Silvas
Well-known member
Well, it took me a while to complete it (and i was building at the same time the D-AOC, PM670, and REV J 1176, all of them coming soon) but here is it. A real pleasure to build. No troubles except making that damn holes for the meters on the front panel. It is pretty much a stock follow-the-BOM D-LA2A with some changes.
Some details :
Case is from my local metal shop. They make some 19" cases, but with nonstandard heights and the finish is not what i like. So i took the closest one to a 3U, put rubber feet to make up for the height, then put my own laser-engraved 3mm aluminium 3U front panel (made by the same shop, but to my specs).
For the power trafos, i used Antek AN-1T250 IIRC. Plus a small 6V 10VA trafo for running the relays and meter leds. This is working wonderfully at a nice price.
All signal trafos are edcors. Inputs are XSM600:15K (as suggested by ssltech, thanks Keith !) , outputs are XSM10K:600. So far no problems with high freq. loss. I just tested the frequencies a very crude way, using tones with the comp inserted on a protools session on studio´s HD rig. There is some small variations above 16K, but very small, like 1.5dB on some frequencies. I am very satisfied with this transformers, maybe i´ll put the sowters on the inputs someday.
Tubes are from EH, JJ and GE 6AQ5.
I wanted 24 step controls on gain and peak reduction, for easier recalls. These are the uraltone switches i bougth from a chinese seller on Ebay, at 10 USD a piece incl. Shipping. They doesn´t feel like the elmas or something more expensive, but they get the job done. It is a good idea to shield the back of the switch.
I left the "limiter response" control on the front. I always wanted a LA2A like this, and i made the right choice. When fully CCW, it is like "flat". When turning CCW, it gets less sensitive to low frequencies, thus preventing exessive pumping on bass and other bass-heavy instruments. What an useful feature ! (at least for me). These aren´t stepped controls but standard 1M alpha pots.
The "comp/limit" switch is gone. "comp" by default.
T4B´s are drips. He´s done a great job with the matching. After carefully adjusting the stereo adjust, the tracking is quite accurate, and the needles reflect very closely the G.R i´m measuring in pro tools. I have to test extensively on mastering but for now, i´m quite satisfied with tracking and metering.
The VU´s ? these are Nissei. I purchased some samples from them. Love them, except for the damn Ashdown logo. I have to put my own scale.
All audio cabling is leftover canare snake cable. Almost all cabling is done with this cable except power, switches and lamps. The unit is dead quiet.
For the coupling caps, i used a combination of ERO MKP1840, wima, orange drop and of course the solen fast.
This thing has lots of gain (as i expected). My "unity" gain for using as insert on digi interface is on "3", and it goes to "24" !!! someday i´ll try a lower gain tube on the first stage.
I couldn´t be happier with this build. Just what i wanted, and just what i expected. Everyone here is impressed. Finally, the first "Made-In-Colombia" D-LA2A. I´m very proud.
A big thanks to Volker for the PCB´s, Bryan and John for the trafos, Keith for the advice on input trafo, and everyone else for their advice.
HAVE A REALLY NICE CHRISTMAS !
Some details :
Case is from my local metal shop. They make some 19" cases, but with nonstandard heights and the finish is not what i like. So i took the closest one to a 3U, put rubber feet to make up for the height, then put my own laser-engraved 3mm aluminium 3U front panel (made by the same shop, but to my specs).
For the power trafos, i used Antek AN-1T250 IIRC. Plus a small 6V 10VA trafo for running the relays and meter leds. This is working wonderfully at a nice price.
All signal trafos are edcors. Inputs are XSM600:15K (as suggested by ssltech, thanks Keith !) , outputs are XSM10K:600. So far no problems with high freq. loss. I just tested the frequencies a very crude way, using tones with the comp inserted on a protools session on studio´s HD rig. There is some small variations above 16K, but very small, like 1.5dB on some frequencies. I am very satisfied with this transformers, maybe i´ll put the sowters on the inputs someday.
Tubes are from EH, JJ and GE 6AQ5.
I wanted 24 step controls on gain and peak reduction, for easier recalls. These are the uraltone switches i bougth from a chinese seller on Ebay, at 10 USD a piece incl. Shipping. They doesn´t feel like the elmas or something more expensive, but they get the job done. It is a good idea to shield the back of the switch.
I left the "limiter response" control on the front. I always wanted a LA2A like this, and i made the right choice. When fully CCW, it is like "flat". When turning CCW, it gets less sensitive to low frequencies, thus preventing exessive pumping on bass and other bass-heavy instruments. What an useful feature ! (at least for me). These aren´t stepped controls but standard 1M alpha pots.
The "comp/limit" switch is gone. "comp" by default.
T4B´s are drips. He´s done a great job with the matching. After carefully adjusting the stereo adjust, the tracking is quite accurate, and the needles reflect very closely the G.R i´m measuring in pro tools. I have to test extensively on mastering but for now, i´m quite satisfied with tracking and metering.
The VU´s ? these are Nissei. I purchased some samples from them. Love them, except for the damn Ashdown logo. I have to put my own scale.
All audio cabling is leftover canare snake cable. Almost all cabling is done with this cable except power, switches and lamps. The unit is dead quiet.
For the coupling caps, i used a combination of ERO MKP1840, wima, orange drop and of course the solen fast.
This thing has lots of gain (as i expected). My "unity" gain for using as insert on digi interface is on "3", and it goes to "24" !!! someday i´ll try a lower gain tube on the first stage.
I couldn´t be happier with this build. Just what i wanted, and just what i expected. Everyone here is impressed. Finally, the first "Made-In-Colombia" D-LA2A. I´m very proud.
A big thanks to Volker for the PCB´s, Bryan and John for the trafos, Keith for the advice on input trafo, and everyone else for their advice.
HAVE A REALLY NICE CHRISTMAS !
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