Mezmerize B1 Buffer Preamp

Please forgive me for the question above and ignore it. I have too many projects going at once and have confused them.

I would like to know, however, if some benefit might accrue to having the power supply housed in a separate chassis, moving the rectifiers and reservoir caps there from the Mez B1 pcb, or would this be a wasted effort with this design that has no gain stage at all?

Removing power supplies to external chassis just replaces one set of problems with another set of problems.
This thing is really low power anyways, and the layout is nicely done.

-Josh
 
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Signal area Resistors

sorry to bother you again.

I just started populating/boarding the PCB, it's the ten years after.
I just realize that on the PCB the resistors are stated "220 / 220K" while the BOM says "221 /221K". (If it's the correct position)

Wrong place or not a problem?

Thank you!
david

Those are the audio path resistors:

Signal area 50ppm Dale resistors:
221R (4pcs) CMF60221R00FHEK
221k (2pcs) CMF60221K00FHEK
1M (2pcs) CMF601M0000FHEK

(Copied from the 2018 BOM + notes)
 
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You could use Mez boards in this config.
 

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Question to start the work

Hi, I am am Italian diyer, in my career I assembled 2 speakers and some power amp. Now I am running a My-Ref C power amp with an old venerable AM-AUDIO preamp. I would like to smell some solder wire again and I was planning to assemble a Mesmerize. I am not an electronic guru, honestly my mechanical training does not help me very much with 'schematics' and DC OFFSET stuff.

I have the idea to put the mesmerize in the same box with an headphone amp board. The two boards will have their own PSU (clearly one AC socket for both) and I would like to use the mesmerize input selector to obtain a single audio source.

I am not sure about the idea of sharing the input between the mesmerize and the headphone amp. I thought about using an ELMA switch to direct the input to the mesmerize amp section or alternatively to the headphone amp. The best would be also to use one single volume knob, so I guess I should intercept the signal at the ALPS potentiometer output, direct it to an ELMA switch and from there back to each board.

Question: does it make any sense? I would like to think that there is some better solution out there.

Another question: which kind o thermal fuse I should take for the main AC input?

Many thanks and great design indeed

Gli
 
connect 3 power amps to the Mezmerize B1 buffer preamp

Hi all, I am new here. Soon I hope to build the Mezmerize B1 buffer preamp Ten years after.

I have very little experience in this.

I have 2 questions...

The first quesion is..

I plan to connect 3 power amps.
Amp 1 for the Tweeter
Amp 2 for the Mid
Amp 3 for the Bass

Between the preamp and each poweramp there will be a PLLXO.
Can the Mezmerize B1 buffer preamp control these 3 power amps?

The second question is..

I only use a DAC at the input. So I do not use an input selector.
Can I remove or bypass the PCB 12V relays and 1N4007-E3/54 diodes? Or do I keep the diode in place?

Please can anyone help with this?
 
I would like to add some other thoughts to my original message...being mesmerize a buffer with unity gain I probably need to route its output to a couple of connectors directed to my power amp and to a headamp board. I do not know how to do it, simple a parallel between the two output or other better way (a switch or something more exotic?)
 
diyAudio Chief Moderator
Joined 2002
Paid Member
Hi all, I am new here. Soon I hope to build the Mezmerize B1 buffer preamp Ten years after.

I have very little experience in this.

I have 2 questions...

The first quesion is..

I plan to connect 3 power amps.
Amp 1 for the Tweeter
Amp 2 for the Mid
Amp 3 for the Bass

Between the preamp and each poweramp there will be a PLLXO.
Can the Mezmerize B1 buffer preamp control these 3 power amps?

The second question is..

I only use a DAC at the input. So I do not use an input selector.
Can I remove or bypass the PCB 12V relays and 1N4007-E3/54 diodes? Or do I keep the diode in place?

Please can anyone help with this?

Its just capable regarding signal current control for that setup if the interconnects will not be too long. Its current is only a JFET IDSS you see. Very good proven quality buffer but not high current buffer.

If you will not apply the relays you don't need to apply the diodes either. If you will just bypass them so they will still be energized keep the diode. Its fly back diode for suppressing the coil's back EMF transient.
 
Its just capable regarding signal current control for that setup if the interconnects will not be too long. Its current is only a JFET IDSS you see. Very good proven quality buffer but not high current buffer.

If you will not apply the relays you don't need to apply the diodes either. If you will just bypass them so they will still be energized keep the diode. Its fly back diode for suppressing the coil's back EMF transient.

Thanks for the reply Salas!

What do you think is a better option than?
I have a wonderfull horn loudspeker system. These horns do best with seperat amps and specific frequency range. And I don't like actice crossover that much.

Please give me advice