D-AOC PCBs - the building and help Thread

[[silent:arts]]

There is always one thing you can do in DIY: try it :grin:
I use 600:600 in my D-AOC, works great.
but your transformer models might have a different behavior, we can't say this in advance.

the ouput works fine with Edcor XSM10K/600.
most people used it ...

if you want to try another one feel free to do it.
but we can't test anything in advance, and even with PCBs it is still DIY :green:
(Klaus Wowereit would say: und das ist auch gut so)

 

[maxwall]

Volker,

thanks, I'll try some different transformers for sure, but understanding why one transformer works better than others is really my question. here's why .....

Example : take the different tx's below having qualifying specs for input usage.

A20 1:1 (500:500) max level +15dbm
A22 1:1 (500:500) max level +30dbm
Altec 15335A 1:1 (15K:15K)

based off specs above could you actually make a case that one is better than the other without a sound test.

Even if all these are 1:1, is the 500:500 loading compared to the 15k:15K going to make a difference. Based on what gets plugged into it in the signal chain such as a guitar or a mic for example, will the two react
relatively the same , if so why ? if not why ? It seems to me that there would be a difference due to impedance in the winding between the two. What effect would 600 have over a 15K or a 10K for that matter. What would I expect to hear or not hear if I were just basing my decision solely on transformer specs ? ( complicated enough )

I'm trying to understand the specifics in aquiring a optimal transformer. In many cases , buying a transformer on specs does'nt allow for a sound test until later. So, knowing more about specs might decrease the uncertainties in getting the wrong iron and increase the success for getting a transformer that will be correct. I always feel transformer selection is like gambling, and I want to take the element of chance out of it as much as possible. I've always rely on proven results because who can afford to keep enough transformers around to ensure thru sound testing , you have the right one for the job.

In many instances, having the original iron for a project involves having the vintage iron. The cost of vintage iron has made it popular to go to alternatives due to cost. In this case I always ask the question - what alternative should I use. Well, I usually call the manufacturer and get the suggested alternative, but what if I find something unusual and I want to use it in a project, what then. Here is where knowing specs becomes important and here is where confusion begins.


Basically, When I look at transformer specs, I want to be able to make a experienced decision without wasting to much time and money.

Am I making any sense ?

 

[ChuckD]

I have recently been tweaking/experimenting around on this unit and discovered that I now have caused a 120Hz hum... Any ideas to the root cause of a 120Hz hum? There is no 60Hz present. 120Hz measures approx -60db and does no appear to be linked to the output or input gain.

I am thinking it is either :
a) The Hot Hot Regulator on the 6.3 VDC supply
b) The C102 & C104 caps I only used 250VDC rated ones and maybe I screwed them while experimenting
c) The tubes . Bad tube somewhere?


Anyone want to suggest something else or help me rule something out?

Thanks

-Chuck

 

[[silent:arts]]

maxwall ,
What I can tell you for sure is that I can't tell you the result just from the specs :shock:
you may have seen this:
http://www.groupdiy.com/index.php?topic=26585&start=75
different Input Transformers, with different specs.
no, I haven't compared sound, this was measuring only.
I would have expected some other curves from a few transformers :wink:

 

[[silent:arts]]

ChuckD,
haven't heard of any hum problems yet - what Power X former did you use ?
do you have a scope ?

 

[tommypiper]

Chuck D, Volker, and others... I'm sorry to ask, but what is the "kubi advanced version" and mod that Darius refers to? I've read the threads two times and can't find it.

 

[[silent:arts]]

the Kubi advanced version are just a few changes he did.
haven't tried it myself, but seams to work fine.

 

[tommypiper]

I noticed Chuck D has it written on his front panel. And Darius said it was posted. Which thread? Can someone point me or send a PM please?

 

[mikeyB]

DONE first "FIRE ENGINE" :grin:

BIG THANKS to analag, Volker, Purusha and all who contribute!

This baby runs nice and cool - regs should last a good while
Soft switch is for clear blue LED anti-parallel. Parallel had no effect!

Here's some pics - afraid I'm better with a soldering iron than with a camera
http://i73.photobucket.com/albums/i215/mikerbaker/blurryfront.jpg
http://i73.photobucket.com/albums/i215/mikerbaker/chassisabove.jpg
http://i73.photobucket.com/albums/i215/mikerbaker/front-1.jpg
http://i73.photobucket.com/albums/i215/mikerbaker/heatsinks.jpg
http://i73.photobucket.com/albums/i215/mikerbaker/ironshot.jpg
http://i73.photobucket.com/albums/i215/mikerbaker/pcbabove.jpg

NEXT :razz:


:sam: :sam: first though

ps sorry about pic quality Volker

 

[PimD]

[quote author="mikeyB"]
I had similar voltages to Volker - EXCEPT - neon voltage only 52 volts - any ideas/ should I change something :?:[/quote]

Mikey, is your neon still at 52 Volts? And had any problems with that?

Fired mine up last night, and it also gives 52V.
Without tubes (don't know if that matters )

Congrats on your build.
:thumb: :sam: :sam: :guinness: :guinness:

 

[mikeyB]

PimD - the neon is reference for meter side - will check calibration in studio. The unit seems to be doing the business as expected.
I'm building 2nd one soon - so I will try next with zener reference. Will have that done sometime next weekend :thumb:

 

[[silent:arts]]

[quote author="mikeyB"]This baby runs nice and cool - regs should last a good while[/quote]
looking at your heatsinks I'm sure it runs cool :grin:
Mikey, nice build - and thanks for the pictures.
I just screwed it in the growing rack :thumb: :green:

 

[Purusha]

I am trying to find the recommended values for D-AOC power transformer (toroid). Anyone has it saved near by? :grin:

 

[jrfred453]

Finally got my D-AOC in a presentable state.

Thanks Volker, Analog, and Chae!

If anyone has one of those Sifam meters that works, please let me know.

 

[seavote]

only my 3rd DIY so please bear with me.
! i noticed more than a few builders have mounted their psu heatsinks off the pcb to larger heatsinks. i was wondering if the prototypes were built with the suggested on board heatsinks and if any problems have occurred from overheating?
i salvaged the larger sized hearsink from a switching power supply i pulled from some medical equiptment.

the heatsink came with the "clamp piece you see in the photo and the "sleeve"(in my hand in one photo) that covers the regulator.
What does this "sleeve" do. do i use heatsink paste with the sleeve, toss the sleeve and use paste or use the sleeve and forget the paste?

thanks

 

[[silent:arts]]

Finally got my D-AOC in a presentable state/quote]
nice one - I first thought it is just another purusha case, but while adding it to the D-AOC rack I realized it is your own :thumb:

[quote author="seavote"]i was wondering if the prototypes were built with the suggested on board heatsinks and if any problems have occurred from overheating?

mine was build with the suggested heatsinks, but the heater regulator went too hot in my opinion, thus I mounted that one to a larger heatsink to the case. the two other heatsinks are fine in my unit.

[quote author="seavote"]the heatsink came with the "clamp piece you see in the photo and the "sleeve"(in my hand in one photo) that covers the regulator.
What does this "sleeve" do. do i use heatsink paste with the sleeve, toss the sleeve and use paste or use the sleeve and forget the paste?[/quote]
the "sleeve" isolates your regulator from the heatsink. it may be from a material where no paste is needed.

 

[seavote]

OK off board for the one regulator. thanks for the repy.
i'll be building a Doac with no bypass switch. the third or PSU3 voltage will only be needed for lighting the meters. what is a good voltage for this? it there a standard voltage? also i used the C12 and C13 values listed in the BOM. they should be fine yes?thanks

 

[Sredna]

My B+ regulator actually got wery hot so I used a larger heatsink mounted on the chassis. Safe is better.

Regards,

Anders

 

[[silent:arts]]

[quote author="seavote"]i'll be building a Doac with no bypass switch. the third or PSU3 voltage will only be needed for lighting the meters. what is a good voltage for this? it there a standard voltage? also i used the C12 and C13 values listed in the BOM. they should be fine yes?thanks[/quote]
this just depends on the secondary AC you have on your transformer

 

[[silent:arts]]

Hey Anders,
sounds like you have a finished build ???
show us some pics :green:

see you soon