Hello, I own a SVP-BSP preamplifier, and use it with a Power-Amplifier and two Trace Elliot cabinets, 1X15 and 2X10 with a horn, 200W 8Ohms each cabinet. I also play in a studio through a Gallien-Krueger 400RB-IV and only a 1X15 cabinet, I love the punch of this head, I also like to use my preamp with the GK head to get some distortion, the result is very good. But, there are some bad points about the GK Head: 1- The ventilation is on the top, I will have to leave one rack space between GK head and SVP-BSP. I have a 4 rack space, so I will have to leave my compressor out. 2- The effects loop is in the front panel of the unit (Who was the idiot that had this idea?) So I considered a Hartke HA4000, that is an all solid state head also, this head has a lot of features and would fit better: 1- Send/Return pre and post, (Allows to use the equalizer only on the clean channel of the SVP-BSP using the clean effects loop) 2- Two complete parametric equalizers. 3- The shape circuit allows you to control Frequency and intensity (In GK head the central frequency is fixed in 500Hz, its called contour circuit) 4- More power 400W 4ohms against 280W 4ohms of GK 5- And . The Hartke is cheaper than the GK Head!!! 22% cheaper But Im still in doubt, because I think that the clear, defined and punch tone of GK comes from the power amp section because I cant get the same punch tone from my current set-up (SVP-BSP + Power Amp head), so, it is possible that the HA4000 would not be a good choice too. Maybe the equalizer of HA4000 is not a good quality EQ also... Well, somebody can help me in this matter how is the tone of a HA4000 compared to a 400RB-IV? PS: Of course I will go to a store and try the HA4000 head, just want some opinions before.