BeoGram

Re: MMC 4 loads , Extremly confused preamp

yiancar — Wed, 29 Dec 2010 17:45:08 GMT

Finally guys . the amp is cased up and fully working . I settled with the 220pf and some wima caps. It sounds very very full and balance i can say. Also the RIAA curve of the amp must be dead accurate as the pops have soften out.

Thank you for all the knowlage you gave me :)

Re: MMC 4 loads , Extremly confused preamp

yachadm — Sat, 13 Nov 2010 15:49:49 GMT

In order of preference, make sure you use NP0 or C0G MLCC ceramic caps, for experimentation. They are the most stable of the "cheap" capacitors. Murata or TDK here.

Once you've decided on the correct value, you can install Polypropylene film caps of the same value for added smoothness in sound. Try Wima, Nichicon or Panasonic here.

Menahem

Re: MMC 4 loads , Extremly confused preamp

yiancar — Wed, 03 Nov 2010 14:24:12 GMT

Well it was REALLY bad, everything sounded darkish. It was bad, "stop me now before i burn your ears" bad

Re: MMC 4 loads , Extremly confused preamp

chartz — Wed, 03 Nov 2010 14:06:07 GMT

yiancar:

Guys just realised that i made a huge mistake, in my original trt I used 4700pf instead of 470pf

Oh dear, it must have sounded dreadful!

Re: MMC 4 loads , Extremly confused preamp

yiancar — Wed, 03 Nov 2010 13:40:58 GMT

Guys just realised that i made a huge mistake, in my original trt i used 4700pf insted of 470pf, thats why it sounded so bassy and dead :), Tomorow I will try the 220pf . I also couldent find any 330pf with <5% tolerance :(

Re: MMC 4 loads , Extremly confused preamp

yiancar — Mon, 01 Nov 2010 13:56:47 GMT

Thanks :)

Re: MMC 4 loads , Extremly confused preamp

chartz — Mon, 01 Nov 2010 13:09:22 GMT

yiancar:

Oh another cap to test! Just a quick one, how does the sound gets as capacitance is decreased?

Well usually the response falls down, resulting in a dull top-end. But on some cartridges, the increase gives a horrible lift at about 10 kHz with makes up for a livelier, but more tiring sound. Experimenting is the only way to find out. With B&O MMC series, I settled for 330 pF, although B&O goes for 220pF which gives a flat response, lacking a little in life for my tastes. With SMMC 20EN 220pF is just right! With a Goldring 1022, I also increased the load to 56k to flatten the response.

A can of worms, this.

Re: MMC 4 loads , Extremly confused preamp

yiancar — Mon, 01 Nov 2010 11:54:18 GMT

Oh another cap to test! Just a quick one, how does the sound gets as capacitance is decreased?

Re: MMC 4 loads , Extremly confused preamp

chartz — Mon, 01 Nov 2010 07:28:22 GMT

Hi,

Just to make your decision a little harder, I use 330 pF...

Re: MMC 4 loads , Extremly confused preamp

yiancar — Sun, 31 Oct 2010 11:08:20 GMT

Tnx :) just orders some 220pf caps. I will try a 220in one channel and 470 in the other so I will be able to decide which is better . Am going to post my results later:)

Re: MMC 4 loads , Extremly confused preamp

tournedos — Sun, 31 Oct 2010 05:12:06 GMT

For the earlier MMC20 series the correct capacitance was 220 pF, so perhaps try with something smaller than 470. But in the end, let your ears decide!

MMC 4 loads , Extremly confused preamp

yiancar — Sun, 31 Oct 2010 02:38:32 GMT

Hey guys, I am building a phono amp for my favorite beogram 2000. It includes a MMC4 cartage and its time to adjust the pickup load on the preamp. The input resistance is 47K ohms, thats for sure. However the capacitance is killing me, Beoworld product page recommend 220pf, I have read 100pf or 400pf in other places. The preamp is now working with 470pf, as you guys are much more experienced than me, shall i change it?

Yiangos :)