[tomb]

Quote:

Originally Posted by pabbi1 /img/forum/go_quote.gif It was mostly with 12fk6, but also with 12ae6a... it was buf634, not db, but I have always needed a bit more gain (why I went to the HA2, which was barely enough). Even Pete laughingly told me it would clip, given my gain requirements. The other issue is the wallwart I'm using (and placing in the case (bigger case)) - will this have enough current to drive both channels? wallwart

I'm not certain about your specific application, but if it's truly gain that you need, the 12AJ6 is a drop in tube for the Millett design. It has a basic amplification factor of 55. That's so high it's inappropriate for typical headphone use - unless you have something unusual.

The walwart current is more or less dependent on the output stage. The MAX benefits from a walwart with more than 1A. However, strictly speaking, current does not relate to gain - that is usually a voltage criterion.

Don't know if that helps, but there it is ...

BTW - I use duplicates to that walwart for my MAX's. It is more than enough for 100ma bias in the output stage or much higher, even. (It's a good choice while they have free shipping as mentioned in another thread.)

 

[dsavitsk]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif I'm not certain about your specific application, but if it's truly gain that you need, the 12AJ6 is a drop in tube for the Millett design. It has a basic amplification factor of 55. That's so high it's inappropriate for typical headphone use - unless you have something unusual.

If it is just a problem with clipping, a higher gain tube will just get him to clipping faster. Instead, you need to increase the power supply voltage (and possibly the grid bias) to allow for more swing in the CCS.

 

[pabbi1]

Granted, that was with the HD600, which won't be the case now... what about the 12EL6?

Or, I could just turn the volume down, right?

 

[tomb]

Quote:

Originally Posted by pabbi1 /img/forum/go_quote.gif Granted, that was with the HD600, which won't be the case now... what about the 12EL6? Or, I could just turn the volume down, right?

Well, if you have the HD600, I can pretty much assure you that there's no danger of clipping from normal sources with the MAX - either with 12AE6A or 12FM6 tubes. Even 12FK6 tubes appear to reach deafening volumes with either my HD580's or HD600's - and that's on two different MAX's so far. I typically run 27V and bias the tubes to 13.5V That gives them plenty of swing, IMHO.

One thing you might keep in mind - don't put in any output resistors - just jumper them out. I think you'll find that you have plenty of gain, voltage, current and volume with the basic MAX in that configuration.

 

[pinkfloyd4ever]

I was reading the Max website and was wondering, could the MH be used as a speaker amp with the 12AJ6 tubes? I did see that new adjustable damping amp, but I need to chill on the audio spending at some point before I have to start living in my car to support my addiction

btw, does anyone know where to get the PCBs for the adjustable damping millett?

 

[babbkutz@comcast]

looked at the Greenlee punch today (1") and am wondering about that hole punch size (1.12")? How am I going to get a 1" hole? (Machine shop?) The bushings from Mouser measure out to 1" and 1.12" seems to be pushing it.......

 

[tomb]

Quote:

Originally Posted by pinkfloyd4ever /img/forum/go_quote.gif I was reading the Max website and was wondering, could the MH be used as a speaker amp with the 12AJ6 tubes? I did see that new adjustable damping amp, but I need to chill on the audio spending at some point before I have to start living in my car to support my addiction btw, does anyone know where to get the PCBs for the adjustable damping millett?

Didn't see your last question after I replied to your PM -

Nate has e-mailed Pete about boards, etc. We are expecting his reply. Nate??

 

[tomb]

Quote:

Originally Posted by babbkutz@comcast /img/forum/go_quote.gif looked at the Greenlee punch today (1") and am wondering about that hole punch size (1.12")? How am I going to get a 1" hole? (Machine shop?) The bushings from Mouser measure out to 1" and 1.12" seems to be pushing it.......

You are correct to question that. There is a Greenlee punch that is exactly 1" O.D. I have a Greenlee "Slug Buster" #35178 and it is exactly 1" O.D. and is listed as "Hole Size 1"". Look for this one.

You can pretty much get a Greenlee punch in any diameter, within reason. You just have to be careful to make sure the hole size is 1". Many of the ones for conduit are labeled under nominal sizes only, and will make a hole much larger than their lable indicates. Those will not say "hole size," however. Hole size is hole size, period.

 

[amphead]

It would seem that increased headroom, as Dsavitsk suggests would solve your clipping problems. Running at say 29V, with a reliable power source.
Look at Toms spec here:
http://www.diyforums.org/MAX/MAXps.php

 

[IcantHearU]

So, @ midnight Sunday, I realized I hadn't checked the mailbox on Saturday - It's now 4:50 a.m., and I've been at my two Maxxed Milletts for about 4 hours or so - Colin, thanks for your time, effort and enthusiasm and thanks to all the people who helped with everything from the bill if materials to the trials and testing and tweaks - (and of course P. Millett and the original MH DIY group)
I have to work in 3.5 hours or so - I just don't care - this is just so much better!!
Will definitely be posting pictures and results after this one -
OK, gotta go - my addiction needs to be fed

 

[n_maher]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Didn't see your last question after I replied to your PM - Nate has e-mailed Pete about boards, etc. We are expecting his reply. Nate??

Pete has no problems if we have boards made.

But Pete and I are working on ideas for a couple of tweaks to the design before production. I don't really want to launch into a full fledged redesign right now and I'll report back as soon as I have anything substantial.

 

[tomb]

Hurry up.

 

[n_maher]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Hurry up.

Sorry, there will be no "hurry" in this operation, Pete's a busy guy and so am I. The frenzied masses are just going to have to hurry up and wait.

Seriously I'm hoping the MAX will be plenty to keep folks busy for a good long while. About all you can expect in the near future is that I may start a thread to get some input on what changes if any we might implement but I hope folks will be patient and give us some time to work things out.

 

[UglyJoe]

I'm a very sad diyer right now... 2 beautiful Max boards sitting on my desk and no cash to populate them.... sigh....

 

[colonelkernel8]

Quote:

Originally Posted by UglyJoe /img/forum/go_quote.gif I'm a very sad diyer right now... 2 beautiful Max boards sitting on my desk and no cash to populate them.... sigh....

Same situation, only one board.

Nice quality boards though, thanks Colin.