diff --git a/cmake/Modules/FindLibbladeRF.cmake b/cmake/Modules/FindLibbladeRF.cmake
index 0971344..fc67082 100644
--- a/cmake/Modules/FindLibbladeRF.cmake
+++ b/cmake/Modules/FindLibbladeRF.cmake
@@ -1,5 +1,9 @@
 if(NOT LIBBLADERF_FOUND)
   pkg_check_modules (LIBBLADERF_PKG libbladeRF)
+  if (LIBBLADERF_PKG_FOUND AND LIBBLADERF_PKG_VERSION VERSION_LESS "2")
+    message( FATAL_ERROR "Install version 2 or greater of libbladeRF."
+      " Current version ( ${LIBBLADERF_PKG_VERSION} ) is out of date." )
+  endif()
   find_path(LIBBLADERF_INCLUDE_DIRS NAMES libbladeRF.h
     PATHS
     ${LIBBLADERF_PKG_INCLUDE_DIRS}
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index c7cfec3..4408fc9 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -34,6 +34,8 @@ list(APPEND gr_osmosdr_srcs
     time_spec.cc
 )
 
+set(CMAKE_CXX_STANDARD 11)
+
 #-pthread Adds support for multithreading with the pthreads library.
 #This option sets flags for both the preprocessor and linker. (man gcc)
 if(CMAKE_COMPILER_IS_GNUCXX)
diff --git a/lib/arg_helpers.h b/lib/arg_helpers.h
index 3b02b8f..bef1d74 100644
--- a/lib/arg_helpers.h
+++ b/lib/arg_helpers.h
@@ -153,6 +153,8 @@ inline gr::io_signature::sptr args_to_io_signature( const std::string &args )
     }
   }
 
+  if (arg_list.size() <= 2 && max_nchan > dev_nchan)
+     dev_nchan = max_nchan;
   // if at least one nchan was given, perform a sanity check
   if ( max_nchan && dev_nchan && max_nchan != dev_nchan )
     throw std::runtime_error("Wrong device arguments specified. Missing nchan?");
diff --git a/lib/bladerf/bladerf_common.cc b/lib/bladerf/bladerf_common.cc
index 67bf736..0548027 100644
--- a/lib/bladerf/bladerf_common.cc
+++ b/lib/bladerf/bladerf_common.cc
@@ -49,7 +49,7 @@ static size_t const STREAM_TIMEOUT_MS = 3000;
 using namespace boost::assign;
 
 std::mutex bladerf_common::_devs_mutex;
-std::list<std::weak_ptr<struct bladerf>> bladerf_common::_devs;
+std::list<std::weak_ptr<struct bladerf> > bladerf_common::_devs;
 
 /* name for system-wide gain (which is not its own libbladeRF gain stage) */
 static const char *SYSTEM_GAIN_NAME = "system";
@@ -133,7 +133,7 @@ size_t num_streams(bladerf_channel_layout layout)
  * Public methods
  ******************************************************************************/
 bladerf_common::bladerf_common() :
-  _dev(NULL),
+  _dev(std::shared_ptr<struct bladerf>()),
   _pfx("[bladeRF common] "),
   _failures(0),
   _num_buffers(NUM_BUFFERS),
@@ -1107,7 +1107,7 @@ bladerf_sptr bladerf_common::open(std::string const &device_name)
   /* Add the device handle to our cache */
   bladerf_sptr dev = bladerf_sptr(raw_dev, bladerf_common::close);
 
-  _devs.push_back(static_cast<std::weak_ptr<struct bladerf>>(dev));
+  _devs.push_back(static_cast<std::weak_ptr<struct bladerf> >(dev));
 
   return dev;
 }
@@ -1115,7 +1115,7 @@ bladerf_sptr bladerf_common::open(std::string const &device_name)
 void bladerf_common::close(void *dev)
 {
   std::lock_guard<std::mutex> lock(_devs_mutex);
-  std::list<std::weak_ptr<struct bladerf>>::iterator it(_devs.begin());
+  std::list<std::weak_ptr<struct bladerf> >::iterator it(_devs.begin());
 
   /* Prune expired entries from device cache */
   while (it != _devs.end()) {
diff --git a/lib/bladerf/bladerf_common.h b/lib/bladerf/bladerf_common.h
index 741b1e7..32e8101 100644
--- a/lib/bladerf/bladerf_common.h
+++ b/lib/bladerf/bladerf_common.h
@@ -287,7 +287,7 @@ class bladerf_common
    * Private members
    ****************************************************************************/
   static std::mutex _devs_mutex;  /**< mutex for access to _devs */
-  static std::list<std::weak_ptr<struct bladerf>> _devs;  /**< dev cache */
+  static std::list<std::weak_ptr<struct bladerf> > _devs;  /**< dev cache */
 };
 
 #endif
diff --git a/lib/bladerf/bladerf_compat.h b/lib/bladerf/bladerf_compat.h
index 2ad24be..45e6a16 100644
--- a/lib/bladerf/bladerf_compat.h
+++ b/lib/bladerf/bladerf_compat.h
@@ -66,7 +66,7 @@
     }
 
     /* Changed enums/defines */
-    #define BLADERF_GAIN_DEFAULT BLADERF_GAIN_AUTOMATIC
+    #define BLADERF_GAIN_DEFAULT BLADERF_GAIN_MANUAL
     #define BLADERF_GAIN_MGC BLADERF_GAIN_MANUAL
     #define BLADERF_RX_MUX_BASEBAND BLADERF_RX_MUX_BASEBAND_LMS
 
diff --git a/lib/bladerf/bladerf_sink_c.cc b/lib/bladerf/bladerf_sink_c.cc
index 6ee3acd..ad09d2a 100644
--- a/lib/bladerf/bladerf_sink_c.cc
+++ b/lib/bladerf/bladerf_sink_c.cc
@@ -174,11 +174,9 @@ bool bladerf_sink_c::start()
 
   for (size_t ch = 0; ch < get_max_channels(); ++ch) {
     bladerf_channel brfch = BLADERF_CHANNEL_TX(ch);
-    if (get_channel_enable(brfch)) {
-      status = bladerf_enable_module(_dev.get(), brfch, true);
-      if (status != 0) {
-        BLADERF_THROW_STATUS(status, "bladerf_enable_module failed");
-      }
+    status = bladerf_enable_module(_dev.get(), brfch, get_channel_enable(brfch));
+    if (status != 0) {
+      BLADERF_THROW_STATUS(status, "bladerf_enable_module failed");
     }
   }
 
@@ -210,11 +208,9 @@ bool bladerf_sink_c::stop()
 
   for (size_t ch = 0; ch < get_max_channels(); ++ch) {
     bladerf_channel brfch = BLADERF_CHANNEL_TX(ch);
-    if (get_channel_enable(brfch)) {
-      status = bladerf_enable_module(_dev.get(), brfch, false);
-      if (status != 0) {
-        BLADERF_THROW_STATUS(status, "bladerf_enable_module failed");
-      }
+    status = bladerf_enable_module(_dev.get(), brfch, get_channel_enable(brfch));
+    if (status != 0) {
+      BLADERF_THROW_STATUS(status, "bladerf_enable_module failed");
     }
   }
 
@@ -241,6 +237,11 @@ int bladerf_sink_c::work(int noutput_items,
     return 0;
   }
 
+  noutput_items &= ~(3ULL);
+  if (!noutput_items) {
+    return 0;
+  }
+
   // copy the samples from input_items
   gr_complex const **in = reinterpret_cast<gr_complex const **>(&input_items[0]);
 
diff --git a/lib/bladerf/bladerf_source_c.cc b/lib/bladerf/bladerf_source_c.cc
index 83db677..16cfcac 100644
--- a/lib/bladerf/bladerf_source_c.cc
+++ b/lib/bladerf/bladerf_source_c.cc
@@ -230,11 +230,9 @@ bool bladerf_source_c::start()
 
   for (size_t ch = 0; ch < get_max_channels(); ++ch) {
     bladerf_channel brfch = BLADERF_CHANNEL_RX(ch);
-    if (get_channel_enable(brfch)) {
-      status = bladerf_enable_module(_dev.get(), brfch, true);
-      if (status != 0) {
-        BLADERF_THROW_STATUS(status, "bladerf_enable_module failed");
-      }
+    status = bladerf_enable_module(_dev.get(), brfch, get_channel_enable(brfch));
+    if (status != 0) {
+      BLADERF_THROW_STATUS(status, "bladerf_enable_module failed");
     }
   }
 
@@ -344,7 +342,7 @@ int bladerf_source_c::work(int noutput_items,
     memcpy(out[0], _32fcbuf, sizeof(gr_complex) * noutput_items);
   }
 
-  return noutput_items;
+  return noutput_items/(get_num_channels());
 }
 
 osmosdr::meta_range_t bladerf_source_c::get_sample_rates()
diff --git a/lib/sink_impl.cc b/lib/sink_impl.cc
index 317855a..55d67c6 100644
--- a/lib/sink_impl.cc
+++ b/lib/sink_impl.cc
@@ -30,6 +30,8 @@
 #include <gnuradio/io_signature.h>
 #include <gnuradio/constants.h>
 
+#include <boost/foreach.hpp>
+
 #ifdef ENABLE_UHD
 #include "uhd_sink_c.h"
 #endif
@@ -245,6 +247,13 @@ sink_impl::sink_impl( const std::string &args )
 
   if (!_devs.size())
     throw std::runtime_error("No devices specified via device arguments.");
+
+  /* Populate the _gain and _gain_mode arrays with the hardware state */
+  BOOST_FOREACH( sink_iface *dev, _devs )
+    for (size_t dev_chan = 0; dev_chan < dev->get_num_channels(); dev_chan++) {
+      _gain_mode[dev_chan] = dev->get_gain_mode(dev_chan);
+      _gain[dev_chan] = dev->get_gain(dev_chan);
+    }
 }
 
 size_t sink_impl::get_num_channels()
diff --git a/lib/source_impl.cc b/lib/source_impl.cc
index 8f2028b..46fb0e0 100644
--- a/lib/source_impl.cc
+++ b/lib/source_impl.cc
@@ -32,6 +32,8 @@
 #include <gnuradio/blocks/throttle.h>
 #include <gnuradio/constants.h>
 
+#include <boost/foreach.hpp>
+
 #ifdef ENABLE_FCD
 #include <fcd_source_c.h>
 #endif
@@ -191,6 +193,19 @@ source_impl::source_impl( const std::string &args )
     }
   }
 
+  bool force_arg = false;
+  int force_val = 0;
+
+  if (arg_list.size() <= 2) {
+     BOOST_FOREACH(std::string arg, arg_list) {
+       if ( arg.find( "numchan=" ) == 0 ) {
+         pair_t pair = param_to_pair( arg );
+         force_arg = true;
+         force_val = boost::lexical_cast<size_t>( pair.second );
+       }
+     }
+  }
+
   if ( ! device_specified ) {
     std::vector< std::string > dev_list;
 #ifdef ENABLE_FCD
@@ -258,6 +273,9 @@ source_impl::source_impl( const std::string &args )
 
   for (std::string arg : arg_list) {
 
+    if(force_arg)
+       arg += ",nchan=" + std::to_string(force_val);
+
     dict_t dict = params_to_dict(arg);
 
 //    std::cerr << std::endl;
@@ -403,6 +421,13 @@ source_impl::source_impl( const std::string &args )
 
   if (!_devs.size())
     throw std::runtime_error("No devices specified via device arguments.");
+
+  /* Populate the _gain and _gain_mode arrays with the hardware state */
+  BOOST_FOREACH( source_iface *dev, _devs )
+    for (size_t dev_chan = 0; dev_chan < dev->get_num_channels(); dev_chan++) {
+      _gain_mode[dev_chan] = dev->get_gain_mode(dev_chan);
+      _gain[dev_chan] = dev->get_gain(dev_chan);
+    }
 }
 
 size_t source_impl::get_num_channels()