D-LA2A Support Thread

Another picture...

And another one...

drgrateful said:

Here's my new D-LA2A!

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no front panel pics ???
inside looks good, congrats!

drgrateful said:

Unfortunately, while the left channel is dead quiet, on the right channel I get quite a lot of hum. I tried swapping tubes between the two channels, but the problem persists. I guess this excludes the problem source is in the tubes (am I correct?) Thanks for any suggestions!

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disconnect the pilot lamp and the power switch (in the middle, I guess?) first ...

There you go... Here's a picture of the front panel...

Thanks for the suggestions on the pilot lamp and the power switch: I will try and let you know how it works...

My DLA2A(ugly frontpanel), is alive.  ;D
I love this unit, just needed to finish the layout for the definitive frontpanel. i'll replace the VU switchs by the ITT switchs like others for a 'UREI LOOK' and make a clean wiring to void the ground noise.
Except this points all works perfectly
I'll post others the picture when i recieved the definitve front panel by Frank.
I hope close the box soon
Many thanks Volker for this great project.
PS: Thanks to all, for the precious infos i've found in the thread

[silent:arts] said:

disconnect the pilot lamp and the power switch (in the middle, I guess?) first ...

Click to expand...

It was the power switch! More precisely, the wires going to the power switch needed to stay away from the wires going to the limit/comp switch. Now everything is good (no more hum)! Thanks for all the useful info! 

telefunk said:

But there's one tiny little issue i'd like to fix:

When i crank the Gainpot to around 3 o'clock, there is HUGE amount of gain which is great BUT just before the pot is at full, the signal drops out and the VU meters at the console where the la2a is inserted, start to read FULL, but no sound.

It doesnt really matter that much since i wont ever need that much gain but i'm just interested if this can be fixed and why is it happening.

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Telefunk: I am experiencing your same (very minor) issue. Only on one channel, just before the gain reaches 100%, I here a small pop and the VU meter starts to read full (without sound). On the other channel this does not happen. Let me know if you find out what causes this...

First, thanks to all the members of this forum and especially to Volker the master of the creature...
After one week solving problems in my project, finally partially works.

It works well with a mono unbalanced signal but when I try with a balanced signal a lot of hum appears. The problem is the same in both channels. I have tried to move and shield cables, but nothing changes.

And also I have the same problem as Telefunk and Drgrateful, when the gain pass 3 o'clock the signal drops and the VU meter read full.

Thanks for all suggestions.

Borja

Is there a wiring diagram which shows how all the pots / switches should be wired, or are people just going off the schematic?

I'm assuming that the 5v relay pin by the power supply should go to both the bypass switches, switching power to the other relay pins to take the unit out of bypass?

forgive the dumb questions

thx

tim

@ timmygrimm,
Check the good wiring by stereokilla 

stereokillah said:

should be help you

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rad... thank you

drgrateful said:

telefunk said:

But there's one tiny little issue i'd like to fix:

When i crank the Gainpot to around 3 o'clock, there is HUGE amount of gain which is great BUT just before the pot is at full, the signal drops out and the VU meters at the console where the la2a is inserted, start to read FULL, but no sound.

It doesnt really matter that much since i wont ever need that much gain but i'm just interested if this can be fixed and why is it happening.

Click to expand...

Telefunk: I am experiencing your same (very minor) issue. Only on one channel, just before the gain reaches 100%, I here a small pop and the VU meter starts to read full (without sound). On the other channel this does not happen. Let me know if you find out what causes this...

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I have solved the problem with the distortion in the gain, passing 3 o'clock, using tubes 12at7 instead of the 12ax7. I think the lower mu factor could aid. I'm using edcor 600/15k 1:5 for the input, but I don't know at the moment the origin of the problem.
I have also solved the hum problem, a bad resistor in both chanells...

Hey guys I have looked through the thread and haven't really seen an answer to the sound of different caps here.  I am planning on building a High End version that I can use on the mix buss.  stepped switches and a few mods.  I am now ordering parts and wondering if anyone has any suggestions for these caps for a Mixbuss/mastering version of this comp.

Also, anyone else have any part suggestions for this kind of build?

Note:  I don't care it sounds like an original I just want it to sound great!

I suggested this already in the main LA2A threat but think it's such a great idea I'll post it again 
Install sockets so you can try different caps!

dandeurloo said:

Hey guys I have looked through the thread and haven't really seen an answer to the sound of different caps here.  I am planning on building a High End version that I can use on the mix buss.  stepped switches and a few mods.  I am now ordering parts and wondering if anyone has any suggestions for these caps for a Mixbuss/mastering version of this comp.

Also, anyone else have any part suggestions for this kind of build?

Note:  I don't care it sounds like an original I just want it to sound great!

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What caps are you exactly talking about?

I saw that and i ordered a few extras.  so think i will try that!  Any thoughts on transformers.

Hank Dussen said:

I suggested this already in the main LA2A threat but think it's such a great idea I'll post it again 
Install sockets so you can try different caps!

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C105 and C205.  these are the pricey ones.  The mallory is $27.25 for one.  So I though I would ask before buy those plus the others.

telefunk said:

dandeurloo said:

Hey guys I have looked through the thread and haven't really seen an answer to the sound of different caps here.  I am planning on building a High End version that I can use on the mix buss.  stepped switches and a few mods.  I am now ordering parts and wondering if anyone has any suggestions for these caps for a Mixbuss/mastering version of this comp.

Also, anyone else have any part suggestions for this kind of build?

Note:  I don't care it sounds like an original I just want it to sound great!

Click to expand...

What caps are you exactly talking about?

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russian PIO caps seem to get votes around here. They are very large in physical size, but are still reasonably priced in ebay

c105 & c205. If you want high-end, get Solens. Around 14€ in europe, not a big deal if you consider using them for decades.

I bought Edcor WSM 600/15K & 15K/600, they work like charm.

These? 
http://www.tubedepot.com/cp-so-1000-630v.html