D-AOC PCBs - the building and help Thread

[j.frad]

Sure:
2x115V 50/60Hz primary
-----------------------
250V 0.1A
24V 0.5A
9V 2.5A secondaries

 

[j.frad]

I just got an LM350, I'll try it and post back, but I don't think it'll solve the problem...

 

[ilfungo]

Ciao
is normal with no compression and with full input and output
I half Db difference ( L - R output)?
I measured the voltages and are identical for both channels with a difference of one volt at R105-R205
the difference may be caused by tubes or by transformers (Edcor in out)?
Thanks

 

[ilfungo]

Ciao
is normal with no compression and with full input and output
I half Db difference ( L - R output)?
I measured the voltages and are identical for both channels with a difference of one volt at R105-R205
the difference may be caused by tubes or by transformers (Edcor in out)?
Thanks

???????

 

[ChrioN]

Ciao
is normal with no compression and with full input and output
I half Db difference ( L - R output)?
I measured the voltages and are identical for both channels with a difference of one volt at R105-R205
the difference may be caused by tubes or by transformers (Edcor in out)?
Thanks

Its normal if your input signal is low. Why turn the output knob all the way up?
Half a dB difference? This isn't a digital compressor. You should be fine.

 

[ilfungo]

Thanks ChrioN
I think the difference between left and right could affect the compression ....
then my  stereo link problems dependent from optical cell !?

 

[detonator]

BTW, can you really hear half a db of difference?

 

[ilfungo]

No , the problem not is for half Db
but for stereo link ( different way of  compression for L-R)

 

[[silent:arts]]

my unit tracks L/R better without the stereo link engaged.
however, I use it both ways, depending on the signal.

haven't tested it yet, but putting a little resistance in the stereo link could maybe help

 

[ilfungo]

my unit tracks L/R better without the stereo link engaged.
however, I use it both ways, depending on the signal.

haven't tested it yet, but putting a little resistance in the stereo link could maybe help

and if we put a multi turn trimmer instead fixed value?
2K can work?
Thanks

 

[Eje2005]

I put in 500ohm trimmers and now my unit is dead on accurate in linked mode.

Cheers.

 

[ilfungo]

Thanks silent:arts - Eje2005

I added the 2K trimmer  (I had only this one) and now
-3 DB compression I have a difference on the two output channels of 10mV
Compressive 5db-20mV
10 db 50 mV
Good?

 

[Silvas]

my unit tracks L/R better without the stereo link engaged.
however, I use it both ways, depending on the signal.

haven't tested it yet, but putting a little resistance in the stereo link could maybe help

Could you elaborate on that ?

Mine is stereo-tracking almost perfect without the switch engaged, but with the switch...grrrr.

 

[Eje2005]

I put my 500ohm trimmer on the led of the vactrol, anode side. Like the Forssell opto.

I calibrated with various tones and noise etc...

 

[ilfungo]

ciao  Eje2005
You can post photos to see how you do it?
thanks

 

[Eje2005]

ciao  Eje2005
You can post photos to see how you do it?
thanks

Its really simple, just lift the leg of the vactrol (led side) wich is closest to the tube.

Solder in a trimmer with the washer connected to the board and then the second pin to the vactrol, the last and third pin of the trimmer goes to ground, nearest ground could be cathode of vactrol led or stereolink minus.
Ciao

 

[ilfungo]

I've Kubi mod with 2 vactrol ???

 

[Eje2005]

I've Kubi mod with 2 vactrol ???

Ok, i removed my kubi mod. Too much for me.

But try the trimmers on the kubimod, Start with Anode on the first one then add a trimmer to the cathode on the second vactrol, if it dosent work switch the second trimmer to the anode instead.

Its a couple of minutes of work but all worth it.

Like silent:arts said, should also work with resistance on the stereo link. But i´m not sure on this.

 

[mata_haze]

HEllo,
I am working on my 2 DAOC and trying to decide what transformers to use.
I have a couple of UTC HA100X that I would like to use.
do you guys think I might be able to hook them up as output 600 to 10K output?
Apparently the output impedance of this specific trafo is 60K, maybe I could put a resistor in parallell to drop it?

??? ??? ???

Best,
Mattia.

 

[shabtek]

Mata,  sell the ha100x get some nice 1:2 hi-z input iron.
...i'll trade you a pair of utc a-16 (Z=15k:60k ,20-20k) for 1 ha100x.