Macca's Stereo coffee LDR Build

[Figlet108]

Macca asked me to build his Stereo coffee LDR into one of the spare black acrylic cases I was selling.

Thought I'd post where I am with it:
- I drilled all the remaining holes in the case with a diamond core bit to get a clean cut
- attached the RCAs, on/off switch, power cable, volume pot
- glued down all the components in the PSU that need glueing

https://lh6.googleusercontent.com/-uNiNzd-VFAg/U5uJ2cHcymI/AAAAAAAADKs/63qx7OSjVYk/w957-h638-no/2014-06-13+23.50.27_resize.jpg
I left space for 2 more sets of inputs in case Macca wants to add them later.


https://lh5.googleusercontent.com/-cxCEPA8Tog0/U5uJ2jz24ZI/AAAAAAAADKo/DGB77CoWhC8/w957-h638-no/2014-06-13+23.49.02_resize.jpg
I was told off at Owston for gluing caps down and constricting the fail-safe bottoms, so now I glue them on their sides...


https://lh3.googleusercontent.com/-xiwfK-z4Drs/U5uJ2Qw1UFI/AAAAAAAADKk/LAcZujvwlXc/w957-h638-no/2014-06-13+23.48.35_resize.jpg
I temporarily stole that knob off something else so we can't use it for the final version. Looks good and chunky though...

So questions for Macca:
1) you need to choose a knob you like
I'm really struggling to find some nice big knobs, so if anyone knows of any big knobs please let us know.
This is the best I can find. (http://uk.rs-online.com/web/p/potentiometer-knobs/0499961/)

2) do you want an led, and if so where and what colour?


Tomorrow I'll wire it all up.

[Light Dependant Resistor]

Hi Jason
I have a few silver knobs pictured here on a cased build done for Niels over on the Lenco Heaven forum http://www.lencoheaven.net/forum/index.php?topic=13947.45
they are pretty chunky, let me know and I can post one to you.

Cheers / Chris12674

[Sovereign]

Nice one Jason,

[Figlet108]

Chris, that's a very kind offer and certainly a nice knob.
It's really up to Martin, but it seems wrong to have you post a knob from NZ when surely the UK must be full of suitable knobs, if only one knew where to find them :)

BTW, for reference the one in the photo is ø50mm.


Thanks James - you working on any DIY projects at the mo?
How's the DDDac?

[Stratmangler]

http://www.cliffuk.co.uk/products/knobs/rotary.htm

[Figlet108]

Thanks for the link Chris. I had seen those before but I just can't find where to buy the ones I like.

If you can find me a source for KM50B or KMR50 I'll buy you a couple of pints...

I guess I could just contact them direct and ask them...

[Macca]

Looking good that is Jason! I don't care what the knob looks like as long as it works ;) although I quite like the look of the ones with the little skirts with the 1-10 on them. A volume knob should have a scale on it, it's just more practical. No LED required. Looking forward to getting this - I am going to owe you a few drinks :)

[Sovereign]

[Thanks James - you working on any DIY projects at the mo?
How's the DDDac?[/QUOTE]

I put some pure silver signal wire in the DDDAC last week and copper silver plated RCA plugs, the upgrade was good, better than expected.
I have just bought new components for my xovers, with advice from Paul at RFC. Which I will get going on with next with.

[Blueflash]

Another DIY masterpiece. Is it just me or have you noticed that the standards of DIY construction has risen over the last few years.
Is it because the cases are easier to find and makes us Diyers up our game internally to match.

[Figlet108]

Looking good that is Jason! I don't care what the knob looks like as long as it works ;) although I quite like the look of the ones with the little skirts with the 1-10 on them. A volume knob should have a scale on it, it's just more practical. No LED required. Looking forward to getting this - I am going to owe you a few drinks :)

Ok, so just me then with the fetish for big black shiny knobs...
I'll find a few candidates and post them and you can choose what you like. I'll also see if I can find one that goes to 11 :)

Glad you don't want an LED, it would have spoilt the simple clean aesthetics.

[Figlet108]

I put some pure silver signal wire in the DDDAC last week and copper silver plated RCA plugs, the upgrade was good, better than expected.
I have just bought new components for my xovers, with advice from Paul at RFC. Which I will get going on with next with.

What RCA's did you go for? I'm almost out and fancied some silver plated ones.
The DDDac is defo next on my DIY list. After all I need to find something else to encase in limestone :)

[Figlet108]

Another DIY masterpiece. Is it just me or have you noticed that the standards of DIY construction has risen over the last few years.
Is it because the cases are easier to find and makes us Diyers up our game internally to match.

Could be. In this case the case was designed by me and sent here (http://plasticformers.co.uk/) for a batch of 10 making.
A nice case and good attention to detail go a long way to raising the DIY stakes.
But my theory is that:
a) tools are better, cheaper and more accessible (e.g. those diamond core bits were actually quite cheap and make a perfect cut
b) a lot of us are a bit older and have more disposable income to buy some decent tools
c) more folks seem to post photos of the insides of kit (e.g commercial kit) which I would really encourage as there's a lot to learn from that
d) seem to be a lot of experienced and knowledgable folks on forums that are generous with their time and advice

I always learn something I could have done better and get helpful tips posted when I do a build thread.

[awkwardbydesign]

What RCA's did you go for? I'm almost out and fancied some silver plated ones.
The DDDac is defo next on my DIY list. After all I need to find something else to encase in limestone :)
I like the CMC ones. I used to get them from VintageAudioLab, but they seem to be doing the MS rhodium ones instead now. They are still available here, which is where I buy silver wire. http://www.ebay.co.uk/itm/NEW-CMC-CMC-805-2-5AG-SILVER-Plated-Female-RCA-Jack-Socket-Connector-2PCS-/310979389256?pt=Vintage_Electronics_R2&hash=item4867d0e748

[Figlet108]

Ok, so power supply is done and reading exactly 12.00v

https://lh6.googleusercontent.com/-dJzGLqSTDqA/U5w8l6U_7LI/AAAAAAAADLM/K3hg3ChD7jw/w968-h645-no/IMG_7278.JPG

Incidentally that regulator board is a nice general purpose variable regulator from here on ebay (http://www.ebay.co.uk/itm/400291199026?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649) Only £10 including delivery.


Right, I need to go and exercise my right to be middle class and accompany my wife to John Lewis. I'll see if I can google some knobs while I camp out in the coffee shop :)

[Firebottle]

Hi Jason,

Looking good but here's a quick tip - I know you love them.
Twist the wires into and out of the toroidal traffo. Twist blue and brown together and red and black together, it will reduce the ac magnetic fields so leading to lower hum.

Cost nothing as well, cheers,
Alan

[Figlet108]

Mart, do you like any of the ones below?:
https://lh5.googleusercontent.com/-Gsr0h_tv0eo/U5xq-W5NeiI/AAAAAAAADLk/9Xn7l_7jZ14/w624-h689-no/Screenshot+2014-06-14+16.28.17.png

[Figlet108]

I like the CMC ones. I used to get them from VintageAudioLab, but they seem to be doing the MS rhodium ones instead now. They are still available here, which is where I buy silver wire. http://www.ebay.co.uk/itm/NEW-CMC-CMC-805-2-5AG-SILVER-Plated-Female-RCA-Jack-Socket-Connector-2PCS-/310979389256?pt=Vintage_Electronics_R2&hash=item4867d0e748

Those look good Richard - thanks.

I note it says "Mounting Insulation set to accommodate panels of any thickness"
Really? ANY thickness? My limestone box had 20mm thick panels - I bet they wouldn't go through those...

[Figlet108]

Hi Jason,

Looking good but here's a quick tip - I know you love them.
Twist the wires into and out of the toroidal traffo. Twist blue and brown together and red and black together, it will reduce the ac magnetic fields so leading to lower hum.

Cost nothing as well, cheers,
Alan

Thanks Alan, fixed. Keep the tips and advice coming.

BTW, Ali had one of you phono stages undressed in Owston and we were in awe of the build quality and attention to detail.
I really liked those cap housings that allowed them to be mounted on their sides. What are those? Are they plumber's pipe clamps? Do they come in different sizes, as the 10k uF caps I'm using are thick.

(sorry to everyone else, I don't have a photo of what I'm talking about)

[Macca]

Mart, do you like any of the ones below?:
https://lh5.googleusercontent.com/-Gsr0h_tv0eo/U5xq-W5NeiI/AAAAAAAADLk/9Xn7l_7jZ14/w624-h689-no/Screenshot+2014-06-14+16.28.17.png

Third from bottom, please Jason :)

[Firebottle]

Hi Jason,
Thanks for the kind words about build quality. This is the first snippet I've heard about Owston, would you care to add more?

The nylon clips are indeed pipe clamps, the best looking I have found for 22mm. They are from Screwfix http://www.screwfix.com/p/hinge-clip-22mm-pack-of-100/17283

They do a 28mm one as well if that's any use. Clip shown in situ below:

http://i601.photobucket.com/albums/tt97/Paramotorpilot/Firebottle%20phono/Topview.jpg

Cheers,
Alan

[Sovereign]

Those look good Richard - thanks.

I note it says "Mounting Insulation set to accommodate panels of any thickness"
Really? ANY thickness? My limestone box had 20mm thick panels - I bet they wouldn't go through those...

Funnily those are the ones I bought, but I paid double!
The only problem I had was heating up the return lug hot enough to accept the solder, I battled for ages, even through my soldering iron was set at 400 degrees, does anyone have any tips for heating up chunks of metal like this?

Thanks

[Firebottle]

Hi James,
Use a 50 watt soldering iron, I'm guessing yours isn't as powerful.

Alternatively apply two soldering irons to the joint, done that myself for big joints,

Cheers,
Alan

[Light Dependant Resistor]

Ok, so power supply is done and reading exactly 12.00v

https://lh6.googleusercontent.com/-dJzGLqSTDqA/U5w8l6U_7LI/AAAAAAAADLM/K3hg3ChD7jw/w968-h645-no/IMG_7278.JPG

Incidentally that regulator board is a nice general purpose variable regulator from here on ebay (http://www.ebay.co.uk/itm/400291199026?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649) Only £10 including delivery.


Hi Jason
I have contacted Lily at Electronics Salon ( she also has another eBay shop Audiowind ) to start restocking the little regulator board, she is a very good seller IMO, based in Hong Kong, she has very quick delivery times.

[Ali Tait]

Hi Jason,
Thanks for the kind words about build quality. This is the first snippet I've heard about Owston, would you care to add more?

The nylon clips are indeed pipe clamps, the best looking I have found for 22mm. They are from Screwfix http://www.screwfix.com/p/hinge-clip-22mm-pack-of-100/17283

They do a 28mm one as well if that's any use. Clip shown in situ below:

http://i601.photobucket.com/albums/tt97/Paramotorpilot/Firebottle%20phono/Topview.jpg

Cheers,
Alan

Hi Alan,

Sorry for not getting back to you, had some family issues to deal with. I'll reply to your email later.

[awkwardbydesign]

Hi James,
Use a 50 watt soldering iron, I'm guessing yours isn't as powerful.

Alternatively apply two soldering irons to the joint, done that myself for big joints,

Cheers,
Alan
Two irons is a good idea. But I have a 100w iron for making Tiffany lamps; that gets a good bit of heat in! And my solder station goes up to 450 degrees, which I need for binding posts.

[Figlet108]

Finished. Macca has LDR (or will have when he picks it up):

https://lh5.googleusercontent.com/-6MxCO8jW2k4/U5yyRoutPBI/AAAAAAAADMI/ftFXmJPWIgg/w957-h638-no/2014-06-14+20.48.37_resize.jpg

https://lh6.googleusercontent.com/-HrjR5frcx-8/U5yySLAEULI/AAAAAAAADMM/K6hCTls7dRg/w957-h638-no/2014-06-14+20.49.22_resize.jpg

There's enough room in there for a motorised remote volume pot if so desired in the future.
Also 2 additional inputs can be added without too much effort.
And the final possible addition could be to add an XLR output socket and utilise the second set of secondary transformer windings to provide another regulated linear power supply up to 12v.


And in the system:
https://lh6.googleusercontent.com/-yJAz-Wn_jvA/U5yySpQqCMI/AAAAAAAADMQ/9zzQIT6qoWI/w957-h638-no/2014-06-14+20.51.14_resize.jpg

I've ordered the chosen volume knob.


It's sounding so sweet and real through my ESLs, and actually a little better than my limestone Stereo Coffee. The only explanation I can think of is that I still have J2 connected to ground which Chris recommended removing and I never got round to it (I have now). Also I haven't got round to building a decent PSU for mine yet and it's still running from a £4 switching supply from ebay...

Anyway, my work here is done. :cool:

Marco & Macca, I'll email you guys some proposed dates for coming over and having us 'pre bake off 2'

[Figlet108]

Hi Jason,
Thanks for the kind words about build quality. This is the first snippet I've heard about Owston, would you care to add more?

The nylon clips are indeed pipe clamps, the best looking I have found for 22mm. They are from Screwfix http://www.screwfix.com/p/hinge-clip-22mm-pack-of-100/17283

They do a 28mm one as well if that's any use.
Alan

Thanks Alan. I'll use those if my caps are the right size. Those 10k ones I have that need using are way too big (40mm)

Unfortunately the guys didn't get round to plugging your phono in until Sunday and I was only there for the Saturday, so I only got to enjoy it physically...

[Stratmangler]

The lack of space in the small limestone box might be contributing to the problem too.
There are acres of space in that perspex box, and component field interaction will be at a minimum.

[Figlet108]

Funnily those are the ones I bought, but I paid double!
The only problem I had was heating up the return lug hot enough to accept the solder, I battled for ages, even through my soldering iron was set at 400 degrees, does anyone have any tips for heating up chunks of metal like this?

Thanks

James, the only other advice I can give is to use the biggest tip you can as it transfers more heat, e.g. I use this for chunky work:
https://lh4.googleusercontent.com/-lq9WMMwr1G8/U5y6Vse0RcI/AAAAAAAADM0/_jtkG9Ka-m0/w957-h638-no/2014-06-14+21.44.07_resize.jpg

[Figlet108]

Hi Jason
I have contacted Lily at Electronics Salon ( she also has another eBay shop Audiowind ) to start restocking the little regulator board, she is a very good seller IMO, based in Hong Kong, she has very quick delivery times.

Nice one Chris. I've been meaning to do that myself as I need a few more of those. Saved me a job.
Yes, she's an excellent seller and highly recommended.

[Figlet108]

The lack of space in the small limestone box might be contributing to the problem too.
There are acres of space in that perspex box, and component field interaction will be at a minimum.

That could be a contributing factor Chris, but remember there's no power supply in my limestone box, it's just the LDR circuit.

Anyway, by the time Macca takes his away I'll compare mine with J2 disconnected and an identical PSU, so we'll find out.

[Sovereign]

Two irons is a good idea. But I have a 100w iron for making Tiffany lamps; that gets a good bit of heat in! And my solder station goes up to 450 degrees, which I need for binding posts.

I use a 60w soldering iron, but still struggle like mad at times, I guess it may be my technique is lacking .

[Stratmangler]

That could be a contributing factor Chris, but remember there's no power supply in my limestone box, it's just the LDR circuit.

Anyway, by the time Macca takes his away I'll compare mine with J2 disconnected and an identical PSU, so we'll find out.

There's a possibility that the switching noise from the wall wart you are currently using is managing to superimpose itself over the audio signal and causing degradation as it does so.
Be interesting to find out if that's the case :)

[awkwardbydesign]

Hmm, it looks like I'll have to make one of these. I have a Consonance Cyber 222 Mk2 pre and a Promitheus TVC, but if this is that good I'll be able to sell one of them!
I have a question though. I've done a little reading on LDR attenuators (in between the footie!), and is there a difference in sound between LDRs? Passive resistors sound different; I use bulk foils in my DAC, they sound better than Shinko tants or Kiwame and Takmans. Is there a similar variation in LDRs?

[Figlet108]

There's a possibility that the switching noise from the wall wart you are currently using is managing to superimpose itself over the audio signal and causing degradation as it does so.
Be interesting to find out if that's the case :)

Agreed, those are my thoughts too, not that I understand the physics of how that happens in an LDR circuit...

[Figlet108]

Hmm, it looks like I'll have to make one of these. I have a Consonance Cyber 222 Mk2 pre and a Promitheus TVC, but if this is that good I'll be able to sell one of them!
I have a question though. I've done a little reading on LDR attenuators (in between the footie!), and is there a difference in sound between LDRs? Passive resistors sound different; I use bulk foils in my DAC, they sound better than Shinko tants or Kiwame and Takmans. Is there a similar variation in LDRs?

Richard, I think that there probably is variation in different LDRs and Chris or Morten can tell us as they are the experts.
However, most all LDR offerings out there seem to use the same LDR part: Silonex NSL-32SR2S (http://ex-en.alliedelec.com/search/productdetail.aspx?SKU=70136789)

[Sovereign]

James, the only other advice I can give is to use the biggest tip you can as it transfers more heat, e.g. I use this for chunky work:
https://lh4.googleusercontent.com/-lq9WMMwr1G8/U5y6Vse0RcI/AAAAAAAADM0/_jtkG9Ka-m0/w957-h638-no/2014-06-14+21.44.07_resize.jpg

Thanks Jason

[Mr Kipling]

Hi James,
Use a 50 watt soldering iron, I'm guessing yours isn't as powerful.

Alternatively apply two soldering irons to the joint, done that myself for big joints,

Cheers,
Alan

Sounds like a VIZ character - Billy Two Irons.

[Mr Kipling]

Third from bottom, please Jason :)

Should have gone for the bottom one. That and a white coat and you could go into boffin mode.

[Figlet108]

I also really liked that one, for an over the top, over engineered volume control

http://static2.tme.eu/katalog_pics/c/1/7/c1756e6a39fd86c38d6e906a1b129d7f/2606.jpg


If Macca had gone for it I was going to build in a safe that would open with the exact combination :)

[Mr Kipling]

When i used to work at the local AEI Cables factory i used to operate a pair of stranding machines; one of three types. One type of the three used that very same item on the control panel.

[Figlet108]

Stephen, how does it work? In the photo I posted it has 10 in the little window but at the 26 mark?

[Light Dependant Resistor]

Richard, I think that there probably is variation in different LDRs and Chris or Morten can tell us as they are the experts.
However, most all LDR offerings out there seem to use the same LDR part: Silonex NSL-32SR2S (http://ex-en.alliedelec.com/search/productdetail.aspx?SKU=70136789)

Hi Richard and Jason
The specifications of each LDR can be compared here: http://ex-en.alliedelec.com/products/?navigation=4294872390-4294965060&show=60&sort=alliedstocknumber
The NSL32SR2S gives us some flexibility over range of resistance and is a very good audio use LDR, but the NSL32SR3 although lower in cost, has 60 ohms specification vs 40 ohm and is an excellent low distortion part as well.

We have recently contacted Advanced Photonix as to any development, and we are not glued to just using the NSLS32R2s that we presently get great result from, or NSL32SR3, as our outlook is always to achieve the best audio quality with whatever it takes.

[Mr Kipling]

It's just a vernier type of control that allows small, precise levels of adjustment. Ten complete revolutions might give a reading of 1 in the window. I think the adjustment would be too fine to be practical for use as a volume control - although it would depend on what the ratio was.

[Light Dependant Resistor]

Hi
Lily advises "due to the LT1764ET or LT1764AET very difficult to purchase, I redesigned the PCB, use new IC LT1963EQ or LT1764EQ.The next week will listing to my shop. LT1963EQ, low noise 1.5 amp version.

[awkwardbydesign]

Hi
Lily advises "due to the LT1764ET or LT1764AET very difficult to purchase, I redesigned the PCB, use new IC LT1963EQ or LT1764EQ.The next week will listing to my shop. LT1963EQ, low noise 1.5 amp version.
So lower noise than LM317? Of which I have several!

[Light Dependant Resistor]

So lower noise than LM317? Of which I have several!

Yes it is a lower noise spec device than LM317, however noise rejection with regulators is very much about layout. From reviewing Lilys information about the low noise regulator Jason used , there is quite a bit of care taken with her circuit boards. If you want to try the LM317 which you already have its a very trusted design, and bypassing the adj pin with up to a 10uf cap is a good known method to optimize the LM317. anything over 10uf you need to use protection diodes.

[Figlet108]

It's just a vernier type of control that allows small, precise levels of adjustment. Ten complete revolutions might give a reading of 1 in the window. I think the adjustment would be too fine to be practical for use as a volume control - although it would depend on what the ratio was.

Ok, I see. That would be a total pain to use.

[Macca]

Jason that looks like a great job you have made of the LDR. I can't wait to get my hands on it. Send me a PM re the meet as I am not back at work until Tuesday and I can't access my e-mail from home.

Are you not going to Cranage today?

[Figlet108]

Hi
Lily advises "due to the LT1764ET or LT1764AET very difficult to purchase, I redesigned the PCB, use new IC LT1963EQ or LT1764EQ.The next week will listing to my shop. LT1963EQ, low noise 1.5 amp version.

That's a shame as I don't know if 1.5 amps is going to be enough for some of the applications I want to use them for.

Checking on farnell (http://uk.farnell.com/jsp/search/results.jsp?N=0&Ntk=gensearch&Ntt=LT1764&Ntx=mode+matchallpartial&suggestions=false&ref=globalsearch&_requestid=653771) there seem to be plenty in stock...

[Light Dependant Resistor]

That's a shame as I don't know if 1.5 amps is going to be enough for some of the applications I want to use them for.

Checking on farnell (http://uk.farnell.com/jsp/search/results.jsp?N=0&Ntk=gensearch&Ntt=LT1764&Ntx=mode+matchallpartial&suggestions=false&ref=globalsearch&_requestid=653771) there seem to be plenty in stock...

Hi Jason
For more demanding current applications a NPN pass transistor with heat sink enables higher current. I will obtain a few of the new boards when she stocks, test and provide you a schematic wiring diagram showing how higher current can be obtained.

Cheers / Chris ,

[Light Dependant Resistor]

Hi
The new Low Noise Regulator Lily has, based on the LT1963 1.5 amps is now available:
http://www.ebay.com/itm/Ultra-low-Noise-lt-40-V-Adjustable-Voltage-Regulator-Module-1-25-20V-1-5-Amp-/201109723894?ssPageName=STRK:MESE:IT#ht_4141wt_990

Have ordered one myself to assess with the stereo coffee kit, and work out a pass transistor where more current is needed. Might have to stock a few.:)

[Figlet108]

Hi Jason
For more demanding current applications a NPN pass transistor with heat sink enables higher current. I will obtain a few of the new boards when she stocks, test and provide you a schematic wiring diagram showing how higher current can be obtained.

Cheers / Chris ,

Thanks Chris, much appreciated.