D-AOC PCBs - the building and help Thread

[dagoose]

Telefunken is expensive, watch your pocket!
(but ask waldorfcave for the difference in a D-LA2A)

Yeah, never knew those telefunken tubes where that pricey. Thought they where quite a lot cheaper. Found a matched pair somewhere for $400(!). Some ultra special NOS series and only 4 available and things like that. Not worth it..
Maybe i will go for some mullards, could be worth it.. anyone know a place where to get them in the EU?

@radiance: never used them on the pultec i bought 'm for, used edcors for that one and so the lundhals are in my d-aoc and i'm totally happy with them. Way better then the edcors which sound a bit muddy to my ears.

 

[Script]

$400 for Telefunzen? Sounds like fetishism to me...

Tubetown have Mullards (AT7) for 25€ per piece, plus 8€ for shipping to NL. Website says something about possible import tax though. There might be cheaper places. Let us know.

 

[dagoose]

$400 for Telefunzen? Sounds like fetishism to me...

Tubetown have Mullards (AT7) for 25€ per piece, plus 8€ for shipping to NL. Website says something about possible import tax though. There might be cheaper places. Let us know.

What is their website? google just comes up with tube-town.de and tubetown/tube-town.com is a non existing domain,

 

[Script]

it's tube-town.net

 

[dagoose]

too bad.. they only have ecc81, i also need 4x ecc82. You can even get a matched pair ecc81's for 60 dollar directly from mullard so even cheaper.

 

[Script]

...You can even get a matched pair ecc81's for 60 dollar directly from mullard so even cheaper.

Can't beat that

Matched pair of ECC82 for $125 directly from Mullard, probably can't beat that either... but I guess I'll opt for cheapo JJs in sidechain position first.

 

[dagoose]

I ordered Mullards for my d-aoc, can't wait to get 'm in and find out if it really makes a difference.  ;D

I was also doing some testing and finetuning (still really love it for mastering) and found out that the 470r resistor right after the rectifier in the high voltage section was still running really hot. So hot that it started to get brown again and the paint got loose. According to the BOM this is 470r 2w but to me this is just to low to power the 6 tubes? I ordered a 10w version which should be more then enough  ;D and for now i have 2x 1k 2w in parallel but they are still running pretty hot. Did anyone elso notice this?  ??? Could it be the tubes? well.. in that case that should be solved soon with the new Mullard tubes.

Also wondering about the output transformer. I have a lundahl on the input which made a pretty big difference and so i was thinking of getting a LL1540 on the output. Will that make a difference compared to the Edcor? I always thought the output trafo is less critical (check the output trafo tests that holger did on the first page) and so i'm a bit in doubt if it will make a big difference.

 

[ilfungo]

help
how connect  Jensen JT-11P-1 on DAOC input?

 

[zayance]

help
how connect  Jensen JT-11P-1 on DAOC input?

Scroll down:

http://www.nu9n.com/tx.html

 

[ilfungo]

thanks zayance
I don't know why but after some test with edcor and jensen
I prefer unbalanced input...
other have the same impression?
Thanks

 

[ilfungo]

Sorry I have a doubt ....
if I use Jensen JT-11P-1 I need to change the value of R101?
Can you tell me what should be?
thanks

 

[ilfungo]

???

 

[zayance]

Dunno if you "should" change the R101, on Silent arts input transformer test, it seems all was connected as is in a 1:1 configuration.
So just try it out.

 

[ilfungo]

I did some tests and I noticed that I lose about two dB compared to the unbalanced ....
Is this normal?
I also noticed something strange about the sound
I'll try to change R101 from  15k to 10k

 

[jsefer]

Am I  late to the party???


Getting ready to start my build and after reading all 53 pages of this thread I have a few questions that are a little unclear, and hopefully some one can shed some light on me:

1.If I am doing the Kubi Mods, I assume that I do not need the Red or Blue LEDs for curve characteristics

2. I noticed some people use the zener, and some use the Neon lamp, what is the reason for choosing one over the other?

3. I will be using this for mastering, would people recommend the kubi opto mod, or zayance approach with selectable hard/soft curve adjustments??

Also there are many recommendations on i/o transformers... Besides the brand, I am reading a 10k/10k input and a 10k/10k output since I am working w short cable runs and are mostly going to use this as a bus on my DAW...

Am I correct to understand this? Sorry to ask these questions, Transformer choices always confuse me!


Thanks in advanced.  8)

 

[Hank Dussen]

I'l by no means an expert but her it goes:

1.If I am doing the Kubi Mods, I assume that I do not need the Red or Blue LEDs for curve characteristics

There a many way to change the compression curve. Some use leds, The Kubi Mod uses a second vactrol. (see link on page one)

2. I noticed some people use the zener, and some use the Neon lamp, what is the reason for choosing one over the other?

As I believe the neon is more 'traditional', the zener more 'reliable'. I'd say go with the zener.

3. I will be using this for mastering, would people recommend the kubi opto mod, or zayance approach with selectable hard/soft curve adjustments??

Also there are many recommendations on i/o transformers... Besides the brand, I am reading a 10k/10k input and a 10k/10k output since I am working w short cable runs and are mostly going to use this as a bus on my DAW...

For mastering purposes use switches instead of pots. There are these cheap blue 2 deck switches you can use but I always forget the brand.
Input should be 10k:10k (1:1)  to 600:10k (1:4), output 10k:600. For mastering go for good transparant transformers like Jenssen or Lundahl or so.
check this threat:http://www.groupdiy.com/index.php?topic=37166.msg457204#msg457204

 

[zayance]

There are these cheap blue 2 deck switches you can use but I always forget the brand.

http://uraltone.com/kauppa/index.php?cat=c53_Rotary-switches.html&XTCsid=dun72svt72bo1u6m068nhu58m0

No more on ebay for the 2 Decks  :'(, the guy who sold them before was doing even cheaper prices...

 

[seavote]

There are these cheap blue 2 deck switches you can use but I always forget the brand.

http://uraltone.com/kauppa/index.php?cat=c53_Rotary-switches.html&XTCsid=dun72svt72bo1u6m068nhu58m0

No more on ebay for the 2 Decks  :'(, the guy who sold them before was doing even cheaper prices...

i bought some 4 deck switches. took them apart, removed 2 decks and reassembeled them.(very easy to do once they are open and you see how they work. i also drilled a new hole in the switch and put in a metalpost making the 24 pos a 16 pos switch)  you can also leave the 4 decks and only use 2.  for the price it is still worth buying the 4 deck switches
8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8)

 

[zayance]

There are these cheap blue 2 deck switches you can use but I always forget the brand.

http://uraltone.com/kauppa/index.php?cat=c53_Rotary-switches.html&XTCsid=dun72svt72bo1u6m068nhu58m0

No more on ebay for the 2 Decks  :'(, the guy who sold them before was doing even cheaper prices...

i bought some 4 deck switches. took them apart, removed 2 decks and reassembeled them.(very easy to do once they are open and you see how they work. i also drilled a new hole in the switch and put in a metalpost making the 24 pos a 16 pos switch)  you can also leave the 4 decks and only use 2.  for the price it is still worth buying the 4 deck switches
8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8)

Yes true, but one thing, when taking a deck out, you're left with the center axis beeing too long iirc, you cut that also then, i didn't bother on mine, but did the metalstop pin, thanks to "dagoose" for that tip.

 

[jsefer]

I'l by no means an expert but her it goes:

1.If I am doing the Kubi Mods, I assume that I do not need the Red or Blue LEDs for curve characteristics

There a many way to change the compression curve. Some use leds, The Kubi Mod uses a second vactrol. (see link on page one)

2. I noticed some people use the zener, and some use the Neon lamp, what is the reason for choosing one over the other?

As I believe the neon is more 'traditional', the zener more 'reliable'. I'd say go with the zener.

3. I will be using this for mastering, would people recommend the kubi opto mod, or zayance approach with selectable hard/soft curve adjustments??

Also there are many recommendations on i/o transformers... Besides the brand, I am reading a 10k/10k input and a 10k/10k output since I am working w short cable runs and are mostly going to use this as a bus on my DAW...

For mastering purposes use switches instead of pots. There are these cheap blue 2 deck switches you can use but I always forget the brand.
Input should be 10k:10k (1:1)  to 600:10k (1:4), output 10k:600. For mastering go for good transparant transformers like Jenssen or Lundahl or so.
check this threat:http://www.groupdiy.com/index.php?topic=37166.msg457204#msg457204

Great thanks for the info, I was planning on going w these type of transformers... How do you guys like Cinemag, they are local to me and have always built quality transformers for various projects of mine in the past.. Shoot wish I would have read more in depth before i bought the pots, well I can build it as is and switch out the pots for switches as they come.. Still unsure how they work since i dont have them infront of me so Id would be a little lost on what to look for.. I asume Im looking for something like a 24 position Single pole of the exact value of the pot im replacing?

Edit: I think I just answered my own question, I do need a 24step 2 pole... Just found some on the evil bay

http://cgi.ebay.com/2P-24-Step-Attenuator-Volume-Control-Pot-Log-100K-Mono-/260806367240?pt=LH_DefaultDomain_0&hash=item3cb9455808#ht_2229wt_1082

11$us a pop, now I replace all pots with these? or just the compression pots?? My guess is all of them, will probably order them right now...

Also Bout the neon bulbs, will try out how it works and will probably switch to the zeners if i run into trouble, thanks and your time is much appreciated fellas..

In addition, if some one could be so kind to give me some metering specifications or a link to a good VU meter, ive read all 53 pages and there is very little vu meter talk. I know that the VU driver is the same as the LA2A searching through the pages theres so many opinions on what to use, Im just looking for something sleek, plug and play if possible :

http://hairballaudio.com/shop/product_info.php?products_id=86

I like this meter, but dont know for sure if this will work, also the price is a little steep, just looking to get some feedback on some meters in the same style as the hairball meters...

Thanks again for the info