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DIY High or Low Ouput Moving Coil Phono Stage

slial said:
Philip,

Do you have a part number on this? Is it Mouser?

Scott
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I got them from Digikey they are 10mm Terminal Blocks and found they are a bit big for my liking so I would suggest these, the legs are 7mm apart and the holes in the board need to be approx 50 mils or 1.25mm.

ED655/2DS Terminal Block 7mm

ED600/2DS Terminal Block 10mm
 
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I finally got around to putting the dual op amp PC3 and the SSP (super simple preamp) in the same case (6"L x 4"W x 2.5"H). The good part is it's the only thing between the turntable and the power amp, no nasty tone control or other circuits to molest the sound. It draws around 15ma so it's easy on the batteries. And by using terminal blocks to mount the gain resistors I can swap them out to suit different carts without having to desolder anything.:thmbsp:

I am very pleased with the sound, I ended up using a pair of OPA2134's in the PC3 and an AD823 in the SSP.

PC3SSPFront.jpg


PC3SSPInside.jpg
 
Great Phillip,
Your PCBs look great.Can you start a new thread regarding PCB making at home.

Regards,
Sachin
 
Finally listened to my Phonoclone last evening. Surprisingly good sound from a unit with no time on it! A little too much gain for the Benz Ace @0.8mv we were using and a bit less sparkle to the cymbals than the Joleda phono stage it replaced. Bass seemed deeper, tighter and better defined. The two others listening felt it was good also. Overall, pretty happy with the build of this and the VSPS I built
 
WntrMute2 said:
Finally listened to my Phonoclone last evening. Surprisingly good sound from a unit with no time on it! A little too much gain for the Benz Ace @0.8mv we were using and a bit less sparkle to the cymbals than the Joleda phono stage it replaced. Bass seemed deeper, tighter and better defined. The two others listening felt it was good also. Overall, pretty happy with the build of this and the VSPS I built
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Give it a week or two to open up.

You can use 200 ohm resistors for R2 with the Benz Ace Medium output if you find the gain is too high.

If you find you want more detail and more top end you can put in AD797's in place of the OP27GP's in IC2. (They won't work in IC1) The Burr Browns typically have a laid back sound which I like but doesn't suit everyone or every system.

There is also another "trick" I employ and that's putting a 0.1uf cap in parallel with the 2.2uf output cap it brings out the detail as without them it seems the top end is a little rolled off IMO.

I use these: http://search.digikey.com/us/en/products/ECW-F2104JB/PF2104-ND/248822
 
slial said:
Philip,

What are the dial controls on the front of the box for?

Also, what recommendations does everyone have for standoffs, spacers, etc for mounting the PCBs to the chassis? I went with Hammond 1590 DBK from Digikey (http://www.hammondmfg.com/pdf/9c2pg42-43.pdf)

Scott
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They are left and right volume pots, I have the dual op amp phonoclone and super simple preamp in the one box. So I only need this between the turntable and the power amp.
 
Philip,

You'll have to pardon my ignorance but I am feeling a bit lost. What is the need for the SSP if the Phonoclone is the Phono preamp? Does it remove the need to hook the Phonoclone up to my current preamp?

Scott
 
slial said:
Philip,

You'll have to pardon my ignorance but I am feeling a bit lost. What is the need for the SSP if the Phonoclone is the Phono preamp? Does it remove the need to hook the Phonoclone up to my current preamp?

Scott
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The SSP is a line stage preamp and is only used if you want to plug a phono stage, tuner or Cd player etc into a power amp. If you already have a preamp you don't need one.

However it's a very simple circuit that provides few interruptions to the signal so it is better than a lot of preamps in this respect. It runs on the principal that simpler is better.

Phonoclone is a phono preamp but to make it less confusing I call it a phono stage as it goes before the preamp.
 
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So the volume pots are not necessary if I intend to run this phono stage through a preamp?

If I decide that the SSP is something I would like to incorporate, is the PCB available through you or elsewhere?

Scott
 
slial said:
So the volume pots are not necessary if I intend to run this phono stage through a preamp?

If I decide that the SSP is something I would like to incorporate, is the PCB available through you or elsewhere?

Scott
Click to expand...

The volume pots are only used with the SSP not the phono stage.
 
So I'm running my Sumiko Blackbird into my DIY VSPS but I want to listen to it through the Phonoclone I've built. Assuming I select the correct resistors for R1 and R2, will this work without damaging something? The output of the Blackbird is 2.5 mv and the internal resistance is 135 ohms. This works out to R1=135 and R2=540. Any disasters up ahead if I do this?
 
WntrMute2 said:
So I'm running my Sumiko Blackbird into my DIY VSPS but I want to listen to it through the Phonoclone I've built. Assuming I select the correct resistors for R1 and R2, will this work without damaging something? The output of the Blackbird is 2.5 mv and the internal resistance is 135 ohms. This works out to R1=135 and R2=540. Any disasters up ahead if I do this?
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Can't see any problems with this.
 
Got to say, sounds just wonderful. One can imagine Lucinda Williams in the room. Something is coming together. The terminator tonearm just lets the music fliw. Even the wife is impressed.
 
HypnoToad said:
The main thing is I am putting these in for R1 & R2 so the resistors can be changed out quickly, no soldering, it will make it much easier when changing carts and adjusting the gain.

ED600%5E2DS.jpg
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After looking at that I got an idea to salvage it from normal 5mm lead spacing terminals. Look at the attached picture. This may be useful for those he can not get above mentioned terminals.

image684screwterm.jpg


  • Remove screw, remove clip and remove metal terminal straight from plastic base.
  • Assemble all those metal parts outside again in the same way by putting clip and screw back as it was in plastic base.
  • If insulation is required over this then I can put 5mm heat-shrink tube over this.
  • Solder in same required direction, you are done.
What do you say?
 
Sounds like an excellent DIY solution. I ordered several of the DEGSON terminals from a supplier in Bangkok, on a slow boat from Thailand. The DEGSON site indicates that these terminals are available in a variety of lead spacings, pin numbers, type of insulator, confifuration, etc.

I plan to use these as the interface for my PCB connections, until a better solution is created. Your idea will make it fit any hole configuration, as soon as my OPS (Omishra's Power Supply) PCB arrives.

Good call - - -
.
 
jimreeves said:
I wonder if the poorly shielded OEM interconnects coming from my QL-A75 could have anything to do with it? It's long overdue for a upgrade anyway. Perhaps I should order a pair of those panel mount RCAs along with the 100pf's and fix it properly.
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Jim, wondering if you ever solved the RF issue in your PC3. I'm still chasing it in my system and it seems to be getting slightly worse over time (or maybe I'm just becoming more aware of it :) ).

Also, generic question for other PC3 owners: what opamps have you settled on?
 
My RF wasn't a big deal so I didn't do anything. I have to turn the volume up to 80% without playing anything to hear it at all (I'd pop my woogers if I played it that loud!). I just moved the pre around until it was minimal. Better interconnects seemed to help a bit.

AD797's and LME49710's for me. Sounds terrific! :thmbsp:
 
I am wondering if it's to do with sunspots, Solar Cycle 24 is at it's worst this year, just a thought. I notice some mornings on the way to work my regular local radio station sometimes fades in and out and I can hear another station over the top of it when it does.

If you are really having trouble try putting 100pf poly caps across the inputs of the PC3 to see if it fixes it.

As for op amps after trying OPA2134's in my own creation I would try the OPA134's in the PC3.
 
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