pstcho

Re: new la-2 pcb
« Reply #880 on: January 11, 2009, 08:38:10 AM »
ah ok i must buy already done PCB i can't do it from myself

thank you

David


Bluzzi

Re: new la-2 pcb
« Reply #881 on: January 11, 2009, 02:41:38 PM »
If you mean make your own PCB then yes you can make your own if you want to go through the hassle of getting it right. If you want a PCB then either get Greg's version or there is also another member that has a PCB version of the LA2A.

I built both of mine P2P and that is another way to go although its more work than  PCB and you do not save money really (take into account a turret board wire and terminals and you basically come to the same cost).

So if you want ease of build go with a PCB.

Jim

ah ok i must buy already done PCB i can't do it from myself

thank you

David

pstcho

Re: new la-2 pcb
« Reply #882 on: January 14, 2009, 03:25:08 AM »
ok thank you

i was asking to make my own pcb not to save money but i likethe style of the shop i make my pcb

it's ok the typon may be top secret haha

i will order one to Greg later

thank you

Bye

kato

Re: new la-2 pcb
« Reply #883 on: January 14, 2009, 10:24:50 AM »
pstcho - this is a project you can wire point-to-point without a circuit board - if you are comfortable doing it. There is probably more info about doing it this way. Although I went with Greg's PCB because I had no experience with high voltage projects and thought it would be easier.

pstcho

Re: new la-2 pcb
« Reply #884 on: January 14, 2009, 05:58:29 PM »
yes i know i can do it but it's more easy to do when there is a pcb

thank you also

bye

deuce42

Re: new la-2 pcb
« Reply #885 on: January 30, 2009, 09:15:35 PM »
Can anyone of you folks tell me whether I can use a 90vac NE2 bulb for this circuit. I can't seem to locate a 65vac one in Australia anywhere.

Thanks

alexc

Re: new la-2 pcb
« Reply #886 on: January 31, 2009, 07:16:14 AM »
I don't think so.

You can also use 2x 33V zener diodes in series for 66V total.
I do this because I have found neons to add noise.

You can get the 33V zeners from RS Electronics in Australia

I ping therefore I am

Sredna

Re: new la-2 pcb
« Reply #887 on: January 31, 2009, 07:26:57 AM »
Hey deuce42!

If you're still looking for a NE2 (65V), send me a PM with your address.

Cant beat that vintage noise!  ;)


Regards,

Anders
Hmm... in which direction do the electrons actually go?

Re: new la-2 pcb
« Reply #888 on: January 31, 2009, 03:48:38 PM »
Hi,

does anyone know if drip electronics has stopped selling boards?
Because the page is offline and i got no answer after emailing greg'.

Does anyone know where to get drip opto 3 boards?

Greetings

Daniel

bugfight

Re: new la-2 pcb
« Reply #889 on: January 31, 2009, 04:46:05 PM »
i had an email exchange with him a few weeks ago, he said he would have new pcbs soon...
hmmmm

edit* the old site is gone, but the new one is up:  http://dripelectronics.com
« Last Edit: January 31, 2009, 04:53:08 PM by bugfight »
be the strange you want to see in the world


Re: new la-2 pcb
« Reply #890 on: January 31, 2009, 04:57:23 PM »
Hi,

sorry my fault.
I followed a link to his old page http://www.lomayesva.com/drip_opto_manual.pdf (posted here in this forum).
Meanwhile he's got a new page (dripelectronics.com).

Greetz

Daniel

jrfred453

Re: new la-2 pcb
« Reply #891 on: July 21, 2009, 12:44:46 AM »
Hey guys,
I just fired up one of these Ver1.0 Drip Boards for the first time tonight. The unit is passing audio but I'm having a bit of trouble. I'm using the Allied power transformer and Sowter In/Out transformers.

My first question is pretty basic and if I wasn't second guessing myself right now I would know the answer. Across the 6.3v heater supply I get 6.7v but between each winding and the CT I get 3.3v. Is this correct?

I'm also getting some DC voltage across the Gain and Reduction pots making them scratchy and the front panel a bit microphonic. Any ideas where to look for the cause of the DC?

Thanks.
« Last Edit: July 21, 2009, 06:52:37 PM by jrfred453 »

kazper

Re: new la-2 pcb
« Reply #892 on: July 21, 2009, 01:56:20 AM »
Hey guys,
I just fired up one of these Ver 1.0 Drip Boards for the first time tonight. The unit is passing audio but I'm having a bit of trouble. I'm using the Allied power transformer and Sowter In/Out transformers.

My first question is pretty basic and if I was second guessing myself right I should know the answer. Across the 6.3v heater supply I get 6.7v but between each winding and the CT I get 3.3v. Is this correct?

I'm also getting some DC voltage across the Gain and Reduction pots making them scratchy and the front panel a bit microphonic. Any ideas where to look for the cause of the DC?

Thanks.

Version 1.0 PCB?
The heater voltage is correct, but the center tap should be landed to the star as with the Red/yellow.

Good thing to do is look at the manual for a version 2 (he now called it the Drip Opto) as the original docs were good but more complete in the version 2 build instructions. If you can't find it shoot me a pm with your email and I'll send it over.

How much DC?

did you check your voltages from CJ's handy dandy voltage chart? All your ground in and verified...?
Intentionally left blank

kazper

Re: new la-2 pcb
« Reply #893 on: July 21, 2009, 02:54:33 AM »
Thanks again to CJ for this chart...

http://vacuumbrain.com/The_Lab/LA2/la2_voltages.jpg


« Last Edit: July 21, 2009, 02:59:11 AM by kazper »
Intentionally left blank

jrfred453

Re: new la-2 pcb
« Reply #894 on: July 21, 2009, 07:17:33 AM »
Thanks posting the link for the chart. I'm slowly making my way through it.
So far I have 53v across NE2 (I haven't messed with the zero adjust as I have no vu meter yet)

I'm getting 19.8v dc across the compress/limit switch and to pad #1 of both the Gain and Reduction pots. Voltage on the wiper changes as you move the pot obviously. I also read this at R7 and Pin 7 of the T4b but no ac voltage like in the chart.

Should I be getting 65.7v dc at Pin 5 of the T4b?

kazper

Re: new la-2 pcb
« Reply #895 on: July 21, 2009, 02:00:50 PM »
Thanks posting the link for the chart. I'm slowly making my way through it.
So far I have 53v across NE2 (I haven't messed with the zero adjust as I have no vu meter yet)

I'm getting 19.8v dc across the compress/limit switch and to pad #1 of both the Gain and Reduction pots. Voltage on the wiper changes as you move the pot obviously. I also read this at R7 and Pin 7 of the T4b but no ac voltage like in the chart.

Should I be getting 65.7v dc at Pin 5 of the T4b?

With my limited knowledge I would suspect V3 or V1. Since the gain reduction is tied in between R6 and R7 and is the only way to share common DC voltage unless you have some solder bridges. Set your equipment up as described by CJ.  Lack of VU shouldn't be a issue because it's ran off one of the Photoconductive cells or off the output transformer. Measure around and see where you have issues and report back..

I would also expect from the chart that you would have DC on Pin 5 of the T4B, as the NE2 acts like a simple voltage regulator.

One thing we both should do is look up Chris Sugar's LA2A circuit explained document, I believe it was once on the Gmail account.

Now off to finish a version 2
Intentionally left blank

jrfred453

Re: new la-2 pcb
« Reply #896 on: July 21, 2009, 08:08:23 PM »
Kazper,
Thanks a lot for your help on this. I had not grounded the HAX GND to the case. I guess I thought it was already connected and I just needed to  connect the transformer there. With it connected everything seems to work great.
One more question about the Stereo Adjust and Limiter Response controls. Where should these be set? I used the PEC panel controls so I may have somehow mis-wired them but I thought they were both supposed to be turned counter-clockwise all the way. I don't seem to get any compression with them set like that...... I'll wait till I get a VU meter and then see what's up with them.

Again thank you. I'm so excited to have this thing working!!

kazper

Re: new la-2 pcb
« Reply #897 on: July 22, 2009, 01:10:48 AM »
http://www.jblproservice.com/pdf/Vintage%20JBL-UREI%20Electronics/UREI-LA-2A%20manual.pdf

Page 6 and 7 talk a little bit about the response adjustment.

I'm ready to power this beast up but I'm missing the 12ax7's.... :(

Intentionally left blank

Stagefright13

Re: new la-2 pcb
« Reply #898 on: July 22, 2009, 01:20:41 AM »
How could you be missing 12Ax7's? Just teezing. Should always have some of them. The JJ's work fine. I put a NOS Telefunken in there and is a bit bright for my taste. I had a Tele 12at7 in there? And used it alot more. I may get some more tubes and try and test them. But like I said the Tele was almost too clear... But the actual compressor is awesome. And the tubes do change the sound alot. If I remember correctly it is V1 in the audio path. And a good NOS Bh7a . But correct me if I am wrong on that. Been a while.

John
« Last Edit: July 22, 2009, 01:31:59 AM by Stagefright13 »
Amateur experimenter

kazper

Re: new la-2 pcb
« Reply #899 on: July 22, 2009, 05:22:14 PM »
When I was close to my tube surplus shop I figured I could get them anytime I wanted... now that I've moved well you know..

I think I was planning on buying all new tubes for this beast and it's brother...
Intentionally left blank


 

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