All things LA2a related

[amishsixstringer]

Haha.  I did think that, but I'm a believer in Karma. 

I have 4 api pres (real ones), 2 vintech pres, la2a (yay), DBX 118 compressor, DBX 129 compressor, UREI 2 channel graphic eq, 2 grace 101 pres.  I want to start putting a lunch box together and put some gear in there.  I think the the 500 series rack is right up my alley.  A pultec eq might be nice too.  I'm lacking in eq.  Maybe a neve style pre with a full eq, or just neve eq.  I don't know yet.  I'm not done with this stuff though.  Too much fun when it all works. 

What is funny is that all the problems I was having with this thing were just from the meter not working.  If it would have worked, I would have had a perfect build first try.  Not that I'm bragging, but that is cool to me.

Neil

 

[jeerzee]

Hey Neil what did you do to correct the meter circuit ???

 

[amishsixstringer]

Hey Neil what did you do to correct the meter circuit ???

The meter was bad.  My circuit was ok from the beginning.  Are you having a problem?  I may be able to help.  I have a fairly decent understanding of how the meter circuit works now after doing about 6 days of trouble shooting on it. 

Oh, and By the way.  I got my last tube.  T4b is in....WORKS PERFECTLY!  I have a noise free, working La2a!  I'll get some pics up early this week.  Thanks everyone that helped!  1176 is next I do believe.

Neil

 

[jeerzee]

Just ordered a sifam al29WF from IMS
Did they at least replace the defected meter?
What was their reason for the defected meter?

 

[amishsixstringer]

I bought the meter almost 2 years ago, so there was no replacing it.  I'm pretty sure the thing was damaged in shipping.  I just fixed it myself.  No big deal.  I'm sure you'll be ok.

Neil

 

[btproductionsaustralia]

Hey all,

I'm lookin at building a drip LA-2A v 3 and was wondering what the approximate cost of building it would be?
I'm in australia but in US$ is fine...or any other currency...

Thanks

Ben

 

[canidoit]

Hey all,

I'm lookin at building a drip LA-2A v 3 and was wondering what the approximate cost of building it would be?
I'm in australia but in US$ is fine...or any other currency...

Thanks

Ben

Just a rough estimation:

Purusha case= $280 AUD shipped
Drips La2a Board = $165 AUD shipped
T4b = $150 shipped
Sowter transformers = $260 AUD
VU meter = $52 AUD
Case parts like knobs and switches = $60 AUD shipped
parts from Triode electronics = $103 AUD
parts from Digikey = $150 AUD
parts from Allied = $75 AUD
parts from Mouser = $150 AUD

Total $1450.00 there abouts.

I still do not have the lamp for the VU meters, cables for the wiring, but I am hoping to use scrap cables. I have not bought the tubes, which I am expecting to be about $300 for 4 tubes for decent ones or maybe $160 for cheaper ones.
Also I spent a bit of money on tools, so lets says another $300 on that which includes, drill press vice, soldering iron, solder, flux, heatshrink, etc. But I am using the tools for my 1176 build as well.

Which state are you from? If you want to buy the 6 volt festoon lamps for the Hairball VU meters, I will be having some available?

 

[canidoit]

I will be using an IEC socket with built in fuse for my La2a. I use 240 volts to power the La2a, so what rating fuse do I use for my IEC socket? How many milliamps, will it be slow blow or fast blow? I know it has to be 250 volts but what about the remaining specs?


What size capacitors are these in the Drips La2a V3 manual?
- Power Snubber 0.1 @ 600 volts. Is that 0.1 uF, pF, nF? Are you meant to install these?
- X-Cap Ceramic 0.1 @ 400 volts. Is that 0.1 uF, pF, nF? Are you meant to install these?

- The arco 465 range is only 75 - 380 pF for the Frequency Response. Aren't you better off with the Arco 464 whos range is 45 - 280 pF?
Isn't the cap there 68pF, so therefor Arco 464 would be a better choice since it can go as low as 45. Is there a reason Drips why you chose the Arco 465?

What kind of damage or results are we looking at if any, if you adjust those arco 465 caps to the extreme clockwise or anticlockwise? eg. the caps are for 68pf, so if I were to install a 464 and adjust it to 45pf, what will be the result. Same goes if I went with the 465 and adjusted it to 380pf.

What is the wiring for the SPDT Toggle switch for ground on the Output Transformer?
Is this correct?

 

[wassx]

Hi guys!

Just stuffed all parts together but have to recognize that nothing works  :-\ (drip opto ver3)
Situation: Tubes installed, no T4B, neon lamp doesn't lighten up on any zero adj position, tubes are lit, 6.3V AC is present, power xformer has 230V and 280V on High Voltage outputs.

So I have some questions please:
1) What is the voltage after the Hexfred (4007) Diodes from High Voltage input? I have a reading of 0,6V DC  ??? I tried Hexfreds and 4007, checked positions
2) I checked CJ's voltage chart, but I have 0,5V nearly everywhere in the circuit

Seems to me as a main power problem but I measured the voltage at the high voltage outputs of the power xformer..

Anybody some ideas which things I can check or fix please?

Cheers

edit: I'm using a torodial transformer with primary 2x115V, sec1 2x 250V 0,05A, sec2 2x6,3V 2A, sec3 9V 1A


Just made screenshots of the signal:

First when unit is turned off:

Second when unit is on:

No response from gain or reduction controls, when i switch off the sine wave goes slowly back as shown in pic 1

Some hints please? Gonna hunt the signal path....

 

[wassx]

ok, I unveiled the sense of the center tap...... Oh my. Now everything works fine.

The unit sounds GREAT! 

 

[regularjohn]

Thought I'd share some pics...I've built a number of these.  I always love seeing other people's creations here in the forum. 
The 2A style comp is my all time favorite!  Hands down!  So easy to use, sounds fantastic...
Built this one a while back for a hip hop guy named, "The Beatslayer"...hence the custom engraving!

 

[debby]

hi everyone  :-*

i am making one of those bloo kits and i had a friend order a special sowter 1009 transformer with a ratio of 1:4 when it is usually 1:10. anyone tried doing it this way to reduce the gain or do you think it will be problematic? wil this be a simple solder in or do i have to use different components somewhere to compensate for the reduce in ratio.

also, the tb4, is there anyway of modifying it to give different attack or release response?

thank you

btw, that green la2a would look better in pink 

 

[regularjohn]

hi everyone  :-*

i am making one of those bloo kits and i had a friend order a special sowter 1009 transformer with a ratio of 1:4 when it is usually 1:10. anyone tried doing it this way to reduce the gain or do you think it will be problematic? wil this be a simple solder in or do i have to use different components somewhere to compensate for the reduce in ratio.

also, the tb4, is there anyway of modifying it to give different attack or release response?

thank you

btw, that green la2a would look better in pink 

You shouldn't need to change any components to use the 1:4 trafo.  You'll simply have a less beastly input section - which is a good thing in my opinion!  I usually use the Sowter 1009 (1:9.1 version), but I use a 12AY7 for the input tube to lower the input gain.  Six of one half a dozen of the other.

A pink LA2A...I could dig it!  ;D

 

[debby]

thanks john, your a sweetie!

hi everyone  :-*

i am making one of those bloo kits and i had a friend order a special sowter 1009 transformer with a ratio of 1:4 when it is usually 1:10. anyone tried doing it this way to reduce the gain or do you think it will be problematic? wil this be a simple solder in or do i have to use different components somewhere to compensate for the reduce in ratio.

also, the tb4, is there anyway of modifying it to give different attack or release response?

thank you

btw, that green la2a would look better in pink 

You shouldn't need to change any components to use the 1:4 trafo.  You'll simply have a less beastly input section - which is a good thing in my opinion!  I usually use the Sowter 1009 (1:9.1 version), but I use a 12AY7 for the input tube to lower the input gain.  Six of one half a dozen of the other.

A pink LA2A...I could dig it!  ;D

 

[ricothetroll]

Just a rough estimation:

Purusha case= $280 AUD shipped
Drips La2a Board = $165 AUD shipped
T4b = $150 shipped
Sowter transformers = $260 AUD
VU meter = $52 AUD
Case parts like knobs and switches = $60 AUD shipped
parts from Triode electronics = $103 AUD
parts from Digikey = $150 AUD
parts from Allied = $75 AUD
parts from Mouser = $150 AUD

Total $1450.00 there abouts.

well i did a cost estimation yesterday (ptp wiring) :

mouser parts (with hammond power transformer) : 167€
sowter trafos : 110€
tubes+sockets (tubedepot) : 40€
engraved frontplate (fpe) : 50€
case (selectronics) : 42€
T4B (drip electronics) : 77€

so total is : 486€ = 817 AUD

you'll have to add shipping for everything (excepted mouser stuff), ptp terminals, wire and nuts&bolts. i know shipping to australia may be more expensive than to europe... parts may not be the best you can get (better tubes, hexfred...) but i guess that's a good start ! btw i would be quite scared to start a project spending near 1000€...

here is the mouser "project" (bom). i simply copied the part numbers from drip electronics document an added a few extra stuff :

http://insidecircus.free.fr/mouser_la2a_project.pdf (feel free to correct me if you see any mistake)

i can send it to your email as a shared project for easier order if you'd like to.

btw i also have my little question : honestly, do you think this is a realistic first tube project AND also a first point to point project ? i already successfully built a 8ch green pre, a G1176, a 16ch passive (trafo) splitter, DI boxes, a bunch of guitar stompboxes...

ptp link :
http://www.vacuumbrain.com/docs/la2.html

thanx a lot to drip electronics and vacuumbrain people for sharing all those great knowledges and facilities about that project !

 

[Bluzzi]

btw i also have my little question : honestly, do you think this is a realistic first tube project AND also a first point to point project ? i already successfully built a 8ch green pre, a G1176, a 16ch passive (trafo) splitter, DI boxes, a bunch of guitar stompboxes...

Absolutely!  Seems to me you are more than ready. Just the fact that you are asking opinions shows that you realize its not totally easy project (every project is easy after its finished right?). Just be careful with the HV of course. I had less DIY than you done before I built 2 LA2As P2P. Best piece of DIY I have! Go for it!

Jim

 

[CJ]

165 just for a pc board?

???

 

[ricothetroll]

Absolutely!  Seems to me you are more than ready. Just the fact that you are asking opinions shows that you realize its not totally easy project (every project is easy after its finished right?). Just be careful with the HV of course. I had less DIY than you done before I built 2 LA2As P2P. Best piece of DIY I have! Go for it!

thanx a lot ! that's motivating...

i think i'm gonna start very soon  ;D

 

[regularjohn]

165 just for a pc board?

???

That's Aussie dollars...but I hear ya, it's still alot.

 

[Bluzzi]

What kind of noise? Hum? 60hz, 120hz? Buzzing? Hiss?

Jim