Jump to content

DIY audio: what are you building?


Recommended Posts

My latest cobbled together amplifier has been running without smoke for a month or so now. Not sure if it will ever get a proper case or not. It runs really hot - specifically the output coils get much hotter than I'm comfortable with. Hypex say it's normal. Also, the connexelectronic SMPS is pretty noisy EMI/RFI wise - forget using this with a tuner. Shielding it didn't seem to make any difference. The Hypex SMPS I use with my UcD180s is dead quiet in this regard. Those issues aside, it sounds fine and is surprisingly punchy for such a lightweight. 

 

 

P1010242.jpg

  • Like 2
Link to post
Share on other sites
  • Replies 7.1k
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

Stereo Subs & Two Way Monitor Build   It’s been slow going on my two way monitor with stereo sub build but I’ve finally finished finished one of the two subs!!!   The subs are 10inch CSS drive

Thanks Pete Sure! Pretty much just used common spray acrylics (cans) for the whole job. Not shy of using 2k but just trying to save on costs.  After the cabs where routed i gave th

Finally finished my 6sn7 preamp. 😀 not a bad outcome considering 50% material was recycled. Thanks a lot mwhouston for schematics.

33 minutes ago, betocool said:

Never seen a cardboard amp before.

 

Heh - yes there's certainly better materials out there for amp chassis! 

 

The module is a UcD102. It's an oem module that's used in the NAD D3020. 

  • Like 1
Link to post
Share on other sites
My latest cobbled together amplifier has been running without smoke for a month or so now. Not sure if it will ever get a proper case or not. It runs really hot - specifically the output coils get much hotter than I'm comfortable with. Hypex say it's normal. Also, the connexelectronic SMPS is pretty noisy EMI/RFI wise - forget using this with a tuner. Shielding it didn't seem to make any difference. The Hypex SMPS I use with my UcD180s is dead quiet in this regard. Those issues aside, it sounds fine and is surprisingly punchy for such a lightweight. 
 
 
P1010242.jpg


Love your work Stevesie.
  • Like 2
Link to post
Share on other sites


Here is a blast from the past - a Silicon Chip phono stage (I have two other kits). Nice part is you can switch between three different EQ stages if you really wanted. Comes with a PCB and all the parts required. It uses the LM833 OPAMP but it can be swapped out for a OPA2134.

 

Apart from leaving a few parts off and installing the wrong cap in the EQ stage and having to play with the gain, all went well. The original idea was to have variable gain but a $2 pot in the gain stage of the second stage seemed a bad idea. It is a two stage preamp where Mimic is a single stage.

 

Sound is bright and immediate where Mimic is more about tone this one is about detail.

 

PC073552 (800x600).jpg

PC073554 (800x600).jpg

PC073555 (800x600).jpg

Edited by mwhouston
  • Like 3
Link to post
Share on other sites
2 hours ago, betocool said:

What's the input connector at the front and the top one in the back?

The front blue RCA is a battery test point so you don't have to pull the unit apart to test the battery. The back point is an earth for TTs with earthing wires.

  • Like 1
Link to post
Share on other sites


5 hours ago, mwhouston said:

The front blue RCA is a battery test point so you don't have to pull the unit apart to test the battery. The back point is an earth for TTs with earthing wires.

 

Very smart, if I may say so myself. Might Will have to implement that too.

  • Like 1
Link to post
Share on other sites
On 12/10/2016 at 2:43 PM, mwhouston said:

Here is a blast from the past - a Silicon Chip phono stage (I have two other kits). Nice part is you can switch between three different EQ stages if you really wanted. Comes with a PCB and all the parts required. It uses the LM833 OPAMP but it can be swapped out for a OPA2134.

 

Apart from leaving a few parts off and installing the wrong cap in the EQ stage and having to play with the gain, all went well. The original idea was to have variable gain but a $2 pot in the gain stage of the second stage seemed a bad idea. It is a two stage preamp where Mimic is a single stage.

 

Sound is bright and immediate where Mimic is more about tone this one is about detail.

 

PC073552 (800x600).jpg

PC073554 (800x600).jpg

PC073555 (800x600).jpg

Which kit is this? I've built a jaycar phono but with one opamp

  • Like 1
Link to post
Share on other sites


Looks like the one from Altronics

I built one of each to try and teach myself a bit more about diy.

 

I did add the OPA2134 op amps to the Altronics one. I need to go back to the LA833 now that I know a bit more and hear what differences there are.

Not very neat but they do the job.

 

 DSC03600_zpspyyikuxr.jpg

Edited by btd
  • Like 1
Link to post
Share on other sites
On 10 December 2016 at 10:53 PM, betocool said:

 

Very smart, if I may say so myself. Might Will have to implement that too.

 

On 10 December 2016 at 10:53 PM, betocool said:

 

Very smart, if I may say so myself. Might Will have to implement that too.

Remember when dealing with OPAMPs you will generally have a split PS. I earth (signal earth) my enclosures so the outside of the blue RCA is the earth between +/- rails. The centre of the RCA is connect to the positive rail. When the preamp is on you will only ever read half the battery voltage. When off you will see close to full battery voltage. You cannot conect the negative rail to the outside of the RCA. You will short the batteries. 

 

The way I get a differential PS from series 9V batteries is with a resistive network where the centre point is ground. Two 220uf caps sit across each resistor (2 X 4.7K) to provide a clean +/- voltage. This only works with low current builds but works well and cheap and easy to implement.

Link to post
Share on other sites

@mwhouston Mark, I was refering to the idea of having an external point to measure batteries, pretty smart. I'm going to use a 9V battery as startup power for my power amp design. I hate amps that do not turn off completely, so the battery will initially power a microcontroller that does the whole startup shebang and turn on the relay to mains power. Then the battery is off the grid. Useful to know when to change batteries. And the whole thing came because I want to turn on the damn thing with a pushbutton, not a switch.

 

I still have a lot to go though... been slow and Xmas coming and rellies means I will be about three weeks off DIY.

 

 

  • Like 1
Link to post
Share on other sites


G'day all, having built both phono stages over the years, my feeling is that it is the different RIAA networks that give each phono stage their distinctive sound.  I simply changed the RIAA network in the Jaycar two op amp design to the same values as used in the Bruce Heran/ Mimic design which now has the easy/smooth sound of the Bruce Heran/ Mimic design.  Regards, Felix.   

  • Like 2
Link to post
Share on other sites
14 hours ago, catman said:

G'day all, having built both phono stages over the years, my feeling is that it is the different RIAA networks that give each phono stage their distinctive sound.  I simply changed the RIAA network in the Jaycar two op amp design to the same values as used in the Bruce Heran/ Mimic design which now has the easy/smooth sound of the Bruce Heran/ Mimic design.  Regards, Felix.   

Well I have room for one more RIAA network so I could install it and choose between the two. I'm hoping to get another to come and have a listen to see what they think. I did a quick A/B with my well loved tube phono pre and thought there may not be much in it. More listening today and back on my tube power amp, the sound of which is better known to me. So we'll see.

Link to post
Share on other sites
On 12 December 2016 at 6:03 PM, catman said:

G'day all, having built both phono stages over the years, my feeling is that it is the different RIAA networks that give each phono stage their distinctive sound.  I simply changed the RIAA network in the Jaycar two op amp design to the same values as used in the Bruce Heran/ Mimic design which now has the easy/smooth sound of the Bruce Heran/ Mimic design.  Regards, Felix.   

Well I have room for one more RIAA network so I could install it and choose between the two. I'm hoping to get another to come and have a listen to see what they think. I did a quick A/B with my well loved tube phono pre and thought there may not be much in it. More listening today and back on my tube power amp, the sound of which is better known to me. So we'll see.

Link to post
Share on other sites

Well want a difference a cap makes. The Silicon chip 2006 phono stage I recently assembled never really sounded 100% complete. Reading the notes with the kit they talk of the buffer stage being a HF filter. What they were referring to is it is a rumble filter. There is a roll off at 20Hz.

 

The kit was designed with the thought that TTs were never gong to come back in 2006. And you were using you father's old TT. And convert all your old worn LPs to mp3s - yuk!. So a rumble filters "may have" been a good idea. Not!

 

By changing the 1uf NP coupling cap to a 2.2uf cap drops the roll off to 10Hz. Perfect. The bass is back. Not only is the bass back but the whole preamp is rich sounding and vibrant where before it felt a little strangled.

 

And it is a fabulous MM phono stage. And I have three more kits. Lov'n it!

  • Like 1
Link to post
Share on other sites

 G'day all, yes that's interesting as that additional bass roll off didn't impress me either, I removed the requisite filter components and bypassed it completely.  I concur....much better!  Regards, Felix. 

  • Like 1
Link to post
Share on other sites
3 hours ago, 125dBmonster said:

Nice work Mark.

Might build a pre amp next, got a spare kit ?

Mate, sure have. You can have  it for what I paid for it in 2006. I'll even throw in the better interstage caps to give you the extended bass.

 

And at no additional cost, I'll give you the wiring spec to make it battery powered. But the kit includes full rectification and dual +/- 12V regs so you can run it from a AC plug pack. PM me. 

 

I think it just sounds bloody excellent - aggressive and detailed. And I always wanted a LM833 based phono preamp. The chip has a bipolar front-end where the OPA2134 has a jFet front end. Different sound, difffernt prentention a whole new feel to the music. Lov'n it.

 

 

Link to post
Share on other sites
On 12/14/2016 at 2:56 AM, mwhouston said:

Mate, sure have. You can have  it for what I paid for it in 2006. I'll even throw in the better interstage caps to give you the extended bass.

 

And at no additional cost, I'll give you the wiring spec to make it battery powered. But the kit includes full rectification and dual +/- 12V regs so you can run it from a AC plug pack. PM me. 

 

I think it just sounds bloody excellent - aggressive and detailed. And I always wanted a LM833 based phono preamp. The chip has a bipolar front-end where the OPA2134 has a jFet front end. Different sound, difffernt prentention a whole new feel to the music. Lov'n it.

 

 

Excellent, your on . :party

PM in mail 

Cool battery powered pre, I am guessing similar to the mimic with a split, 24v supply ? Go easy I'm a newbe

Cheers

Link to post
Share on other sites
3 hours ago, catman said:

 G'day all, yes that's interesting as that additional bass roll off didn't impress me either, I removed the requisite filter components and bypassed it completely.  I concur....much better!  Regards, Felix. 

There is a calculator on the 'net which easily calculates capacitive impedance (reactance) based on frequency and capacitance. All I did was play around with varying capacitance until I got 7.5Kohms at a much lower frequency, a -3db drop. 

 

With a 2.2uf NP in place of the 1uf cap the -3db roll off occurs about 10Hz. That easy.

Link to post
Share on other sites

A qik refresh for some old diy bookshelf speakers i posted a couple yrs ago,

Been infatuated with the look of the Q acoustic range of rounded edge
speakers specialy in white gloss!

The old square wood veneered boxes get the flick for a more modern look and added some diy magnetic grills!


Drivers are the old Vifa D25AG tweet P17WJ woof  combo.... great value for a sub $50 pairing!     gotta love jaycar runouts.

 

 

1 (9).jpg

1 (8).jpg

1 (11).jpg

1 (4).jpg

1 (10).jpg

1 (12).jpg

1 (13).jpg

1 (15).jpg

  • Like 9
Link to post
Share on other sites
A qik refresh for some old diy bookshelf speakers i posted a couple yrs ago,
Been infatuated with the look of the Q acoustic range of rounded edge
speakers specialy in white gloss!
The old square wood veneered boxes get the flick for a more modern look and added some diy magnetic grills!

Drivers are the old Vifa D25AG tweet P17WJ woof  combo.... great value for a sub $50 pairing!     gotta love jaycar runouts.
 
 
1 (9).jpg
1 (8).jpg
1 (11).jpg
1 (4).jpg
1 (10).jpg
1 (12).jpg
1 (13).jpg
1 (15).jpg

Very tidy looking little speaker mate. Well done!
  • Like 2
Link to post
Share on other sites

Thanks guys :D got the weekend pretty much to my self so had a good run @ getting these knocked over.

 

I really really like the sound they punch way above thyr budget. Got the second unit painted and assembled, both still need a good chop and polish to shine. But as they are only acrylic i'll let them sit for another month or so.

Finished the second magnetic grill and covered them both. I used yesterday to run them in on the main system and try some fine tuning on stuffing and port lengths.  They seem to sound best "well stuffed" and a short port.

 

Then moved them over to the new home on the ent system. The stands also got a sand and good splash of white.

I'm thinking next might be some diy stands.   Anyways heres a ton of piccys :D

 

 

 

 

5.jpg

1.jpg

2.jpg

16.jpg

17.jpg

6.jpg

7.jpg

8.jpg

9.jpg

10.jpg

11.jpg

12.jpg

13.jpg

14.jpg

18.jpg

19.jpg

20.jpg

15.jpg

Edited by St_Luke
  • Like 6
Link to post
Share on other sites

Thanks Pete :)

Sure!

Pretty much just used common spray acrylics (cans) for the whole job.

Not shy of using 2k but just trying to save on costs. 

After the cabs where routed i gave them a quick sand with the orbital using 200 grit dry.

Then a quick sand with some 320g dry.

Next was to hit em with some primer,nothing to flash just a dusty few coats.

Next was to start hi filling(spray putty) again acrylic can paint.

I pretty much loaded em up (really loaded em up!) 4-5 heavy wet coats and let this sit overnight.

I'd usually say to let sit longer but we had a really hot day and the cab was left to sit in the sun for a good 10 hours.

Next was to dry rub the hi fill using 400g to get it flat, being care full not to rub thru to the wood.

Then a slow chop with some wet and dry 1200.(wet being care full not to rub thru and swell the wood)this get the primer filler nice and flat for final paint.

The paint again was just gloss white can acrylic.

Next was to hang the cab and paint, i used a full can of the gloss white per cab.

This gave about 6 full heavy wet coats.  Again i got lucky Saturday was a hot stinker and paint was drying quicker then i could apply the next coat.  (This cab i'll let sit for a few weeks). 

This time allows the paint to settle and "sink back"  then i'll decide if i will chop and buff or maybe a couple more "flow coats" then chop and buff.

The one you see in the pics getting a buff was the cab painted last week.

1500 wet and dry is used to get the white paint flat before using the buffing compound and buff.

I used a watered down G3 compound.

All the paints were brought @ Super cheap auto.

I used the SCA brand,

2 x SCA spray putty          $24
1 x SCA primer                 $12
2 x SCA Generic white      $24

2 sheets 320
2 sheets 400
1 sheet  1200 w/d
1 sheet  1500 w/d

Generic cutting/buffing compound.

(Being acrylics i will also wax @ the very end)


Wood, 1 sheet 25mm MDF...   

 

Drivers are the "ever lasting"   Vifa D25AG tweeter Vifa P17WJ-00 pairing. 

The most recent brought from jaycar runout stock. 

Vifa P17WJ-00  @ 29.00 each
Vifa D25AG     @ 19.00 each

All the x-over parts i got from Speaker Bug....  about 50 all up from memory.

Magnets cloth and misc   $10
Amazing Value and sound for a project sub $350! :)

 

After thoughts,  i may still use a 2k clear over the top..... i'll just wait and see how the well the acrylic shines up.


 

1.jpg

2.jpg

3.jpg

4.jpg

5.jpg

6.jpg

7.jpg

8.jpg

9.jpg

10.jpg

11.jpg

12.jpg

14.jpg

  • Like 15
Link to post
Share on other sites

monster amp build nearing completion, may even have these going later on today., that is,  all 6 that occupy the bench space.

Project has taken the better part of 6 months since ordering the first parts. 

Merry Xmas to the DIY Gang  !!.

IMG_1130.JPG

IMG_1132.JPG

IMG_1133.JPG

IMG_1129.JPG

Edited by Guest
Link to post
Share on other sites
  • Recently Browsing   0 members

    No registered users viewing this page.




×
×
  • Create New...