Hey, 

I recently complete a TS 500, my second unit after building a CP5176. The TS 500 seems to be all working and today I decided to do some proper testing and at first I thought the unit wasn't working as expected, I couldn't hear the BIAS/EQ or the IPS working so checked with a noise oscillator and on Fab Pro Q can see that they are working very subtly,

For testing Im running white noise and sine waves at -18db, drive at maximum and output at half way so its level matched in and out. On 30" the BIAS/EQ seems to have about a quarter of a DB boost in the lows on a sine wave at C2 and no effect that I can hear or see on Fab Pro Q with white noise. The high roll off appears to be imperceptible - is this just because thats what 30ips would be like on a tape machine? My knowledge of tape machines is theoretical, not practical. 
At 7.5 and 15 theres about 1db roll off in the highs from 10k up. 

As for the Tape Sat, I can hear a noticeable difference in level on the + setting, it drops about 2db in volume. 

Im a fan of the sound and if the settings are just this subtle, thats no problem, but I just wanted to check, without another unit to compare, if this seems normal behaviour?

Thanks, 
Alex