sonicwarrior

Re: D-LA2A Support Thread
« Reply #720 on: June 28, 2011, 03:32:39 AM »
The PCB from [silent:arts] has the connections for the Sowters printed on it.

I compiled the informations from this thread into a PDF which should answer your questions, too.


[silent:arts]

Re: D-LA2A Support Thread
« Reply #721 on: June 28, 2011, 04:08:59 AM »
1. how to wire the rondo muller psu,I can't understand what is the function of the three black wires in volker's picture  neither the connection of the on off toggle switch ( in the pcb i can notice that it have only two pins)
look at the picture in the pdf sonicwarrior posted above.
the PSU transformer only has 2 black wires, which are one of the two heater secondaries.
there is no main power on the PCB, you wire the on/off switch between the IEC connector and the PSU transformer primaries.

2.  what is the small box  next to the power connector?
it is a 120V/220V switch

3.  how to wire the sowter transformers and the switches on-on  with the  six and three   ends? (terminals)
for the sowter transformer use the color code printed on the PCB.
for the switch wiring use the sonicwarrior pdf (thanks btw)

sea_man

Re: D-LA2A Support Thread
« Reply #722 on: June 28, 2011, 10:27:02 PM »
Thanks for your reply , the sowter and all the switch ( except the on/off) are ready !!!

The only part i can't understand now is the AC input for rondo power transformer ( PSU transformer primaries)... this have 4 cables in pairs whit black thermo-retractable (  one wire yellow and other white inside) each .. and i see in many pics two of this wires connected together and in others not..
Can you please guide me to connect this to the IEC connector and the on/off switch ?

Also , i left today to buy the cap for C8.. but this comes in different voltages.. which is the correct ??  0.1uf wima ***v??

Thanks !!
« Last Edit: June 29, 2011, 02:59:19 AM by sea_man »

[silent:arts]

Re: D-LA2A Support Thread
« Reply #723 on: June 29, 2011, 03:04:14 AM »
The only part i can't understand now is the AC input for rondo power transformer ( PSU transformer primaries)... this have 4 cables in pairs whit black thermo-retractable (  one wire yellow and other white inside) each .. and i see in many pics two of this wires connected together and in others not..
well, for 110V mains those 4 wires are parallel, for 220V seriell

rob_gould

Re: D-LA2A Support Thread
« Reply #724 on: June 29, 2011, 05:53:43 AM »
I'm interested in adding LED meters to this project.

This subject doesn't seem to have come up since most people go for analogue meters for their builds, more in keeping with the classic look.

Is it possible to add LED meters to an LA2A circuit?

Would something like this be of any use?

http://www.groupdiy.com/index.php?topic=23977

Cheers,

Rob

sea_man

Re: D-LA2A Support Thread
« Reply #725 on: July 01, 2011, 03:39:58 AM »
The only part i can't understand now is the AC input for rondo power transformer ( PSU transformer primaries)... this have 4 cables in pairs whit black thermo-retractable (  one wire yellow and other white inside) each .. and i see in many pics two of this wires connected together and in others not..
well, for 110V mains those 4 wires are parallel, for 220V seriell

Thanks ! it work fine.

For now i need wire all cables again whit shield.. i forgot this  ;D .. because this i have a lot of noise...

Also i will make a pics tomorrow for the forum .

Again.. thanks for your help , it is my firs tube project !

sea_man

Re: D-LA2A Support Thread
« Reply #726 on: July 05, 2011, 08:14:04 PM »
I finish my project !  8)

Here are the pics:

http://www.flickr.com/photos/mar1o_bross/sets/72157627001849463/

Thanks for your help !

[silent:arts]

Re: D-LA2A Support Thread
« Reply #727 on: July 06, 2011, 05:31:19 AM »
I finish my project !  8)

congrats! nice work, and you are still allive 8) 8) 8)


sea_man

Re: D-LA2A Support Thread
« Reply #728 on: July 07, 2011, 04:23:57 AM »
Thanks !

The only problem i have now is a hum sound in the right channel

can you give me any advice?

sea_man

Re: D-LA2A Support Thread
« Reply #729 on: July 08, 2011, 09:39:17 PM »
Hum sound is solved swapping the tubes and wiring better the front and the rondo ! ( your advice   ;) )

Now is working fine !

Thanks for all your help and for the signature/banner !
« Last Edit: July 08, 2011, 09:45:39 PM by sea_man »


briomusic

Re: D-LA2A Support Thread
« Reply #730 on: July 22, 2011, 03:27:02 PM »
finally finished my stepped-switch D-LA2A, and ready to collect my banner  ;D

frontpanel by NRG CNC, almost made my way through all of frank's anodized colors now.
I should add: little scratches happened during assembly not at NRG.


pcb and power transformer by silent:arts, T4B by Drip, meters by Hairball


thanks to the posters in these threads for helping with the stepped switches:
http://www.groupdiy.com/index.php?topic=44553.msg558003#msg558003
http://www.groupdiy.com/index.php?topic=44800.msg561075#msg561075
I went for a custom spacing on the input gain: 1dB steps from -9 to +8dB, then 5dB steps from +10 to +35dB.
the uraltone type switches i got from ebay actually have 24 positions.
Additionally, I used a lorlin with 8 steps for the HF response trimmer. I will see over time if that's enough....



rob279

Re: D-LA2A Support Thread
« Reply #731 on: July 29, 2011, 11:27:43 AM »
wher can I buy a circut board from

Re: D-LA2A Support Thread
« Reply #732 on: July 29, 2011, 12:27:43 PM »
Welcome to the forum Rob. These circuit boards are available in the White Market section...

[silent:arts]

Re: D-LA2A Support Thread
« Reply #733 on: July 29, 2011, 05:45:55 PM »
Brio, I nearly missed your D-LA2A - I'm sorry ...
Need a stepped switched version too 8)


briomusic

Re: D-LA2A Support Thread
« Reply #734 on: July 30, 2011, 06:31:12 PM »
Brio, I nearly missed your D-LA2A - I'm sorry ...
Need a stepped switched version too 8)



Thanks for the banner  :D 
This guy on ebay does 24step switches now, and even pre-resistor-soldered as log pot replacement:
http://cgi.ebay.de/2P-24-Step-Attenuator-Volume-Control-Pot-Log-100K-Mono-/260806367240?pt=LH_DefaultDomain_0&hash=item3cb9455808

MicDaddy

Re: D-LA2A Support Thread
« Reply #735 on: July 30, 2011, 06:34:37 PM »
briomusic nice build,  8)

Are those 24p switches ready to go, any circuit mods to be aware of?  Thanks

briomusic

Re: D-LA2A Support Thread
« Reply #736 on: July 31, 2011, 12:53:21 AM »
briomusic nice build,  8)

Are those 24p switches ready to go, any circuit mods to be aware of?  Thanks

Thanks!

You could get the 100k log pre-configured switches as a drop in replacement for the 100k log pots (gain and peak reduction). I wanted a different scale for the gain, so I made up my own with  higher resolution around unity gain and bigger steps towards the higher gain settings.

telefunk

Re: D-LA2A Support Thread
« Reply #737 on: August 27, 2011, 02:21:39 PM »
Hello everybody!

I need a little bit help with this one....

The thing is: My D-LA2A has been working wonderfully for something like 8 months now, everyday. Then, suddenly today the other channel stopped working.

Like this, it passes audio when I turn the gain, normally. But when I turn the Peak Reduction pot CW, instead of more compression, it works like reversed gain pot: sound disappears. And when it's fully CW nothing comes out.

I tried changing all the tubes and switching the T4B's no change. All tubes and the T4b's work in the other channel.

So, any ideas where to start looking?

BTW, the broken channel compresses and works normally when the Peak Reduction pot is fully CCW and Stereo Link is switched on and the control voltage comes from the working channel.

[silent:arts]

Re: D-LA2A Support Thread
« Reply #738 on: August 27, 2011, 04:10:51 PM »
...
BTW, the broken channel compresses and works normally when the Peak Reduction pot is fully CCW and Stereo Link is switched on and the control voltage comes from the working channel.

which leads us to the potentiometer and its connections to the PCB, isn't it.
or maybe something around VX03 ...

Re: D-LA2A Support Thread
« Reply #739 on: August 27, 2011, 06:15:43 PM »
Just got my first one up and running. I had trouble finding info on the 25K +75K mod for gain, I put the 75K between the wiper and pin 2 on the molex. Should I have put it between pin 3 and the pot?

Also I have one channel working perfect and the other with just low thin sound, pretty sure it's the gain pot being not right so one thing at a time


 

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