*** The DIY Audio Thread ***

[Founder_film]

Got my transformer wired up tonight. Getting a steady 20V AC out of each secondary . I also built myself a bulb mains lead.

Nice work Justin looks very pro, might be coming to you for some help when I make my interconnects!!

 

[J1234]

Thanks ^

Started the case work for my Starving Student tonight, coming along nicely. Hopefully the tubes and caps should be arriving tomorrow.

Pics:

This picture makes the volume knob look a lot closer to the switch than it is, but it's in the middle.

 

[adamau5]

looks good mate!

 

[J1234]

Great! Still no tubes

 

[gurusan]

Sorry to hear that.

Anyway I just finished the casework finally on my SS millet.

Panasonic FC and Nichicon PW power caps, Nichicon Muse ES output caps bypassed with Wima MKP10 .33uF, all Dale RND55 resistors, Sylvania Tubes...sounds really very good!

 

[adamau5]

A bit of dolmio and that would be lovely!

only joking.

I do thin you could tidy that up though.

I always draw my wiring out on paper first - takes ages but shorter wiring = less noise.

 

[adamau5]

I did a bit more to the Bijou today.

I socketed the bias resistor so i can roll tubes more easily. I also swapped some output bypass resistors to obbligato golds..... stunning things!.

Put in some russian 6n1p tubes, fired it up. Nice change in sound, less warmth, more clarity, dare i say it... a bit more solid state.

 

[J1234]

I always draw my wiring out on paper first - takes ages but shorter wiring = less noise.

Good to hear this, that's exactly what I've done for mine. Wasn't sure if I was wasting my time.

 

[adamau5]

When you start out yout tend to spend ages on case work and building.

After 5 or 6 projects you spend a lot longer on preparation, and a lot less on the building.

 

[J1234]

Yeah, case work is taking a lot longer than I expected. Just need to mount the tube sockets when they come and I can get on with it.

I don't suppose anyone knows where I can find a data sheet for the 19J6 tube sockets, the 7-pin chassis mount ones [These are the exact ones I bought.]

 

[Founder_film]

Got my rectifier boards built today. Then wired it all up and gave it a test. +/- 27 V DC :

Already mounted the boards in the enclosure properly and started wiring up the amplifier boards. Very close to finishing now but I had to stop to eat.

 

[Founder_film]

I have finished!! Checkout the photos of testing and the amp all finished with the full enclosure:

I am very pleased with the result. The sound is very crisp and clear. The bass is a bit lacking but I think thats a combination of small drivers and the fact they are 4 ohms so the amp can't output its full power.

I will purchase some new full size bookshelf speakers when I get some more money to spare.

Going to make myself a passive pre-amp next, but again I need some spare cash. The interconnects might be a cheaper option.

Justin where did you source your materials for your cable? Also did you follow a tutorial?

 

[J1234]

Justin where did you source your materials for your cable? Also did you follow a tutorial?

I got all my bits from Canford. They sell everything including heat shrink and sleeving.

I didn't follow a guide as such, just looked at the 'how to build a interconnect' thread on Head-fi for some guidance. It's fairly straight forward to do.

 

[Sp00n]

I was thinking about replacing the drivers in my cheapo eltax concept 200's but I can't seem to find anywhere that sells them, is there a good place for things like that?

 

[Founder_film]

I got all my bits from Canford. They sell everything including heat shrink and sleeving.

I didn't follow a guide as such, just looked at the 'how to build a interconnect' thread on Head-fi for some guidance. It's fairly straight forward to do.

Cool thanks for the link. Seems like a piece of cake. Will give it a go soon.

 

[J1234]

KING OF THE CASTLE (in borat voice)

Where did you get those feet from?

 

[MikeHunt79]

Hey guys, long time no post, been really busy recently...

Anyway, I'm having to use my DCX2496 as a DAC, and I've got a 4 gang pot wired up on it's output to control the volume.

It works fine, but the only thing my Amp9B is very sensitive, and the DCX2496 gives out pro-sound voltages (higher than consumer level).

Now, this means that my volume pot goes from silent to earsplittingly loud in a quarter of a turn...

I was wondering if I could make the pot have less gain with some in-line resistors somehow?

 

[Dr.EM]

Founder film;

Nice looking amp! The 1875 is a nice little chip, I built an amp with the TDA2030AV which is similar and it gave impressive results.

You may be finding less bass impact through using relatively small capacitors, yours look like 4700uf tops? Also good grounding and low resistance power connections will help. I have built all my recent power supply boards with copper clad boards. The simple layout needed can be scored with a knife and the breaks created by pulling the track up with tweezers, its easy with the right tools and technique.

Heres some pictures of a standard capacitor board made this way, the bridge on there is actually part of a mains loop breaker and is not the rectifier; the small PCB is a speaker protection board mounted there for convenience




Do you yet have your chassis grounded? You should do this if you haven't and ideally connect circuit ground to earth too but this can cause problems with earth loops (hence the use of the breaker on mine, if you using your amp with portable mp3 players or most CD players you shouldn't need a breaker, using with a desktop PC you would do).

 

[adamau5]

mikehunt - have you got a linear pot? should be audio taper (log). and, are you having to turn your pot clockwise for more volume? if its linear then just replace it with a log pot.

 

[MikeHunt79]

mikehunt - have you got a linear pot? should be audio taper (log). and, are you having to turn your pot clockwise for more volume? if its linear then just replace it with a log pot.

Sorry, forgot to mention what pot it was... It's an Alps Blue, I've just looked up the model number and it's 20K log. I think the problem is that the DCX2496 gives out too much voltage on it's pre-outs. I can't find a switch to lower it either...

My setup is like this:

PC source > SPDIF > DCX2496 > Quad gang pot > 41Hz Amp9 basic > 2.1 speakers