D-LA2A Support Thread

[MartyMart]

I ordered the prewired 2 pole / 3 pole and a few more besides.
That really saves some VERY boring wire-up time on Molex .... hate that stuff !!

Got the octal sockets and the small .022 solen fast caps too.

Thanks Bernd, you are a star

 

[Kingston]

Now if only someone would come up with reliable replacement to all things Molex KK standard. Crimping tool or not my success rate is 9/10 good crimps at best, which is nowhere near reliable enough or even adequate.

I hate them with a vengeance. Of all things soldering and build related, they have caused me most grief. 

 

[jplebre]

@kingston could it be your crimp tool?

I still apply a blob of solder afterwards just to be extra sure.

 

[Kingston]

I still apply a blob of solder afterwards just to be extra sure.

Me too.

I like the idea of prewired Molex KK. Unfortunately they don't cater for the common shielded cable scenarios, or thicker wire for more amps and/or less wire resistance.

 

[MartyMart]

I still apply a blob of solder afterwards just to be extra sure.

Me too.

I like the idea of prewired Molex KK. Unfortunately they don't cater for the common shielded cable scenarios, or thicker wire for more amps and/or less wire resistance.

Yes, that did cross my mind too, still for some duties it will be great, will still wire I/O with my shielded
cable, but it may well mean 40 + crimps I can avoid !
My vote goes for "screw terminal" though it takes up a little more space, tin leads - test = lock with nail polish.

Marty.

 

[sonicwarrior]

Crimping tool or not my success rate is 9/10 good crimps at best

What kind of wires do you use? 0.25 mm²?

 

[Kingston]

Crimping tool or not my success rate is 9/10 good crimps at best

What kind of wires do you use? 0.25 mm²?

Various sizes, but mostly the standard 0,22mm2 hookup wire. 0,5mm2 seem to give more grief, don't think the crimps are designed for that, even if the connector amp rating is.

 

[MartyMart]

Yup, my hookup wire is 2.0mm and I also add a tiny dab of solder to crimps.
They just take SOOO much time to do, which I don't have enough of.

BTW - the pre-crimped leads arrived and they seem pretty good. ( plastic housing is cheap though )
Will test 'em before installing though, just to make sure that i don't lose my mind chasing faults !!

MM.

 

[baadc0de]

Guys

any idea why my DLA2A is only stable with C14 bumped up to 22nF? Grid stoppers installed, shielded cable throughout. Anything below 4nF oscillates like crazy when you push "reduction" and "makeup". Tried with 12ax7 stock, then 100k plate resistors, then 6072A (love this sound). With 22nF it sounds "OK" and compresses well at first glance, but I thought to pick your brains on this if you have an inkling. If nothing else, what to check?

 

[jplebre]

Anything below 4nF oscillates like crazy when you push "reduction" and "makeup".

you have oscillation when you do reduction as well or just make up?

Where are your transformers (eg. near the XLRs) someone had issues with this and moving the transformers helped.

 

[baadc0de]

Anything below 4nF oscillates like crazy when you push "reduction" and "makeup".

you have oscillation when you do reduction as well or just make up?

Where are your transformers (eg. near the XLRs) someone had issues with this and moving the transformers helped.

If you push just makeup, there is no oscillation, even if you up the reduction quite a bit. Just reduction also does not oscillate, but push reduction to anything above about 1/2 and it will oscillate if there is at least some makup applied (not zero).

transformers are not that close to XLRs, are shielded UTCs and have shielded wire going to them. Any ideas mates?

 

[jplebre]

does it happen without the T4B installed?

 

[baadc0de]

does it happen without the T4B installed?

Nope, no oscillation with T4b pulled. I have several to choose from and they are all exhibiting this behavior, so it must be the compressor not the T4b.

 

[[silent:arts]]

Nope, no oscillation with T4b pulled. I have several to choose from and they are all exhibiting this behavior, so it must be the compressor not the T4b.

Must be in the sidechain ...

 

[MartyMart]

Have just started the project

Will take a while, as I do it whenever I have a few spare hours.

Mistake No 1 : ( and hopefully my last )

Fitted a 2,200uf cap at the 25v rail rather than a 3,300uf as spec'd !

It doesn't want to come off so I stopped before I kill the part & board !

Any issue with this? or should I dremel it off, remove the leads and fit the 3,300uf?
( possible but may mark to board a little )

Cheers,
Marty.

 

[bernbrue]

Hi Marty,
leave the cap where it is. It won´t hurt.
regards
Bernd

 

[MartyMart]

Hi Marty,
leave the cap where it is. It won´t hurt.
regards
Bernd

Thanks Bernd = you're a star
Was just worried about "ripple" but I have space to "tack on" a 1uf poly or something if need be.

Marty.

 

[bernbrue]

Hi,
the 5V rail is just for the relays and other stuff, it´s not in the audio path. The 2200uF will do the job fine.
regards
Bernd

 

[jonathanmorbin]

Hi,

I posted a while back about my VU meter LED's Flickering/not turning on. I really dont know what could be causing this, I have tried new LED's, new VU meters. i have since built another D-LA2A and it has just happend to this unit. One VU now does not light up. all the flickering LED's I have still flicker when i try them in the new unit.

I am using Hairball Audio 8020 meter. I know that other people have used these meters fine with no flickering or anything. Can any body assist me? My second unit has all screened cabling inside.

http://www.hairballaudio.com/shop/product_info.php?cPath=25&products_id=86

 

[Harpo]

I posted a while back about my VU meter LED's Flickering/not turning on...
I am using Hairball Audio 8020 meter.

Two (maybe white, different colour has different parameters) LEDs connected in series, so double forward voltage drop at same current for your meter illumination.
These LEDs come with a max.allowed Ifwd of maybe 20mA that you don't want to exceed.
What is your raw DC voltage in front of the 7805 voltage regulator (regulators left side pin 1 or +side of C5, from where you pick your voltage feed for this LED string with current limiting resistor in between) in respect to  its reference voltage at PL2-2 ? ([this measured raw DC voltage] - 2* Vfwd for your two series connected LEDs) / maybe 10mA LED current that you decided to allow to not exceed parts limits and not to build a headlight = value of current limiting resistor needed. For example (9V - 2*3.4V)/0.01A=220ohm.