Another Super High End Phono Stage! No expense spared...
- Thread starter Fasterdamnit
- Start date
shelly_d
Not An Audiophool
Yes :yes:
Andy_H
Behind the Wall of Sleep
Just some advice on parts sizes for the CNC. The suggested BOM is in the package with the PCB.
I made the board to suit the parts I used on the prototype and they work very well and easy to obtain, all parts are in stock at Digikey and most probably Mouser.
The film caps are low values and I found that Panasonic Stacked Plastic 50v film worked and sounded best, these have a tolerance of 5% but on testing they were all very close to spec so that is not an issue.
You can use polypropylene's such as Wimas or Panasonics which will work fine as well if you can obtain them, the lead spacing on the PCB's for the film caps is 5mm so the lower voltage (Less than 200v) Panasonics and Wima's will go straight in. Some of the lower values even up to 400v will fit also.
But be careful is you buy high voltage caps they are much bigger and the legs are up to 20mm apart, this isn't the whole problem with them. The leads are usually .8mm or thicker and the PCB holes are .72mm so they won't fit through the holes, meaning you have the ream them out even if you bend the legs to suit.
So check the lead spacing and the legs diameter before you buy.
People using the parts in the BOM I supplied or lower voltage caps will not have a problem at all.
Here is a pic to demonstrate what I mean, we have some lower voltage box type caps, Red Wima and Blue Evox also the brown lower voltage Panasonics on the left and right. You can see the 100v orange cap at the top is fine as well. All are lower voltage caps.
But look at the huge brown cap in the middle, it's a 400v 1uf cap and the legs will not fit through the holes without surgery.
I made the board to suit the parts I used on the prototype and they work very well and easy to obtain, all parts are in stock at Digikey and most probably Mouser.
The film caps are low values and I found that Panasonic Stacked Plastic 50v film worked and sounded best, these have a tolerance of 5% but on testing they were all very close to spec so that is not an issue.
You can use polypropylene's such as Wimas or Panasonics which will work fine as well if you can obtain them, the lead spacing on the PCB's for the film caps is 5mm so the lower voltage (Less than 200v) Panasonics and Wima's will go straight in. Some of the lower values even up to 400v will fit also.
But be careful is you buy high voltage caps they are much bigger and the legs are up to 20mm apart, this isn't the whole problem with them. The leads are usually .8mm or thicker and the PCB holes are .72mm so they won't fit through the holes, meaning you have the ream them out even if you bend the legs to suit.
So check the lead spacing and the legs diameter before you buy.
People using the parts in the BOM I supplied or lower voltage caps will not have a problem at all.
Here is a pic to demonstrate what I mean, we have some lower voltage box type caps, Red Wima and Blue Evox also the brown lower voltage Panasonics on the left and right. You can see the 100v orange cap at the top is fine as well. All are lower voltage caps.
But look at the huge brown cap in the middle, it's a 400v 1uf cap and the legs will not fit through the holes without surgery.
I am waiting for you to post a pic of yours.
Besides this has made me way to busy to even order parts for mine.
perryinva
IS it vintage????
Would it be too much to ask to post the BOM? I have a Digikey order I was just getting ready to send out & it's be nice to save on shipping. I have most of what's needed already, and can glean what's on the PCB from the photo's, but I'd rather see your recommendations, and the power supply & box recommendations too. I know you HAVE to be way too busy, but thought I'd ask.
Done:
Quantity - Digikey Part Number - Description - Reference
2 X P4518-ND / CAP .027UF 50V STACK METAL FILM / RIAA Capacitor
2 X P4519-ND / CAP .033UF 50V STACK METAL FILM / RIAA Capacitor
2 X P4521-ND / CAP .047UF 50V STACK METAL FILM / RIAA Capacitor
2 X P4675-ND / CAP 1UF 50V STACK METAL FILM / DC Blocking
4 X BC1084CT-ND / CAP .10UF 50V CERAMIC X7R 10% / Power Supply Filter
4 X 604-1061-ND / CAP ALUM 10UF 35V 20% RADIAL / Power Supply Filter
2 X CP-1413-ND / CONN RCA JACK METAL RED PNL MNT / Cheap RCA Jacks Red - Optional
2 X CP-1414-ND / CONN RCA JACK METAL WHT PNL MNT / Cheap RCA Jacks White - Optional
2 X AD823ANZ-ND / IC OPAMP JFET R-R DUAL LN 8DIP / AD823 Op Amps
2 X ED90105-ND / IC SOCKET 8PIN .300 SOLDER TAIL / Op Amp Sockets
1 X 67-1107-ND / LED 5MM RED TRANSPARENT / Std Red LED
1 X P8.20KCACT-ND / RES METAL FILM 8.2K OHM 1/4W 1% / LED Loading Resistor
4 X P100CACT-ND / RES METAL FILM 100 OHM 1/4W 1% / Gain Resistor - Increased
4 X P150CACT-ND / RES METAL FILM 150 OHM 1/4W 1% / Gain Resistor - Std
2 X P18.0KCACT-ND / RES METAL FILM 18.0K OHM 1/4W 1% / Input Loading Resistor
2 X P2.20KCACT-ND / RES METAL FILM 2.20K OHM 1/4W 1% / Noise Blocking Resistor
2 X P200CACT-ND / RES METAL FILM 200 OHM 1/4W 1% / RIAA Resistor
2 X P27.0KCACT-ND / RES METAL FILM 27.0K OHM 1/4W 1% / RIAA Resistor
2 X P33.0KCACT-ND / RES METAL FILM 33.0K OHM 1/4W 1% / Input Loading Resistor
2 X P47.0KCACT-ND / RES METAL FILM 47.0K OHM 1/4W 1% / Input Loading Resistor
2 X P62.0KCACT-ND / RES METAL FILM 62.0K OHM 1/4W 1% / Input Loading Resistor
2 X P750CACT-ND / RES METAL FILM 750 OHM 1/4W 1% / RIAA Resistor
4 X RNF14FTD3K32CT-ND / RES MF 1/4W 3.32K OHM 1% AXIAL / Feedback Resistor
4 X 3.83KXBK-ND / RES 3.83K OHM 1/4W 1% METAL FILM / RIAA Resistor
2 X CT2064-ND / SWITCH SPST GOLD 4 SEC / Input Loading Dip Switch
2 X 235K-ND / STRAP BATT ECON 9V T STYLE 4"LD / 9v Battery Connectors
1 X S114-ND / SW TOGGLE DPST 5A SOLDER LUG / On Off Switch
I have not included the 10pf input caps as they are not necessary IMO, if you need to have a higher shunt capacitance that whats in the tonearm and turntable cables then you can add the difference here. Most carts do not need more than 200pf which is already in the cables and tonearm. If you do want to put them in anyway you can use in order of preference Polystyrene if you can find them, Micas (2 X P/N 338-1061-ND / CAP 10PF 500V MICA RADIAL), or Ceramics (only if all else fails).
The box is up to you and I recommend batteries, a 9v per side will last over 40 hours of listening, or what I am suggesting is 2 x 6v lantern batteries per side which will last up to two years. These can be had for around $5.00 per pair at Walmart.
We have had several discussions about this but batteries give the best performance IMO.
You can build a well filtered 15v per side PSU powered by a walwart but to me that's a downgrade not an upgrade. Hagerman has one, Rod Elliot has one, schematics are not hard to find.
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perryinva
IS it vintage????
I love you, man.....
Wow. Even with part numbers. From Digikey, no less....."I'm not worthy....."
I read the whole thread, I agree, batteries make the most sense, but since size fro me is a consideration where I need it, here, the whole toolbox thing is bit much for me!! I was thinking 3- 9 volts in parallel per side in a small enclosure, but I just didn't know if you had some recommendations. This is great, seriously, WAY above and beyond the call of duty, etc, etc
Wow. Even with part numbers. From Digikey, no less....."I'm not worthy....."
I read the whole thread, I agree, batteries make the most sense, but since size fro me is a consideration where I need it, here, the whole toolbox thing is bit much for me!! I was thinking 3- 9 volts in parallel per side in a small enclosure, but I just didn't know if you had some recommendations. This is great, seriously, WAY above and beyond the call of duty, etc, etc
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I plan to put the batteries in another box somewhere out of sight and run a 3 conductor cable to the CNC.
bobrown14
Super Member
What is everyone doing regarding a box for the board?
Also regarding shut capacitance; how would you know if you need more? I've got Petra cables on one of my TTs that I will be using with this board and the capacitance with the Petra cables is VERY low. I know the tone arm and associated cables and wires add some capacitance but I'm way low and am wondering what "too low" would sound like? I know I can add caps to the rca jacks so installing more would be no problem once I build this kit.
Cheers,
Bob
Cartridge loading is pretty much explained here:
http://www.vinylengine.com/phpBB2/viewtopic.php?t=6674&postdays=0&postorder=asc&start=0
LPMike
Vinyllicus Diversicus
Got mine in the mail today!
Nice job!
The BOM is awesome... Now heres an idea that crossed my mind... would it be feasable to replace the dip switches with a small 4-way rotary switch instead?
I dunno.. just a thought.. nothin wrong with the DIP switch tho...
And Ive never seen lantern batteries ANYWHERE for $5 a pair.. seems they are running about $6-to-$8 EACH at Wal-Mart... hmmph... I assume (4) total would be required? (12v per channel spec)
Nice job!
The BOM is awesome... Now heres an idea that crossed my mind... would it be feasable to replace the dip switches with a small 4-way rotary switch instead?
I dunno.. just a thought.. nothin wrong with the DIP switch tho...
And Ive never seen lantern batteries ANYWHERE for $5 a pair.. seems they are running about $6-to-$8 EACH at Wal-Mart... hmmph... I assume (4) total would be required? (12v per channel spec)
ghazzer
Senior Member
Aha! I'll put a set of 9V batteries "out of sight" on a harness behind my TT, run the 2 rails thru a relay in the TT, and use a 4 conductor phone wire to get that over to the CNC. The phone wire will fit in the sleeve with the RCAs and the dedicated chassis ground. That should turn the CNC on/off with the TT and the CNC will be clean with only the LED on top.
Cool.
.
I saw them they are Rayovac, they were $4.88 a twin pack IRC in the camping/sporting goods section, not at the front of the store.
Fasterdamnit bought them at his local Walmart for the same price.
You can see them in this post:
http://www.audiokarma.org/forums/showpost.php?p=4800599&postcount=158