Batery powered DIY CNC phono stage

[haisaikat]

@sachu888 need suggestion, its 4 years i have your CNC. Earlier running with rechargeable batteries. Now one of the rechargeable Envie battery leads rusted and its charge holding capacity has reduced and drains easily if idle. So time to replace. A new pair 300 mah each Envie 9 volt on Amazon is 380 x 2 = 760 rupees. Whereas 600 mah Duracel 9 volt pair costs 440 rupees. So thinking if i should use Duracell for some time which has lower drain current, of course its not rechargeable.

I have 2 questions, as below
1. How much is the load current for CNC, to gauge how long will 600 mah duracells last
2. I was looking as DC battery options and every battery lowers its voltage gradually with time, some place it says 9v batteries drop to 6 - 7 volts over time. Does this impact the output capabilities of CNC? I had earlier not considered the PSU option assuming DC battery is better but looking at this voltage drop problem wondering if its time to switch

Thanks in advance

 

[sachu888]

@sachu888 need suggestion, its 4 years i have your CNC. Earlier running with rechargeable batteries. Now one of the rechargeable Envie battery leads rusted and its charge holding capacity has reduced and drains easily if idle. So time to replace. A new pair 300 mah each Envie 9 volt on Amazon is 380 x 2 = 760 rupees. Whereas 600 mah Duracel 9 volt pair costs 440 rupees. So thinking if i should use Duracell for some time which has lower drain current, of course its not rechargeable.

I have 2 questions, as below
1. How much is the load current for CNC, to gauge how long will 600 mah duracells last
2. I was looking as DC battery options and every battery lowers its voltage gradually with time, some place it says 9v batteries drop to 6 - 7 volts over time. Does this impact the output capabilities of CNC? I had earlier not considered the PSU option assuming DC battery is better but looking at this voltage drop problem wondering if its time to switch

Thanks in advance

Hi Saikat
Power supply would be a better option, and some people reported CNC sounds better at =/-12V or +/-15V. We have now got a compact version of OPS power supply, designed by Omishra. I would suggest you to opt for a power supply instead of batteries. I would solder a board for you if you like. The connections and voltage settings are very simple. Here is a pic of OPS_Rev1 power supply.

Regards
Sachin

 

[jls001]

....and some people reported CNC sounds better at =/-12V or +/-15V.

+/-13.5V

 

[reubensm]

what a beautiful layout. Well done!!

 

[sachu888]

what a beautiful layout. Well done!!

Thanks, credit goes to Om

Regards
Sachin

 

[haisaikat]

+/-13.5V

This can be adjusted too?

 

[jls001]

This can be adjusted too?

Yes, the voltages of OPS power supply that Sachin posted is highly adjustable. One set of supplies is typically +15V/0/-15V. This can be adjusted to lower values. The second supply is 0/+24V and this too can be adjusted.

 

[haisaikat]

Hi Saikat
Power supply would be a better option, and some people reported CNC sounds better at =/-12V or +/-15V. We have now got a compact version of OPS power supply, designed by Omishra. I would suggest you to opt for a power supply instead of batteries. I would solder a board for you if you like. The connections and voltage settings are very simple. Here is a pic of OPS_Rev1 power supply.

Regards
Sachin

Will pm you

 

[haisaikat]

A small word of thanks to @sachu888 and @sadik to express my gratitude for building a powered CNC and fitting it nicely in a beautiful cabinet. I received it yesterday they have been extremely helpful in the building process resorting to my noob questions all the time. Here are some pics. Internal very neatly done.

thanks again.

 

[reubensm]

beautiful build, totally a fan of Sadiks cab work.

on another note, this is the first time I've seen input jacks and output jacks mounted in a horizontal config, but who cares, looks really cool.

 

[Deleted member 79865]

TT 1 (With Shure M44-7) -> CNC -> Amplifier
TT 2 (With AT 95E) -> Little Bear T7 -> Amplifier

@reubensm thanks for your comments. Sorry for late response.

BTW, can you throw some light one EAR 834P clones available for DIY implementaion in Aliexpress / ebay etc., mainly with respect to:

1. Their sound in comparison to CNC. I like to have a open sound with air.
2. Regarding the degree of difficulty involved in assembling and readying the kits.

Any suggestion for any other DIY PHONO preamp kit with sound comparable / better than CNC.

Ay..Parthobabu...This is awesome... Within a years time you are already looking for another phonostage...which I don't mind..But you are posting that requirement in CNC thread..doing kind of insult of the hardship involved behind CNC stage...This thread is dedicated to CNC...and you need to look for some other place to enquire something else... Don't you think that will be decent?
Moderators give me a thought on this please.

 

[peace_sells]

So, I recently got the CNC phono stage from Sachin for a friend. Took some time to make the enclosure. But it got finally ready a few days ago. Really happy with the way it sounds. The balance is so perfect it's almost scary.

A big thank you to Sachin in helping me to understand the technical aspects. Much appreciated! The wires are messy but I'll do it better next time

 

[sachu888]

Nice build, considering your first DIY. Good to know you are happy.

Regards
Sachin

 

[reubensm]

So, I recently got the CNC phono stage from Sachin for a friend. Took some time to make the enclosure. But it got finally ready a few days ago. Really happy with the way it sounds. The balance is so perfect it's almost scary.

A big thank you to Sachin in helping me to understand the technical aspects. Much appreciated! The wires are messy but I'll do it better next time

View attachment 39129View attachment 39130View attachment 39131

Nice build but i couldn't help supressing the chuckle on reading the label on the tranny - Sharp 500 amp (the would have meant milli-amp)

Also the primary winding circuit of the tranny exiting the cabinet should be re-done in my opinion. If the cabinet gets a little damp, you may end up with a small jolt

 

[Beginner_N]

Recently finished couple of CNC phonostage. Chassis design and manufactured by me.

 

[reubensm]

love the ground screw idea
Kindly give some more info about the tranny, would that be external?

 

[sachu888]

love the ground screw idea
Kindly give some more info about the tranny, would that be external?

The transformer is actually a 0/12, AC-AC wall wart. This way we can keep the transformer outside the case, so no issues of noise, buzz, hum etc from transformer.

Regards
Sachin

 

[Bloom@83]

Just wanted to share my experience of the CNC phonostage, pics of which are already shared by @Beginner_N (Nishant) on Sept 26.

Couple of months back I DM-ed Sachin (@sachu888 ) for a good DIY phonostage that would fit my limited budget. I had heard the famed Schiit Mani sound on my system on loan so that was my only reference point. Sachin explained shortly and succinctly why the CNC Phono would give much better sound , and I looked up the huge thread on Audiokarma, spoke with few other very respected senior FMs here (@reubensm amongst them ) and decided to go ahead with CNC.
Just to mention that my existing phono was the built in one in Marantz PM5005 with two in-built OP Amps, basically a single IC basic phonostage - but it sounded quite good to my ears till then.

Owing to pandemic induced difficulties the CAB for the CNC phono took some time - Nishant will probably remember my endless bugging as to when the thing will finally materialise.
Finally the finished CNC - quality checked by both Nishant and also Sachin at my request , arrived and I have had two days with it running some of my favourite records - from King Crimson progressive rock to Scott Hamilton jazz to Kishore Live at Los Angeles to RD Burman’s Shalimar and Saagar.

And boy (here I desperately need to check and control myself ) - the sound is , for lack of a better word- OUTSTANDING. I wasn’t prepared for it. Yes Reubensm did tell me that the CNC was a very high end phono sound but never having used a DIY before my brain had certain preconceived notions about possible quality.
All these notions shattered as soon as the new phono was put in my chain - the bass suddenly was tighter (I could literally feel the lower end punching me in Saagar) , the midrange , especially vocals more forward and present , and where the highs on tenor sax seemed to roll off a bit in Scott Hamilton’s record earlier here it was fully defined !
I could not move with the record spinning with the CNC in my chain - the sound became so much more engaging.

I wish more people listening to TTs on their entry level integrated amp phonos get the CNC and experience a BIG upgrade for very little money. Indeed , if it were not DIY, experienced people have commented it can easily be priced with phonos costing upwards of 35K INR.

My deep gratitude to Nishant , reubensm and most of all to Sachin.

 

[reubensm]

Thanks for the kind words but honestly, the credit should go to sachu888 and beginner_N who's efforts are really a huge bonus for the DIY community.

 

[sanjivnayak]

Thanks @Bloom@83 for CNC phono review. But let us know your gadgets TT, AMP etc in the chain. Do you use the CNC with battery? And if CNC sounds better than Schiit Mani ?