My MOSFET MAX Build

[jdkJake]

Nice build dbfreak!



Where did you get your volume knob? It looks to be a good size and of good quality.



I am almost ready to start my build. Just waiting on the MOSFET heatsinks. I am really looking forward to this amp!

jk

 

[dbfreak]

It is a good volume knob (hard anodized finished).  I got it off ebay from a merchant in China.  I don't remember the merchants name.  What I do remember, is all of his wares (mainly audio parts) are advertised as, "An old wise man in a fleamarket told me that this is the volume knob to use for the best sound."  The same goes for all of the other things he sells, like capacitors, resistors, etc.  Kind of odd in my opinion he is.

 
Quote:

Nice build dbfreak!



Where did you get your volume knob? It looks to be a good size and of good quality.



I am almost ready to start my build. Just waiting on the MOSFET heatsinks. I am really looking forward to this amp!

jk

 

[tomb]

Just an FYI, but I've updated all the drawings and the templates on the MOSFET-MAX website:
http://www.diyforums.org/MOSFET-MAX/MOSFET-MAXtemplate.php

 

[tomb]

Colin got me the newest schematic and it's been updated on the website:
MOSFET-MAX Schematic

 

[schubert]

I've lived with this amp for a few months now, and I must urge anyone who is thinking of building it to heed TomB's advice about the C7 caps (p. 5 of this thread) - the Elnas are superb, and much better than the Muses.  I don't think you can do better for the money - at least it outpaces my PPA handily, and that's a fine amp as well.

 

[funch]

 
Amen, brother!   Mine actually sounds better than my very tweaked Bijou with my diy/markl Denon D7000's.
 
Of course, the Bijou and HD600 combo is killer!

 

[BobSaysHi]

I want myself one of these...
 

 

[jdkJake]

I agree with schubert and funch (sounds like a law firm).

The MOSFET-MAX single handedly kept me from selling my SR-225s. It really, really matches well with those phones.

 

[tomb]

You guys are really too kind.  I will make certain that cetoole sees your comments, too.
 
I'm hopeful that during the holidays I can put more work into the website to make building this amp a bit more user-friendly.  Not that it's any more difficult than a Millet MAX/MiniMAX, it's just that I don't have things documented as well as I should.

 

[BobSaysHi]

OK, so I've finally convinced my parents to allow me to build a new amp (the last one was a disaster), and I have a couple questions.
 
1. Is this the official thread for the Mofset MAX? I did a search but even this thread didn't even show up.
 
2. This is a more basic noob circuitry question. I'd like to hook up a switch that allows the tube lights to turn off with a flick of a switch. I figure I need a DPDT switch, and hook one end up to the resistor at RA5L/R and the other up to the led at L/R. I'd just like to make 100% sure that this would work, to avoid problems. Also, is there a switch that can turn on/off 3 things with one flick? I checked wikipedia, but wasn't able to find anything. Also, it's late. 
 

(My room is DARK at night, I'd like to keep it that way)
 
3. I wan't to use this switch (http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=60_374_375&products_id=22162) and I'd like to hook up the led to the center led. specs say 3v to 12v. I think that that will work, but I'd like to double check anyway.
 
I'm not ready to finalize my orders yet (I'll be combining many different BOMs for different amps/DACs), so I have plenty of time to think about the build. I really hope this lives up to the hype.

 

[tomb]

Quote:

OK, so I've finally convinced my parents to allow me to build a new amp (the last one was a disaster), and I have a couple questions.
 
1. Is this the official thread for the Mofset MAX? I did a search but even this thread didn't even show up.
 
2. This is a more basic noob circuitry question. I'd like to hook up a switch that allows the tube lights to turn off with a flick of a switch. I figure I need a DPDT switch, and hook one end up to the resistor at RA5L/R and the other up to the led at L/R. I'd just like to make 100% sure that this would work, to avoid problems. Also, is there a switch that can turn on/off 3 things with one flick? I checked wikipedia, but wasn't able to find anything. Also, it's late. 
 

(My room is DARK at night, I'd like to keep it that way)
 
3. I wan't to use this switch (http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=60_374_375&products_id=22162) and I'd like to hook up the led to the center led. specs say 3v to 12v. I think that that will work, but I'd like to double check anyway.
 
I'm not ready to finalize my orders yet (I'll be combining many different BOMs for different amps/DACs), so I have plenty of time to think about the build. I really hope this lives up to the hype.

1. Actually, the original Millett Hybrid MAX thread is where I've posted most of the details of the MOSFET-MAX, but this thread is as good as any.
 
2. There's nothing that says you can't parallel everything you want off of a single SPST switch, as long as voltages and loads are the same (with all the LEDs, they are).
 
3. Now you've gone and complicated things something awful.  AMB did a special design PCB to handle switches such as the Bulgin: http://www.amb.org/audio/epsilon24/ .  What you're asking to do is not as complicated if you're just wishing to switch all the LEDs, but understand that the illuminated part of the switch you referenced is made for 3.3V.  Everything on the MAX PCB is going to be at 27V.  You'll need an 1150 resistor at 1W to cut down that voltage.  (Yes, I know the switch specs say up to 12V, but you don't want to risk that and prematurely burn out the switch's LED.)  To make matters worse, even though I said there's nothing to stop you from paralleling the LEDs, the switch is only rated for 50ma.  The three LED's on the MOSFET-MAX may go beyond that when added up.  We haven't sized the LEDs for their max current (3 @ 20ma = 60ma), but it'll be close.
 
If you used a regular power switch, even a very small one - no sweat, but those Bulgin's (or Lamptron) aren't setup that way.  A very simple SPST toggle switch would do everything you asked and not add to your room's light pollution.

 

 

[jdkJake]

This is the original thread:

http://www.head-fi.org/forum/thread/233941/new-millett-hybrid-maxed-amp

The last dozen or so pages at MOSFET MAX 1.2 related.

IMO, you shouldn't build an amp because of hype, rather, because you find it of interest and/or of value to you. The differences between the MOSFET-MAX and miniMAX are indeed significant, especially for low impedance phones. However, they are not going to be night and day. At a certain point, the subtleties are what you strive to improve upon.

 

[BobSaysHi]

Quote:

This is the original thread:

http://www.head-fi.org/forum/thread/233941/new-millett-hybrid-maxed-amp

The last dozen or so pages at MOSFET MAX 1.2 related.

IMO, you shouldn't build an amp because of hype, rather, because you find it of interest and/or of value to you. The differences between the MOSFET-MAX and miniMAX are indeed significant, especially for low impedance phones. However, they are not going to be night and day. At a certain point, the subtleties are what you strive to improve upon.

I'm not expecting miracles. My only headphones are the sr60i (modded to hell and back) and I figured this amp would be a little better matched than the MiniMAX. Also, I'd like to try my hand at casework.
 


Quote:

Quote:

OK, so I've finally convinced my parents to allow me to build a new amp (the last one was a disaster), and I have a couple questions.
 
1. Is this the official thread for the Mofset MAX? I did a search but even this thread didn't even show up.
 
2. This is a more basic noob circuitry question. I'd like to hook up a switch that allows the tube lights to turn off with a flick of a switch. I figure I need a DPDT switch, and hook one end up to the resistor at RA5L/R and the other up to the led at L/R. I'd just like to make 100% sure that this would work, to avoid problems. Also, is there a switch that can turn on/off 3 things with one flick? I checked wikipedia, but wasn't able to find anything. Also, it's late. 
 
 
(My room is DARK at night, I'd like to keep it that way)
 
3. I wan't to use this switch (http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=60_374_375&products_id=22162) and I'd like to hook up the led to the center led. specs say 3v to 12v. I think that that will work, but I'd like to double check anyway.
 
I'm not ready to finalize my orders yet (I'll be combining many different BOMs for different amps/DACs), so I have plenty of time to think about the build. I really hope this lives up to the hype.

1. Actually, the original Millett Hybrid MAX thread is where I've posted most of the details of the MOSFET-MAX, but this thread is as good as any.
 
2. There's nothing that says you can't parallel everything you want off of a single SPST switch, as long as voltages and loads are the same (with all the LEDs, they are).
 
3. Now you've gone and complicated things something awful.  AMB did a special design PCB to handle switches such as the Bulgin: http://www.amb.org/audio/epsilon24/ .  What you're asking to do is not as complicated if you're just wishing to switch all the LEDs, but understand that the illuminated part of the switch you referenced is made for 3.3V.  Everything on the MAX PCB is going to be at 27V.  You'll need an 1150 resistor at 1W to cut down that voltage.  (Yes, I know the switch specs say up to 12V, but you don't want to risk that and prematurely burn out the switch's LED.)  To make matters worse, even though I said there's nothing to stop you from paralleling the LEDs, the switch is only rated for 50ma.  The three LED's on the MOSFET-MAX may go beyond that when added up.  We haven't sized the LEDs for their max current (3 @ 20ma = 60ma), but it'll be close.
 
If you used a regular power switch, even a very small one - no sweat, but those Bulgin's (or Lamptron) aren't setup that way.  A very simple SPST toggle switch would do everything you asked and not add to your room's light pollution.

 

1. All right, cool.
 
2. Sounds good. 
 
3. I was planning on using the latching Bulgin switch to power on the amp, I'd have another switch in the back to turn all the leds off. Just a regular old switch. I'll read up on the epsilon24.
 
I'd like to make it look nice, since I probably won't be building another amplifier, since I'll be off to college soon.

 

[MrDavis]

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[MrDavis]

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