| digi01 |
Revised repeatedly,optimization...I finished this PCB project at last.Thanks for 1audio, carlmart, jcarr very much.please look at the primitive scratch for more detail:smash: :smash: :smash: :D
I have set up some 'leap' points on pcb, it is joined that it is convenient to expand.bridge or parallel is easy.
yours
-digi |
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| digi01 |
:hot:
MUSE and ELNA-bp caps,HOLCO and DALE resistors. |
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| thomas997 |
Looks good.
Now send me some for free :) |
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| otaku |
| Looks very nice!! Can I buy some? |
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| carlmart |
| quote: | Originally posted by digi01
Revised repeatedly,optimization...I finished this PCB project at last.Thanks for 1audio, carlmart, jcarr very much.
I have set up some 'leap' points on pcb, it is joined that it is convenient to expand.bridge or parallel is easy.
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The pcb looks very, very good. Just three things, some mentioned on one previous mail of mine:
1) The tracks to +V and -V should be wider. If the pins are N/C, as the data specifies, you can use that area to make the track wider, on the top or bottom.
2) Provide some area on the bottom to use an SMD output resistor, like the Dale type that Rowland uses.
3) You should bypass the mute pin to ground, like the datasheet specifies. I didn't use it on my first prototype, but it's provided on my revised pcb.
The rest is very good. Congratulations! Is it possible to get some, paying of course?
Carlos |
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| digi01 |
carlmart,thanks for you helpful suggestions again;)
Pins of LM3886 arranges very inconvenient,when you lay out with fat tracks,those NC pins is really a hell:whazzat:its mute pin and gorund pin let the things become complicated too.
btw,please check you mail:D
digi |
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| rabstg |
Hi digi-
"for more infor pls mail to vcgft@yahoo.com.cn"
Is this contact handling a "group buy" or outright sales of these boards?
And the boards look great. Only request I have is for a separate mounting hole on the supply capacitor side to suport that end of the board.
Also, are these boards available with the regulartor boards on this post?
http://www.diyaudio.com/forums/show...&threadid=38636
Thanks Troy |
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| carlmart |
| quote: | Originally posted by digi01
carlmart,thanks for you helpful suggestions again;)
Pins of LM3886 arranges very inconvenient,when you lay out with fat tracks,those NC pins is really a hell:whazzat:its mute pin and gorund pin let the things become complicated too.
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Digi01,
We can't get away from some complications when they should be dealt with. The bypass capacitor on the mute pin should be there. Find a way to lay a track on the side, need not be wide, and bypass it to a ground, any ground.
Recently I read on this forum that N/C pins are really so: they are not connected.
If that is so then you can put a pad, solder the N/C pin to it and still put a track or fill over that same area. When I designed my pcb I simply snipped the N/C pins away and used their area for more copper surface.
The -V and +V tracks should definitely be wider, and it shouldn't be hard to do it. I did a single sided pcb for all this, with no wire bypasses, and everything went fine.
Carlos |
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| digi01 |
Hi Troy,I will start another thread for group buy soon.Now, just share with you my DIY precious..hehe...:D
the regulated psu lay out projects is sitll in progress.the board cooperates with my 3886IGC.
| quote: | | Recently I read on this forum that N/C pins are really so: they are not connected. |
Carlos,it is really?Soooooo pretty tidings:hot: :hot: :smash: I will test it. |
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| peranders |
| Nice work digi but where have you the signal and speaker ground? I see only one hole for this. |
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| digi01 |
Thank you,please look at the attached pic for signal trace.
digi |
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| digi01 |
| here are standard PCB hook method,need 2 boards for dual mono stereo amp buliding. |
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| rabstg |
Hey digi01-
The board looks great!
You mentioned earlier a group buy, so I was checking to see about when that was planned, and if I could request the regulator boards be an option in the group buy.
I would "hope" the options would include:
1. PCB LM3886 IGC bare
2. PCB LM3886 IGC + components
3. PCB LM3886 IGC bare + regulator PCB bare
4. PCB LM3886 IGC, regulator PCB + all components
Or if you have a web site, just have each set as an item:
1. PCB LM3886 IGC
2. PCB Regulator
3. PCB Buffer ":-)"
4. Components, LM3886 IGC
5. Components, Regulator PCB
6. Components, Buffer PCB
7. Shipping
Any chance of a buffer circuit being available also? I am planning on paralleling 2-4 of the LM3886's for a more robust output and the buffer would help drive the paralleled inputs.
Thanks again and I look forward to trying them,
Troy |
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| digi01 |
rabstg,thanks for your helpful suggestions.
Sorry for so slow reply.because I am very busy during weekend.
the 3886IGC is available now,it is finished.
the regulator PCB is in progress,may take about 6days available.when finished it,I will start a group order.
about the buffer circuit,I have a final project.but it is based on the tube,no common indeed:o
I am making a chip buffer project now,it is minimum,double side PCB board,including regulat psu parts.I set up it may be used for paralleling or bridging my 3886IGC.
another,I have lay out a BPA200 PCB board,it is based on the original NS bpa200 article,with DC serv.I wonder anyone interesting it,maybe can go ahead...
glad for your appreciation:)
yours digi |
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| peranders |
| quote: | Originally posted by digi01
another,I have lay out a BPA200 PCB board,it is based on the original NS bpa200 article,with DC serv.I wonder anyone interesting it,maybe can go ahead... |
Have you built any prototype or is it only in the computer? |
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| digi01 |
| quote: | Originally posted by peranders
Have you built any prototype or is it only in the computer? |
it's only a PCB project,double side board,the size is 149mm x 33mm.I have optmize it again. |
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| Nisbeth |
Hello digi,
That tube buffer looks interesting, can you post a schematic? Will you have pcb's available for it ?
/U. |
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| digi01 |
Nisbeth,
here are tube buffer sch file.
and very sorry,the PCB board is not available :) |
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| Nisbeth |
OK, thanks. Which tubes can be used for the buffer?
/U. |
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| digi01 |
you may use 6DJ8 or 6922 for the buffer.it is so simple and so good.
enjoy;)
digi |
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| samsagaz |
digi01 how u build so professional PCB? thats amazing :)
wich method u use? u have some machine to do that?
can u tellme some link abt the hardware or how u build that stuff?
thanks |
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| peranders |
| He uses regular pcb CAD software which can create Gerber files. Those files are then given to a pcb factory. |
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| samsagaz |
| oh, ok, so he didnt made the board, he just design it |
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| goering |
Hi digi,
one newbie question about your design, which BTW I think looks really very nice: what goes into the null pads and what does it do?
thanks |
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| digi01 |
thank you.
I like substantial pads on both sides of the board for any connections. the null pads for installation unused pins of LM3886.those NC pins do not need pads but they need holes. |
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| rabstg |
Hi digi01-
I think he was referring to the three holes with the silkscreen rectangle around them labeled "NULL".
The place is next to the mounting hole.
My guess was a 10 turn pot since it is labeled with an Ohm value and has 3 holes.
Thanks,
Troy |
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| digi01 |
thank you rabstg,maybe you are right:)
| quote: | Originally posted by goering
Hi digi,
one newbie question about your design, which BTW I think looks really very nice: what goes into the null pads and what does it do?
thanks |
"null" in chinese sounds like "turn".
you can put a 10 turn pot(220k) on the "NULL" pad.it is set up to adjust output dc drift.can short it in normal used. |
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| digi01 |
here are sch file:
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| Tim__x |
Wanna post a high resolution layout? As in a seperate image for top, bottom and silk-screen layers. Pretty please? :angel:
Edit: On a side note, how wide is the offset adjust range? |
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| digi01 |
ok,pdf file attached:)
1st,top layer |
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| Tim__x |
| Thank you very much. |
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| digi01 |
here is 3886 gianclone partlist:
2 PCBs for stereo amp:
3886igc PCB *2
1000uf/50v *4
LM3886 *2
220k 1/2w *2 (gain setting)
10k 1/2w *2 (gain setting)
20k 1/4w *2 (mute)
0.1/5w *2 (option,can be shotr.for output)
220k trim *2 (option,can be shotr.for dc offset)
heat sink,screw,hook wires.
enjoys |
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| rabstg |
Hey digi01-
Quick question.
The dimensions of the board, they are 1800 x 1720 Mils. That can't be mili METERS can it?
Thanks again in advance,
Troy |
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| peranders |
Mils is standard in the pcb cad business and is 1/1000 of an inch.
1.8 x 1.72 inch :D
... and the reason for using mils is that the programs in the early days had 32000 x 32000 or 32768 x 32768 as max values of the coordinates. This gave us 32 x 32" as max board size. Worth noting is the program "Boardmaker(?)" or something had 4 x 4 billions in max values. The resulation was 0.1 um and was used for silicone chips. It ran on Mac in the 80's and could be connected to a mainframe. Those where the days. |
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| rabstg |
Hey peranders-
Rgr that and thanks for the clarification.
As the saying goes, "more about Penguins than I wanted to know".
But thanks for the history.
Troy |
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| digi01 |
BTW,100mil is standard in the common electronic parts.
for example:
the caps leg always in 200/300/400(mil) and 100mil=2.54mm.
another:
like the holes board,the distance between every hole is always 100mil.
-digi |
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| wim |
I am building the amp with the PCB's of Digi01 and can't find the capacitor (Cin) from 4,7 mu with a distance of the legs from 5 mm of 10 mm. All what i can find is far too big.
Does anyone know were to get is???
Thanks a lot. |
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| rabstg |
Hi Wim
If you look at Zangs picture his cap is raised. I don't know if the board was designed to have the cap sit on the PCB.
I just rx'ed a new set of boards from Zang and they have pads for surface mount components.... I may go that route.. |
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| wim |
You are right Rabstg, it is mounted above the board. By the way, it looks like a bipolair capacitor (Black Gate).
Thanks anyway for your reply. |
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| kzar |
| Hi I was wondering if there are any of these pcbs kicking about as I was thinking of making a stereo amp? |
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| digi01 |
Hi kzar and all,
the 3886igc boards are not available now.I am planing to make a updated version.
any recommand input are welcomed.
Zang |
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| Evilsizer |
| quote: | Originally posted by digi01
Hi kzar and all,
the 3886igc boards are not available now.I am planing to make a updated version.
any recommand input are welcomed.
Zang |
none that i can see ... still tring to figure out why mine arent working... i might buy some new lm3886s to see if the ones i got by chance were bad...everthing else on the boards are correctly installed checked them over 3 time before soldering and 3more times afterwards... only thing left is the IC. |
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| kzar |
| Hmm what circuit would be a good one to make then? I liked the sound of the gain clones because they are supposed to be easy to make but sound good. I would like somthing better than my mission cyrus one basicly. Thanks |
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| rabstg |
| quote: | Originally posted by Evilsizer
none that i can see ... still tring to figure out why mine arent working... i might buy some new lm3886s to see if the ones i got by chance were bad...everthing else on the boards are correctly installed checked them over 3 time before soldering and 3more times afterwards... only thing left is the IC. |
Steve @ Apex . jr sells them cheap. Where are you in TX? Email direct with answer.. stgrab@yahoo.com
I have some of these boards still unassembled, and we can build / photograph each step and component used. |
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| Evilsizer |
| quote: | Originally posted by rabstg
Steve @ Apex . jr sells them cheap. Where are you in TX? Email direct with answer.. stgrab@yahoo.com
I have some of these boards still unassembled, and we can build / photograph each step and component used. |
cedar park...10mins outside of Austin.. well im using pretty much all dales for resistor and miss ordered some parts and had to reorder... let me find my invoices and ill post what i used...
im leaving in a few hrs so i wont be able to get to it ... |
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| rabstg |
| I'm going to E-Rock next weekend to climb. Need me to bring a board or 2 to compare with yours? |
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| Evilsizer |
| wont be able too i work retail this was one of the rare times i had the whole weekend off.. but here soon i will get pics taken... |
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| digi01 |
| quote: | Originally posted by wim
I am building the amp with the PCB's of Digi01 and can't find the capacitor (Cin) from 4,7 mu with a distance of the legs from 5 mm of 10 mm. All what i can find is far too big.
Does anyone know were to get is???
Thanks a lot. |
I have realized this issue.I will make enough room for the ver#2 3886igc. |
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| peranders |
| quote: | Originally posted by wim
I am building the amp with the PCB's of Digi01 and can't find the capacitor (Cin) from 4,7 mu with a distance of the legs from 5 mm of 10 mm. All what i can find is far too big.
Does anyone know were to get is???
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You will probably not find it. Normally 1 uF/63V is the limit for small caps. |
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| Nordic |
Why is there an input and output coupling cap in this amp?
Also if my buffer has a 1uf cap on the output can I skip the input cap? |
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| peranders |
| quote: | Originally posted by Nordic
Why is there an input and output coupling cap in this amp?
Also if my buffer has a 1uf cap on the output can I skip the input cap? |
Where is the output coupling cap? Hardly in digi01's pcb? |
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| Nordic |
| Sorry at a glance it looked like a 1uf cap on the input and 4.7uf on the output... |
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| mercator |
| quote: | Originally posted by digi01
the 3886igc boards are not available now.I am planing to make a updated version.
any recommand input are welcomed.
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I have a few of the first boards, very nice indeed. The only suggestion I would make would be to move the chip a little further toward the edge of the board. I found that I had to grind off the edge of the board in order to mount it flush to a heatsink.
/Dave ... still a loooong way from that 6 ch amp I decided to build in 2004. |
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| Nordic |
| What is the DC tab for? |
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| digi01 |
| quote: | Originally posted by Nordic
What is the DC tab for? |
its a node for work together with mine preamp. |
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| digi01 |
| thank you mercator,I have realized this issue. |
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| digi01 |
Hi all,
here is a updated version inverting gc I am working on.
the changes below:
*star grounding concept
*compact layout
*universal pootprint
enjoys,
Zang |
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| wim |
Zang, the last boards you send me were the "updated version", but there isno BOM available.
Can you plese post a BOM of this version?
Thanks a lot. |
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| digi01 |
ok,the bom list below:
C1,C2 -----2200uf35V
Cc ----------0.1uf63V
Ci -----------4.7uf160V ,I use ero 4.7uf63V for Ci
Ct -----------0.1uf63V
Rm ----------10K 0805 smt packaged
Rf ------------220K smt
Ri ------------10K smt
Ro -----------0.1ohm 3W
Rt ------------220K adjustable
LM3886 chip
wires
2 x PCB standoff
heatsink
2x18VAC 100VA transformer
Zang |
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| wboyd |
Hey Zang, are these boards still availabale? I would love to try a set...Just tell me how and how much and I would be happy to order a pair.
Thanks,
Wayne |
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| digi01 |
wayne,
I have the pcb available.you can order from my website.I would like including all smt parts.
Zang |
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| Evilsizer |
Hey digi!
nice to see you still helping out other DIY'ers.
Few Q's for ya.
What improvments are seen with this new PCB over the first ones you did?
sorry to say from a new job and lack of time i havent been able to build my BPA-200 with your boards i bought from you.
As well guys Digi01 is a great person to buy from, have no regrets when you do. Im in Texas and it took roughly 2wks to get from him to me. |
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| digi01 |
Hello Evilsizer,
Thank you for your nice words.
The new version is a compact device.the feedback and the others resistors are all 0805 smt packaged,it will get extremely signal route.the bigger parts C1,C2,LM3886 and coupling cap will perfect fit its station.more gnd connection trunks.
kind rgds,
Zang |
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| AndrewT |
Hi Digi,
is the inverting 3886 PCB available yet?
I see no prices or ordering information on www. |
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| wboyd |
| This is true...I went to your site and did not see a "Buy Now" button for the 3886. |
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| Evilsizer |
| im a tad slow some times, whats you site address digi? |
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| AndrewT |
Hi Slow at times, :D
click his www button.:cool: |
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| Evilsizer |
| quote: | Originally posted by AndrewT
Hi Slow at times, :D
click his www button.:cool: |
Server not foun
Firefox can't find the server at www..com.[/url
*...www.example.com
* If you are unable to load any pages, check your computer's network
connection.
* If your computer or network is protected by a firewall or proxy, make sure
that Firefox is permitted to access the Web.
getting that when i click your link as listed "www./" is not a site address.
hmm well last time i looked his site was not in his sig but its there now. |
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| theAnonymous1 |
Firefox = Failed?:smash: :smash: :smash: :smash:
IE works just fine.:cool:
www.assemblycraft.com |
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| Evilsizer |
| take a closer look andrew t's link... thats the one i was using. |
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| digi01 |
to all,
assemblycraft.com is my new site,and i have built a album that is a collection of my hobby.
i plan to offer a full kit of 3886igc.please wait for a couple of days i will add the button on the page.
Zang |
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