Marantz 7 Questions

So is there a different between 7 and 7C?
Is there a 7B?

Atranz:

The "7" is SS (medicore even in it's time) and the "7C" is a tubed unit (stellar in it's time) but now surpassed, both line and phono sections, by current standards when compared to decent modern designs - some of these being even low cost/budget offerings.

Sorry if this upsets anyone. My opinions are based upon using these units long prior to them having any vintage distinction and since thrn using a restored 7C in my setup in order to compare it to more modern designs.

This is not to say that a refurbished/stock 7C does not sound nice and musical (it does), but most of its value is of a historic nature, IMO.

On a sound quality only basis many dumped their 7C's in the mid/late 70's (in my area anyway) and replaced them with the preamp/phono sections of the then new Advent 300 SS receiver (probably spent the proceeds on herb:-).

So, does one run out an pick up an Advent 300 for better sound quality? Well, probably not w/o having it rebuilt/refurbished (same thing for a 7C) as with any vintage piece the caps and other time dated parts are well past their prime.

Never heard of a 7B.

There is only one model, the 7, which is erroneously called the 7C. 7C refers to the optional wood enclosure ("C"ase).
The 7T was the transistor model.

i believe the actual model designation of the tubed version is Model 7. The "7C" is the 7 with the wooden cabinet. Hence the "C."

Ess & anonymous:

Yes, that is what the "C" refers to. Many of the early 7's were installed in larger floor standing and/or wall cabinets (the case was an option).

As far as sound quality goes, I will add that a local friend had the volume pot of his 7C upgraded (think that Hovland, the tube preamp/amp guy, did the work) and his is one of the nicer sounding preamps I have ever heard.

He said that this was the only mod, but when I was checking out the work I also noticed a couple of small cast metal rectangular boxes, near the power supply that did not seem stock to me (but maybe they are).

This made me wonder what my old Pilot 690A (preamp/tuner) would sound like with a nice/budget stepped volume pot, or perhaps one of my vintage integrated amps?

The custom hand built stepped pot in the 7C was expensive, but screening/matching the resistors for each stereo step alone would be a lot of work (plus putting it together and retesting/replacing anything that ended up being out of wack).

One obstacle with some vintage tube units (in regard to volume pot replacement) is that they have a combo on/off-volume pot. Not certain if simply separating the on/off switch will work.