The Optical Comp Again

[ask]

I could be interested in one, however it would depend on the total build price, which would have to be quite a bit less than the DIY PCB LA2A (or is it B now?).
Does anyone have an estimated price?

 

[bernbrue]

Volker,
I'm in for two pcbs. Thx a lot for your work and contribution for this forum.
regards
Bernd

 

[radiance]

in for two boards as well..thanks!

 

[Kamel]

i'm in for 2 board too

great job :thumb:

 

[ChrioN]

I'm in for 2-4 boards. I think its better to start a feeler-thead in the black market though. This is great btw :guinness:

 

[[silent:arts]]

[quote author="ChrioN"]I think its better to start a feeler-thead in the black market though.[/quote]
you are right. did it. please post your interest here:
http://www.groupdiy.com/index.php?topic=25906
(if you didn't here before)

 

[nielsk]

I want to try this out, too....but aren't the vactrols known for having temperature stability problems?

 

[[silent:arts]]

nielsk,

haven't heard of any temperature stability problems of vactrols yet.
do you have a source for us ?

anyway, after one hour the temperature will be stable warm if you put 6 tubes in a 2U enclosure :green:

 

[mik]

2 bord here, please !

M.

 

[solder_city]

me too! me too! meeeeee tooooo!

o wait a minute, did anyone actually BUILD this thing yet?

:roll:

 

[[silent:arts]]

[quote author="solder_city"]o wait a minute, did anyone actually BUILD this thing yet?[/quote]
yes, Jaakko did (and some others):
http://www.groupdiy.com/index.php?topic=24265 :grin:
if you want to do a proto of the pcb drop me a line.
I will send you all the files needed for etching one your own.

 

[clintrubber]

[quote author="[silent:arts]"][quote author="solder_city"]o wait a minute, did anyone actually BUILD this thing yet?[/quote]
yes, Jaakko did (and some others):
http://www.groupdiy.com/index.php?topic=24265 :grin:
if you want to do a proto of the pcb drop me a line.
I will send you all the files needed for etching one your own.[/quote]
Hi,

Solder_city brought up a valid point. I guess he also means whether the PCB itself is 'validated'.
As in: with the forecast of many a PCB to be made by the PCB-manufacturer, will they send a 'sample' which can be used to make a unit and then proceed if all is well?
Apologies if I missed this and this step has already been done.

Thanks all involved for doing this design & PCB etc :thumb:

Peter

 

[Michael Tibes]

[quote author="[silent:arts]"]nielsk,

haven't heard of any temperature stability problems of vactrols yet.
do you have a source for us ?

anyway, after one hour the temperature will be stable warm if you put 6 tubes in a 2U enclosure :green:[/quote]
LDRs are sensitive to infrared light. I had a programmable tube guitar amplifier using those 20 years ago and the sound changed constantly - even after hours of being in use.
On the other hand voctrols are also successfully used in other compressors, maybe the problem isn't that big in compressors - which are normally used in a more temperature stable environment than my old rehearsal room was.
Anyway something to think about, even if it's only to rule it out as a possible problem.

Michael

 

[[silent:arts]]

Peter,

I decided to order some test pcbs next week.
kubi (and me) will build one.
kubi has some nice suggestions to improve the PCB design I will do.
it will take some time, but the offered PCBs will be proofed.

 

[clintrubber]

[quote author="[silent:arts]"]Peter,

I decided to order some test pcbs next week.
kubi (and me) will build one.
kubi has some nice suggestions to improve the PCB design I will do.
it will take some time, but the offered PCBs will be proofed.[/quote]
Hi,

Good to hear, thanks for the info :thumb:
[stating the obvious]Please don't get me wrong, there's no suspicion that it wouldn't have been good all, but especially with such a big run as this seems going to be, it'd save everybody quite some hassle.[/stating the obvious]
And me not in a hurry.

Cheers,

Peter

 

[ChrioN]

[silent:arts] Thats great. Maybe add a VU meter circuit?

 

[[silent:arts]]

[quote author="ChrioN"]Maybe add a VU meter circuit?[/quote]
there is the LA2A gain reduction meter circuit on the board.
(with either neon or zener)

 

[clintrubber]

[quote author="ChrioN"][silent:arts] Thats great. Maybe add a VU meter circuit?[/quote]
Hey this is a tube-circuit, so why not do it in style ? Magic-eye !
Say EM84 or something like that... could be a nice add-on for those inclined.
I guess this loss in accuracy is not killing for GR.

 

[MrZpliff]

A magic eye would be
I seldom look at the VU on my LA2a...
Nice photos you got there Clintrubber :thumb:
sometimes we have northern lights here where I live, but nothing like that...
Edit: I forgot the "n" in your nickname :razz:

 

[clintrubber]

[quote author="MrZpliff"]A magic eye would be
I seldom look at the VU on my LA2a...
Nice photos you got there Clintrubber :thumb:
sometimes we have northern lights here where I live, but nothing like that...
Edit: I forgot the "n" in your nickname :razz:[/quote]
I do realize the magic eye won't be to everyones taste and would make it less feasible, so it's just a suggestion for those willing to go the additional mile. In other words: not my intention to mess with the project/PCB as it is now of course.

IIRIC there are a few magic-eye PCBs out there, getting these makes for an easy add-on... but some PtP will do the trick as well.

W.r.t. those pics, it's part of some lame joke (long story), they're not mine but from friends of my parents. But they're sure nice. Cool you have them there, over here it's nothing.

Yes please don't forget the N