jtfoo

Wow !!! Very interesting! Thanks for sharing huangyong!

 

I wonder how much the CD-PRO2 transport kit cost Can start to build our own CD player.

 

I 'm also interested with the Step Attenuators, for SGD 35.- they are really a bargain.

 

Huangyong you can start to arrange a group buy, I can help with the plastic later.

I remember someone mentioned at diyaudio that the stepped attenuator fromdiyzone has pop noise with each turn. This is due to it's design of break before make. unlike the more expensive stepped attenuator which are make before make. But then where to get stepped attenuator so cheap, except the fake alps one.

Gilmore power supply??!!

Interested!!

But there is a problem of sourcing opa548 in singapore..

and the GIlmore PSU uses 4 5uF Solen Caps.

my experience tells me that add in 5uF of Solen Cap in the PSU will extent the high and soundstage.

Did he use Solen??, I didn't know, instead I got a few polycarbonate 4.7uF from Koba. I might change them to solen then.

He.. He.. sorry to ask, but I'm too lazy to browse headwize. Don't mind to give us the shortcut for the power supply?

 

Why you use META2 for the Jung multiloop? Why not the PPA one?

 

Thanks!

I omit the gnd channel buffering so it looks like a meta42. No distinction between input & output gnd, so much easier.

Here's the powersupply schamatics, taken from heawize, http://headwize.com/projects/showfile.php?...ilmore3_prj.htm

Jtfoo....what kind of topology that ur building ?... care to share ?

Rojak, abit of PPA, abit of meta42...

Biasing using PPA's method...Jung multiloop using meta42, power supply using Gilmore amp project in headwize,

Another point I thought, maybe you want to consider using a small multi-turn pot instead of the 100ohms. I'm in the process of building a opamp base preamp, and am considering this using the pot for biasing. That way I can adjust the biasing current.

IMHO, I think you can omit the BUF634 for the rail splitter, since you're already have a +ve and -ve voltage regulator, which should maintain the Vs+ & Vs- consistently. Morever without the BUF34, you're only limited by the current the regualtor can handle rather than the BUF634.

Wow, I never seen that casing in SLT. Looks solid and profesional I think I haven't browse SLT well enough.

 

Thanks for the info guys! I will try Martin and Bytetron to see what they have

Bytetron is in SLS, not SLT. She has other not so nice looking casing too. But to be honest, I don't really like the look of that casing, just that it's cheap and look better than most of the SLT casing. If got money I would go for the anodised silver aluminium, for more than $100 at Larry HiFi.

You'd be surprised. I bought a nice case from SLT for $29. It's like a small rackmount chassis about D32cm * W22cm * H10cm. Powder coated black and with a 2mm thick steel faceplate too boot.

All 6 sides + faceplate are held together by screws. It definitely doesn't look like a cheap case in any way at all. I guess you just have to look around more closely to find the gems.

Firefox,

Are you referring to this type of casing? Can get from Bytetron, 4th floor SLS. The auntie boss is friendly.

Hard to find any good looking casing at SLT.. try farnell for their hammond casing.

Are you leaving the 2 huge Nichicon gold tune lying there, or have you secure it with glue?

Finally finished my PCB.. But I'm shooting elephants with my drill. I'm using those gigantic 550W hand drill and find it diffcult to aim. Guess I have to spend a little extra to ge that mini electrci drill.

Thanks jtfoo!

 

Any other cheaper, smaller, and good pot beside the BLUE ALPS?

Try MArtin electronic also at Burlington.. They have cheaper OMEG brand. Don't know the price though.

Thanks for the tips! I've bought some OPA2134 from farnell as well as other components. I like this company Actually my company used to buy connectors from them, and I just forgot about Farnell when looking for elecronics components.

 

Well this is not my first time DIY, but probably will be the first time after I'm graduated... And that is more than 7 years ago

 

I saw (in catalogue) an ALPS pot (big one) especially for audio... wow, around SGD 47 per piece

 

Any suggestion for a good pot for volume control ?

$47 for the Alps blue very ex at Farnell. Go to Well Audio (Burlington Sq), Larry hifi(Peaples Park basement) or at Bytetron (4th flr SLS) at around $30++.

Try Farnell @ http://international2.farnell.com/SG/Welco...egistered.jhtml

If you're student and go down to Farnell at Tai Seng Rd personally, you get 10% discount upon showing your student card.

lol...why so ?

Come to tube stuff, Frankie is a nice fellow. But bring in amp base on sand, it was a different story.

But recent times he seem to have changed for the better. Had a rather pleasant experience when I told him I'm doing a sand project.

Hi Digi...

Nice to see you around here too. I've finished a zen amp using your board.. Good quality board.

Thanks again Jason..

I've just began playing around with the Eagle software. I notice that the drill holes of the resistors is a little too big, causing very little copper left on the pins hole. Any solution to reduce the drill holes of those resistors and small caps? I'm thinking of just use a ink marker to cover up the holes. Quite siong, as there are many holes to cover.

Mogami starquad microphone cable. Part number 2534.

Where can I buy them?

do you sell the SR325 alone?

Thanks Jason.. I may be tempted to try this myself. Some questions, how strong is the smell from the chemicals? I understand we're not allowed to dispose the chemicals down the kitchen sink or toilet, so how?

thanks... yup the other end is to the IEC socket.

btw what wld i be looking at if it were normal wiring? each earth, live and neutral cable chaining all the duplexes?

Yup, some distributor use cable or copper strip to chain all the outlet..

Assuming the other end leads to a single plug, then yes, it is star wiring.

Jason,

When can you start your PCB lesson? Though I may not venture into it, won't hurt to know something more.

So the yellow thingy is the same thing when I asked you why you tie rubberband around the transistors. So temp of both transistor are uniform..

yes, i have heard stacked opamps before. they sound good.

 

it is unlikely they fight each other especially if they are from the same batch...

 

 

hacknet,

If you recommend stacking opamps, which btw many people don't, it helps to put some word of cautions.

. Because you have to get matched opamps

. Unlike mosfet which can be matched via measuring Vgs, how do you matched opamps?

. Even on the same batch, chances of mismatched are still high.

. Stacking two opamps is already a gamble, now what's the probability of having 8 matched opamps, the number you recommend?

. It all boils down to predictability. Stacking two opamps don't guarantee it work, it just luck, taking from the same batch just increase your odds. Unlike buffers (e.d EL2001) where you take any good one and they can be stacked in numbers irregardless of batch, predictable results. Parallel opamps with output resistors are predictable.

. Result of opamps fighting each other can lead to opamp burn out. Damage opamps, very expensive if all 8 goes.

. And your disclaimer of 'try at your own risk, not responsible for any damaged'.

Circuit with stacking opamps, haven't seen one yet, probably you can share with us your circuit.

Parallel opamps, I seen a few and even on some application notes.

Parallel with master slave config, the Apheared47.

Very nice.. What are those yellow ting that you put around the transistors?

BTW, nice PCB and layout..