Break in phono with a cd player

[zmffna]

Hello !

I have a Diy MM phono preamp that I want to use a cd player to break it in. Hopfully I can put a cd on repeat and let it play for som days, before start to listen to it With my turntable.

I under stand that this is posible with a resistor on the cable, buth dont know the value in ohm. Do anybody have eksperience With this ?

Regards

 

[planet10]

A CD player should have an output of 2V, yourl MM stage likes how much input, mA?

dave

 

[zmffna]

Hello planet 10 !

I dont know in mA, but the cartridge output is 2-4 mv. I would like to have a resistor on the interconnect to bring the 2v Down.

Frode

 

[scottjoplin]

Hi Frode, speakers break in, phono preamps don't

 

[planet10]

Capacitors are mechanical devices, they break-in.

dave

 

[rayma]

I have a Diy MM phono preamp that I want to use a cd player to break it in.

You would best use an inverse RIAA equalizer between the CD player and the phono input.
This would give a normal signal spectrum to the phono input.
Reverse RIAA

 

[zmffna]

Hello scottjolin !

I can not fully agree about that, as I have eksperiensed that cd, amplifier, preamplifier and cable have sounded bether after playing som hours.

 

[planet10]

What rayma said.

dave

 

[zmffna]

Thank you rayma !

This is to mutch work, im not gone listen to it, just put a cd on repeat and let it play for some days. I only need the in signal to be simular mv from cd as from a MM pick up

 

[scottjoplin]

Capacitors are mechanical devices

What?

 

[scottjoplin]

Hello scottjolin !

I can not fully agree about that, as I have eksperiensed that cd, amplifier, preamplifier and cable have sounded bether after playing som hours.

It depends what you mean by "break in". Some circuits perform on spec when they have warmed up, including your ears

 

[rayma]

I only need the in signal to be simular mv from cd as from a MM pick up

The inverse RIAA circuit does exactly that.

If you just want to use resistors, then you could use a series 100k and a shunt 1k,
though this will not work as well as the inverse RIAA circuit.

 

[zmffna]

Hello rayma !

100 k in series and a shunt 1 k. I was thinking of using a cheep interconnect and cut it in two, and solder a resistor between them. Do Your sugestion mean 100k between them in the positive wire and 1 k between the positive and negative wire ?

 

[rayma]

Yes, the 100k is in series with the center wire. The 1k goes after the 100k (nearer the phono preamp),
between the two wires.

 

[zmffna]

Thank you rayma !

I have looked at The inverse RIIA again, and I think I have the parts. Maybe I go for that solution. Thank you again for Your advice.

Sincerely
Frode

 

[rayma]

That will work better, especially for the capacitors in the circuit.
Any parts values that are reasonably close (even 20% off) will be fine.

 

[scott wurcer]

Capacitors are mechanical devices, they break-in.

dave

Then you need to mechanically break them in, this nonsense is an insult to the intelligence of most here.

 

[Mark Tillotson]

Re capacitors, read these articles for a more nuanced approach to real-world capacitors and their imperfections, including changes with time under bias. Cyril Bateman's Capacitor Sound articles | Linear Audio NL
(and no, they don't need burning in)

My inverse-RIAA circuit I stuck in a little diecast box:

888k = 820k + 68k
3.7nF = 2.2nF || 1.5nF
600 ohm = 1k2 || 1k2
Can't remember the attenuation factor, I forgot to write it on the box! It definitely worked reasonably well with playing music and test tones through my RIAA preamp designs, not that I claim its hugely accurate.

 

[Tromperie]

Capacitors are mechanical devices, they break-in.

dave

They were 'semi-mechanical' devices when large sheets of metal were suspended by insulators at a time when Marconi was attempting trans-Atlantic radio transmission. Are they still being used in modern electronics?

I can not fully agree about that, as I have eksperiensed that cd, amplifier, preamplifier and cable have sounded bether after playing som hours.

That is your brain 'breaking in' and has nothing to do with the components.

 

[egellings]

With a 2V signal from the CD player, you will really beat up your phono stage, which maxes out at maybe 100 or so mV input. It would be driven into hard clipping all the time. Take Rayma's advice.