Ceramic Phonostage Build

[reubensm]

Have been taking my own sweet time, contemplating on what to do with regard to equalization for my Garrard RC210's EEI CS2000 Stereo Ceramic Cartridge. Have been looking up various designs and finally, after listening to the ceramic cartridge playing, directly through the Aux input of the 3020, I realized that something extremely complex was not required. By itself and without equalization, the EEI CS2000 sounds quite pleasant with the loudness switched on, bass control in full boost and treble control in flat position. So finally shortlisted this circuit from the lot I've been looking through:

Got the opportunity to go down to the electronics bazaar last evening and picked up the components for this project. Talk about phonostages costing 1000s of dollars, I was surprised that all the components, inclusive of the bread board came up to around Rs.40/-. I have decided to keep it low end and not use any expensive components like bi-polar caps and paper caps. Have gone with common electrolytics and ceramics. Now, I'll sit down one of these weekends and put this together. Here are the pics of the components:

close-up of the underside of the bread board:

Watch this space for more.

 

[reubensm]

Also, the circuit foot notes specifies that metal film resistors are suggested for use. I've decided to go for the regular El-cheapo carbon ones.

More info about resistors can be found here: http://en.wikipedia.org/wiki/Resistor

Here's how to read the colour coding, on resistors:

 

[reubensm]

Using bread boards for projects is something that most of us (those into DIY) may have done at some point, especially with school projects.

Before starting, don't forget to drill holes for mounting screws:

There are many ways and methods of wiring electronic circuits on bread boards. However, the key to a successful and neat project is an effective component layout and clever component wiring. The first lesson is never to clip the component legs and solder them to the board. You'd then have to make messy inter-joining connectors under the board. Also, never leave component legs un-soldered just because you've routed the leg under the board to another tag. Finally, don't use too much of flux, this is extremely untidy. Take a look at an untidy example:

Instead, insert the components without clipping the legs, solder every exiting component leg to its concerned tag, then use the additional wire-length to cross connect to another tag. Similar to this:

Finally, leave about 2 mm gap between each component and the bread board. If components have to be replaced at a later stage, you can always clip the component legs over the bread board surface (component layout side) and solder the replacement. Use sockets and connectors where ever possible to avoid de-soldering and soldering as much as possible.

The secret for getting your bread board to look good and effective after wiring is to design a good and effective layout. The layout must not only look neat but should also facilitate easy access for servicing/replacement. Here is an example on how to design a good layout:

Finally use proper soldering techniques, don't apply too much heat on components, especially semi conductors.

 

[reubensm]

trying to do this real old school, early this morning, drew out the circuit diagram on a piece of paper from one of my son's old note books (just like the old times when my school rough note book had a lot of circuit diagrams drawn on the back pages). Also drilled the mounting holes on the bread board. While doing so, sufficient space must be left by the edges to avoid chipped edges while drilling and also while mounting. I did not use my electric drill but used an old scissors, just like we used to do back in the day.

 

[reubensm]

here's a useful table for interpreting the value of a capacitor from the marking (printing) on it. Particularly useful for ceramic disc capacitors.

VALUE

 

[haisaikat]

Is this project complete? eager to know the sound output

 

[reubensm]

Is this project complete? eager to know the sound output

Nope, have just started with the circuit board today. Hope to solder the components together later in the evening. Watch this space for more pics and updates.

 

[quad]

Our FM Shaan is a master of general purpose boards. His work is an education -

http://www.hifivision.com/diy/29968-simple-symmetrical-amplifier-andrej-lackner.html

Post Pictures of Your Vero Board Designs Here. - Page 7 - diyAudio

Post Pictures of Your Vero Board Designs Here. - diyAudio

 

[omishra]

Our FM Shaan is a master of general purpose boards. His work is an education -

http://www.hifivision.com/diy/29968-simple-symmetrical-amplifier-andrej-lackner.html

Post Pictures of Your Vero Board Designs Here. - Page 7 - diyAudio

Post Pictures of Your Vero Board Designs Here. - diyAudio

+1, you posted this same thing I was searching for.

Reuben, this is great examples of work with perforated boards. It's more elegant and need not be dirty.

 

[reubensm]

yes, was looking for that myself but could not find it.

 

[breadyoures]

I did not use my electric drill but used an old scissors, just like we used to do back in the day.

 

[Robert Bose]

For Ceramic Cartridge I wuld recommend a simple FET Buffer

with one resistor in the Source leg to Ground and a coupling capacitor

of 2 microfarad ( 2 nos 1 microfarad in parallel )

From Gate to Ground 1 Meg and drain is connected direct to supply

of 12-18 V DC with one 120 Ohm and 47 microfarad supply decoupling

I built this circuit 20 years back on a small PCB ( no tracks only standoff )

and put it inside Cosmic Lab 3000 , it still works today

The Problem with EEI Ceramic is compliance is less and it wears out

the record over multiple playing times

Thanks and regards

Robert Bose

 

[reubensm]

FETs are always a good choice for phonostages. But honestly, given the fact that I am working with a record changer, thought I'll not go too high as I wanted to maintain some of the old vintage feel. The RC210 was one of the better changers (and work horses) from the Garrard stable and has a huge fan following. Its look and feel is very traditional and hence, it would be good to get some old-time ceramic (or crystal pick-up) cartridge signature sound out from it. That's why I'm keeping the phonostage very simple. However I must say that I've gone for low noise BC109C transistors.

Here is the transistor's datasheet: https://www.sengoku.co.jp/item/pdf/BC109.pdf

 

[reubensm]

Finally I got some time earlier yesterday to finish the layout and solder the components to the bread board. Now, need to sit down and test it with the TT. Pictures to follow.

 

[vmscbe1974]

Dear Mr.reubensm

I too was contemplating for a board like this but more as noise reducer where in amplify the 78 rpms in the RIAA and passed through a equalizer where only the 30 hz and below frequency and 8 khz and above frequencies are not amplified to reduce the noise from 78 rpm records would this be possible? kind of parametric equalizer. Is it possible to design one like what i presume or could something even better ?

regards
Srinivasan

 

[reubensm]

Dear Mr.reubensm

I too was contemplating for a board like this but more as noise reducer where in amplify the 78 rpms in the RIAA and passed through a equalizer where only the 30 hz and below frequency and 8 khz and above frequencies are not amplified to reduce the noise from 78 rpm records would this be possible? kind of parametric equalizer. Is it possible to design one like what i presume or could something even better ?

regards
Srinivasan

Yes, this can be designed. I have done some simple filters for 78rpm in my younger days. I've put this phono stage together but am yet to test it. Shall do so this week end.

 

[reubensm]

here's an example of a scratch and rumble filter:

 

[vmscbe1974]

Dear Reubensm

Have you tested your filter? Kindly guide me to do this set up. Can this be enhanced for more clear audio from 78 rpm bit worned out records? I have a collection of 1200 78 rpm records so need one to be connected.
Regards
Srinivasan.

 

[reubensm]

Sure, why not

I am going to test my phonostage (ceramic) this weekend. I have not built the scratch and rumble filter yet but can do it. From my experience, the surface noise from 78rpm records can only be controlled but not completely eliminated. Hence, these filters are not likely to clear out the sound for you (especially if you have 78s that were played on needle gramophones)

 

[quad]

Rod Elliott's ESP - P99 is an excellent rumble filter.

http://sound.westhost.com/project99.htm

Another one - from "Signetics Analog Data Manual," Signetics, Sunnyvale, CA, 1977, p 638-639.

NE5534 - Used after pre-amp in high-quality audio system to improve reproduction of phonograph records. Two-pole Butterworth design has switchable breakpoints providing any desired degree of filtering.