LA2A PCB ver 2.0 build thread

[Neil]

Great job on the Ver 2 pcb and manual!

I'm down for a couple of V72s when you get that going, keep us posted.

And did I hear Fairchild 660? Can't wait to see that!

Neil

 

[dripelectronics]

:thumb: im thinking by summer or fall i will be purchasing the 660 to begin dismanteling it .

it's half the price of a 670 , but the 670 does have the stereo image section , wich i might need to reproduce.

manley designed a 'T' bar replace ment for the
super expensive tubes,

and sowter has already designed all the x formers.

i love the sowter folks <3

i dont trust schematics for anything , there are always wierd subtle
things that are not showing how it's really done.

for example the la2a would be a real pain in the a$$ based off of
schematics the ground structure alone is so damn finicky about how it wants to
be.

so if all goes well 660 , but if things change its 670.
then comes the pcb / and the book.

*fingers crossed*

i know im going to hell for using that logo , lol

 

[louder]

Hi
so,do you have ver2 for sale,with t4b?.
if so i want two.
best regards
pedro

 

[kazper]

I am down for 2 units of version 2.

Stick with the heavy boards, offer what you got done. If you think about some of the caparison projects costs your right in line with them based on exchange rates etc.. plus your excellent how to's set the bar rather high.

I said all that to say this, I'm in for 2 units (version 2 boards and T4B) but I've been waiting for you to say the T4B are cool. Been watching them come and go on the bay but would rather spend the money with you. Looks like your there but now I have to wait about 4-5 weeks till I have the funds.

Kevin S.

 

[ECC82]

What would the total cost (not including the case) be for building an LA...ehh ( :wink: ) I mean Drip opto-compressor?

Best regards

 

[mikka]

[quote author="dripelectronics"]i know im going to hell for using that logo , lol[/quote]Change the "n" and the "k" around.....

 

[dripelectronics]

great idea with the TELEfUNken
:razz:
i have enough panels for 10 t4bs at the moment .
then it will take 4 weeks to get the rest of the panels.
untill i get cells made ,prices will be higher due
to loss rate.

pcb ver 2. : 80$ (shipping usa 10 / int 15)
t4b : 70-80$ (fast / slow) shipping 5$
tubes and sockets: 55$
mouser : 50$ (caps/parts/xlrs/ne-2/fuse/in4007 etc.)
radioshack : 5$ switches and stand offs
allied elec : 32$ (10uf cap / usa power xformer)
sowter/ prodigy pro : 65$ input xformer pcb mount
sowter/prodigy pro : 100$ output xformer pcb mount
digi key : 50$ pots (x5 pec 2 watt)
resistors : 10$

aprox $537us
with out case

g.

 

[tommypiper]

Great. Apologies if I missed it in another thread, but to clarify, you were working on a stereo version, I believe. How is that coming? And how easy is it to stereo link the v2 boards - stereo linking them in two separate chassis?

 

[Knarleybass]

Well,
I gotta' say, I did one of the Drip Electronics la-2a 2.0 pcb's and it's amazing sounding. I had a little trouble with some trouble shooting and Gregory was super kind to help me out.

The case and front panel came from Tat Purusha. I have one more La-2a to build. Bottom line, it sounds great!

Big props to Gregory!

 

[guavatone]

I like that this version seems to have more space for Orange Drop Caps. Is was a bit tight on the V1.

 

[Stagefright13]

Where can I get the meter and case pictured?

Thanks

 

[ruairioflaherty]

[quote author="Knarleybass"]
The case and front panel came from Tat Purusha.[/quote]

Meter looks like a Sifam AL29 (just guessing)

cheers,
Ruairi

 

[misterbill]

Version 2 looks great!

Count me in for (2) ver. 2 boards and (2) T4b's

Thanks.

 

[Stagefright13]

Got board and looks great! Thanks!
One quick question tho. The bom says c10 is 47uf @ 25 volts but board says 100 uf @ 25 volts. I put the 47 there. That's the reissue value right? Also I can't find the 6.8k resistor listed in bom on the board. LA-2A schematic says it is R23. Oh and having trouble finding a tc72 mallory 10 uf if anyone has one?
OOps that was 3 questions!

Thanks

 

[Pierrelegere]

I still have two older pcbs(LA-2A PCB REV10) and I wanted to start that project soon, should I still use those? Or do I have to get the Vers.2 pcb? Are there a lot of bugs in the older version? I also really like the manual for the re-designed pcb (absolute amazing job!), are there any major differences? Thanks!!

 

[Pierrelegere]

I mean, I see the differences in the two versions... the question is: if I start a project like this and invest time and money for parts, would you suggest to take the new board? Have some of you made experiences building the "old" version wich would justify buying the "new" version?
Thanks!!

 

[dripelectronics]

hi there ,

there is no -10 metering on this board.
most people never used it , so i took it out to save the often
confussing meter hook up problems.

i can pull a mod diagram togeather , if you would like it back

thats what the 6.8k resistor is for .

as far as the c10 , i find both values will work ,
but you are correct why i changed the value in the bill of materials.
------------------------------------------------------------------------

the ver 1 board is a good board ,

the ver 2 is a whole new beast in it's self , over all it out performs
the v1 board and is built to a different class.

i would be happy to refund your money and apply it towards a ver 2
board if you would like , of course the v2 costs more.

contact me through email if you like.

otherwise your v1 is very cool too.

i explain what the v2 board is all about in the begining of the
opto compressor build manual.

best ,

gregory

 

[wmb]

Hello all,

This is my first post on this board after months of lurking. I just received my drip/OPTO ver 2.0 PCBs. Stunning work and satisfyingly large in a fisher pricey christmas sort of way. Made me want to buy two more!

More parts to arrive over the next few days.

Cheers, William

 

[Stagefright13]

Thanks for the reply Gregory. -10 metering is not very useful to me so a mod is not nessessary. My board is done already just about woohoo. But I still need the in and out trannies and a meter. Hope to order them soon. I also ordered a couple cases from Tat Purusha. Can't wait lol!

 

[wmb]

I've nearly stuffed the entire board and I have a few questions.

1. C10 is listed as 100mf@25 but I think the BOM calls out a 47mf@25. Cross refernecing a very old schematic (has a T4a in lieu of a T4b) it lists a 50@25 so I figured 47 was okay. Is it okay or did I misunderstand something.

2. The two places marked "GRID" near the 12bh7 are for grid resisters to stop oscillations with sowter iron. I think they are 1k and that's what I put there but should I wait to see if oscillation is a problem or is it a given with sowters?

3. C4 ARCO is listed as 68pf but the BOM suggests a 150pf as a fixed value. Is 68pf an error? Just curious.

Other than those questions and waiting for parts it has been enjoyable so far and going smoothly.

wm.