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

Thanks for sharing your plans. Your board looks nice - will be looking forwad to some pictures when you get your boards.
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Great work Omishra and welcome to AK.

Fasterdamnit aka Jim is responsible for kicking this thing off, I just came in on the end and Sachu888 has been kind enough to get more PCB's made and distributed to AK'ers.

Many others on here have given valuable input as well.

It's just good AudioKARMA all around. :thmbsp:
 
omishra,

I like the flooded ground plane. I hadn't seen that for a while and it makes sense. The routing of components becomes more open and the signal path more compact because of it.

Looking at the schematic, I wonder if R1 and R2 are necessary. The input draws no (negligible, pA) current. The effect of these is questionable.

Edit: If left in, remember these resistors are in the signal path. Since they are not like a grid or plate stopper the best sounding resistor, in your opinion, should be used here. The same can be said for the two 2k2 resistors, the two 27k, the two 750 ohm, and the feedback resistors which are 3k32. I'm not sure if these values have been changed.
 
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Grainger49 said:
omishra,

I like the flooded ground plane. I hadn't seen that for a while and it makes sense. The routing of components becomes more open and the signal path more compact because of it.

Looking at the schematic, I wonder if R1 and R2 are necessary. The input draws no (negligible, pA) current. The effect of these is questionable.
Click to expand...

Another example of 'standard' practice, they use the Miller effect of the front end of the chip to suppress sensitivity to RF freqs. Probably optional in reality except when there is a definite problem.
 
Alright, got everything soldered in last night, except for the dip switch that I just noticed was backordered as I was putting the parts on the board so I called them up today and ordered the sealed dip switch CT2064ST-ND. I also noticed I need a smaller tip on my iron, that got a little tight for my chisel tip.
 
Sachin has some for sale last time I checked for AK's that want one.
I think Omishra designed a slightly different laid out board than the ones Sachin and Hypno produced.
 
Hi,
I can get the PCB done,if there are 7-8 members.I will also take one.I have found a good source for PCB(better than my existing one).Please express your interest here if anyone needs CNC PCB.

Regards,
Sachin
 
Grainger49, thanks for your kind words.

Dukiedook said:
Sachin has some for sale last time I checked for AK's that want one.
I think Omishra designed a slightly different laid out board than the ones Sachin and Hypno produced.
Click to expand...

Original layout PCB from Hypno which I got from Sachin is working great. Idea after this layout was to minimize signal path and make all (left, right & power) current paths symmetrical. This is using same schematic and components but parts are adjusted nearby for above reason.

Now this PCB is neither available nor given for fabrication. But I am planning to do so. It will take 2-3 weeks to get in hands.
I am planning to make 10-15 boards. So thought of getting this layout verified by all of you. I talked to Sachin and thought of publishing this layout before getting money spent over it.

P.S. Just saw Sachin's post. His help in getting PCB is appreciated. Thanks
 
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HypnoToad said:
Great work Omishra and welcome to AK.

Fasterdamnit aka Jim is responsible for kicking this thing off, I just came in on the end and Sachu888 has been kind enough to get more PCB's made and distributed to AK'ers.

Many others on here have given valuable input as well.

It's just good AudioKARMA all around. :thmbsp:
Click to expand...

That's why I like AK so much.

Regards,
Sachin
 
PCB mod

omishra said:
Now this PCB is neither available nor given for fabrication. But I am planning to do so. It will take 2-3 weeks to get in hands.
I am planning to make 10-15 boards. So thought of getting this layout verified by all of you. I talked to Sachin and thought of publishing this layout before getting money spent over it.
Click to expand...

Omishra: How much effort would be required to mod the PCB layout to add tracks for HT's Simple Preamp? The mfg cost would go up because of board size, etc. Output RCAs could be connected between the CNC and the SP for those who only want the Phono Preamp.

What say you all??? Anyone else interested?
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ghazzer said:
Omishra: How much effort would be required to mod the PCB layout to add tracks for HT's Simple Preamp? The mfg cost would go up because of board size, etc. Output RCAs could be connected between the CNC and the SP for those who only want the Phono Preamp.

What say you all??? Anyone else interested?
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Click to expand...

Can you please point me out exact schematic/diagram which you are referring? Do you want that preamp as separate PCB or same CNC PCB to be extended for third OPAMP of simple preamp?
 
^^ Thanks Sachin. I think the last post has latest design. It could be done but I am not sure how many takers are there? Otherwise if added to existing CNC PCB then these part of the board can be kept unpopulated for only CNC use.
 
omishra said:
^^ Thanks Sachin. I think the last post has latest design. It could be done but I am not sure how many takers are there? Otherwise if added to existing CNC PCB then these part of the board can be kept unpopulated for only CNC use.
Click to expand...

I think there are many takers of CNC PCB.Simple peramp PCB can be made separately if there is enough interest.

Regards,
Sachin
 
omishra said:
Can you please point me out exact schematic/diagram which you are referring? Do you want that preamp as separate PCB or same CNC PCB to be extended for third OPAMP of simple preamp?

It could be done but I am not sure how many takers are there? Otherwise if added to existing CNC PCB then that part of the board can be kept unpopulated for only CNC use.
Click to expand...

I will attempt to poll members who have expressed interest in additional CNC boards, but will have to wait until I finish a few errands this afternoon.
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I've already contacted Sachin about another CNC board but I'd be very interested in the simple preamp board as well. Can the preamp be altered to accept more than one input (have a switch)?
 
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