I've never even heard one in real life, yet for some reason I lust for one. :roll:

Fantastic Work :thumb:

 

[Stagefright13]

The LA-2A sounds like nothing else. It has a lusty sound! :green:

 

[wmb]

While I'm still trying to get mine working I've been doing pre-production at another studio and the scratch vocal mic is running though one. Holy moly! It sounds fantastic and it's a reissue.

I have a reissue LA3A and it sounds great but totally different than the LA2A. I can definately hear the price differnce. Not sure if it's $1300 worth of differnce but it can be heard.

Cheers,

 

[[silent:arts]]

Hi hejsan,
you know the transformers ? :grin:
thanks again
[quote author="hejsan"]Is this some standard power transformer you are using?[/quote]
no. it is custom wound from Mueller Rondo. really nice company!
[quote author="hejsan"]Have you checked if the matching is satisfactory? Did you somehow match the t4b's?[/quote]
I didn't match the T4b's (since I only have two of them :green: )
but I matched all resistors for both channels.
the tracking is fine - oddly better without the stereo link switched in :? , but still within 1dB.
the gain reduction Metering doesn't track fine, but who cares ...

[quote author="matta"]VERY cool looking, amazing you got it into the 2U rack. You now have more space for other gear!!!![/quote]
thanks - and yes, place is an issue in my place. more to come of my "blue series" tube gear collection ... :green:

[quote author="Lowfreq"]I'm constantly trying to convince myself I don't need an LA2A[/quote]
everybody needs a LA2A. you will know when you have heard one :green: :green:

[quote author="wmb"]I have a reissue LA3A and it sounds great but totally different than the LA2A. I can definately hear the price differnce. Not sure if it's $1300 worth of differnce but it can be heard.[/quote]
for a little more of that money you can build a dual version ...

 

[bernbrue]

Cool and sexy, Volker, as I mentioned before.
regards
Bernd

 

[Handcrafted Tone]

Seriously bad ass

You've convinced me, I need to make an LA2

 

[gerardmanvuca]

gotta say this build looks friggin amazing! Did you design the circuit or is it from a schematic? I've looked on the net for a pcb layout of the L-ay-2-ay but cant find anything

 

[[silent:arts]]

no, I'm not the designer of this circuit :green:
it is just a standard LA2A
I can send you the schematic and PCB layout in as a Target file. Other formats have to wait until my new MacBook Pro arrives, since my Virtuel PC installation is lost in the land of bad blocks :roll:

 

[gerardmanvuca]

thanx very much silent that would awsome....i PM you with my details....cheers

 

[[silent:arts]]

*** removed ***

 

[bernbrue]

Thanks a lot, Volker. Good to have this one.
regards
Bernd