In Reply to: ll1660 phase splitter problem- help needed posted by slav1 on April 8, 2012 at 06:26:58:
Slav1,
Your driver plate impedance is too high for the this application. The IT primary will reflect the impedance of the driver so it needs to be fairly low.The rub is that when use a driver with low enough impedance the MU is usually not enough for a two stage amp. In my experience,the only driver that might work here is the 417a /5842. It has low plate impedance and a MU similar to the 407a.
I use the 6h30p in this position using the LL1660s SE/PP but I put a line stage in front. You need all the inductance the LL1660 SE primary can get so connect the primaries in a configuration that get you the most inductance 1:1. I worked with a ECC88 in this position driving a LL1660 SE/PP and I was never satisfied with sound. I removed the input pot, added grid chokes for a load and switched to a 6h30p, put some gain up front and found the magic. Note, I'm driving PP EL84s.
Good luck, the IT solution has a wonderful tone and sound stage when it's applied properly.
Stuben
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Follow Ups
- RE: ll1660 phase splitter problem- help needed - Stuben 04/8/1218:36:52 04/8/12 (0)