DIY Moving Coil phonostage

[sachu888]

Hi Sachin,

Can you post a link to the calculator or email me the calculator? I could not find it in your links on AK. I would need it for carts later on.

Thanks
Steve

Hi Steve,
I have sent you a mail.

Regards,
Sachin

 

[gopib]

Steve,

I built one for my friend...and within a few days he changed the cart..using Sachin's calculator fixed new values...it was a breeze...my friend is quite happy..

gopi

 

[captrajesh]

I will order parts for you,let me know which cart are you going to use with this pre.

I'm putting the cart before the horse (pun intended)

I do not have a cart at present, only looking for a horse, which you seems to have bred. Cart will come later.

 

[sachu888]

I'm putting the cart before the horse (pun intended)

I do not have a cart at present, only looking for a horse, which you seems to have bred. Cart will come later.

We are in a same boat capt.

Regards,
Sachin

 

[sachu888]

Steve,

I built one for my friend...and within a few days he changed the cart..using Sachin's calculator fixed new values...it was a breeze...my friend is quite happy..

gopi

Hi Gopi,
Can you write some review.Did you like it?

Regards,
Sachin

 

[stevieboy]

Hi Gopib,

Thanks for that info! Yes it will be easy with those screw things sachin has built into it. Sachin emailed me the calculator. Sachin, the zip file on ak wasn't getting extracted you might want to inform the relevant uploader there. Or maybe I should have been logged in to download it...

Regards


Tapatalking. Look ma, no computer!

 

[gopib]

Hi Gopi,
Can you write some review.Did you like it?

Regards,
Sachin

Sachi,

Will do in a few days...

thanks,

Gopi

 

[sachu888]

Hi Gopib,

Thanks for that info! Yes it will be easy with those screw things sachin has built into it. Sachin emailed me the calculator. Sachin, the zip file on ak wasn't getting extracted you might want to inform the relevant uploader there. Or maybe I should have been logged in to download it...

Regards


Tapatalking. Look ma, no computer!

Which zip file Steve?

Regards,
Sachin

 

[stevieboy]

Sachin, was there on the thread on AK, the long one, somewhere in the middle pages.

Regards


Tapatalking. Look ma, no computer!

 

[jls001]

I got the R1/R2, etc resistors from a local electronics parts store. They had only 10% tolerance parts. I could not travel to the other end of town to Lamington Road market, so I ended up buying the nearest available values from this shop:

1. R1: supposed to be 14 Ohms but got 15 Ohms. Actual measured values are 16.3 and 16.4 Ohms.

2. R2: supposed to be 420 Ohms but got only 390 Ohms. Actual measured values are 393 and 394 Ohms. For experimentation with R2 = 10xR1 idea, I also bought 150 Ohms resistors (actual values were 147-ish Ohms). Will see which one sounds better.

Total damage: 3 rupees for 6 resistors.

 

[omishra]

I got the R1/R2, etc resistors from a local electronics parts store. They had only 10% tolerance parts. I could not travel to the other end of town to Lamington Road market, so I ended up buying the nearest available values from this shop:

1. R1: supposed to be 14 Ohms but got 15 Ohms. Actual measured values are 16.3 and 16.4 Ohms.

2. R2: supposed to be 420 Ohms but got only 390 Ohms. Actual measured values are 393 and 394 Ohms. For experimentation with R2 = 10xR1 idea, I also bought 150 Ohms resistors (actual values were 147-ish Ohms). Will see which one sounds better.

Total damage: 3 rupees for 6 resistors.

There few standard values which could be used in series ->

For 14 ohms ~ 10+3.9 ohms series (For 10 X -> 100 + 39)
or -> two 27 ohms in paralleled

--------------
For 420 ohms ~ (390 + 27) ohms series or (220 + 200) or (150 + 270)

or 470 and 3.9K paralleled will result 419.xx

 

[jls001]

There few standard values which could be used in series ->

For 14 ohms ~ 10+3.9 ohms series (For 10 X -> 100 + 39)
or -> two 27 ohms in paralleled

--------------
For 420 ohms ~ 390 + 27 ohms series or 220 + 200
or 470 and 3.9K paralleled will result 419.xx

That's brilliant thinking!

By the way, what are the generally available resistor values in a normal electronics parts shop? I think I will go back this evening itself and get these parts.

 

[omishra]

That's brilliant thinking!

By the way, what are the generally available resistor values in a normal electronics parts shop? I think I will go back this evening itself and get these parts.

Look description of this product (this is SMD, dont buy unless you would like to venture into SMD DIY)

These are most commonly useful, see table in description of this.
These are general standard values mostly found everywhere. There are some more odd values but difficult to find.

Edited more combinations in previous post.

 

[sachu888]

That's brilliant thinking!

By the way, what are the generally available resistor values in a normal electronics parts shop? I think I will go back this evening itself and get these parts.

I am gong to order parts for this PS.I will order those resisters for you.

Regards,
Sachin

 

[jls001]

I completed soldering last night. R1/R2 and R9/R10 are locally procured resistors. The leads were a bit rusty but nothing good ole scraping could not cure.



Uploaded with ImageShack.us

Now, where's that cart?

Need to start planning cabinet.

 

[sachu888]

I completed soldering last night. R1/R2 and R9/R10 are locally procured resistors. The leads were a bit rusty but nothing good ole scraping could not cure.



Uploaded with ImageShack.us

Now, where's that cart?

Need to start planning cabinet.

It looks good Joshua,use CAT5 cable for RCA.Its very easy to work and has good quality copper.

Regards,
Sachin

 

[jls001]

It looks good Joshua,use CAT5 cable for RCA.Its very easy to work and has good quality copper.

I do have some nice and thick silver clad copper cables. Let me see if I can dig them up.

 

[sachu888]

I do have some nice and thick silver clad copper cables. Let me see if I can dig them up.

Thick wire could ruin PCB traces and solder pad.Twisted pair of CAT5 would be a better option IMO.

Regards,
Sachin

 

[captrajesh]

Got lost in flurry of posts I guess. Could you comment on it Sachin.

Another noob question. If the resistance has to be so varied for different carts, can't we use an LDR in place of these resistors?

 

[sachu888]

Got lost in flurry of posts I guess. Could you comment on it Sachin.

Hi Capt,
I don't think LDR can be used for this purpose.LDRs are very costly and need to be matched.

Regards,
Sachin