Batery powered DIY CNC phono stage

[omishra]

Santosh, look for 3 pin connector for battery connector. Like this.
http://www.hifivision.com/phono-tur...owered-diy-cnc-phono-stage-36.html#post337131

 

[vktarun]

Sachin,

Just completed the board, will power it up tomorrow.:yahoo:

please check and confirm the pin position of
OP AMP in my build.

Regards,

Vipin

 

[sachu888]

Sachin,

Just completed the board, will power it up tomorrow.:yahoo:

please check and confirm the pin position of
OP AMP in my build.

Regards,

Vipin

Hi Vipin,
Everything looks perfect.Opamp position is also correct.Please connect batteries as shown in the manual.Don't forget to make provision for TT ground.

Regards,
Sachin

 

[vktarun]

Sachin,

Just completed the board, will power it up tomorrow.:yahoo:

please check and confirm the pin position of
OP AMP in my build.

Regards,

Vipin

Powered it up Yesterday Night and was able to connect it with Rotel[in line bypass mode] and Magnepan.

The sound was amazing , Accurate Frequencies, wide sound stage and pinpoint imaging [Silsila LP & meraj-e-Ghazal].

In comparasion to technics in build Phonostage the sound was more Wholesome particularly in below 500Hz region.

Now its time to build a powersuply for it and start hunting for a suitable cabinet.

Thanks to sachin.

Happy Listening

Vipin.

 

[jls001]

Just completed soldering the CNC, but I made one major undoable mistake - forgot to use the 8-pin adaptor for the opamp. I tried hard to desolder it but it's beyond my current patience and equipment level (no desoldering gun). I have to console myself with the fact that the AD824 is one of the best audio opamp in the world.

Will rig up in, out and power connections when I get some more time.

PS: is the 10 picoF cap across the L and R inputs optional?

PS2: how to set capacitive loading?

 

[sachu888]

Just completed soldering the CNC, but I made one major undoable mistake - forgot to use the 8-pin adaptor for the opamp. I tried hard to desolder it but it's beyond my current patience and equipment level (no desoldering gun). I have to console myself with the fact that the AD824 is one of the best audio opamp in the world.

Will rig up in, out and power connections when I get some more time.

PS: is the 10 picoF cap across the L and R inputs optional?

PS2: how to set capacitive loading?

Hi,
they are not very hard to desolder,try using desolder pump with desoldering wick.I once managed to desolder fully stuffed PCB including Op amp socket.
Leave it blank 10pf,they are not required.
You can set resistive loading with 2 DIP switches.You try try capative loading using SIP socket with different value caps like OM did here

Regards,
Sachin

 

[sachu888]

Powered it up Yesterday Night and was able to connect it with Rotel[in line bypass mode] and Magnepan.

The sound was amazing , Accurate Frequencies, wide sound stage and pinpoint imaging [Silsila LP & meraj-e-Ghazal].

In comparasion to technics in build Phonostage the sound was more Wholesome particularly in below 500Hz region.

Now its time to build a powersuply for it and start hunting for a suitable cabinet.

Thanks to sachin.

Happy Listening

Vipin.

Hi Vipin,
glad you liked it

Regards,
Sachin

 

[jls001]

Rigged up the in/out and power connections today, using battery power. So far I have spun 4 record sides. First impressions are positive indeed. Being spanking new the bass is still a bit bloated, highs are rolled off and the mids are yet to bloom.

I will be able to give a more realistic assessment after the mandatory 20-30 hours. But I am happy with the tonality which sounds correct to my ears. It also has decent imaging, and the sound stage is laid back just the way I like it. Also awaiting more details to show up in due course.

 

[sachu888]

HI Joshua,
replace Ad823 with OPA 2134 and everything will be balanced.Which loading did you select on DIP?


Regards,
Sachin

 

[jls001]

HI Joshua,
replace Ad823 with OPA 2134 and everything will be balanced.Which loading did you select on DIP?


Regards,
Sachin

OK, this calls for de-soldering the AD824s. I tried an impromptu de-soldering wick last night (on something else) and it did work out well. Will swap to the OPA2134 tonight.

Loading: I used 32K as that is the optimal value recommended for my Decca London SG. Will try 47K as well.

 

[sachu888]

OK, this calls for de-soldering the AD824s. I tried an impromptu de-soldering wick last night (on something else) and it did work out well. Will swap to the OPA2134 tonight.

Loading: I used 32K as that is the optimal value recommended for my Decca London SG. Will try 47K as well.

Use solder flux on wick and heat it over solder joint.This method takes little time but works very well.Pleas don't heat too much in one place.
You can even try 62k loading.

see this
http://www.youtube.com/watch?v=htrcZuK_ZsY&feature=related

EDIT: Silver solder is very hard to remove.It requires higher temperature to melt.

Regards,
Sachin

 

[murali_n]

Hi sachin,

I have used desoldering pump with good results.

N.Murali

 

[jls001]

Hi sachin,

I have used desoldering pump with good results.

N.Murali

The desoldering pump I had used in the past literally sucked at doing its job so I stopped using it. I have had better results with the shielding braid of any coax cable acting as a wick (provided the braid is not too tightly woven).

Any recommended pump I can look for? I understand a pump (if it works!) is definitely better for more delicate components as one doesn't have to use extended heating.

 

[santhosh]

For desoldering, I have found that a soldering tip with a larger surface area works better than the pointed tip like the Goot.

Also, Goot makes a wick for desoldering. Works well even with desoldering silver solder. It is easily available atleast in Bangalore in SP Road.

 

[sachu888]

The desoldering pump I had used in the past literally sucked at doing its job so I stopped using it. I have had better results with the shielding braid of any coax cable acting as a wick (provided the braid is not too tightly woven).

Any recommended pump I can look for? I understand a pump (if it works!) is definitely better for more delicate components as one doesn't have to use extended heating.

A copper braid can be used in absence of proper desoldering wick.

Regards,
Sachin

 

[omishra]

OK, this calls for de-soldering the AD824s. I tried an impromptu de-soldering wick last night (on something else) and it did work out well. Will swap to the OPA2134 tonight.

Don't forget to put DIP8 IC socket for OPAMP. This will ease your life for changing OPAMP for sake of taste.

 

[jls001]

Don't forget to put DIP8 IC socket for OPAMP. This will ease your life for changing OPAMP for sake of taste.

I forgot, and this chain of desoldering discussions started by me

 

[murali_n]

The desoldering pump I had used in the past literally sucked at doing its job so I stopped using it. I have had better results with the shielding braid of any coax cable acting as a wick (provided the braid is not too tightly woven).

Any recommended pump I can look for? I understand a pump (if it works!) is definitely better for more delicate components as one doesn't have to use extended heating.

Hi jls,

I will post pics of the desoldering pump that I am using. It does a fair job for me.

N.Murali

 

[jls001]

I managed to desolder both opamps, fixed the 8 pin adaptors and try the 2134. It definitely sounds better than the 824. I don't know if I ended up frying the AD824s in the bargain.

Question: I have seen pics of how to wire up DPDT on this thread, but this pic has 4 pins in two rows. The DPDT I bought has three pins in two rows. The switch throws to two positions.

Is this the correct DPDT switch? Does DPDT have three positions of the switch? I couldn't figure out how to wire the battery on-off switch yet. Please advise.

 

[sachu888]

I managed to desolder both opamps, fixed the 8 pin adaptors and try the 2134. It definitely sounds better than the 824. I don't know if I ended up frying the AD824s in the bargain.

Question: I have seen pics of how to wire up DPDT on this thread, but this pic has 4 pins in two rows. The DPDT I bought has three pins in two rows. The switch throws to two positions.

Is this the correct DPDT switch? Does DPDT have three positions of the switch? I couldn't figure out how to wire the battery on-off switch yet. Please advise.

Hi Joshua,
I am using DPST switch.You got the correct DPDT switch.Please find below pic for your switch.You can leave upper or lower terminals,but middle should be used.

Regards,
Sachin