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New Millett Hybrid Maxed Amp - Page 435

post #6511 of 6589

Ok wow, I love this thread so far best of all [there is a priced out part's list at the very begining!]

 

My next Question is does some one have the Schemtaics for this! As well as any updates to the now 3 year old Part's list! ^^ I think I can shell out and Extra $30 to build what sounds like a very awesome Millet hybrid. :D Glad I found this ^^ 

post #6512 of 6589
Quote:
Originally Posted by Mshenay View Post

Ok wow, I love this thread so far best of all [there is a priced out part's list at the very begining!]

 

My next Question is does some one have the Schemtaics for this! As well as any updates to the now 3 year old Part's list! ^^ I think I can shell out and Extra $30 to build what sounds like a very awesome Millet hybrid. :D Glad I found this ^^ 


The Millet Mosfet Max is going to be closer to ~$200. All of the build info is here: http://www.diyforums.org/MOSFET-MAX/MOSFET-MAXoverview.php

 

The Millett is not the same as the Millett Mosfet Max, they use entirely different buffers. The Millet Max is a production board, and for the Millet Minimax, there is a full kit (~$200). The Millett hybrid is not in production, and hasn't been in 20 years, you are just making the circuit on your own.

post #6513 of 6589
Quote:
Originally Posted by scootsit View Post


The Millet Mosfet Max is going to be closer to ~$200. All of the build info is here: http://www.diyforums.org/MOSFET-MAX/MOSFET-MAXoverview.php

 

The Millett is not the same as the Millett Mosfet Max, they use entirely different buffers. The Millet Max is a production board, and for the Millet Minimax, there is a full kit (~$200). The Millett hybrid is not in production, and hasn't been in 20 years, you are just making the circuit on your own.

Sadly I found a Modded Indeed G3 for around $100... will it sound as nice as the Millet Max... no but for half the price and with all the Bravo V2 mods I was going to make already impliment or improved... it's a pot o gold to me! Non the less. I may still build this... seeing as it will b twice what I'm paying for the Indeed G3, plus if I like the G3 [seeing as it's an intro Tube Hybrid] it will make me more certian I need to build a Millet Max [seeing as if I don;t like tubes... I'm out $200 and coutnless hours] So i'ma try a good intro tube amp first! 

post #6514 of 6589
Good plan.
post #6515 of 6589
Quote:
Originally Posted by scootsit View Post

Good plan.

I know right! 

post #6516 of 6589

One of my 12FM6 tubes won't behave - the bias is not consistent from day to day.

 

Yesterday, after having my Millett on for about an hour, I checked the bias and found the tube bias for this particular tube at 15.75V.  I adjusted the trim pot and brought the bias down to about 15.10V.  Today, after having the amp on for about an hour and listening to a movie through it from my laptop, the tube is reading 14.64V!

 

The other 12FM6 tube in my system is fairly consistent and ranges around 15V - 15.25V after a 30-60min warm up.

 

Both tubes were matched by Beezar.

 

The MOSFET biases are pretty consistent and typically are around 230mV after a 30-60min warm up.

 

 

Any ideas as to why one of my 12FM6 tubes might be inconsistent?  Could it be due to the fake ALPS pot?

post #6517 of 6589
Quote:
Originally Posted by ModMax View Post

One of my 12FM6 tubes won't behave - the bias is not consistent from day to day.

 

Yesterday, after having my Millett on for about an hour, I checked the bias and found the tube bias for this particular tube at 15.75V.  I adjusted the trim pot and brought the bias down to about 15.10V.  Today, after having the amp on for about an hour and listening to a movie through it from my laptop, the tube is reading 14.64V!

 

The other 12FM6 tube in my system is fairly consistent and ranges around 15V - 15.25V after a 30-60min warm up.

 

Both tubes were matched by Beezar.

 

The MOSFET biases are pretty consistent and typically are around 230mV after a 30-60min warm up.

 

 

Any ideas as to why one of my 12FM6 tubes might be inconsistent?  Could it be due to the fake ALPS pot?

 

 

 

what about swapping the tubes between the original sockets and see if the problem follows the tube? at least that would eliminate any other issues...

post #6518 of 6589

Vixr has a good suggestion.

 

Honestly, though, I'm wondering what's the deal with your tube that just varies between 15 - 15.25V. wink.gif

 

My experience with most Millett tubes is what you describe for the one you're complaining about.wink.gif  If you check the bias after an hour, it's always dropped by about a 1/2 volt.  I regularly set my tube bias at 1/2 to 1 V higher when the amp is cold.

post #6519 of 6589
Quote:
Originally Posted by tomb View Post

Vixr has a good suggestion.

Honestly, though, I'm wondering what's the deal with your tube that just varies between 15 - 15.25V. wink.gif

My experience with most Millett tubes is what you describe for the one you're complaining about.wink.gif   If you check the bias after an hour, it's always dropped by about a 1/2 volt.  I regularly set my tube bias at 1/2 to 1 V higher when the amp is cold.


I misspoke. My one "good" tube starts out at about 15.7V and usually settles between 15V-15.25V after about an hour. I will try setting tube bias to +1/2V higher when cold. If that doesn't help, then I will swap tubes to see if behavior follows tube or not.
post #6520 of 6589
Quote:
Originally Posted by ModMax View Post


I misspoke. My one "good" tube starts out at about 15.7V and usually settles between 15V-15.25V after about an hour. I will try setting tube bias to +1/2V higher when cold. If that doesn't help, then I will swap tubes to see if behavior follows tube or not.

OK - let me know if it's a Beezar tube, you decide it's bad, and I will replace it.

post #6521 of 6589

In a stroke of bad luck, while removing the "fake" ALPS pot from my MOSFET-MAX build, I also removed one of the top-side PCB pads + corresponding via for one of the ALPS pot pins.  I have attached a pic below showing the through-hole PCB pad in question.  The bottom-side PCB pad is still there, though I don't know if it is making solid contact with the PCB trace any longer.  

 

So here's my question:  After soldering the new "genuine" ALPS pot to the PCB, and if I don't measure continuity between the PCB trace and the ALPS pin in question, can I solder a 22AWG, silver plated copper wire between the ALPS pin and the pin on the 3 pin header which shares the same trace?  Will this affect performance negatively or should I be alright?

I am unsure if AWG vs trace width and length makes a big difference here.

 

 

1000

post #6522 of 6589

A resistor lead jumper on the bottom would suffice.  It's possible to do it on the top since the Alps sits a bit above the PCB surface and gives you access to the pins.  However, a soldering mask should never take the place of insulation, so if you do it on top, it should probably be an insulated hook-up wire.

 

You're not going to notice any effect at all with such a short patch.wink.gif

post #6523 of 6589
Quote:
Originally Posted by tomb View Post

A resistor lead jumper on the bottom would suffice.  It's possible to do it on the top since the Alps sits a bit above the PCB surface and gives you access to the pins.  However, a soldering mask should never take the place of insulation, so if you do it on top, it should probably be an insulated hook-up wire.

 

You're not going to notice any effect at all with such a short patch.wink.gif

 

 

I lucked out afterall.  The through hole eyelet on the bottom side of the PCB still had a solid connection to the trace.  Thanks for the advice, Tom re: the resistor lead jump.

 

By the way, does a new ALPS pot mean I should start over with the setup and biasing of the amp?


Edited by ModMax - 12/12/12 at 1:26pm
post #6524 of 6589

Anyone have advice on recommended bias settings for each of the different Millett MOSFET-MAX tubes.  The MAX website recommends 13.5V for each tube given a 27V supply bias.

 

In and earlier post to me, Tom recommended approx 15V for the 12FM6.

 

What about the 12AE6 and 12FK6 tubes?  What's the recommended bias setting for each of these?

post #6525 of 6589
Quote:
Originally Posted by ModMax View Post

Anyone have advice on recommended bias settings for each of the different Millett MOSFET-MAX tubes.  The MAX website recommends 13.5V for each tube given a 27V supply bias.

 

In and earlier post to me, Tom recommended approx 15V for the 12FM6.

 

What about the 12AE6 and 12FK6 tubes?  What's the recommended bias setting for each of these?

Default is 13.5 only because that gives you the maximum voltage swing up and down, but anywhere between 13.5 and 15 is fine.  Why not experiment and see if it makes a difference to you?

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