Greetings everyone! I heard back from the man himself (Steve McCormack) on my crazy idea regarding modifying the DNA-HT1 into a dual mono. There's good news and bad news.
First the bad news per Steve: "To answer your first question - no, I have never converted an HT-1 (or HT-3) into a pair of bridged channels. There is no reason why this couldn't be done - I have just never done it. As you know, the center channel output is a already a bridged pair, and you certainly could add a bridging circuit to the other pair of channels to form another bridged pair. What you probably don't realize is that the center-channel pair has only 2 output devices per side, while the other (main) output channels have 4 (2 x NPN & 2 x PNP). This gives the main channels greater current delivery capability, although the circuit topology is otherwise the same for all. As you can see, this would mean that the bridges channels would not be truly matched, at least in terms of current delivery."
Now the good news regarding the HT1, again from Steve: "On the other hand, using just the main L-R channels (while leaving the center channel unused) works very well. In fact it has a distinct advantage over a regular DNA-0.5 in that the power transformer is a high-quality toroid, and much larger than the standard 0.5 transformer. I know of several people doing this, and they are very pleased with the result. You would have to add the Plitron transformer to the DNA-0.5 (one of the upgrade options) to equal or exceed this advantage."
Oh, and one last point that would killed the HT1 dual-mono idea out of the gates: "Please note that I do not offer upgrade work on the HT-1 or HT-3 - they have proven to be too fussy and time-consuming to be done economically."
Looking at my system and thinking about the various options I will likely go with some SMc mod'd monoblocks from the get-go.
Just wanted to post this information in case it was helpful/useful to anyone else out there in the Agon universe.
First the bad news per Steve: "To answer your first question - no, I have never converted an HT-1 (or HT-3) into a pair of bridged channels. There is no reason why this couldn't be done - I have just never done it. As you know, the center channel output is a already a bridged pair, and you certainly could add a bridging circuit to the other pair of channels to form another bridged pair. What you probably don't realize is that the center-channel pair has only 2 output devices per side, while the other (main) output channels have 4 (2 x NPN & 2 x PNP). This gives the main channels greater current delivery capability, although the circuit topology is otherwise the same for all. As you can see, this would mean that the bridges channels would not be truly matched, at least in terms of current delivery."
Now the good news regarding the HT1, again from Steve: "On the other hand, using just the main L-R channels (while leaving the center channel unused) works very well. In fact it has a distinct advantage over a regular DNA-0.5 in that the power transformer is a high-quality toroid, and much larger than the standard 0.5 transformer. I know of several people doing this, and they are very pleased with the result. You would have to add the Plitron transformer to the DNA-0.5 (one of the upgrade options) to equal or exceed this advantage."
Oh, and one last point that would killed the HT1 dual-mono idea out of the gates: "Please note that I do not offer upgrade work on the HT-1 or HT-3 - they have proven to be too fussy and time-consuming to be done economically."
Looking at my system and thinking about the various options I will likely go with some SMc mod'd monoblocks from the get-go.
Just wanted to post this information in case it was helpful/useful to anyone else out there in the Agon universe.