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Originally Posted by tf1216 /img/forum/go_quote.gif
Hey all,
I did a search and I could not find a definitive answer for some of my questions. One question I have is, what are the different versions of the Millet Hybrid Max availalbe? I know there exists a MOSFET and BJT output stage. Are there earlier versions and these are the most up to date? I know there exists a diamond buffer, how does it change the performance of the amp?
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There are four distinct board designs. Only three have been produced so far. There are also options with each:
1.
Original-original Millett Hybrid - this may still be found on Pete Millett's website:
Pete Millett's DIY Audio pages. It was published as an article in Audio Xpress magazine and got this whole thing going. Way to go, Pete!
The board is designed to be built in an open fashion with a case bottom and exposed top. The "hybrid" portion of the output uses TO-220 versions of the BUF634 mounted on heat sinks. The board was sold for a time at DIYCable.com.
2.
revMH Millett Hybrid. Drew Dunn and Nate Maher teamed up on this one and really started the Millett Hybrid craze. They created the DIYForums.org website, where all the info you ever wanted to know may be found.
This design went a step further than Pete's original and designed a slightly different board with a bit more flexibility in output stages. It was also designed to a specific case: the Hammond 1455N1601. Output stages were converted to DIP-8 opamp style, with options for BUF634's (which could also be stacked), Intersil HA3-5002's, and OPA551's (championed by AMB).
Later on, Steinchen designed what's now known as the Millett DB - Diamond Buffer board. Those were constructed with pins to plug into the two opamp-buffer sockets. With what we call "boutique" transistors, it brought the Millett into a new level of performance, making it very competitive with many mid-level headphone amp designs (IMHO).
3.
Millett Hybrid MAXed - Cetoole (Colin Toole) designed the MAXed version of the Millett Hybrid last year. As far as know, it broke records for Group Buy sales - over 400 boards to 175 users in 20 different countries.
Colin brought all the various disparate accessories that people had used with the Millett Hybrid and brought them together in one board. He upgraded the DB's with true board-mtd, extruded heat-sink capability (meaning bias is only limited by the size of the sink). He also included a top-notch power supply and elements of AMB's relay-delay for headphone protection from power on/off tube spikes. The fact that all of this is on one board was a major achievement, IMHO.
Even then, there are two versions of the MAX - one option for BJT Diamond Buffers, or MOSFET Diamond Buffers. The BJT's are tried and true. AMB recently made some changes to his MOSFET buffer design. Initial reports have been outstanding. I hope to update the changes officially after I build a couple.
4.
The MiniMAX is currently in board development. This takes all the features of the full-size MAX and shrinks it down to a board size that fits into a Lansing MicroPak enclosure. Very little, if any, sacrifices are made. It simply squeezes and optimizes all of the available space.
I just posted pics of a finished and built prototype of the MiniMAX in the main MAX thread here on Head-Fi last night:
MiniMAX Pics
5. An as yet, un-official "Super MAX" (name guess) that Colin is just now conceptualizing. We'll have to wait on the details for that one and don't expect it soon.
As always, almost any information you need to know about the Millett Hybrid or the Millett Hybrid MAXed may be found here:
DIYForums.org
and here:
MAX
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| Last, if you have experience with both, would you choose a Millet Max or SOHA? |
I have experience with both, but not yet with the SOHA using the JISBOS' buffers. However, I think there's a Gentleman's Agreement amongst the various developers to not compare designs, so I'll just forego comment on that one.
