Hi,
Sorry for digging out this old post...
I have bought components to build an attenuator similar to Aiken's, to simulate my Greenback. My circuit is : 6,8R + 100uH in series with the input (Re, Le), 12R + 20mH + 235uF to ground (Res, Lces, Cmes)
I bought this inductor for Lces :
http://be.farnell.com/wurth-elektronik/744825320/choke-common-mode-20mh-3a/dp/1636301I use the dummy load in parallel of the speaker (8 ohms), using the 4 ohm output of my amp.
The problem is, there is some very noticeable distortion on low frequencies. You can clearly hear it when hitting a palm mute on the E string. That excepted, the tone is much better than with a simple 8 ohms resistor in parallel of the speaker, though there is still some noticeable treble loss, like turning the tone pot of my AC15 at 12 o'clock (that I tend to like actually). When I remove Lces, the distortion disapears, but the tone is (slightly) worse.
Is there some kind of rule of thumb for determining if a specific inductor is prone to saturate, given its size, core material and the power it is used at ? I have seen some inductors made for speaker crossovers but they are expensive and generally rated for like 300W, that is way too much for my tiny AC15... Do you know any source for lower power ones, and thus less expensive and heavy ? I have some bobins and corresponding laminated cores that I could easily wind (EI type, about 44*11*35mm), but would it be big enough to avoid core saturation ? It's actually difficult to find infos on the internet about core size/saturation current.
Best regards.
Eric