• Please note that Audiokarma will be offline briefly for updates early on Monday morning, September 28th.

Another Super High End Phono Stage! No expense spared...

sachu888 said:
Thanks Grainger,your drawing looks good.

Regards,
Sachin
Click to expand...

The lines are very distinct on the drawing but then I had to scan it to get a JPG. I should have increased the line size, width, before scanning. I'm glad you can read it well enough.
 
Alright after getting referred to this build article I am on for one board- maybe two depending on the cost. I already have a 12V 10AH SLA ready to use when I thought I could readily hook it up to my Musical Fidelity LP phono stage.

How much does a board cost Hypnotoad? And are they available anytime soon?
 
Dukiedook said:
Alright after getting referred to this build article I am on for one board- maybe two depending on the cost. I already have a 12V 10AH SLA ready to use when I thought I could readily hook it up to my Musical Fidelity LP phono stage.

How much does a board cost Hypnotoad? And are they available anytime soon?
Click to expand...

Talk to Sachu888 he may have some.

You need two batteries to run it.
 
PCB available

Hi,
I have some boards available with me.I can get it done more locally,if needed.

Regards,
Sachin
 
Ok. Poop, I thought I could get away with one but I may have to buy another 12V SLA- got it semi-cheap from amazon- may have to look into what the local interstate batteries has to offer- they were not that cheap when I was looking into my PSU battery replacement on my LP phono stage.
 
I had a pair of SLA 12V batteries that were almost dead. Yesterday I recharged them (in parallel) with a float charger I got for $6 at Harbor Freight.

I intend to use it to keep them topped up with this charger when not driving a phono stage.
 
Kiss - - -

I think that I will ride with HypnoToad on this one. I'll get the 6V batteries at Walmart on my next weekly visit. Maybe I can find one of his plastic tubs that is the right size, but will have to figure out another place to put the larger box.

The economics is a no-brainer: ~$11 for up to 2 years and I don't have to mess with a charger.

I finally got around to ordering more opamps. Got some cheaper LM833s in case I pop those as well, and got 2 more LME49720s to use when I get it right.

.
 
I bought 5 PCBs from Sachu. I have pieced together 2 with the parts in my parts bin, but they are missing the critical RIAA components. I just placed an $80 Digi-Key order to finish them out. I'm keeping one, of course and giving the others to friends.

Hope my wife doesn't get after me. I waited for another billing cycle to order.
 
Last edited:
Grainger49 said:
I bought 5 PCBs from Sachu. I have pieced together what I have for 2, missing the critical RIAA components. I just placed an $80 Digi-Key order to finish them out. I'm keeping one, of course and giving the others to friends.

Hope my wife doesn't get after me. I waited for another billing cycle to order.
Click to expand...

Five?? You are an industrious soul! I find it hard to believe this little build took off in such a big way. Thanks to everyone that has been involved. :thmbsp:
 
Fasterdamnit said:
Five?? You are an industrious soul! I find it hard to believe this little build took off in such a big way. Thanks to everyone that has been involved. :thmbsp:
Click to expand...

Look at the numbers: Almost 600 posts and Probably 36,000 "views" by the time you read this.

I think it was a good ball that you got rollin'. Thanks - - -


Now I'd like to see someone get some PCBs made with the CNC & the SP (HypnoToad's Simple Preamp) on the same board. Designed with a gain control and it could be slipped under my Christmas tree any day of the year.

.
 
Alright, I ordered the parts through Digikey including the Hammond aluminum box.
The 100, 150, 18K, and 750 ohm resistors in the original BOM were not available so I ordered some Vishay/Dale and Stackpole metal film resistors at the same values as replacements.
I am eagerly awaiting the parts and boards- I can't wait to solder this stuff up and see how it sounds!!
 
Last edited:
With the box the parts were $59.27 and sales tax $5.05- why am I getting charged sales tax?

BOM ID #46729
BOM Name- CNC MM Phono Stage

Should be a public BOM.
 
Parts in, that was quick- now I am awaiting the boards from India.

Gotta finish up my father in law's roof repair and my rear caliper on my car before I get to huff some solder fumes and get this puppy cranking!
 
HT posted a picture in his Simple Preamp thread showing the circuit board in a plastic "tub" that sliced lunch meat comes in. I just emptied one and I'm going to "mount" the board and RCA jacks. I doubt I can insert an RCA plug without holding on to the plastic but it is just the kind of thing I like to do.

I have now finished 4 of the 5 CNC boards. I'm going to burn them in using a spare pair of 9V battery connectors and some wall warts from old cell phones. More than enough voltage and no killed batteries for burning in (while not listening).

Just for yucks I will test the wall warts against fresh 9V batteries.

I am planning on using 12V SLA batteries but will have to go with new ones. My charger (on sale at Harbor Freight for $6) will work well since it charged my almost dead batteries. One will only come up to 10.3V the other is good at 12+V.
 
Last edited:
Schematic and PCB

ghazzer said:
Sorry, I got side tracked this afternoon. Here is a .jpg schematic that you can use if you want something you can alter. Hypnotoad has looked at it so I musta got most of it right. I still don't understand why there are 2 sets of 10 & 1uf caps to ground on B+ and B-.

I tried to make it look like the PCB so it would be easier to follow.
Click to expand...
Hi ghazzer, those caps are 10uF and 0.1uF for keeping noise away from power lines coming at OPAMPs +ve and -ve pins.

I built this kit with PCB from Sachin. I liked it very much. So thought of making small contribution to thread. Also thanks to Fasterdamnit for providing this design & HypnoToad for PCB. I too tried to make same thing with CAD software. These are files. I took reference from you.

  1. I did not had AD823 in software's CAD library so I used AD822 for diagram purpose only. But BOM has AD823 which need to be used.
  2. Also double sided did not make any advantage and I kept original layout similar to HypnoToad's.
  3. Only thing I tried to keep tracks minimum with no component crosstalk.
  4. Here power supply noise filter caps kept near OPAMPs power supply pins by keeping minimum distance from OPAMPs.So I took liberty to scatter them where they are required most (near to OPAMP power supply pin 4, 8).
  5. Ground plane flooded on same side. This will not add any capacitance to circuit.
  6. Size is 4"x3".
This is schematic redrawn -
CNC-phono-pre-sch.png

This is PCB layout -

CNC-phono-pre-brd.png

Any thoughts are welcome. I think these can be made here in India in batches if required or I can provide Gerber files on request. I am eager to hear his thoughts from HypnoToad and members.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom