Mezmerize DCB1 Building Thread

Some pictures

still something to mount...

x Salas & Andrew:

Do you think i can hot rod this , just to add little more gain?
and how?
 

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diyAudio Chief Moderator
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Only if you had mounted the mosfets to the floor *see ramallo's a few pages back. Then you could use 10R 5W or 22R//22R 2W where your 68R//68R are now and achieve around 200mA CCS with your Vdrops. With the little sinks you got its dangerous. Hot rod achieves more robust sonics from the regs, not voltage gain by the way.
 
Hey guys,

I've just powered up my Mesmerize for the first time and something seems wrong ;)

One of led arrays won't light, it's the one containing 5 leds. The other side does light up however. I've been looking at pictures from your builds and from the looks of it I got all the parts oriented correctly (caps, transistors, leds).

I've measured the voltage drop accross 68R CCS resistors which is as follows:
- 5.2V accross the side that's working
- 2.3V accross the side that's not working

I guess that's not correct.

I'm using a 230V/2x12V 50VA tranny.

Do you guys have an idea of what might be wrong?

Cheers!
Erik
 
diyAudio Chief Moderator
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Maybe the Jfet under the array which pulls current through is dead? One array faces the other way than its opposite as a whole mind you. Also 5.2V across the 68//68R on the side that IS working is too much. Are the Mosfets the correct types in each position?
 
Maybe the Jfet under the array which pulls current through is dead? One array faces the other way than its opposite as a whole mind you. Also 5.2V across the 68//68R on the side that IS working is too much. Are the Mosfets the correct types in each position?

Well I've spotted at least one thing that's wrong with it.... It turns out I've got the different Jfet soldered in the wrong positions, not something to be proud of ;) I'll switch them around this weekend and I'll keep you updated on the results!

Cheers,
Erik
 
Well I've spotted at least one thing that's wrong with it.... It turns out I've got the different Jfet soldered in the wrong positions, not something to be proud of ;) I'll switch them around this weekend and I'll keep you updated on the results!

Cheers,
Erik

Ok, i've switched the Jfet's and now all the leds are working. The voltage accross the CCS is 2.2V and 1.8V, which seems better ;)

I'm going to test it later and I'll keep u posted! ;)

Cheers,
Erik
 
I've just measured it and it reads 2.0mV and 3.2mV. Unfortunately I don't have much time tonight so I'll be testing it with some music tomorrow.

Thanks for your help up to now! ;)

Cheers,
Erik

Hey guys,

I've just hooked it up to an amp (My_ref revC) and there's a big buzz coming from my speakers at full volume. This is when I turn on my amp, without even turning on the mesmerize itself. This seems weird to me and I can't discover anything wrong. Could it be that it has something to do with my amp?

I've included a picture of the mesmerize in my test setup.

Cheers,
Erik
 

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Hi,
the Mezmerize (and the Hypnotize) disconnect the output when turned off.
This leaves the cable acting as a high impedance aerial connected to the receiver and that is very susceptible to interference.

There is an easy fix that cuts much of the interference. It is already incorporated in the Blue Hyp.
 
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Hi,
the Mezmerize (and the Hypnotize) disconnect the output when turned off.
This leaves the cable acting as a high impedance aerial connected to the receiver and that is very susceptible to interference.

There is an easy fix that cuts much of the interference. It is already incorporated in the Blue Hyp.

Hi guys,
The T-Mod is incorporated into the Turn on relay on blue mez, the new run of blue hypno's will have it incorporated into it.
 
diyAudio Chief Moderator
Joined 2002
Paid Member
Hey guys,

I've just hooked it up to an amp (My_ref revC) and there's a big buzz coming from my speakers at full volume. This is when I turn on my amp, without even turning on the mesmerize itself. This seems weird to me and I can't discover anything wrong. Could it be that it has something to do with my amp?

I've included a picture of the mesmerize in my test setup.

Cheers,
Erik

Does the amp buzz even with nothing connected to its input? Do that check. The Blue Mez shorts its output to ground when off.
 
Does the amp buzz even with nothing connected to its input? Do that check. The Blue Mez shorts its output to ground when off.

Yes it does, although only slightly. I've included a picture of the inside of the amp. There is no capacitor connected to the input, like suggested in the My_ref revC ultimate BOM. Could this be part of the problem?

Thanks for hour help!

Regards,
Erik
 

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