It's always exciting to start a new audio adventure with vintage hi-fi electronics, and I'm particularly excited about my new vintage audio adventure with the vintage monaural McIntosh C-8 'Professional Audio Compensators' as McIntosh called them, or phono preamplifiers, as the rest of us call them.
A pair of monaural McIntosh Model C-8 Professional Audio Compensators.
I read where the original principals at McIntosh thought that the monaural McIntosh C-8 Professional Audio Compensators, produced from 1955 to 1959, were the finest phono preamplifier that McIntosh ever produced, which of course intrigues me greatly.
Vintage monaural McIntosh C-8 Professional Audio Compensator (phono preamplifier).
You need two C-8's for stereo, and they have to be powered either by connecting them to vintage McIntosh amplifiers, like my vintage McIntosh MC30 monaural amplifiers, via the C-8's umbilical cords, or by separate D 8 or D 8A power supplies.
Mac C-8 installation drawing for monaural connection.
Just under the Belden 8402 IC you can see the funny looking plug labeled 'Preamplifier' that is made for plugging the C-8's umbilical into to serve as a power supply.
The vintage monaural McIntosh C-8 Professional Audio Compensators are difficult to come by, and a matched pair are almost impossible to come by, believe me, I tried!
They're not expensive, and you can pick them up a decent example of a C-8 for about $400 to $500 USD each, but given they're as old as I am, you can figure they're going to need some TLC to get into tip-top playing shape.
Mac C-8 Serial No 7687.
I bought a restored one off of eBay, and another one that "was checked by a technician" and found to be in good shape, about six months apart, so you have to be patient when looking for C-8's.
Mac C-8 Serial No 6424.
I'd love to have found a matched pair with matching period wood cases, but during the time I was looking there were none to be had.
You'll notice that the back panel layout is different on my two C-8's. All the same controls, etc., are there, but they're in a different layout configuration, so apparently McIntosh changed the back panel design sometime in between when C-8 Serial No 6424 was produced, and when C-8 Serial No 7687 was produced.
I am intrigued that the original principals at McIntosh thought that the monaural McIntosh C-8 Professional Audio Compensators were the finest phono preamplifier that McIntosh ever produced, and I'm curious to find out why.
Excerpt from McIntosh C-8 record EQ chart.
No doubt a large part of the reason why they thought the C-8 was McIntosh's finest accomplishment as a phono preamplifier was the extreme adjustability of the C-8's design, as you can read about in the excerpts from the record compensation settings charts for the C-8.
Below you can see the settings for various record labels. The C-8 is quite a sophisticated device!
Excerpt from the C-8 EQ chart for various record labels.
The power of this level of adjustability is that you can theoretically adjust the playback of any record to perfection, to match your listening room, associated equipment, and personal taste.
The adjustability of the vintage McIntosh C-8 Professional Audio Compensator is both powerful and a little bit intimidating, as the C-8 isn't exactly a plug & play device, rather it is a deep learning exercise, which to me is an adventure of the grandest scale!
Excerpt from the C-8 EQ chart.
Consider this to be the briefest of introductions to my latest vintage McIntosh C-8 Professional Audio Compensator adventure, and I'll fill in more details about the C-8's as we go.
I'll do my best to get the C-8s figured out and up & running, which after looking at their operating instructions, is not a trivial task.
In my next post I'll pop the covers of the C-8's so we can have a look inside, and find out if they're operational, or need new 12AX7's to freshen them up, etc., so there is much more to come!
Just think of all the potential wire, resistor, capacitor, rectifier, tube swapping, and listening adventures these little buggers could generate! Should be fun!
As always, thanks for stopping by, and may the tone be with you!
