Mezmerize DCB1 Building Thread

[Salas]

Prefer PF5102 as it runs from 5mA up to 11mA idss in samples while the J111/113 series tend to very high idss these days. At least those I sampled during the last two years or so. If you got Jxxx samples up to 10mA, ok use them. Because the JFETs run full throttle in this circuit, too high idss is going to slowly fry them.

 

[edd9000]

Here is the DCB1 I built for a friend.

 

[kpsthakur]

Thank you...will be careful as you mentioned

 

[1543]

Here is the DCB1 I built for a friend.

Very nice build!

 

[Eric]

Super clean build! Nice work!

 

[dewdrop]

Very creative layout!

 

[WalterW]

Nice! It is with a double bottom…. is that a kind of black cardboard you used?
I like the idea!

 

[edd9000]

Thanks for the kind comments.

Nice! It is with a double bottom…. is that a kind of black cardboard you used?
I like the idea!

Black acrylic, it cuts quickly on the cnc router and will take a thread.

I built one for my self, alps pot instead of the Khozmo attenuator, but a see through lid

 

[edd9000]

They were built to match the Aleph 30 and 60 power amplifiers I have built.

 

[nzlowie]

Just looking at heatsinks for my DCB1 build, going to hotrod with 10r bias resistors. I've got a case the same as I used for my ACAs, each heatsink is 245x85 finned, is one enough for all 4 driver's or should I use both heatsinks? If I was to use both I'd probably need to attach the drivers with short lengths of wire, not directly to the PCB, shouldn't be an issue should it?

Thanks

 

[Salas]

Just looking at heatsinks for my DCB1 build, going to hotrod with 10r bias resistors. I've got a case the same as I used for my ACAs, each heatsink is 245x85 finned, is one enough for all 4 driver's or should I use both heatsinks? If I was to use both I'd probably need to attach the drivers with short lengths of wire, not directly to the PCB, shouldn't be an issue should it?

Thanks

One's more than enough for their dissipation when set with 10R.

 

[Audio Zen]

Are Mez PCB still available for purchase ? I would like to build another one.

thx
Neville

 

[nzlowie]

Are Mez PCB still available for purchase ? I would like to build another one.

thx
Neville

Neville,

I've just completed the board and I'm working on the case. I got a kit from TeaBag, everything you need, good quality parts and PCB. Save yourself the trouble of sourcing the parts and get a kit, makes life easy!

 

[Audio Zen]

Neville,

I've just completed the board and I'm working on the case. I got a kit from TeaBag, everything you need, good quality parts and PCB. Save yourself the trouble of sourcing the parts and get a kit, makes life easy!

Didn’t know TeaBag was still sourcing them. I’ ll hit him up. Thx

 

[Salas]

That should be the Hypnotize (no on-board source select, more reservoir capacitors). The Mezmerize was on the DIYA store only. Jason wanted to restock the Mez but I don't know when.

 

[nzlowie]

All good at power up, voltage is a bit low, 9.88 & 9.87 . I used the 12v taps on my transformer, should I change to the 15v? Also have plenty of heatsink area so should I change the bias resistor to 5r while I have the soldering iron on?

Sounds good, nice and quiet - just listening now to see what it's bringing to the system.

Thanks

 

[Salas]

What's the DC across the reservoir capacitors? I hear that in Australia you have strong mains usually so the 12VAC taps may prove enough.

P.S. You can measure that same Raw DC at the bridge diodes ends also.

 

[Salas]

About pushing the CCS mA alright no problem as long as the trafo and bridge diodes also remain acceptably hot, not only the heatsink.

 

[nzlowie]

OK, 16.6v on the ps caps.1.8 & 1.7v across the 10r bias resistors. Everything seems OK and sounds good apart from the voltage check point being low.

Any idea's?

 

[Salas]

9.88 & 9.87 are not low rails in dcb1 practice and 16.6vdc rectified from 12v taps indicates strong mains so all is well. 15v taps would give more heat to the input Mosfet due to higher dc drop across but less Ciss capacitance. Try those taps also since you got the sinking but keep them in use only if you find the result bit more open in the treble. Else its just a waste in heat that it will be felt after you push the mA to high hot-rod.