Hello all! I'm new to this site, and I've come here for one main reason: unlike a number of other forums I lurk around on, you all really do seem to know what you're talking about. So, I have some questions for you all about two different Yamaha power amps. (And from the discussions I've seen on this site, these will likely be insultingly simple questions, so I apologize in advance for my naivete). Here's the deal--I'm looking for an amp to power my Yamaha NS-10s in my little studio. After much research on amps, thoughtful reflection on my needs, and fretful consideration of my budget, I've pretty much decided to go with a Yamaha P2150. But here's the issue--there seem to have been at least two different versions of that amp made. One is the standard P2150, and the other is the P2150C. They have quite a lot in common, but they are different. The standard P2150 is pretty straightforward as far as the input/output connections go, but the P2150C is quite different and seems almost designed for a specific kind of use (even its attenuator knobs on the front are smaller and differently shaped). Anyway, I'm attaching pictures of the backs of both amps. If anyone can tell me anything about the C version (it's the one with the Transformer In/Out switch in the input section), I'd really appreciate it. What I'm interested in most is why the C has screw terminals, what the Transformer In/Out switch does, what the large, round inputs in the Input section are for, and how difficult repairs on this amp might be (for a pro to do, not me). I've scoured the web trying to answer these questions for myself, and I can't even find a manual for this thing. All I know is that the one I'm looking at came out of a church. So, any info would be much appreciated.
The octal sockets are for the two optional, switchable audio input transformers. Useful if you have hum problems.
Pros used to use lugs with a barrier strip for more reliable speaker connections. The C stands for the "commercial" version.
Pros used to use lugs with a barrier strip for more reliable speaker connections. The C stands for the "commercial" version.
The P2150C service manual is available as a paid for download here:
https://themanualsservice.com/produ...g-pcbs-schem-diag-and-parts-list-28-pages-eng
https://themanualsservice.com/produ...g-pcbs-schem-diag-and-parts-list-28-pages-eng
Thank you all so much for your replies! I knew this was the site to come to. Ultimately, my choice came down to the regular P2150 or the P2150C, and I chose to go with the regular P2150 because it's more suited to my needs. I mean, the C version I was looking at doesn't come with a set of octal transformers, so I would've had to track them down and (worse yet) pay for them. And honestly, that amp just kind of scares me. But I really wanted to learn about it before I made the decision, and everyone here was so helpful. So, thank you all again for your help. I think I'll go to the link that Galu posted to find the service manual for the P2150 since it will have to have a check-up before I use it. 🙂