I designed and built 3 pairs of mono amps around the Musical Concepts PA7 MKII / PA8 and am super impressed with the PA-8, its layout, ease of installation and use. It sounds astounding, small amp delicacy and finesse, with HUGE AMP effortless ease and an unflappable sense of drive. I am struck by how quiet the amps are (no fan is nice) the music emerges from velvety (almost eerie) silence. These amps are rendering the most musical detail I have ever experienced with any of my amp builds or systems, without grain or etch... the music event is very relaxing, with a harmonic more like vacuum tubes. (without excessive heat or required fans)
I powered the amp up, checked / set DC offset, gradually brought the bias up... the most challenging part, as with any build, is the couple hundred hours of burn-in (as with most components). When something sounds like this, so great from the get-go, you know it will only get better and better. Incredible Macro and Micro dynamics, increased sense of space around instruments, with an immense sound field. I cannot say enough great things about the sum of my project(s) built around a known standard. I am also "burning-in" a Mundorf MLytic HC (LOCO cap) power supply version, not shown.
It was actually easy, I knew exactly what I wanted in a power supply, after designing, building and modeling dual mono supplies with Hafler 500/600 amplifier modules over the past 6-8 months. I have wanted a Driver PCB solution like this, although I was prepared "to hack" or reconfigure a PA7 to flat, into a point to point layout for the output stage. When John mentioned the TO-247 / TO-264 output option, I request / committed to 2 pairs right off the start... knowing just how great the PA7 is... this elegant circuit is a breakthrough in system transparency in the over a dozen amps I have used them in...
Background / my inspiration to do this... **I wanted to build something that I could not go out and buy**
I have *dreamed of* wanted to build *own* an amp like this for many years. I will just say it... I wanted an amp to "equal" and/or mirror my "old" Levinson No. 336, a beast for power, one that I could no longer pick-up after L & R shoulder surgerie(s), I sold it in 2011. The total / combined weight of my 2 channel beast, is about 15lbs. lighter than No. 336 and I can pick them up and carry them = A REAL WIN!!!
I believe these amps are more delicate, open (literally), equally powerful and do not require 50-60 amp electrical service to deliver spec... though I am considering wiring the main sound room with a 240v (amp) feeds... which is only 10 feet from my electrical panel. Where does this hobby end???
~ I will admit to buying most of the initial PA8 production run ~
I feel that certain = that confident in it to, build more amps...
with this most elegant DIY solution.
I powered the amp up, checked / set DC offset, gradually brought the bias up... the most challenging part, as with any build, is the couple hundred hours of burn-in (as with most components). When something sounds like this, so great from the get-go, you know it will only get better and better. Incredible Macro and Micro dynamics, increased sense of space around instruments, with an immense sound field. I cannot say enough great things about the sum of my project(s) built around a known standard. I am also "burning-in" a Mundorf MLytic HC (LOCO cap) power supply version, not shown.
It was actually easy, I knew exactly what I wanted in a power supply, after designing, building and modeling dual mono supplies with Hafler 500/600 amplifier modules over the past 6-8 months. I have wanted a Driver PCB solution like this, although I was prepared "to hack" or reconfigure a PA7 to flat, into a point to point layout for the output stage. When John mentioned the TO-247 / TO-264 output option, I request / committed to 2 pairs right off the start... knowing just how great the PA7 is... this elegant circuit is a breakthrough in system transparency in the over a dozen amps I have used them in...
Background / my inspiration to do this... **I wanted to build something that I could not go out and buy**
I have *dreamed of* wanted to build *own* an amp like this for many years. I will just say it... I wanted an amp to "equal" and/or mirror my "old" Levinson No. 336, a beast for power, one that I could no longer pick-up after L & R shoulder surgerie(s), I sold it in 2011. The total / combined weight of my 2 channel beast, is about 15lbs. lighter than No. 336 and I can pick them up and carry them = A REAL WIN!!!
I believe these amps are more delicate, open (literally), equally powerful and do not require 50-60 amp electrical service to deliver spec... though I am considering wiring the main sound room with a 240v (amp) feeds... which is only 10 feet from my electrical panel. Where does this hobby end???
~ I will admit to buying most of the initial PA8 production run ~
I feel that certain = that confident in it to, build more amps...
with this most elegant DIY solution.
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I had my Hafler DH200 upgraded with the Musical Concepts PA8 upgrade, 6 Exicon MOSFETS per side, and upgraded power supply with new power transformer-in other words the, the complete works. I am using a Marantz SACD 30n, and Philharmonic audio BMR speakers. The BMR's have a RAAL tweeter. This is a very revealing setup. The amp has quite a bit of controlled punch on the bottom end, tremendous transient response, the background has no perceivable noise, the sound is uncolored and extremely clean and detailed and yet it is musical and often gives a you are there impression. It is spectacular on well recorded CD's and SACD's. That means perhaps only 10% of what is out there. It is merciless on less than excellent recordings. It makes you wonder about the competency of recording engineers, or they just do not care, or they do not listen to the playback on good equipment. Multi miking and mike spotlighting is ruthlessly revealed and it is damned annoying. With the real good recordings, the set up sounds sweet, detailed and yet musical. Soundstage can be very deep and wide and instrument separation is very good. I highly recommend the updating of the DH 200 to the PA8 level along with the complete power supply upgrade.
Mike
Thanks for posting your thoughts and pictures of the PA8 mods. You must have a special relationship with John Hillig to obtain the PA8 boards as his website doesn't have then listed. The PA8 boards were previously mentioned on his website as "coming soon", but that reference has disappeared and replaced by the PA7 V2 boards. So to clarify, is the PA7 V2 the same as PA8? Does the PA7 V2 offer flat mounting of the TO247/TO264 MOSFETs as per your pictures? Oh and before any smart a..e says "why don't you email or phone John", I have, in fact, several times, but with no reply. Having brought and used several of his kits in the 90's and 00's this is disappointing. Can you please enlighten us.
Thanks for posting your thoughts and pictures of the PA8 mods. You must have a special relationship with John Hillig to obtain the PA8 boards as his website doesn't have then listed. The PA8 boards were previously mentioned on his website as "coming soon", but that reference has disappeared and replaced by the PA7 V2 boards. So to clarify, is the PA7 V2 the same as PA8? Does the PA7 V2 offer flat mounting of the TO247/TO264 MOSFETs as per your pictures? Oh and before any smart a..e says "why don't you email or phone John", I have, in fact, several times, but with no reply. Having brought and used several of his kits in the 90's and 00's this is disappointing. Can you please enlighten us.
HERBS465
Sorry bit of mis-communication there. I was addressing my comments to Ozark HiFi Doctor who goes by the name "Mike Mount" on Audio Asylum. Apparently we two "Mikes". Anyway, thank you for your comments. Did you phone John? The several times I've tried no one answers. Wanting to build this amp to power my Magnepan LRS, seems a good solution for the power and straight forward to build with the PA8.
Sorry bit of mis-communication there. I was addressing my comments to Ozark HiFi Doctor who goes by the name "Mike Mount" on Audio Asylum. Apparently we two "Mikes". Anyway, thank you for your comments. Did you phone John? The several times I've tried no one answers. Wanting to build this amp to power my Magnepan LRS, seems a good solution for the power and straight forward to build with the PA8.
Yes I did speak to John before ordering. In fact I spoke to him about 2-3 weeks ago to tell him how impressed and how happy I was. The PA8 upgrade with complete power supply upgrade is not your "grandfather's Hafler DH200."
I installed MC's PA3-B boards in my Hafler 500 about 21 years ago. I recently installed his discounted PA6 boards in one of my DH-220's because I'm a cheap basstid. I also just restored my other 220 in stock fashion, it had good PC-19C boards that sound great as is . I did replace the electrolytics with Nichicon FG and Muse bipolar at stock values. The 220 with MC boards rotates with my tube amp. It does sound very sweet with my Cornwall clones and surpasses the tubes in the bass department, tighter and more controlled. I bias the Hafler at 375ma and with 100db sensitive speakers it cruises with ease in Class A. What the OP is doing with power supplies is impressive, a fun read. I have a mint XL-280 that will only get new elecrolytics.
