PS - This is exactly my complaint wiht Pass amps, always and forever. :)
The 26 dB of amplifier gain is the convention/standard.
Too Much Gain the Issue ? (preamp and amp)
I have a Cary SLP-05 preamp- 24db gain with balanced and 17db single ended.
Using a Pass Labs XA30.8 (26db gain) and even with the 17db of the single ended output of the Cary preamp the sound can frequently be sibilant in the upper midrange.
Have not had the sibilant sound with other amps (Parasound JC5) but did lower the gain on that amp to 50% of dial.
Thanks.
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- 39 posts total
An indication of too much gain is how much you need to turn the volume knob to achieve room filling sound. Say, for example: some here, find their volume too loud, when the volume knob is at the 8 or 9 o`clock position. Two ways to rectify this. One, send your preamp back to Cary, and have them change the gain of the preamp. The second, cheaper way, is to purchase inline attenuators and insert them at the amp inputs. |
@pmm +1! |
24dB is an awful lot of gain for a preamp. 26dB is sort of a surprisingly high gain for a 30 Watt SS power amp. Yeah, that might not be the most optimal match - but the volume attenuator on the preamp should keep the amp's input stage from getting overloaded and causing the sort of sonic issues you describe. So as @erik_squires mentioned, your main artifact of too much gain should just be noise floor. The Cary is tubed - LOTS of 6SN7 - so you can tube roll to try and mitigate some of that sibilance. If you have Electro Harmonix 6SN7 in there now, then starting to replace them with any decent vintage tube should help a lot. In modern era, preamps with gains over 20dB (almost always tube based 6SN7s or 12AX7s) are sort of an awkward fit. |
- 39 posts total