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The Millett Hybrid Maxed - Output Stage
MOSFET Diamond Buffer
Please NOTE: This section on the MOSFET option for the Millett MAX diamond buffers has been superceded. Please refer to the MOSFET-MAX website for details on the new, JFET-mod MOSFET-MAX. This section will remain here for posterity, or in case the market's supply of JFETs runs out for the JFET-mod version.
photo by Neil Rothschild |
NOTE - Differences from the BJT Diamond Buffer (DB) version and updates from prototypes:
(same as DB version, but updated from protos) (these are jumpered out on the BJTs) |
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NOTE: You must decide which output stage to use - either BJT Diamond Buffer or MOSFET Diamond Buffer.
You cannot build both.
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| Recommendations for the MOSFETs can be found in the Bill of Materials
The MOSFET output stage option for the MAX uses the same MOSFETS that are used in Amb's M3 headphone amplifier. Due to the relative high currents and the potential difficulties in trimming the bias at the high levels needed, it is recommended that the MOSFETs are tested. Amb's Audio Shop is probably the most convenient source and is referenced in the MAX Bill of Materials. |
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 Image by user "Ferrari". User Ferrari was also the first MAX builder to point out the proper use of these compensaion caps - thanks! |
From Ti Kan (Amb) on the MOSFETs: "For each channel, if you use 100Ω resistors for RB8 and RB9, then you should also install the 220pF capacitor CB8. The N-channel MOSFET's gate capacitance is less than that of the P-channel, and this capacitor equalizes them. An alternative to this approach would be to omit CB8, but change the values of RB8 and RB9 to 121Ω and 75Ω, respectively. This will assure symmetrical slew rates for positive going and negative going square wave pulses." (referenced from Amb's M3 amplifier, but part labels - in bold - have been altered to agree with the MAX's MOSFETs)
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