Batery powered DIY CNC phono stage

[hildebrand]

Three cheers for Sachin.

I have used those kind of "jumpers" in my PCBs at work. They can be bought from any electronics market. They are available as single row and double row 0.1" Bergstik headers which are easy to use on the board. (I am talking of the through hole type though SMD and other types are also available). The rows can be broken as per requirement easily. Their female counterparts can be seen in some of the arduino controller boards available these days too. They are quite convenient for configuration for PCBs.

 

[shafic]

Thanks Shafic,
I am not guru.I did not notice that sentence,else would have edited I am a learner and still learning.

OK then, we will call you "YOUNG MASTER".hyeah:

 

[reubensm]

Many so called 'GURUS' are very miserly with their 'knowledge', and they are only interested in extracting from others. One such person once gave me ( i had asked for it) a little amount of local made 'contact cleaner' after carefully removing the label from the can.:lol:

This happens, especially in the modern world. When a local friend of mine saw one of the ceramic phonostages which I had built (this is the one which was for my good friend RP), he asked me to paint the components and the contact side of the bread board, black so that nobody can either service or duplicate the design. What a joke!! But that's the way people think I guess

 

[reubensm]

Three cheers for Sachin.

I have used those kind of "jumpers" in my PCBs at work. They can be bought from any electronics market. They are available as single row and double row 0.1" Bergstik headers which are easy to use on the board. (I am talking of the through hole type though SMD and other types are also available). The rows can be broken as per requirement easily. Their female counterparts can be seen in some of the arduino controller boards available these days too. They are quite convenient for configuration for PCBs.

I am doing my version of the CNC for FM JK_Chaos. I am using jumpers instead of the dip-switch. This is because it keeps costs to a minimum. Another friend of mine built the CNC using 4 LM741 ICs and it sounded quite good. Got inspired by him. I am using 4 Hitachi UM741 vintage ICs, which I got back in the 1980s. I have used these 4 ICs in various projects over the years which included tape head preamps, tone controls, microphone preamps and buffer amps, and they've sounded brilliant. As I have them lying around as spares, thought I'll give them to my good friend JK_Chaos, so that he can make good use of them. The total cost of the CNC project, including bread board, sockets, battery connectors, components, solder and ICs is just below Rs.250/-

 

[hildebrand]

I am doing my version of the CNC for FM JK_Chaos. I am using jumpers instead of the dip-switch. This is because it keeps costs to a minimum. Another friend of mine built the CNC using 4 LM741 ICs and it sounded quite good. Got inspired by him. I am using 4 Hitachi UM741 vintage ICs, which I got back in the 1980s. I have used these 4 ICs in various projects over the years which included tape head preamps, tone controls, microphone preamps and buffer amps, and they've sounded brilliant. As I have them lying around as spares, thought I'll give them to my good friend JK_Chaos, so that he can make good use of them. The total cost of the CNC project, including bread board, sockets, battery connectors, components, solder and ICs is just below Rs.250/-

Its always good to use components that are lying around. I am personally biased towards using LM124 or its cheaper cousin LM324 in the few circuits I have made for work as it takes less space, is a quad opamp which also gives flexibility in design and its a quite good IC. Sometimes I don't need all four but its good to have spares for expansion

 

[hildebrand]

This happens, especially in the modern world. When a local friend of mine saw one of the ceramic phonostages which I had built (this is the one which was for my good friend RP), he asked me to paint the components and the contact side of the bread board, black so that nobody can either service or duplicate the design. What a joke!! But that's the way people think I guess

That's abonimable but very true of many people. I try to stay away from them (as I do from hoarders of records, booklets, movies etc). I keep telling such people that hiding and doing so doesn't make them the creators of the thing and that you will get more than you give, but they don't listen. I guess its an inherent quality to share. Some just don't have it.

 

[Tanoj]

Hi,

If HFV ever conducts elections to become Mod/some good position, i think sachin will win the elections for sure

There must be hardly anyone who does not know him, and who all know him praise him lot for everything he does



Regards


Tanoj

 

[john_k_antony]

Hi,

If HFV ever conducts elections to become Mod/some good position, i think sachin will win the elections for sure

There must be hardly anyone who does not know him, and who all know him praise him lot for everything he does



Regards


Tanoj

+ 1 MILLION votes to above :clapping:

 

[kuruvilajacob]

Sachin has been a wonderful person in helping many solve their " phono stage" hiccups. I am enjoying a phono stage which was originally a Sachin origin. Some modifications like isolation of power supply etc made by me. Reuben heard it yesterday and was impressed. Thank you Sachin. You made life affordable

 

[murali_n]

+ 1 MILLION votes to above :clapping:

Yes sure Sachin is a Mod(i) of a person in this forum.

N.Murali

 

[reubensm]

so finally after a lot of posts and anticipatory commitments, here goes...

Finally got down to wiring up my version of the CNC phonostage which I have built for my good friend FM JK_Chaos. Connected it up with the batteries and had my SL3200's M44-7 provide the source feed. The output of the CNC went into the axillary input of the NAD 3020

Here are the long awaited pics, please note that I ran out of 3.3K resistors (son was playing with a couple of them and lost them) and had to use salvaged components from the junk box. Also I could not get the jumpers from local stores and hence had to make the pins myself.

I have used 2 Japanese Hitachi vintage (humble) 741 OP amps per channel (these were lying in my junk box since I was in college) but the rest of the circuit and design remains the same.

First impressions without engaging any of the loading resistors:

Dead silent, not background hiss or hum or anything, without the record playing
Good output gain, sounds very loud with the volume control in 9 o' clock position
Sound quality is superb, silky highs, deep lows, pronounced mids, left the NAD 3020's phonostage far behind (yes, this is true). I am sure this will even better up after some serious burn-in.

After adding the jumpers, thought it sounded very fluid with the 47k input loading. Shall experiment a bit more with it and post my findings.

There is an old saying - seeing in believing, in this case I would say, hearing is believing. This is indeed a brilliant phonostage and I am now a believer.

Thanks Sachin.

 

[peace_sells]

so finally after a lot of posts and anticipatory commitments, here goes...

Finally got down to wiring up my version of the CNC phonostage which I have built for my good friend FM JK_Chaos. Connected it up with the batteries and had my SL3200's M44-7 provide the source feed. The output of the CNC went into the axillary input of the NAD 3020

Here are the long awaited pics, please note that I ran out of 3.3K resistors (son was playing with a couple of them and lost them) and had to use salvaged components from the junk box. Also I could not get the jumpers from local stores and hence had to make the pins myself.


I have used 2 Japanese Hitachi vintage (humble) 741 OP amps per channel (these were lying in my junk box since I was in college) but the rest of the circuit and design remains the same.

First impressions without engaging any of the loading resistors:

Dead silent, not background hiss or hum or anything, without the record playing
Good output gain, sounds very loud with the volume control in 9 o' clock position
Sound quality is superb, silky highs, deep lows, pronounced mids, left the NAD 3020's phonostage far behind (yes, this is true). I am sure this will even better up after some serious burn-in.

After adding the jumpers, thought it sounded very fluid with the 47k input loading. Shall experiment a bit more with it and post my findings.

There is an old saying - seeing in believing, in this case I would say, hearing is believing. This is indeed a brilliant phonostage and I am now a believer.

Thanks Sachin.

Looks great! Good to hear that it sounds so good too! BTW why 4 opamp ICs? I thought 2 would be enough.

 

[reubensm]

Looks great! Good to hear that it sounds so good too! BTW why 4 opamp ICs? I thought 2 would be enough.

Sachin's design uses dual OP amps which literally means that each IC has 2 OP amps built in. Hence his design requires just 1 IC per channel. My design uses simple single OP amps and hence it requires 2 ICs per channel.

 

[sachu888]

Very nice work :clapping: We did experiment CNC with dual mono,but original National Semiconductor design sounds more open.Batteries also last long in 2 Opamp design.
I think I first time I am seeing your TT. It looks in a mint condition :thumbsup:

Regards
Sachin

 

[reubensm]

This was a maverick design as JK listens to predominantly hard rock and heavy metal. Hence I thought that a high level of accuracy was not required.

Yes my 3200 is in mint condition both functionally and cosmetically (some mild scratching on the dust cover only), got it from my good friend FM Flanker who incidentally is also the very first friend I made on the forum.

 

[reubensm]

Still playing and it sounds so nice, don't feel like turning it off

 

[Thad E Ginathom]

Considering the very high prices that people pay for phono pre-amps, it is wonderful and inspiring to see such results with modest-cost DIY!

Sachin, Reuben, and all... Keep up the good work!

 

[reubensm]

Final cost of my CNC build:

Components, board, solder, sockets, ground screw, battery clips, etc (excluding ICs): Rs.125/-
9 volt batteries: Rs.20x2, Rs.40/-
Hitachi LM741 x 4: Paid Rs.5/- for each from my pocket money back in the day (think it was 1989), current price of a Chinese 741 is Rs.7/-, hence taking Rs.28/- as the cost
Yet to decide on the cabinet

Spend as of now: Rs.193/-

 

[omishra]

Reuben, nice build!
these delicate circuit should get you on cloud #9 with well made PCB and low noise component adds to performance. still it would be nice to have some design consideration of phono stage. Each ground current should end towards power supply ground, isolation of OPAMPs. And I am believer OPAMP does affect sound and each sounds differently.

 

[reubensm]

Reuben, nice build!
these delicate circuit should get you on cloud #9 with well made PCB and low noise component adds to performance. still it would be nice to have some design consideration of phono stage. Each ground current should end towards power supply ground, isolation of OPAMPs. And I am believer OPAMP does affect sound and each sounds differently.

yes agree 100%

With the result speaking for itself, I am now contemplating 2 proper CNCs with high grade components for my Garrard 401 and Lenco L75 (currently in the works with Mr. Kuruvila). The other thing is currently I am running on batteries. Would love to build your high grade PSU for it.

What tickles me is that with such a rudimentary build, I was able to out-beat my 3020's phonostage. Can't wait to match this one up with the 106's phonostage but I know that will be a tough ask for this CNC avataar.