David Scherfy has been a real pleasure to work with. Really knows McIntosh equipment. Made recommendations which saved me a fortune and which did not compromise my audio/visual experience. Always answered my many (stupid) emails promptly and with detail and precision as to enable me to understand and follow his suggestions. I await his bi-amping of my B&W 802s and, if perfection is still not achieved, to adding 2 MC275s to reach nirvana. And the MC121 is doing a fine job, operating all of my McIntosh stuff. Thank you and good job, David Scherfy!