Upgrade or keep?


Over the past few years I have accumulated peices of vintage audio gear that I have been fortunate enough that they work well and look and sound very good.The pieces are.
NAD 3020
SONY TA-N55ES
HAFLER 220
MARANTZ 2220B
JVC XL-Z1050
MAGNAVOX CDB 473
TECHNICS SL-1700
TECHNICS SL-1900
ADS L470
CELESTION DL4 II
Found good deals on all the above but was wondering if I'd be better off selling the equipment for something new or keeping what I have? I'm content with what I have,just curious about other alternatives.Do not know the exact value of what I have,"I feel that equipment is a bit overpriced",but could I do better selling and purchasing new?Thanks for any suggestions.  

john421
If you are happy with what you have, just keep it and enjoy the music.
The upgrade merry-go-round can become dizzy and expensive.

As for exact value, well there is no exact value. An item is only worth what someone is willing to pay for it. Asking folks to guess what someone might pay for something is a waste of time.
If you are looking to sell right now, you need to understand that it is a buyers market now, and you will not get as much money as you think you will get for your items. Some offers are downright insulting, and your choice as a seller is to sell for cheap, or just keep it.
Personally, I have decided to keep some of my gear for now, as opposed to giving it away.

I think that by selling your gear and purchasing new you will get a different sound, but not necessarily better.
Thank you for your input and I tend to agree with your thoughts. 
I had vintage gear for several years, some was fairly well regarded but nothing extravagant.

The biggest revelation I had regarding more current gear is when I bought a preowned preamp for a few hundred dollars that was originally around $4000. I heard a big difference in my system. Since then I've switched over to gear that gave that same transparency.

If you have an opportunity to hear a well regarded modern preamp with your system, it may be worth the time and effort. Of course you may feel differently, but it was a game changer for me. 

Gary
What would be a good tube preamp choice to match let's say with the Hafler new or used?Had used the 3020 as my pre but using it by itself for now.
I had a two DH Hafler's a 200 and a 220. We parted company mainly because I found them a too polite in the mid and upper frequencies. I never did try a tube preamp with them, I don't think I would want to. 
I would just upgrade Celestion speakers. The rest are keepers.

In your post, you really don't say what you're trying to accomplish. Your list contains some decent, middle-of-the-road equipment that could be found in any typical stereo setup. However, if you're looking to assemble just one reference system (I'm assuming here), then I would sell everything and look for the highest-quality, highly reviewed used equipment I could find. Please understand that that is what I would do, what you decide to do is up to you. Also, be prepared to accept "giveaway" prices as it is definitely a buyer's market for used equipment today.
A lot of different opinions,but yes tonykay your assumption is correct.Looking for one reference system though it may be easier to keep what I have from the other suggestions. 
For sure if you're happy, keeping what you have would be easiest. It may be just right for you. I wouldn't change for the sake of it.

On the other hand, upgrading can be fun and rewarding. If you're patient and enjoy reading about different gear, you can put together a nice system cost effectively in my opinion. 

Enjoy,
gary
Happy with what I have yes,but as we all know we are always looking for that best possible system.I paid just south of $200 for the equipment listed above.Some through trades,others from thrift stores,Craigslist,Audiogon and similar sites.So getting dollar value if I decide to sell and upgrade should work out well.Some will like what I have and some will not.By the way I'm using Morrow and older MAC rca cables along with WE 16 gauge and canare for speaker cable.
$200 for everything! You must be quite a negotiator (LOL). Could that have been $2000? If not, good for you.
Lucky,but some have been just honest people not looking to make a hugh amount of money.Some equipment just needed a little TLC.
John, sorry to take long to respond. I have not owned many tube preamps, but reading through the forums Jolida has a pretty good reputation for value and service after the sale if needed. 

May be worth asking for suggestions in the preamp forum. Also, you'll get more useful responses if you specify a target budget or range.

Fyi, I have some Morrow cables as well. I like them. 

Regards

Newer equipment may or may not improve your listening experience.

First you have to figure out what sonic qualities are most important to you. For instance, I value musicality over all else.

I find most gear made in the last 30 years to be completely lacking in this regard!
john421-

some of the older gear was the best ever built. If you are happy w/ what you own- keep it.

(Most) newer gear is made in china and not worth anything, IMO.
Soundmann from what I've heard the NAD 3020 and JVC XL-Z1050 are very musical and have read where many feel the same.
That's funny, because I use to own a 1050, along with a Proton D940! Musical? Yes!
I greatly prefer vinyl over digital for natural, musical sound however.
Proton and NAD where basically the same weren't they?
Yes, but the Protons had premium parts!
I use a Sony ES amp that I am very happy with as well.
Which of your Technics tables do you like the best?
I enjoy both but believe the bottom end is a bit better with the 1700.Trying to purchase a Dual 510 from a gentleman that is moving and selling for a very reasonable price.