Modified my Yaqin MS-12B

[gabriel1998]

MS-12B is used for phono stage only.

Performed Mod 1 and Mod 2, although used relatively cheap Vishay resistors and capacitors purchased from RS. Also, changed the 15R resistor to 22R.

More pronounced bass and treble appears to be less harsh.

anyone have a pic of that resistor change? Mine runs very hot at times by the 12au7

[seanb]

hi on mod 1 the 47k resistor change which resistors do you remove. i have done the other mods and their is definitely an improvement.do you have any pictures of the resistors to remove on mod 1 please. thanks for your great ideas

[gabriel1998]

hi on mod 1 the 47k resistor change which resistors do you remove. i have done the other mods and their is definitely an improvement.do you have any pictures of the resistors to remove on mod 1 please. thanks for your great ideas

Hi,

You can see it on the MOD 2 pics. I didn't like the caddocks. I installed Z201 Z-FOIL RESISTOR and I love them!! So friggin Clear!

[fks76]

what value sonicaps would I use for the 110v preamp in the U.S.? would they still be 1uf?

[fks76]

Also are the resister mods in mod 1 only effecting the phono stage? or would they do good if you only used it for a line stage?

[ebj29]

Also are the resister mods in mod 1 only effecting the phono stage? or would they do good if you only used it for a line stage?

Yes, they only effect the phono stage.

Yes, 1uf is the same for US 110v.

Also, It has now been a year since I made these mods and I have to say, the sound is everything I want! Textural, but never aggressive, and quite detailed. I have no desire to look further!

[fks76]

so I should get 1uf 220v caps even though the preamp runs off 110v in the U.S.?

[ebj29]

so I should get 1uf 220v caps even though the preamp runs off 110v in the U.S.?

Absolutely.

Have fun!

[Laudanum]

so I should get 1uf 220v caps even though the preamp runs off 110v in the U.S.?

It's not the line voltage that directly determines the caps voltage rating, it's the voltage through the circuit that the caps themselves will "see" that determines the necessary rating. Voltage is stepped up or stepped down throughout different sections of a pre-amp, phonostage, amp etc. I dont know that particular preamp / phonostage, just referring to things in general.

[fks76]

OK great, would it be alright to use 1uf sonicaps 200VDC instead of 220?

[ebj29]

OK great, would it be alright to use 1uf sonicaps 200VDC instead of 220?

Yes, 200vdc is fine.

[fks76]

Thanks for the great advice, last thing I need to know is if I put in the phono tape out mod, can I run that out of the tape out to something else and back in the cd/dvd input.

-Jake

[ebj29]

Thanks for the great advice, last thing I need to know is if I put in the phono tape out mod, can I run that out of the tape out to something else and back in the cd/dvd input.

-Jake

Yes, that'll work. The phono stage will work independently from the preamp stage.
By the way, I feel that the phono out mod was by far the most important improvement. The phono stage of this thing is much better than the line stage. The line stage isn't bad, but it has its defects. It needs a grid blocker mod to eliminate ringing and I haven't taken care of that yet.

[Rolli666]

Do you guys know if auricaps would do the trick in the 1uf and should I get 3 matched pairs. Only would run me 3 bucks more. I found them and 40% off.