Mezmerize DCB1 Building Thread

[Tea-Bag]

Guys I am waiting for some mesmerize boards I got from the diyaudio store and I am currently planning on the rest of the parts.
What I was wondering is if there is a way to get two outputs from the board, so that I can drive 4 monoblock amps (dual - dual mono setup driving woofers and mid-twitters separately)
Thanks a lot
Dimitri

I just jumper the outputs together from the RCAs.
Often I use a 100R resistor from the hot signal to jumper.
I believe this can reduce noise, but I am uncertain if this is true or not.

 

[KatieandDad]

Guys I am waiting for some mesmerize boards I got from the diyaudio store and I am currently planning on the rest of the parts.
What I was wondering is if there is a way to get two outputs from the board, so that I can drive 4 monoblock amps (dual - dual mono setup driving woofers and mid-twitters separately)
Thanks a lot
Dimitri

The usual trick is to use the Reverse Summing circuitry. i.e. feed each output through its own series resistor (for DC coupling) or a cap and a resistor (for AC coupling)

 

[Salas]

Forgot to ask you if worth to buy some BL grade transistors if i have matched GR transistors with Idss around 5.5

A bit less THD if you will use circa 8mA IDSS BL.

 

[AndrewT]

Forgot to ask you if worth to buy some BL grade transistors if i have matched GR transistors with Idss around 5.5

in some locations of the DCB1 gr are the preferred grade.

 

[weskoki]

I had bit of accident with my Mez the other day.While listening i managed to spill some Tea on my uncased board 😱 Not full cup but still...
I fan dried it immediately and left it off.Thank God it still works.Anyway i compared the sound using the dcb1 and going straight from source to amp and i have to say the dcb1 makes Huge difference.Without it the sound is very 2 dimensional coarse and disjointed.Adding the dcb1 makes my speakers sound twice as big,dynamics are great,textures and micro details as much as you need.:And just to think i haven't hot rod it yet!
Thanks Salas 😀

 

[atupi]

I want to order some parts from Mouser and i dont know for the main smoothing caps what to choose; low ESR, low impedance or Audio grade as mouser is offering these choises.

 

[Salas]

I had bit of accident with my Mez the other day.While listening i managed to spill some Tea on my uncased board 😱 Not full cup but still...
I fan dried it immediately and left it off.Thank God it still works.Anyway i compared the sound using the dcb1 and going straight from source to amp and i have to say the dcb1 makes Huge difference.Without it the sound is very 2 dimensional coarse and disjointed.Adding the dcb1 makes my speakers sound twice as big,dynamics are great,textures and micro details as much as you need.:And just to think i haven't hot rod it yet!
Thanks Salas 😀

Nice that you liked it. You are welcome.

 

[Salas]

I want to order some parts from Mouser and i dont know for the main smoothing caps what to choose; low ESR, low impedance or Audio grade as mouser is offering these choises.

Use main smoothing capacitors like the ones you like best in power amplifiers.

 

[KatieandDad]

I had bit of accident with my Mez the other day.While listening i managed to spill some Tea on my uncased board 😱 Not full cup but still...
I fan dried it immediately and left it off.Thank God it still works.Anyway i compared the sound using the dcb1 and going straight from source to amp and i have to say the dcb1 makes Huge difference.Without it the sound is very 2 dimensional coarse and disjointed.Adding the dcb1 makes my speakers sound twice as big,dynamics are great,textures and micro details as much as you need.:And just to think i haven't hot rod it yet!
Thanks Salas 😀

What caps did you have in the Mez ?

Poor caps would give poor results.

 

[weskoki]

What caps did you have in the Mez ?

Poor caps would give poor results.

Nichicon Muse and Elna 😉 I will try to hot rod it just to see if there's improvement.

 

[IZHAKKATZ]

Hi All,

I'm looking for a low cost vol pot for my dcb1
was thinking of one of the following:

VALAB 23 Step Attenuator:

VALAB 23 Step Attenuator Potentiometer 10K Stereo Log | eBay

or a ALPS Blue Velvet Dual 20K

Japan ALPS RK27 VOLUME potentiometer Dual 20K knurled | eBay

any recomendations as for what would be a better

Thanks
IK

 

[ramallo]

Hello,

The Valab tends to fail prematurely, I have two and both have bad contacts. IMMO best with the Alps.

 

[IZHAKKATZ]

Thanks for that Ramallo,

I just hope the ebay alps are not fake

 

[nar]

Thanks for that Ramallo,

I just hope the ebay alps are not fake

The "ribbed" shaft doesn't seem legit to me

Better buy one here, by Zhou Fang :

http://www.diyaudio.com/forums/vend...12-dual-20k-b1-rk27114-quad-50k-balanced.html

Sure 100% genuine

Best,

nAr

 

[IZHAKKATZ]

thank you nar

 

[nar]

thank you nar

You're welcome 🙂

nAr

 

[wengtech]

hi,
i have 100k alps blue beauty.
can i use it for dc b1 buffer pots?
any value of parts i have to change?

thanks.

 

[Salas]

Avoid, 100K value cuts speed. Filters with the JFET input capacitance enough.

 

[wengtech]

hi salas,
thanks for the info.
btw what is the max transformer voltage can be used for dc b1 mezmerise?
i have a stock of RCore 2x18vac 0,5A is that OK ?

 

[Salas]

Its OK if you have good sinks especially for those Mosfets towards the transformer connector side. Not so much in normal mode, but if you try hot rodding the current.