After chasing the perfect hp amp for two years, I went to the meet in Atlanta where I got to sample lots of gear in the course of an afternoon. I heard lot's of amps that easily bested the lyr, which at the time was end game for me (don't get me wrong, I love the lyr still). But while those amps had all the power and refinement that I'd always looked for, bottom line they weren't in my budget. Not even close to what I was able to afford.
Then I noticed that several guys were huddled around a vintage receiver/amp someone had brought. I was curious and went over and talked with Michael about his vintage amp. He talked to me about the specs and features and I was even more curious about what the "old steel beauty" was capable of. I asked if I could try my Maddog with the Sansui receiver. He obliged. I couldn't believe the sound that came out of the maddogs. How was it possible that this 35 year old receiver could make the maddogs sound better than my prized lyr with cherry picked tubes. But yet, it did. I ran back to my bag to grab my hd650's. I asked Michael if the Sansui would be too much power for my 650's. "Oh not all, just hit the -20db button and you'll be all set," he says. I got the same improvement with the 650.
I knew then that I must have myself one of these aged beast. I found the very same Sansui 9090 I listened to at the meet just 3.5 hours from my home in Atlanta. So I drove 7+ hours in the pouring rain to some dudes double wide in Sevierville TN. After I offered to fix his ailing PC as part of a barter, I walked out of there with one of the best hp amps I'd ever heard for $150. I felt like I'd just won the lottery.
IMO the maddog loves power and scales well with an amp that has refined power. The old amps do this so very well.
My point is that there are other ways to get the most of out orthos and the MD in particular seems to love vintage amps. Consider what they bring to the table:
*gobs of refined power perfect for MD and other orthos (turned my he-4 into everything I'd always hoped it would be)
*triple tone control (bass, treble and mids)
*dual hp jacks-great for auditioning 2 hp's at the same time
*works with low and high impedance hp's
*variable but usually can be had for moderately low prices
*they can also seriously rock a set of hard to drive speakers
*they are huge-my Sansui weighs 50+ pounds and would register on the richter scale if it were to fall over
*no warranty and may need repair