MARANTZ MODEL 10 TUBE AMP/ TUNER AND MARANTZ 7 TUBE PREAMP

Pictures, please!

Hold on to them in 50 years they will be worth  a fortune.

Have they been refurbished? If not, I would only plug them in long enough to see that they light up; any longer than that and the power transformers are at risk due to failing filter capacitors in the power supplies.
If they have been refurbished, what sort of warranty do you have? The power transformers will likely have to be re-manufactured should one fail, which is not cheap.

The owner told me that amp and preamp was used from time to time and they stopped using it when they removed their ceiling speakers recently.

Are you sure the Model 10 is a "tube amp/tuner"?  I believe it is just a tuner, like the 10B.

Good luck.  Regards,
-- Al
 

Yes it is the Tuner, like the 10B but the first model.

The 7C was a great, perhaps the best sounding preamp of the mid 60s.
I bought one used around 1970. By the time I sold it the switches and potentiometers had started to get scratchy. Back then sealed switches and potentiometers were not used at least in consumer electronics. They may not have been available at all. By now unless the toggle switches and pots have been upgraded and power supply rebuilt it would be nothing more than a conversation piece. 

FWIW, during the early to mid-1990s I owned several of the classic Marantz tube components, including a 7 (aka 7C), as well as a pair of Model 1 mono preamps, a pair of Model 2 monoblock amps, a pair of Model 9 monoblock amps, and two different 10B tuners.

After performing some routine minor maintenance on each, such as spraying contact cleaner into the controls, testing tubes and replacing them as necessary, and powering them up for the first time very slowly (i.e., over the course of several hours or more) using a variable AC power supply, all of them worked fine and sounded great, with one exception. That being one of the 10Bs, which if I recall correctly had an intermittent problem affecting channel separation, possibly due to a problem with one of its opto-couplers.

The 7 was especially good sounding, as I recall, and it was a close call as to whether I preferred its sonics to those of the Mark Levinson ML-1 I also had at the time, and used for many years afterward.

My sonic favorite among all of these models were the Model 2 mono amps, used in triode mode. The 18 or 20 watts or so which they could provide in that mode were not enough for my purposes, though, with the 90 db speakers I had at the time and when playing classical symphonic recordings having particularly wide dynamic range. So I eventually sold them, although I felt a sense of loss for a long time afterward.

Regards,
-- Al

The owner told me that amp and preamp was used from time to time and they stopped using it when they removed their ceiling speakers recently.

Sounds to me like a bit of luck that the stuff is still running in that case. It really is a good idea to get this stuff serviced. You'll be hating yourself if a power transformer fails otherwise!
Its not that hard for any good technician. I've rebuilt several model 7s and 10Bs.

Any older tube gear that you expect to press into service will need the filter capacitors in the power supplies replaced at the bare minimum.

Thank you all for your input. Im still negotiating the price so if somebody would give me any idea on how much should I pay or how much are they worth? 

The only reported sales of the Model 10 that I am aware of occurred 15 or 20 years ago. In those cases prices were similar to those of the 10B, roughly around $2K at that time. The 7 is much more common, of course, and relatively recent selling prices shouldn’t be hard to find. (In searching, keep in mind that the 7 and 7C are the same thing, and can be found with or without an original wood cabinet).

I would add that the value of all of the Marantz tube products is dramatically affected by cosmetic condition. For example, if the top of the chassis of the 10 has signs of rust or significant discoloration, or if the 7 has scratches on its faceplate or elsewhere, value would be lowered significantly. Also, burn-marks or other imperfections on the face of the 10’s oscilloscope will reduce value.

If you cannot view these pieces in person prior to purchase, you should obtain photos that are as detailed as possible before committing to a price.

Also, of course, missing or non-original parts can adversely affect value, in some cases even if the non-original parts restore or improve performance. That can present a dilemma when it comes to classic pieces such as these.

Regards,
-- Al

Also, of course, missing or non-original parts can adversely affect value, in some cases even if the non-original parts restore or improve performance. That can present a dilemma when it comes to classic pieces such as these.

Yes- back when the Japanese were scouring the country looking for equipment like this (1980s and 1990s), it was really important to them that the equipment was in original stock condition, despite that meaning that it was essentially unusable! 
So a restoration should be done that makes it really hard to tell it happened.

Did the sale go through? I own a Model 10 and keep a database of surviving units. I've never seen a rack mounted version. I would love to add it to my list of survivors!