Recommendation please: Small inexpensive DAC for smart phone to receiver

I have a late '80s McIntosh mac4280 stereo receiver and have been using the headphone output of my Android phone connected to the Aux input of the receiver. 

I'd like to install a small inexpensive USB DAC between the phone an receiver to improve the sound quality.

I went to eBay and Amazon and was overwhelmed with all the Dacs, many from China, some with headphone output only, others with rca outputs which I need. I don't know where to begin looking. I'd like to keep it around $100 - $150 for a first phone Dac for my Android phone to stereo receiver.

What do you recommend?
Look at Audioquest, Oppo, Fiio, Ifi. 

Most of these are battery operated headphone amp/Dacs.  Most also have a line output capability. The Audioquests will need a cable adapter.   

Love my Oppo HA-2 purchased here for $250.  
As per dbtom2, check out the new Dragonfly Black (v1.5) or Red from Audioquest.  They were developed specifically to work with phones.  

ALSO, check out Schiit Modi 2.

The Black v1.5 and Modi2 are in your price range and should do what you want.  

I have a question, can I use any usb DAC with my smartphone with the proper adaptor cable that will allow me to plug my Android phone into the DAC.
You need an OTG cable (on the go).  They are relatively cheap.  It plugs into your connection port on the phone and has a USB on the other end.
Schiit claims Modi will work with an iPhone not sure about Android.  See discussion at link here.  Start at discussion post #154

From the Audioquest site...
Can I use DragonFly with Android devices?
Yes. DragonFly Black and Red will work with most Android devices running on Lollipop OS (and some Android devices running on KitKat), provided that the device manufacturer has adhered to the USB specification and implementation, and supports audio over USB.

To verify that your Android device complies with isochronous USB audio, download and run USB Host Check.

Android devices use a USB format known as “OTG” (On the Go). In order to connect an Android device in USB Host Mode to a DAC, an OTG adaptor must be used. (See

Visit the AQ site for additional info.
It depends on how the dac is powered. In your config, the phone powers the dac. 

I am not familiar with other techniques at your price point. 
I really like the UFO DAC's but mine died after like a month, however when it did work it was marvelous, very close to the Pono or best Fiio outboard headphone amps.

I'm thinking of getting the Auris BluMe bluetooth receiver/Dac. Anyone have experience with this one for use w/ a smart phone and vintage receiver?
I use the Auris bluMe and very highly recommend it. Look at my system page. Though I use a Samsung tab for Spotify and other apps, I also use it with my smart phone. You will be amazed what it can do. It is amazing that Bluetooth audio can sound so good. My only concern - it does not come with the power adapter. I use a Apple 12W power adapter with mine. They have dropped the price on Auris, at Amazon to $141 for the Black one.
Will love to hear from you, if you get it. I love mine.