All things LA2a related

[Deepdark]

yup, exactly like that. Do you have the file?

 

[rainton]

yup, exactly like that. Do you have the file?

pm me your email address 

 

[Deepdark]

Done thanks a lot

 

[thomasdf]

Hi everybody

I have two old Vactrols at home, they are NOS VTL 1B5 "Vactec 8846". I have found a datasheet. I am a bit of a rookie when it comes to tube designs, can I use these in a LA2A sidechain? What are the required tweaks if any?

Here is the datasheet.

Any help is welcome, thanks a lot!

 

[thomasdf]

Can someone give me the precises T4B specs so I can check if this is compatible with my vactrols?

Thanks,

Thomas

 

[Biasrocks]

Can someone give me the precises T4B specs so I can check if this is compatible with my vactrols?

Thanks,

Thomas

I doubt they'll be compatible without a lot of side chain modifications, check out the Manley OPTO comp. They use Vactrol's for gain control.

Mark

 

[thomasdf]

I was planning on redesigning the whole sidechain anyway, I am just wondering to what extend... I'll check the Opto comp! Thank you

 

[ilfungo]

Hi
any of you have tried,  Carnhill VTB 2380 as an output ?
It's 15k:600
it should work?
Thanks!
http://www.audiomaintenance.com/acatalog/CA-18-VTB2380_extended_info.html

 

[Bonsaimaster]

Is 300V rated wire good enough to build a P2P LA-2a?

Thanks
Bonsaimaster

 

[dbonin]

Plenty good, yes.

Is 300V rated wire good enough to build a P2P LA-2a?

Thanks
Bonsaimaster

 

[dbonin]

I would like to add the power snubber to my diy la2a - has anyone done that?  Does it just go in-line on the main power switch to catch any MAINS spikes with you flip the switch?

Thanks for any tips!!

-Don

 

[Bonsaimaster]

I got a Hammond 369JX for my point to point La-2a. Does anyone have the wiring diagram for it? I am using Cayocosta's layout.

Thanks in advance,

Bonsaimaster

 

[dbonin]

I got a Hammond 369JX for my point to point La-2a. Does anyone have the wiring diagram for it? I am using Cayocosta's layout.

Thanks in advance,

Bonsaimaster

it's exactly the same wiring as described in the DRIP opto4 or opto5 manual - I got mine wired up and voltages are looking good so far.

 

[sr1200]

The hammond trafo also has the colors and voltages listed on the side of it.  Youre gonna wind up trimming back a bunch of the wires and tying them off.

 

[Bonsaimaster]

Ok wired everything up. Powers on with all tube except the T4B. I am having two issues

Meter is not registering in GR mode -20
However in +4 I get full deflection
In +10 I get -1.5

I am having voltage issues with V4

Here are my voltages
After 1N4007 - 353V
After 4.7K2W 257V

V4
Pin 2 - 6.6V
Pin 5 - 215V
Pin 6 - 98V

V3
Pin 1 - 107V
Pin 3 - 0.845V
Pin 6 - 91V
Pin 7 - 0V
Pin 8 - 0.845V

V2
Pin 1 - 127V
Pin 2 - 0V
Pin 6 - 215V
Pin 8 - 130V

V1
Pin 1 - 108V
Pin 3 - 1.4V
Pin 6 - 115V

Any suggestions?

Thanks
Bonsaimaster

 

[Deepdark]

hey guys, quick one for you. for the C7C/D, am I ok with 33uf/350V or is it too short?

 

[dbonin]

hey guys, quick one for you. for the C7C/D, am I ok with 33uf/350V or is it too short?

I wouldn't go under the recommended 450V - while that may be over spec, 350V may be pushing it.

 

[Deepdark]

ok. Am I ok ok with some 22uf/450v, as the reissus? I saw that cayocosta's la2a is made with 22uf.

 

[dbonin]

ok. Am I ok ok with some 22uf/450v, as the reissus? I saw that cayocosta's la2a is made with 22uf.

Give it a shot and see - likely ok for those filter caps.  You can always replace them later.

 

[Deepdark]

cool. Thank you