diff --git a/artiq/coredevice/dac34h84.py b/artiq/coredevice/dac34h84.py
index 6d40826b3..155096a1e 100644
--- a/artiq/coredevice/dac34h84.py
+++ b/artiq/coredevice/dac34h84.py
@@ -121,10 +121,11 @@ class DAC34H84:
     path_c_sel = 2
     path_d_sel = 3
     # swap dac pairs (CDAB) for layout
-    dac_a_sel = 2
-    dac_b_sel = 3
-    dac_c_sel = 0
-    dac_d_sel = 1
+    # swap I-Q dacs for spectral inversion
+    dac_a_sel = 3
+    dac_b_sel = 2
+    dac_c_sel = 1
+    dac_d_sel = 0
 
     dac_sleep_en = 0b1111  # msb a
     clkrecv_sleep_en = 1
diff --git a/artiq/coredevice/phaser.py b/artiq/coredevice/phaser.py
index 787e4990e..8acaf9010 100644
--- a/artiq/coredevice/phaser.py
+++ b/artiq/coredevice/phaser.py
@@ -651,7 +651,7 @@ class PhaserChannel:
         :param frequency: DUC frequency in Hz (passband from -200 MHz to
             200 MHz, wrapping around at +- 250 MHz)
         """
-        ftw = int32(round(frequency*((1 << 31)/(250*MHz))))
+        ftw = int32(round(frequency*((1 << 30)/(125*MHz))))
         self.set_duc_frequency_mu(ftw)
 
     @kernel
@@ -689,7 +689,7 @@ class PhaserChannel:
         :param frequency: NCO frequency in Hz (passband from -400 MHz
             to 400 MHz, wrapping around at +- 500 MHz)
         """
-        ftw = int32(round(frequency*((1 << 31)/(500*MHz))))
+        ftw = int32(round(frequency*((1 << 30)/(250*MHz))))
         self.set_nco_frequency_mu(ftw)
 
     @kernel
@@ -831,7 +831,7 @@ class PhaserOscillator:
         :param frequency: Frequency in Hz (passband from -10 MHz to 10 MHz,
             wrapping around at +- 12.5 MHz)
         """
-        ftw = int32(round(frequency*((1 << 31)/(12.5*MHz))))
+        ftw = int32(round(frequency*((1 << 30)/(6.25*MHz))))
         self.set_frequency_mu(ftw)
 
     @kernel