Hi everyone. I really hope you can help me. I have a Crown Psa2 amplifier, to drive Infinity Kappa 8. For aesthetic reasons, which cannot be resolved, I would like to replace it with other used amplifiers, including McCormack DNA1 Deluxe, of which I will post some photos, hoping that you can help me verify the authenticity and exact revision, and a Rotel RHB 10 MICHI whose solid construction I really like. Have you had the opportunity to listen to the endings in question? Would they be a real upgrade? In your opinion could they be a leap forward for the Infinity Kappa 8 or should I keep my Crown PSA2 dusted? My preamp is a Classè audio Dr-6. Thank you
McCormack DNA 1 vs Rotel RHB 10 Michi
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Blue Shadow
Waiting for Vintage Gear from this century
In our listening tests the DNA-1 was the best of the sand amps followed by the Citation 22 then the Crown which had new small caps, the only new caps in any of these amps. The Crown took the honors in bass performance but the McCormack was a winner overall, a nice sounding amp.
Maybe a call to SMC to talk to them about what revision level is in that DNA-1. It is the amp I would choose. The PSA-2 is now driving Bose 901 V in a large out building and very well liked in that position.
The DNA-1 is my main amp but other fresh recaps have been used this summer a Luxman M-12 (80 wpc true dual mono amp) and the winter amps were the overall winner, Luxman MB3045 tube jobs. Driving DQ-10s with subs so no hard work below about 60Hz. The McCormack is great driving the DQs full range though when the subs are bypassed or not in the system. I do not think the M-12 would displace the DNA-1 for sound quality. We haven’t compared them. The DNA-1 is also great with Magneplanar MG-IIIa speakers which I need to put back in the main rig.
Maybe a call to SMC to talk to them about what revision level is in that DNA-1. It is the amp I would choose. The PSA-2 is now driving Bose 901 V in a large out building and very well liked in that position.
The DNA-1 is my main amp but other fresh recaps have been used this summer a Luxman M-12 (80 wpc true dual mono amp) and the winter amps were the overall winner, Luxman MB3045 tube jobs. Driving DQ-10s with subs so no hard work below about 60Hz. The McCormack is great driving the DQs full range though when the subs are bypassed or not in the system. I do not think the M-12 would displace the DNA-1 for sound quality. We haven’t compared them. The DNA-1 is also great with Magneplanar MG-IIIa speakers which I need to put back in the main rig.
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The DNA will die eventually I believe, they used a bad batch of boards that turn conductive.
Blue Shadow
Waiting for Vintage Gear from this century
Any revision or Deluxe uses new parts that aren't supposed to die. The original DNA-1 did have a board that would cause issues necessitating a major repair. I have not heard of any later versions of the amp having this issue as the problem was found and the new board was designed to resolve the problem.
mondialfan
Well-Known Member
The DNA-1 is an excellent sounding amplifier. Its one of the best sounding amps I've had in my system. It can have issues with the main board as others have pointed out and these issues will typically result in the red protection light remaining illuminated on the front panel. Some owners have reported that they noticed the red light staying on longer and longer over months of use from a cold power up. These board issues are present on both standard and deluxe models, the boards are the same, only a few components are changed out for premium parts in the deluxe version. I've had both models on my bench, one a very early 1992 standard model with the original main board and a local customers DNA-1 deluxe which had a board failure in the late 90's in which it was sent it in to Conrad Johnson for rebuild and they installed a new board. CJ called the board replacement the "R1" board. Upon very close inspection the boards are identical in their layout and design and even the silk screening is identical. The only visual difference is in their color, the later boards are a darker blue color and have a rougher textured finish where the early boards are much more smooth and glossy. I've included an image of an early board, which is what is in the amp that the OP posted, and a later model board.
The issue with the boards isn't that they're becoming more conductive. The problem is a loss of connection on some of the through-hole signals and grounds. Unfortunately the original design of the board isn't very robust. The through hole vias are barely large enough for many of the leads to go through which means that solder doesn't flow through the holes very well and the pads around the holes are ridiculously small, they should've been at least double the size to get a better solder connection. The main boards can be repaired, but extreme attention has to be paid to these through hole connections. Its for these reasons that I don't recommend that novices attempt to mod these amps, they'll wind up with a boat anchor. The older non-deluxe amp that I bought for myself came to me in non-functional condition and had failed due to a botched attempt at upgrading the amp.
The issue with the boards isn't that they're becoming more conductive. The problem is a loss of connection on some of the through-hole signals and grounds. Unfortunately the original design of the board isn't very robust. The through hole vias are barely large enough for many of the leads to go through which means that solder doesn't flow through the holes very well and the pads around the holes are ridiculously small, they should've been at least double the size to get a better solder connection. The main boards can be repaired, but extreme attention has to be paid to these through hole connections. Its for these reasons that I don't recommend that novices attempt to mod these amps, they'll wind up with a boat anchor. The older non-deluxe amp that I bought for myself came to me in non-functional condition and had failed due to a botched attempt at upgrading the amp.
Blue Shadow
Waiting for Vintage Gear from this century
I've got one of those old boards here. Maybe I can bring it back to like...another project, well down the list. When I had on worked on by CJ (easy drop off, no shipping, I asked for the removed parts as they swapped out the RCA jacks and dual binding posts which would have been used in other projects but all I got was the board that was replaced.
The amp sounded better after the upgrade.
The amp sounded better after the upgrade.
do these use component leads as vias ? I have something built that way, what a miserable pain in the neck to work on. Have to be very careful to solder on both sides of the board otherwise it doesn't connect properly and things go stupid.
mondialfan
Well-Known Member
Well yes & no. Originally they didn't use the leads as vias. The holes had ferrules in them, but the connection between the pads and ferrules seems weak, plus many of the leads are really tight going through the ferrules which limits the flow of solder from the back side through to the front. Due to poor solder coming through to the top side of the board this ends up leading to the loss of connectivity over time, especially under e-cap's where you cannot see or touch up the top solder joint. When rebuilding one of these I had to use the leads as the through-hole connection to be certain that the amp would live a long life. I had to stand-off mount all of the leaded e-caps by about 1/4" off the board, bend the cap over slightly and solder the top side of the pads, then stand the cap back up straight. Once they're all standing up its hard to tell that they're offset mounted.
The image of the older original board in my photo above was after I rebuilt the board and has all of the small leaded e-caps mounted 1/4" off the surface of the board.
Your information is always very interesting. As I understand it, however, the amp sounds very good, but is not built as well, and upgrades are not an option but a necessity if you want a machine that will last over time. At least here in Italy there aren't many DNA1s and carefully distinguishing those that are upgraded from those that aren't is not so easy. I believe this will make me desist from purchasing a McCormack, at least on the Italian market. I have also looked into the ROTEL and from some reviews it seems like a good amplifier but with not as high sound qualities as the McCormack. What do you think of the Haflers?
mondialfan
Well-Known Member
I would say that the original McCormack DNA-1/ DNA-1 Deluxe has an above average failure rate due to the main board problems I mentioned. If you do not have the ability to have the unit repaired by a competent tech then you may want to pass up the DNA-1. I also see some things in your images that lead me to believe that the amp shown in your pictures is a standard DNA-1 and not a Deluxe version, there are a number of standard version components & wires displayed that were suppposed to be upgraded in the Deluxe version. So it may be less attractive to you if you were really wanting a Deluxe version.
The Haflers are a generally robust design and they sound good as well. I've owned a lot of the Haflers, DH-200, DH-220, XL-280 and my last one was an XL-600. In my system I do think that the McCormack DNA-1 betters any of the Hafler amps I've used in sound quality, but the DNA-1 comes with reliability issues. The Hafler's also have a few upgrade options and the schematics are all readily available if you decide to take them to another level.
The Haflers are a generally robust design and they sound good as well. I've owned a lot of the Haflers, DH-200, DH-220, XL-280 and my last one was an XL-600. In my system I do think that the McCormack DNA-1 betters any of the Hafler amps I've used in sound quality, but the DNA-1 comes with reliability issues. The Hafler's also have a few upgrade options and the schematics are all readily available if you decide to take them to another level.
Blue Shadow
Waiting for Vintage Gear from this century
Possibly seek out a Rev McCormack. Maybe hard to find but once the board is upgraded the amp seems fine.