Highly recomend using a BBE Sonic Maximizer on the other side of the 2101 (882), That will get you out of the mud! Rock On 2101 User! p.s. (SansAmp PSA-1 to supplement distortions if needed.) saber540ltd <saber540ltd@...> wrote: Knowing that some people consider the 2101's tube pre-amp as being mediocre and somewhat muddy (though I get somewhat decent results by placing an EQ between my guitar and the 2101), I was looking at the schematic of its tube circuit , wondering if anyone ever tried changing some of the filtering in the tube stages. I'm hoping maybe that Dieter could enlighten me on this topic. The following are a few characteristics of the actual tube distortion circuit: 1) Before reaching the tube stages, the signal goes through a different hi-pass RC filter depending on which tube distortion is selected. One filter cuts the lows below around 600Hz which I assume is for the Saturated Tube setting to reduce muddiness. There's a less extreme one of around 90Hz which may be for the Distorted Tube. There's one just below 25Hz, probably for Clean Tube. And also, C112 can be switched in to cut everything above 2.4kHz in certain settings. All this filtering occurs before the signal reaches the tube stages. 2) Between tube V2's two stages, C128 and R210 result in a low-pass cornring at around 3.3kHz. I've seen something similar in "lead" sections of a Mesa pre-amp circuit. 3) After the last tube stage of V2, there appears to be an op-amp filter only for Distorted and Saturated Tube settings. It seems to contain a gyrator circuit built around Q30 but I'm not familiar enough with gyrator circuits to say for sure. Does anyone know this filter's exact characteristics or purpose? I'm just wondering if anyone is known to have experimented with or improved the tube pre-amp by fiddling with these or other elements. And BTW, what is the Blue Dream Upgrade link supposed to be on Dieter's website; does it have anything to do with improving distortion quality? Larry Yahoo! Groups SponsorADVERTISEMENT --------------------------------- Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/gsp-2101/ To unsubscribe from this group, send an email to: gsp-2101-unsubscribe@yahoogroups.com Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. --------------------------------- Do you Yahoo!? Jazz up your holiday email with celebrity designs. Learn more.
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Re: [gsp-2101] Tube circuit technical question.
2004-12-10 by jason stanley