Mesa Boogie Stiletto II Head ... Plate Voltage and BIAS read

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shwing5150
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Mesa Boogie Stiletto II Head ... Plate Voltage and BIAS read

Post by shwing5150 » Sun Aug 10, 2014 6:49 pm

Mesa Boogie Stiletto II Head ... Plate Voltage and BIAS readings. Hi, could someone tell what the stock Plate Voltage and BIAS readings are for a Mesa Stiletto II head ? My amp has fresh JJ EL34L's and fresh JJ and Sino 12AX7's preamp tubes The amp is set to silicon diodes, bold and is set to the tight gain, all knobs are at 12:00 position except master volume which is at 3 for both channels I have a external bias pot added to my amp by my tech and would like to know what the stock BIAS readings are, My tech said that the plate reading was 477/478 (before the external adjustable pot was installed was installed and the bias reading was 38.2 / 40ma After the amp was altered he biased it at 41.6 / 30ma, the amp sounded way better before the mod and I suspect it is biased cold, today I want to bias it correctly... I own both bias and plate voltage probes, currently the amp is hooked up to 2 4x12 16 ohms cabs (properly inserted into the 8 ohms inputs as instructed on the back of the amp) and the amp has been idling for 25 minutes in the on position, When amp is on channel two (dirty), the plate voltage reads between 504 and 518 on my meter... When the amp is on channel 1 (clean) the plate readings are between 504 and the highest it went was 538, I would estimate the lowest idle plate reading seems to be 504 (on the clean channel). If you asked me I would say those plate voltages are very high... Before I bias it I would like to know if those plate voltages seem correct.. and what plate voltage number should I choose for estimating the BIAS, also should I set the bias on the amp using channel 1 or 2 ? I hope I provided enough information so that others may help me through this process :-) Thank You In Advance
Party on Wayne, Party on Garth

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shwing5150
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Joined: Fri May 02, 2014 4:33 pm
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Re: Mesa Boogie Stiletto II Head ... Plate Voltage and BIAS

Post by shwing5150 » Sun Aug 10, 2014 10:27 pm

SOLVED :-)

I decided to do it by ear, since I knew my tech's final bias settings I just did it by ear, using minute turns I could tell within a seconds what way was hot and what way was cold, so I just turned it a wee bit hotter then the tech set it then the BAM it sounded amazing again, truly like a blanket lifted off the speakers, the cleans are lush again and the lead channel sounds even better then before the mod, I only had to turn it, as I said a wee bit, that's all it took......now I can relax lol
Party on Wayne, Party on Garth

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