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Project Specific Discussions => Dynamic Processors => Topic started by: dripelectronics on June 20, 2008, 02:46:55 AM

Title: [build] Dripelectronics.com LA2A pcb v3 (atoms) build thread.
Post by: dripelectronics on June 20, 2008, 02:46:55 AM
(http://lomayesva.com/manual.jpg)

http://lomayesva.com/la2a_pcb_ver3.pdf

it's official :)

here's the manual , 100 pages of pure joy.

still adding more info .

best ,

g.
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: ChrioN on June 20, 2008, 03:01:58 AM
....!

The documentation is amazing.
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: Brizco on June 20, 2008, 04:04:40 AM
respect!!

and a big "thaaaaankss!!!!"
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: delaymix on June 20, 2008, 06:12:25 AM
... without words ...  :shock:  :shock:  :shock:
It's really a contribution to the community and impressive work!
Thanks a lot.
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: mrphotodude on June 20, 2008, 06:27:12 AM
when can we expect the ver3 boards to be out?
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: [silent:arts] on June 20, 2008, 06:40:05 AM
:shock:
respect for this hard work.
a beauty of a PCB, and an artwork of manual :thumb:
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: buschfsu on June 20, 2008, 08:58:50 AM
is the opto3dc something that will be out with the opto3 or is that release far in the future
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: madriaanse on June 20, 2008, 11:49:56 AM
Wooooow, fantastic documentation!! How much are V3 boards?

All the best,

M.
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: ChrioN on June 21, 2008, 03:47:17 AM
Quote
How much are V3 boards?
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: mik on June 21, 2008, 05:24:22 AM
I need 2 of those  :green:

M.
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: papaver on June 21, 2008, 05:35:08 AM
OOH YEEAHHH!  :cool:  :cool:  :cool:

Wich power transformer can I use for Europe apart of the expensive sowter?

Thanks!
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: Sammas on June 21, 2008, 05:53:55 AM
It looks like the Hammond 369JX will be a suitable replacement. €65,00 instead of £96.

You need 250v-0-250v secondary windings @ 40ma or more, and 6.3v CT @ 2amps for the filaments.
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: wassx on June 21, 2008, 10:00:00 AM
Thank you for the amazing work!


a v72 in a la-2a.... freaks...  :wink:  :thumb:

stef
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: Stagefright13 on June 21, 2008, 11:27:43 PM
COOL Greg! Your V2 got me back into DIY. When I started here on this board. Thanks to you I have met and hopefully not offended anyone with my ignorance. But have learned tons about audio electronics.

(Long way to go) Lemmie gonna slap ya for the crooked T4 ;)

Hope you are doing well! Best wishes.

I use my version 2 on a daily basis. And it delivers time and time again. Thanks for the work involved in design and also documentation!

You rock.  :thumb:  :thumb:  :thumb:  :thumb:
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: dripelectronics on June 22, 2008, 01:10:51 AM
hi there , thanks so much ,

ah ran out of t4bs so i used the ua one for this shoot ,

the drip t4's align square :)
.

the opto 72 should be released in 2 to 3 weeks, pending a quick revision.
and the manual for it .


send an email for price info ,
did a small run of 25 boards , so i had to add 10$ for this batch .

originally this was gold plated , then i did some research on how gold doesnt take to solder very well ,  grrrrr.


the dc version with the filament transformer , is having a metal can made
for it , (rf shielding )
but it should be out in the coming month .

best ,

g.
Title: limiter response
Post by: cwalcott on July 22, 2008, 01:36:59 PM
i'm ordering my parts now and i'm wondering if i should pull the limiter response pot out to the front.

what is the limiter response pot for?  is this for fine tuning the attack/release?  if so, it seems like this might be a good thing to have on the front.

- chris
Title: Re: limiter response
Post by: SSLtech on July 22, 2008, 01:42:01 PM
Quote from: "cwalcott"
i'm ordering my parts now and i'm wondering if i should pull the limiter response pot out to the front.

what is the limiter response pot for?  is this for fine tuning the attack/release?  if so, it seems like this might be a good thing to have on the front.

- chris


Covered before...

Consensus = don't bother. Leave it fully clockwise, it doesn't really do anything good that you'd want to play with.

Keith
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: feza on September 04, 2008, 07:58:12 AM
Great man!

Are there any plans of releasing a dual version of this? Stereo LA2A!

Purusha is selling dual cases but when is the PCB for sale? Any info will do.  :thumb:
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: rob_gould on September 04, 2008, 09:16:19 AM
Quote from: "feza"

Purusha is selling dual cases but when is the PCB for sale? Any info will do.  :thumb:


http://www.groupdiy.com/index.php?topic=27273

Closed I'm afraid.  

You could ask to be put on a waiting list perhaps?
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: feza on September 04, 2008, 10:19:51 AM
Yes yes, done already.  :thumb:
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: TornadoTed on September 29, 2008, 01:33:20 PM
My components turned up today and I have stuffed the board, it looks fantastic and is so easy with the excellent instructions.
 
I have a few questions if you don't mind answering them. I apologise in advance as I am really new to electronics and some of these may be stupid questions!
 
 
I ordered exactly what was on the BOM. I have several parts left over.
 
1x .022uf Orange Drop, the BOM says 4 but I can only see 3 on the PCB
 
2x 3.9k Resistors, I used one at R24 above the Zero adjust trimmer.
 
1x 6.8k Resistor. I can't find this on the PCB anywhere.
 
1x 1k 1/2 Watt Resistor, I used 7 of them at R20, Grid/1k, R18, Grid 1k, R36, R31 and R32. The BOM says 8, where do I use the other one?
 
2x 1M Resistors. Where do I use these?
 
 
I currently don't have anything at,
 
NE-2 What do I need here?
R7/2k A bit confused as there is no 2k on the BOM.
J2 Do I jump or use a 1k?
J3 Do I jump or use a 1k?
R38/22k Do I jump or use a 22k?
.1 400v C-Cap Ceramic It says optional, should I use something here.
 
The diodes I have are these,
 
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=651-6135
 
Are they ok as I notice they are different to the ones in the instruction manual?
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: dripelectronics on September 29, 2008, 03:57:03 PM
sorry , ive been meaning to update the manual ,
as feed back and questions arrive.

spare .022 was for the power switch rc network (anti pop) if not using the
mallory quench arc .

one of the 3.9 resistors was intended , if you wanted a bit deeper
limiting , (replace R7)

6.8k was a total typo   :oops:

spare 1k , typo  :oops:

2 x 1m resistors are for the ground lifts on xlr in and out.
           (refrence manual)

NE-2 is a NE-2 neon light needed for regulating the meter

i missed the 2k on the bom ,  it is normally a 2.7k for R7

for all the jumps , just use wire , unless stated 1k (grids on 12bh7a)
i add things like this for troubleshooting .  just incase.

r38 , use a 22k (some original  versions have it , some dont)

go ahead and add the x-cap , it can help filter junk out of the
power going in .  (ref. audiophile scourcebook)
some times has no effect what so ever.

your diodes are supposed to be in a TO-220 package,
those say DPAK and are surface mount .

one of the pins is actually connected to nothing ,
in that configuation , the metal base is the cathode ,

best to return them and get a TO-220 package ,

sorry about the leftovers .

g.
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: TornadoTed on September 29, 2008, 06:16:08 PM
Awesome Greg, many thanks.

I'm loving the build, it is so well laid out. I can't wait to finish it and run some stuff through it.
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: thehazardharke on October 31, 2008, 02:26:50 PM
Got mine today! Thanks greg!!

I'll have pictures posted soon!
Title: drip la2a pcb ver3 (atoms) build thread.
Post by: peters on November 07, 2008, 05:03:35 PM
I am just getting prepared to build this project, and am wondering if it can easily fit into a 2U (3-1/2") enclosure if tubes are mounted sideways on a length of angle bracket, over the PCB. Am I risking adding significant hum by having jumpers from the board to the sockets (say 2" long)? Would using the DC heaters help?

thanks,
--Peter
Title: parts corrections and clarifications
Post by: Bill Kahler on December 02, 2008, 10:48:44 AM
The following came from Gregory's replies to a couple of my emails:

On the bottom of the caps page the BOM lists 1) 68pf and 2) 150pf caps. Should be the other way around.

BOM says 1 47uf @25 volt, manual and board say 50 V for C10. 25 will work - only 10V passes so either are OK.

Also in the manual C11 says axial leaded cap, but it's not listed in the BOM. Orange drop works fine.

3 [email protected] ceramic 500 v minimum for optional ground lifts
for the lifts - use poly pro caps like the orange drops - only need 2 for ground lifts - the other was for the x-cap. Do not use the x-cap (it was mainly added for trouble shooting )

Part number discrepancy : the Quencharc snubber listed as Mouser part 504M02QA220 should be 539-104M06QC100.



Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: T-rex on December 02, 2008, 11:31:36 AM
Sorry for the newb question, but I didnt see this anywhere.  About what is the total cost (approximate) for this project.  I am getting ready to do a Gssl for the experience but I would much rather build an LA2A if the cost isn't too much greater.
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: cwalcott on December 02, 2008, 11:40:58 AM
i spent about $900 on mine.  that included the case which was about $350.

- chris
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: thehazardharke on December 02, 2008, 12:30:25 PM
spent $400.00 on mine. I got my transformers free.
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: T-rex on December 02, 2008, 10:54:46 PM
Thanks for the info, that gives me a ballpark.

$350 for the case?  That must be one sweet case!
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: cwalcott on December 03, 2008, 02:33:57 AM
sorry, my bad.  it was $350 for 2 cases.  that's still expensive but i needed cases and i'm not much of a metal guy.  but to answer your question, yes they are really nice cases.  the transformers were the next most expensive part.  it's not a cheep project to make from scratch but it's worth it. 

- chris
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: Whoops on December 25, 2008, 12:04:47 AM
The Hexfred diodes aren't easy to order in small quantities.
Mouser's minimum order is 715 and Digikey is 1000.

RS only seems to offer the TO-220 package in 600v max. You need 1000v minimum.

Found an alternative here: (pics are illustrative only both are TO220)

http://www.newark.com/vishay-formerly-international-rectifier/hfa06tb120pbf/fast-recovery-power-rectifier/dp/63J6640

http://www.newark.com/vishay-formerly-international-rectifier/hfa08tb120pbf/fast-recovery-power-rectifier/dp/63J6645

These are the specs you need to look for:

type: Diode Hexfred / Fred
Package / Case: TO-220AC
Minimum values: 1000V (Reverse Voltage)  and 1A


if my info is right , this will probably save you some time.

Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: fazeka on December 25, 2008, 08:08:54 PM
I don't know why you couldn't just get it at digikey? I just checked out their site on my iPhone. 462 qty. @ $1.93 each. I thought it was a 220 package...?
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: fazeka on December 26, 2008, 05:31:08 AM
Yep, double-checked Digikey:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=VS-HFA06TB120PBF-ND

(http://img242.imageshack.us/img242/5349/hexfredbu8.gif)

Also, Allied:

http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=5030305&MPN=HFA06TB120PBF

(http://img68.imageshack.us/img68/8485/hexfredie1.gif)
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: Whoops on December 26, 2008, 09:42:55 AM
Cool,
more alternatives are always better.

Although the price in Newark is $1.14

can't beat that!
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: fazeka on December 26, 2008, 05:22:16 PM
Nice, yes!
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: buschfsu on December 29, 2008, 08:50:31 PM
any word on the dc version?
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: jeerzee on February 14, 2009, 08:41:25 PM
Well how does the ver3 atom SOUND and stack up to the previous versions?
Not a good sign seeing the thread just kind of drop out!
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: jeerzee on February 16, 2009, 07:38:11 PM
WELL????????????!!!!!!!!!!!
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: rrs on February 16, 2009, 08:50:09 PM
Is the manual still available.

Clicked the link and all I got was a pretty girl.  ;D
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: VoiceOverMike on February 17, 2009, 02:35:41 AM
Greg has everything over at his website.
http://www.dripelectronics.com/



Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: jeerzee on February 18, 2009, 08:49:09 PM
I'd rather hear from the few in this thread that have completed
the vers3
I'd specifically like to know if the redesigning greg mentioned
that he did,changed the tone any
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: JoleFIN on February 24, 2009, 07:48:58 PM
Yeah, how is it guys? I'm hungry to get to make one :)
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: Bill Kahler on February 24, 2009, 11:48:01 PM
All I can say is I love mine - very smooth and quiet ad subtle to not so subtle. So far I've mostly used it on vocals. Plannin on mking stereo linked pair and trying mixes, overgeads.

I also have a reissue UA 1176 blackface and I like the drip LA better.

And, Gregory is a super nice guy.

Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: VoiceOverMike on February 25, 2009, 01:42:28 AM
I'm very happy with mine also, it sounds delicious and very quite. It worked perfectly from the moment I plugged it in.
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: jeerzee on February 25, 2009, 07:10:34 PM
Did you guy's go with the sowter input and output?
and did you use the allied pwr transformer?
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: VoiceOverMike on February 25, 2009, 08:16:05 PM
Yes and Yes
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: madriaanse on February 27, 2009, 01:34:32 PM
Quick question on VU meters:

I want to use this meter:
http://www.multimeter.com/index.php?&Class=4&SubClass=008&Model=00015&PartNumber=001990020100202#

Just order the "Backlit Incandescent 6V" and connect to the PCB's "Lamp" pads, right? Or is this where the NE-2 goes?

Thanks!!

M.
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: VoiceOverMike on February 28, 2009, 03:52:41 AM
YES connect to where it says "Lamp / 6V"  Remember that's "6V A.C". NE-2 is for the neon bulb to regulate voltage in the metering section. (Note: page 72 on the instruction/build manual)
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: madriaanse on February 28, 2009, 07:52:59 PM
great; thanks for clarifying!!

M.
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: JoleFIN on March 01, 2009, 10:26:50 AM
Does somebody have the rev3 PDF of LA2A? I'd like to take a look so I could roughly get an estimate of the workload and such... heard it's easy with Drip's instructions but I just made my first DIY (GSSL, which turned out pretty nice btw :)) and am really not that sure about my skills. But I'm hungry to build more! ;)

So if someone could email me the PDF (couldn't get the lomayesva.com link to work... file not found?) to
info ( at ) joelkalsi . com
it would be great!

Been lurking around here a lot lately but trying to make more conversation in future :)

Greez,
- Jole
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: jeerzee on March 01, 2009, 05:19:10 PM
www.dripelectronics.com
under view a product choose LA2 PCB
scroll down to the right is the pdf documentation
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: jeerzee on March 01, 2009, 06:34:31 PM
Hey VOM
what enclosure did you settle for?
I have the PCB and I'm very impressed so far
I can't wait to start stuffing her(LOL, ;D you know what I mean)
I'm currently going through the BOM and the PCB and see the discrepancies people are
talking about. But I would guess that the component labeling on the PCB is what needs to be followed
Any tips would be appreciated
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: VoiceOverMike on March 01, 2009, 11:21:48 PM
I use and old 5" high aluminum enclosure I had. I installed a new face and back plate and drilled and cut away. I'm not finished with the cosmetic work yet (been very busy these days) but once I get it to my specs I'll post a pic.
Purusha's cases would be the way to go if you don't have tools and bit's to do the work. http://www.groupdiy.com/index.php?topic=19428.0

I know Greg has mentioned that he was going to make corrections to the BOM and build sheet, but I don't know if he has of to date.
The discrepancies are well documented on this board and his site, but they are minor in detail and anyone with careful reading and connecting of the dots can figure them out. But these discrepancies mostly amount to part quantities.

My biggest piece of advice is to know and understand the PBC.
Order all your caps and resisters at the same time- once you receive them check each resister on a meter and mark their respective bags, also check and verify the caps too.  When I stuffed the board I check each resistor again before placing. This redundancy of verifying every cap and resister made for a completely error and trouble free build for me.

Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: JoleFIN on March 02, 2009, 09:06:26 AM
Jeerzee, ahh thanks! I don't know how blind a man can be, I must have taken a look at there at least 5 times without seeing the documentation link. Even now I read the border paragraph fully through to see if the link is there, and by the end I finally noticed the link at the bottom. Must have been too much wiring and soldering lately to not be able to see the full picture. ;D
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: jeerzee on March 02, 2009, 10:11:04 AM
Your Welcome
LOL! same sh*t happened to ME!
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: jeerzee on March 02, 2009, 10:35:10 AM
VOM
Purusha's cases do look great but I'm in the USA and
had trouble with the banking transfer service
I was unable to complete the transaction
Pity, but not the end of the world
I'll be ordering a hammond or par metal(located in Jeerzee)
How do you plan on handling the labeling/screening?
c11 is still missing on the cross reference sheet
and 6.8k is still listed on the BOM
also the 150pf(C14 250pf) is only listed in the comments section
I'm pretty much still going over the pcb and the BOM
but I'll be ordering soon and I'm totally psyched
Did use any carbon comps or special caps?
 
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: VoiceOverMike on March 02, 2009, 04:06:48 PM
Screening the face and or back is not a problem for me, I have a friend in the biz and I can get a screen for cost.
But I'm looking to do something a little different.

C11- Check the build sheet page 23 also note the comments on page 27. I used a .01pf 600v orange drop in C11, a Sozo cap would be nice here too (I may try one later). I did however use Sozo caps in in C2 and C3, very happy with this choice. 
If you use Orange Drops, they will need to be 600v, as noted in the BOM. You will however run into a problem trying to fit the Orange Drops in the footprint areas of C8a and C8b, C6 and C12, and in the area of C9, it can get a little chummy. I would seek out ceramic caps for these --again as noted in the build sheet and BOM.

C14, I used 150pf, you can also order a 250pf and change out later if you like, or go with the ARCO 465 variable mica trimming capacitors and remove all doubt.

Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: canidoit on May 08, 2009, 12:30:24 PM
sorry , ive been meaning to update the manual ,
as feed back and questions arrive.
Drips I have just bought your La2a version 3 board and downloaded the manual just now. Is this the latest manual that has been updated, especially the BOM list.
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: DIYnoob! on May 08, 2009, 12:58:02 PM
good question
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: TornadoTed on May 08, 2009, 06:24:41 PM
Well how does the ver3 atom SOUND and stack up to the previous versions?
Not a good sign seeing the thread just kind of drop out!

I have 2 Drip LA2A's a version 2 that I brought from someone on here and a version 3 I built myself. I am getting a little more distortion with the version 2 than the version 3 when pushed hard. The version 2 is great on bass and electric guitars but is a bit much for vocals which the version 3 excells at as well as acoustic instruments. They both appear to be calibrated the same and work the same. I do not know if this is a difference with the versions or if it's the tubes, components etc I haven't been able to find a 'fault' with the version 2. Whether it be intended or accidental I really like the fact that they are different!
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: canidoit on May 08, 2009, 09:14:34 PM
Drip I just noticed on your manual the Opto 3 DC version. When will that be out? I would like to know if there are any sonic differences between the current Atom version and this DC version. Why have you made a DC version, is there any particular reason? Is it more technical or more sound reasons?

I would like an DIY La2a that sounds like the real La2a, is this possible? There's really not much reviews here or online of your Drips La2a from a sonic perspective like they have at audio forums and audio recording reviews for audio equipment. If I am mistaken, can someone give me links to posts or online reviews of the Drips models reviewed. Most posts that I have read have based their opinions on the La2a DIY clones without hearing a real La2a.

Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: canidoit on May 09, 2009, 12:23:38 AM
Also the T4B cell that UA uses comes in two sizes. I have read that the short and long versions are internally the same. The question I would like to know, did you design the Drips card with the long T4B cell in mind that will fit in the La2a Purusha case? I am thinking of maybe getting the long version, but I am unsure as to whether it will fit in the Purusha case, incase the Drips card was build around a shorter T4b cell. I had a look at your T4B cell but it does not state what height it is.
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: VoiceOverMike on May 09, 2009, 03:29:31 AM
<I do not know if this is a difference with the versions or if it's the tubes, components etc I haven't been able to find a 'fault' with the version 2.>

I've rolled a Few tubes in my ver3, and the change can be striking.


<Drip I just noticed on your manual the Opto 3 DC version. When will that be out? >

You should check the Drip Webpage and Board:
http://dripelectronics.com/

<I would like an DIY La2a that sounds like the real La2a, is this possible? >

Yes get the UTC iron.

Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: canidoit on May 09, 2009, 06:03:31 AM
<I do not know if this is a difference with the versions or if it's the tubes, components etc I haven't been able to find a 'fault' with the version 2.>

I've rolled a Few tubes in my ver3, and the change can be striking.


<Drip I just noticed on your manual the Opto 3 DC version. When will that be out? >

You should check the Drip Webpage and Board:
http://dripelectronics.com/

<I would like an DIY La2a that sounds like the real La2a, is this possible? >

Yes get the UTC iron.


What tubes did you change and what brands to and what were the results? Do you have more of a description from a Sound perspective. Striking is a little vague?

How do you compare it to an Original or Re-issue La2a?

Thanks  :)
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: VoiceOverMike on May 10, 2009, 03:01:33 PM
For the 6AQ5A, any old tube would work here. I piked up a bunch of Triad's at the the Groove Tube fire sale

12Ax7A- I'm using RCA's gray plates. Black plates would be nice here too.

12BH7A- This is where I hear the most difference, I've rolled Amperex and RCA. RCA is a little dark, the Amperex is a little more open at the top end.

You can go nuts trying figure out what is the best tube, there is no such thing. Just get strong NOS tubes and you'll be happy- trust me.
You can always roll tubes in and out later.
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: wassx on July 01, 2009, 04:45:37 PM
 :) Just finished my Drip Opto V3  :)
Only problem was my "NOledge" about center tap transformers  :-\
Ok, one thing: I've a 50Hz hum so grounding needs some more work

To all people thinking about it -> go for it, it's nice
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: canidoit on July 04, 2009, 08:30:04 AM
Is this the correct power wiring for 240 volts mains power using a Hammond 369JX Power Transformer?

(http://www.ine-kpro.com/diy/la2a/images/check/iecWiring.jpg)

(http://www.ine-kpro.com/diy/la2a/images/check/powerWiring.jpg)
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: substitute on July 04, 2009, 09:53:14 AM
I just fired mine up yesterday, I'm not absolutely positive about how to wire the primaries for 240v... but seems like you have it all sorted out. 

Get ready for awesome!
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: canidoit on July 04, 2009, 10:33:48 AM
I just fired mine up yesterday, I'm not absolutely positive about how to wire the primaries for 240v... but seems like you have it all sorted out. 

Get ready for awesome!
LOL, thanks mate  ;D
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: ilfungo on January 18, 2010, 08:11:20 AM
hello
I'm almost finished drip opto 4
Where can I connect the lamp on the front panel to power?
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: canidoit on January 18, 2010, 08:25:38 AM
hello
I'm almost finished drip opto 4
Where can I connect the lamp on the front panel to power?
Drips responds to it here:
http://dripelectronics.com/forum/viewtopic.php?f=5&t=347

Just confirm with him the voltage you are using for the lamp.
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: ilfungo on January 18, 2010, 10:16:34 AM
thanks! :)
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: ilfungo on January 27, 2010, 04:21:15 PM
I want to say thanks to dripelectronics ;D
I just finished my  LA2A( opto 4) and sounds so wonderful
I'm waiting to complete the second T4B
Thanks!!!!!!!!!! :-*
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: ilfungo on February 15, 2010, 09:35:28 PM
Ciao
small problems with the VU meter...
analyzing the level of compression with pro tools  I saw that the meter represents twice the real compression
There is a procedure to calibrate the meter?
Thanks...
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: jyrki3101 on November 03, 2010, 01:45:22 PM
HI, I have a question about the meter backlight options... 'Cause I havent found a 6V fuse type lamp for the hairball meter, I'm going to use 2 yellow leds in series.
I know this is easy for experienced people in electronics, but, I'm not sure how to avoid the strobo-effect on the leds if I put only a resistor between the 6,3V pad(pcb) and leds?
Do I need diodes to rectify the 6V AC and what would be the simplest way to do it ?
A simple wiring diagram would help, PLEASE?
I would greatly appreciate your information !!!

jyrki3101
Title: Re: drip la2a pcb ver3 (atoms) build thread.
Post by: pH on November 03, 2010, 01:51:16 PM
http://ledcalc.com/#