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

Yes, it looks well laid out with lots of room. I have been trying to come up with a stacking scheme that would let me put all of this in a smaller enclosure, but you may have the better solution.

Good work - - -
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WOW - just noticed that this thread has more than 900 posts and 67,400+ views. 75 views per post. That is significant readership!
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Progress coming soon

There has been no further progress. I've been kept busy with doctors appointments for my son. To many I must say and we are not done. The boards are coming as you know and the JFET's were sent from HK today. Also, the main capacitors for the B1 are also ordered. The analog vu-meters are also on their way. The parts for the rest of the boards arrived today from Digikey. I have everything I could possibly have here just waiting for a few more things. My expectation is to finish the project sometime in April. I will certainly post pictures as I go along. No worries. My main concern is to drill the holes for the meters. These holes are probably 3cm or perhaps a bit more. There is a machine shop near by so as soon as I get everything I am going to built a template and take the front and back plates to the shop for a professional look. I am thinking about engraving as well. I am checking in the area.

Is going to look nice but is going to take a bit of time. I promise I will keep everyone posted. Email me if you need anything.
 
Hi All,

Just wanted to say thanks to everyone involved in this. Especially FasterDamit / Hypnotoad and Sachin for producing the boards to make it so much easier.

Sachin,

My boards arrived today and I just finished populating them. Just need to wire up the RCAs and Batteries. Hope to get that done tomorrow.
 

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Please forgive my lack of knowledge here, I'm trying to learn a bit of electronics but I seem to have learned just enough so far to make me question the 'simple' stuff.

I hate to sound like a total wank but does anyone have a schematic showing how the switch and LED are wired in? If it were powered by a single battery the switch would be a no-brainer for me but the duel +/- power supply has me a bit flummoxed. (I barely understand why we use a duel power supply) My thought is to use the DPST switch to break the + side of both batteries, each on one side of the switch.

The LED is another issue. Do I just drop one in on the switched side of the circuit, in series after the switch and before the board? Should they be in parallel to the battery, again after the switch? If so, should two be used? One for each side of the power supply? Do I need to add a resistor to drop the current to the LED?
 
sachu888 said:
Hi Switch has to be wired as shown:

You can use LED, with a 8.2k resistor from the negative or shorter lead to the negative wire on the PCB side of the switch. The longer lead goes to the positive wire on the PCB side of the switch.
I am not using any LED,it reduces battery life.

Regards,
Sachin
Click to expand...

Thanks Sach. :)
 
LedSchem.jpg


This setup only draws 2 ma's.
 
Ok. My first is now playing. Sound from both channels and the music sounds pretty good. :) I need to do a real listening - a/b with my Luxman amp. Not a lot of time to do so tonight.

Things I notice.

[Edit, I figured this one out. it is picking up a signal from my wireless router] First is a concern. With no music playing and the volume on the Lux up @ 50% I start to hear a steady 'thump thump thump' at about 2 thumps a second. It does get louder with the volume control.

Second is that with it just sort of sitting on a cardboard box in the open it seems to be a bit 'microphonic' wrong term but close. When I reach in, to flip a dip switch, I start getting a ground hum before I touch it. Somewhere around 1" to a half an inch away. Should I be searching for a shielded box? Or maybe better wiring between the RCA females and the board?

There is also a good amount of static/hiss at high volumes when no music is playing that disappears when the unit is switched off. This happens with the wireless router off and the modem off as well. I expected silence with batteries. I suspect that this could be more cross talk being picked up from somewhere. Any ideas?

I'm new to external phono stages. Where do I ground the turn table ground to? It is currently running to the table but that is preventing me from moving the PS away from the 'rack' to see if the thump is something that it is picking up from outside the system I have turned off everything near it except the amp and the cable box/DVD.
 

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sxty8goats said:
Ok. My first is now playing. Sound from both channels and the music sounds pretty good. :) I need to do a real listening - a/b with my Luxman amp. Not a lot of time to do so tonight.

Things I notice.

[Edit, I figured this one out. it is picking up a signal from my wireless router] First is a concern. With no music playing and the volume on the Lux up @ 50% I start to hear a steady 'thump thump thump' at about 2 thumps a second. It does get louder with the volume control.

Second is that with it just sort of sitting on a cardboard box in the open it seems to be a bit 'microphonic' wrong term but close. When I reach in, to flip a dip switch, I start getting a ground hum before I touch it. Somewhere around 1" to a half an inch away. Should I be searching for a shielded box? Or maybe better wiring between the RCA females and the board?

There is also a good amount of static/hiss at high volumes when no music is playing that disappears when the unit is switched off. This happens with the wireless router off and the modem off as well. I expected silence with batteries. I suspect that this could be more cross talk being picked up from somewhere. Any ideas?

I'm new to external phono stages. Where do I ground the turn table ground to? It is currently running to the table but that is preventing me from moving the PS away from the 'rack' to see if the thump is something that it is picking up from outside the system I have turned off everything near it except the amp and the cable box/DVD.
Click to expand...

The turntable ground goes to the ground on the PCB.

Make sure you have the dip switches set properly. Start with 47k and work from there. As for the thump, thump, not sure what that is I have never experienced that before.

With batteries it should be pretty quite, and at least quieter than the sound of the stylus running through a silent part on a record. There shouldn't be any hum with batteries at all.

Connect the turntable ground wire like I said to the ground connection on the PCB and see if it disappears.
 
Hi,
connect the tt ground as suggested by Hypnotoad.There shouldn't be any hum after connecting ground.

Regards,
Sachin
 
Also, the midpoint of the batteries must got to common/ground on the board, that makes 3 wire connections from the batteries to the board. Skipping the center battery connection will cause instability problems amongst others.
 
Pio1980 said:
Also, the midpoint of the batteries must got to common/ground on the board, that makes 3 wire connections from the batteries to the board. Skipping the center battery connection will cause instability problems amongst others.
Click to expand...

That part I did get right. I think the root of my issue is my improper grounding of the TT to the receiver instead of the PCB. Now I need to find a proper box to put it in. I hope to have a few minutes after work to test the grounding issue. I may not be able to do anything until Thurs.
 
sxty8goats said:
That part I did get right. I think the root of my issue is my improper grounding of the TT to the receiver instead of the PCB. Now I need to find a proper box to put it in. I hope to have a few minutes after work to test the grounding issue. I may not be able to do anything until Thurs.
Click to expand...

Hi,
I think you only need to connect turntable ground to CNC phono.

Regards,
Sachin
 
Thanks for all the help guys.

I connected the TT ground properly to the PCB. All issues have disappeared, including the interference I was picking up from the wireless router. I won't have time to really play with the load settings or sit and give it a critical listen for a few days but it does sound as good or better than my Luxman. :)
 
Here is an odd thing that I think I posted here or another similar thread...

I didn't put a ground lug on my CNC and there wasn't the first hint of hum in my system. When I delivered the third CNC I built, with no ground lug, there was a lot of hum, I added a ground lug and silence!

It is very system dependent.
 
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