Mezmerize DCB1 Building Thread

okay i noted that for hot rodded.

one more thing, about the alps blue 2x100K pots
how about if i parallel with 100K dale resistors, that will give 50K in result.

like this:
normal 2x100K alps blue
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paralleling with dale 100K
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result
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what do you think?

ps. i am a very beginner, please advice if anything goes wrong.
 
A little help if you please

I purchased the Mesmerize board from DiyAudio store.

This board seems to have different main filtering cap size requirements than most of the "Blue" boards which are posted in this thread. ( I didn't see that before ordering) I'm referring to the 4700uF rated ones.
The BOM says Min. 35V, 22mm wide, with 10mm lead spacing.
This board requires ~20mm (Max?) measures 18mm wide and 7.5 lead spacing.

I'm having difficulties finding a high quality cap in the recommended value that fits this size format.
I'm sure others have run into this issue as well. Any suggestions would be greatly appreciated.
Would it be OK to just solder a couple of short legs on a snap in cap?
Heck, I'd even be OK with soldering them on the underside of the board. (may be my only choice)

The Hypno. has 4 caps the Mez has 2 caps. Is there any advantage to increasing the capacity from 4700uF to say 6800uf?

Thanks for the help. :warped:
Ron
 
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The DIYA MEZ used the same gerber as the original Mez (mkII blue). If you got some good caps you wanna utilize be creative with their fit by all means. But use some elastic goo to bond them bases to PCB. If you gonna run it at high current, 6800uF is OK.
 
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P.S. I went and got the BOM from DIY store just now for a check. I clipped the footnote.
 

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Salas,
Thank you for the uber quick reply,
I must be confused, but I am learning. :D
I was reading the same BOM, near the top on the right hand column it says:
"Your Choice - Spacing 10mm" on the Capacitor row 4700uF.
I was also looking at a different board online which has 2 rings at the capacitor location. Hypnotize boards are different in this regard? My mistake.

However I DID find a "New" cap offered from Mouser, it is from Nichicon, the KA series. Here is what the press release says.

"NICHICON CORPORATION has developed the “KA Series” miniature aluminum electrolytic capacitor, which is intended to be used mainly for audio devices. It will be our highest-grade product ever achieving higher quality sound in audio devices than our standard 105°C-resistant “KT Series.”

link: http://www.mouser.com/ProductDetail...qA7GzKJLpb3iV5%2bUD0BtFtfXM6QKMo9p%2b1rwHKyg=

Would this be an acceptable choice for this location? Or is it just marketing BS?

Ron
 

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Salas,
Thank you for the uber quick reply,
I must be confused, but I am learning. :D
I was reading the same BOM, near the top on the right hand column it says:
"Your Choice - Spacing 10mm" on the Capacitor row 4700uF.
I was also looking at a different board online which has 2 rings at the capacitor location. Hypnotize boards are different in this regard? My mistake.

However I DID find a "New" cap offered from Mouser, it is from Nichicon, the KA series. Here is what the press release says.

"NICHICON CORPORATION has developed the “KA Series” miniature aluminum electrolytic capacitor, which is intended to be used mainly for audio devices. It will be our highest-grade product ever achieving higher quality sound in audio devices than our standard 105°C-resistant “KT Series.”

link: UKA1V472MHD Nichicon | Mouser

Would this be an acceptable choice for this location? Or is it just marketing BS?

Ron

Hypnotize are different in PCB details indeed. Because geared up for even heavy hot rod, their filter caps are 4, can be fatter & snap in (2 pitches served), their CCS resistors positions are roomier.

Yummy that new cap. I would taste it if in your shoes. Nichicon has a line of such marketing caps that users seem to like, so it could be a decent good cap at the very least. See also FG series.
 
Just FYI, I used Panasonic FC 4700 uF 25V, and am happy with the result. About half the cost of the Nichicons, but many folks like the Nichicons in general. A higher-voltage part is usually a good idea, especially for electrolytic caps. At risk of heresy, I don't think the brand/type of filter caps makes a significant difference; but then, I guess if I really believed that I wouldn't have bought the Panasonic FC's (there are cheaper capacitors available). So that raises the question: What are the measurable properties of a capacitor that make it "good" in that application? I would assume that low ESR, low DF, and high temp rating are all good things to guide a choice. Other than dubious listening tests, are there any other objective criteria for selecting filter caps? (yeah, I know there are whole threads dedicated to that discussion)
 
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The lower the DF & ESR, the lower high frequency impedance the better are the objective criteria. The smoothness of the paper's fibers used in the winding and some properties that the manufacturers know in the chemical its soaked with are their ''claims'' area. DNM (BHC) had slits on the foil and had some more objective explanations about eddy currents in their literature. http://www.youtube.com/watch?v=kU6NSh7hr7Q
 
My first Preamp

Just finished a Mesmerize (my first preamp).

Getting the following voltages:
AC: 14.04 - 0 - 14.03
DC (rectified): +18.42 / -18.52

over current-setting resistors:
1.932 V (neg) | 1.812 V (pos)

out (of PSU part):
+10.270 V | -9.676

output (DC offset):
+0.5 mV (L) | 0.0 mV (R)

Very happy with the DC offset. :)
The LED quintuplet on the POS rail are slightly brighter than the NEG ones.
Maybe I fudged something up when matching them? The current setting resistors measure 33.8 ohm on each rail (perfect match).
This means that the NEG rail has 57.2 mA and the POS rail 53,6 mA going through them.

- Shouldn't this be matched?

Vdrop over LED quintuplets:
9.025 V (neg) | 9.604 V (pos)

Vdrop over LED triplets:
5.452 V (neg) | 5.455 V (pos)

So far so good.. (?) Even got the input relays up and playing.

Did a scope on the output of the PSU section. Ripple on the line is non-existent (0.5 mV or less). Looking forward to putting some music through this.
 
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No problem, the (+) leds quintet is designed to run more current in the Mezmerize specifically, thus perceptibly a bit brighter, and bit more +V. Goofs the offset and brings a bit different THD profile as I liked it during developement for low CCS feed. No point to match exactly the rails CCS, makes no difference in such Mosfets transconductance by that scale of difference. With a scope on rails you just make sure it has no oscillation waveform and you see a line close to its residual SNR for set bandwidth and probe's scale/pick up.