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

Well, now I have to leave work early to see if my presents arrived!

Edit- No boards today.:tears:
 
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Received my boards as well. Now that the holidays are behind, I can finally sling some solder!

Many thanks Sachin!
 
Still buried in the guts of the Mitz LT-30 and waiting on the finalization of the simplified DIY Hi or Low MC stage. Looks like I'm gonna need parts ordered for four boards total when that happens.
 
Pio1980 said:
Still buried in the guts of the Mitz LT-30 and waiting on the finalization of the simplified DIY Hi or Low MC stage. Looks like I'm gonna need parts ordered for four boards total when that happens.
Click to expand...

I had to redo the design in FreePCB as they couldn't work with ExpressPCB files.
 
I think that I will order one of the 24 step attenuators (ladder, 1/4 watt, 1% resistors) from HK to provide volume control for my CNC&SSP. Cannot decide whether to get the 10K one or the 25K. I'll have to determine the total gain of the combo, then determine the upper & lower levels of attenuation to give me the range that I want.

I don't remember seeing anything about how much additional gain to expect from the SSP.

My goal is to achive ~50 dB of gain, +3 & -6, or about what my previous preamp supplied when I digitized most of my LPs. I am hoping that I can add fixed resistors in series with a 10K step attenuator so that I can get a finer control of the volume. I'll install a 1/8" jack to feed the PC, and RCAs to feed the Sansui.
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ghazzer said:
I think that I will order one of the 24 step attenuators (ladder, 1/4 watt, 1% resistors) from HK to provide volume control for my CNC&SSP. Cannot decide whether to get the 10K one or the 25K. I'll have to determine the total gain of the combo, then determine the upper & lower levels of attenuation to give me the range that I want.

I don't remember seeing anything about how much additional gain to expect from the SSP.

My goal is to achive ~50 dB of gain, +3 & -6, or about what my previous preamp supplied when I digitized most of my LPs. I am hoping that I can add fixed resistors in series with a 10K step attenuator so that I can get a finer control of the volume. I'll install a 1/8" jack to feed the PC, and RCAs to feed the Sansui.
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Click to expand...

This looks interesting (no affiliation)

http://www.ebay.com/itm/24-Step-Attenuator-POT-Volume-Control-Log-25K-Stereo-/320653902671
 
For Volume Control, Stepped Attenuator can be used like this. (no affiliation)

I already posted this to our local forum. Posting here again for benefit and idea of other forum members. I put my CNC along with Pass B1. Most important change is that this CNC phono stage is no more battery powered. Its powered by regulated PS.

Power Supply which I designed is referred here. Sachin' post here

I prepared aluminum faceplate (3" X 13", 6mm thick). I sprayed it chrome spray paint used for car alloy wheels. This is supposed stick to Aluminum. But waiting for com-paint lacquer (clear coat) to arrive as it will give some protection and shine to that color. I will post some pics after that.


Here are some impressions.

Here are some pics.

I will be showing front side of this gadget till I fix the faceplate.
This is 4 input device with CNC MM phono stage as one input.

You can see AC Mains fuse, I put 150mA fuse inside and ferrite bead on the wire to avoid noise.





Mains power inlet wires are fixed and put inside PVC sleeve for protection.



Mains indicator is 3mm LED + series 15K,1/4W resistor fixed to 22-0V of r-core transformer terminals.



There are two 330E, 2W resistances, one for LDR 12V supply and other for input selector's supply. Ground remains same for all PS



Input selector -



CNC MM Phono stage -



LDR Volume control -



Watch out for volume control wires on PASS B1 board.



Color of wires at LDR Volume control board.

 
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Nicely done Om!!! Good layout. Clean installation. Well thought out & good planning. Hope it sounds as good as it looks.

You may have set the bar kinda high.
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Steve is right, that is awesome and sets the bar pretty high. I may have to start my own thread of "Looks Ugly But Sounds Beautiful" for my stuff.

One question without skidding the thread sideways, what are the two resistors coming off the back of D5? I know they are separate feeds to different circuits being isolated, I just wondered where they go.
 
omishra said:
For Volume Control, Stepped Attenuator can be used like this. (no affiliation)

I already posted this to our local forum. Posting here again for benefit and idea of other forum members. I put my CNC along with Pass B1. Most important change is that this CNC phono stage is no more battery powered. Its powered by regulated PS.

Power Supply which I designed is referred here. Sachin' post here

I prepared aluminum faceplate (3" X 13", 6mm thick). I sprayed it chrome spray paint used for car alloy wheels. This is supposed stick to Aluminum. But waiting for com-paint lacquer (clear coat) to arrive as it will give some protection and shine to that color. I will post some pics after that.


Here are some impressions.

Here are some pics.

I will be showing front side of this gadget till I fix the faceplate.
This is 4 input device with CNC MM phono stage as one input.

You can see AC Mains fuse, I put 150mA fuse inside and ferrite bead on the wire to avoid noise.
Click to expand...

Wow, just amazing.

Other than a tangle of wires, what is the main advantage to using the selector board over a simple 2-pole rotary switch? Is there a disadvantage to using a rotary switch (pops, noise, etc.)? I'm getting ideas in my head for a layout and would like to minimize the overall size if possible.

Also, would it be possible to have to "outs", one for route to amp, one for route to, say, cassette deck?
 
I'm pretty sure the switching is done at the inputs selected by small signal relays. The relay contacts are, hopefully, good silver plated contacts. There is little mechanical wear with the relays and the contacts, if silver, will last just about forever because the contacts only close rather than sliding like a selector switch, there is no arcing at line signal levels. So, low resistance, short signal path are two of the advantages.

A cassette output is best wired, and buffered, after the selector switch and before the volume/balance controls. That way you can adjust the volume and balance without changing the signal at the record outputs. The main outputs are after all the circuitry.
 
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Grainger49 said:
Fifth picture down, two (looks like) 110 ohm resistors that have one end soldered to a diode Anode.
Click to expand...

Hi Grainger,
They are two 330 Ohm, 2W resistors, one for LSA 12V supply and other for input selector's supply.I think this is for heat I am not sure though.

Regards,
Sachin
 
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