Customer Projects & Pics with the LDR3x Preamp Controller

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MikeLdiy

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Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #20 on: 14 Nov 2013, 10:39 pm »
ClefChef, that is a very nice case!  How did you do the front panel if you don't mind me asking?
Cheers,

ClefChef

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #21 on: 14 Nov 2013, 11:03 pm »
ClefChef, that is a very nice case!  How did you do the front panel if you don't mind me asking?
Cheers,

Thanks!
Front panel was done using drills, countersinks, glue, and dry transfer lettering.

MikeLdiy

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Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #22 on: 14 Nov 2013, 11:44 pm »
Thanks!  I need to re-do my case.  Will investigate the tools.
Cheers,

tortugaranger

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Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #23 on: 14 Nov 2013, 11:47 pm »
Outstanding job ClefChef!!  :notworthy:

WireNut

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #24 on: 14 Nov 2013, 11:58 pm »

ClefChef, that is a very nice case!  How did you do the front panel if you don't mind me asking?
Cheers,



Yeah, show us how you built it :thumb:

DIY build thread  :bounce:



 

ClefChef

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #25 on: 15 Nov 2013, 12:16 am »

Yeah, show us how you built it :thumb:

DIY build thread  :bounce:

Take something like this: http://www.ebay.com/itm/140879277940?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Take the front panel, carefully mark holes, tap those marks with the punch, drill fine pilot holes, for diode indicators drill larger diameter from inside for snug diode fit, use good deburring tool. To mound IR sensor drill pilot hole, then larger hole, then from the inside drill out the "groove" CNC style drilling two holes and using progressively larger diameter drill bits.
Glue LED's and IR using your favorite superglue. Use permanent black marker to touch up bare aluminum. Do lettering using your favorite dry transfer lettering sheets.

Similar process for back panel RCA - stepped drill tool.

WEAR SAFETY GOGGLES AT ALL TIMES!!!

That's it...:)

Here's the inside of another one. This time I had to build relay input board myself, note slightly different input-output grounding schematic:



Signal wiring is silver, the rest - mil spec Teflon wire. Power supply - LM317T regulated 12V (for relay board) fed by Hammond PT. RCA's - CNC copper.

I build all my gear for my own personal use, sometimes I pass it on when new "challenges" arise.
« Last Edit: 15 Nov 2013, 03:22 am by ClefChef »

AluminatiSound

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  • Machining and Audio What A Great Match!
Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #26 on: 15 Nov 2013, 01:06 am »
I'm half way tempted to buy one of these boards just to make a cool looking case.

But I want to re case a PlayStation 4 as well!
 
So many things to do, not enough time  :lol:

Best,
Matt

tl1000sv

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #27 on: 15 Nov 2013, 09:34 pm »
Clef, nice build on the second one too.  I notice you didn't put in a 5v supply on this one.  Is that simply because you selected 12v relays for the second build?  Also, on the first one, why didn't you use the 5v output on the LDR board?  I'm not using it either, although I am curious of your reasoning.

I'm actually mid-build on a very similar case construction, although I am adding a square LED matrix to the front panel to display the attenuation "step" and input source instead of discrete LED's.  Will post pics when it's together.

No doubt some will wonder how that is possible with no access to the step register in the LDR3x microcontroller, but I have devised two separate strategies that I think will work.  Just waiting for my LDR3x to arrive so I can test them out :-)

Tim

ClefChef

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #28 on: 15 Nov 2013, 09:53 pm »
Clef, nice build on the second one too.  I notice you didn't put in a 5v supply on this one.  Is that simply because you selected 12v relays for the second build?  Also, on the first one, why didn't you use the 5v output on the LDR board?  I'm not using it either, although I am curious of your reasoning.

You are correct - in the first one I used 5V relays and 12V relays in the next one. The 5V output on LDR board is for electronic circuits and relay coil current draw would provide minute interferences. It is always best to keep supply rails separate or at least regulated separately. 7812 to relays +7805 for LDR = double regulated voltage for LDR - good practice.

tortugaranger

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Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #29 on: 19 Nov 2013, 07:38 pm »
No doubt some will wonder how that is possible with no access to the step register in the LDR3x microcontroller, but I have devised two separate strategies that I think will work.  Just waiting for my LDR3x to arrive so I can test them out :-)

One way I know could work is any SPI compatible device that can accept an 8 bit data string. That's how the microcontroller talks to the digital resistors that control voltage to the LDRs so the info is there.

WireNut

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #30 on: 19 Nov 2013, 07:51 pm »

Take something like this: http://www.ebay.com/itm/140879277940?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


That's a heck of a deal on that case. Turned out really good  :thumb:

 

tl1000sv

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #31 on: 19 Nov 2013, 08:55 pm »
Awesome.  Was going to inspect the IC's in front of the LDR's to see if I could figure that out, but you have confirmed a third approach which is probably the simplest.  I actually expected a variable voltage out from the microcontroller for each channel.  Thanks!

One way I know could work is any SPI compatible device that can accept an 8 bit data string. That's how the microcontroller talks to the digital resistors that control voltage to the LDRs so the info is there.

33na3rd

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #32 on: 23 Nov 2013, 08:18 pm »
Thanks to Morten, my Melos SHA Gold is playing music again after being broken for two years! When it broke, there were no parts available to repair it.



Out with the old, and in with the new! These two boards perform the same functions, notice how much smaller the LDR3X board is!






The IR Receiver is mounted in the lower lefthand corner of the Meter, same place as the original. I did enlarge the opening for the IR Receiver, but it probably wasn't necessary. I attached the IR Receiver with 3M automotive double sided acrylic tape. The yellow LED on the right side is for the Status, it replaced the original mute indicator. I chose yellow to keep with the old school look of the preamp.



Playing music again!

I'm really happy to have my Melos back again. While I'm not able to use the entire range of the LDR3X because of the preamps gain, the range between steps is very small & smooth. No problem finding just the right volume level. The LDR3X is major asset to active preamps, as well as being the top choice for passives.

In the near future, I would like to build a LDR3X with either a Pass B-1 Clone or Aunt Corey's Buffer.

I would like to close by saying how impressed I am by everyones' original projects! I feel like I cheated because I merely fixed my broken preamp!

Jeff

 

TrungT

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #33 on: 23 Nov 2013, 09:15 pm »
Jeff
That's a great work and fixed the Melos.  :thumb:

WireNut

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #34 on: 23 Nov 2013, 09:20 pm »

Thanks to Morten, my Melos SHA Gold is playing music again


No kidding, that's great news. Wish I still had my Melos Sha-1...



33na3rd

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #35 on: 24 Nov 2013, 12:32 am »
Thank you TrungT!

WireNut, I keep thinking that a SHA-1 with a LDR3X would be a SHA Gold! I still see nice SHA-1's on Audiogon from time to time. Of course now that my Melos is going again, I hope to be spending less time on that site!

tortugaranger

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Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #36 on: 24 Nov 2013, 12:57 am »
Thank you TrungT!

WireNut, I keep thinking that a SHA-1 with a LDR3X would be a SHA Gold! I still see nice SHA-1's on Audiogon from time to time. Of course now that my Melos is going again, I hope to be spending less time on that site!

Interesting project Jeff. Can you tell if it sounds like you remembered it or if it's any different?

33na3rd

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #37 on: 24 Nov 2013, 01:50 am »
Interesting project Jeff. Can you tell if it sounds like you remembered it or if it's any different?

Hello Morten!

Does it sound different? Well, it's been two years since i've heard it, and the expensive NOS tubes that were in it have mysteriously gone MIA. I stuck a spare pair of regular Electro Harmonix 6922's that are not matched in it, and all I can say is that it sounds marvelous!

I've never had issue with the sound of that preamp. Before I got the SHA Gold, most preamps lasted around here a year or two, at most. I ran the SHA Gold daily for 16 years before the Pho-Tentiometer broke, and never thought about getting a different preamp. There are some pieces of gear that I regretted getting rid of over the years, but there was never a preamp on that list. (Well, OK, the Apt Holman did have a pretty sweet phono section!) The magic of the Melos SHA Gold was the delicate Pho-Tentiometer, and your devices are the modern heir to that legacy, except that you've figured out how to make them rugged and affordable! When I fired the Melos back up, it was like reuniting with an old friend.

Yes, it does sound like I remember, it sounds wonderful. The tonal balance does not change with volume changes, it simply gets louder or softer. I did notice that you can turn the LDR3X all the way down. Even at minimum, the Melos Pho-Tentiometer would send some signal through. The Melos has an old school warmth to it, but yes, I can tell that the LDR3X is not adding or taking anything away from the gain stage behind it.

I can also tell that when the warranty on my Preamp that recently came back home expires, I would love to have one of your LDR units inside!
« Last Edit: 25 Nov 2013, 03:45 pm by 33na3rd »

ClefChef

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #38 on: 30 Dec 2013, 06:00 am »
I am in the process of building Aikido tube preamplifier with Tortuga LDR3x volume control. Here's the pic of the work in progress. Notice the Tortuga board "sandwiched" on top of Aikido board.




TrungT

Re: Customer Projects & Pics with the LDR3x Preamp Controller
« Reply #39 on: 30 Dec 2013, 06:10 am »
^^^^^
Nice.  :thumb:
Please let us know how's sound.
Thanks for posting.