Quandary


I’m really happy with my system. However when a technician, who is also a salesman, came to my house for a stereo repair he complimented my set but said it would sound a lot better if I switched out my Benchmark AHB2 amp (which I think is great) for a Pass 30 wpc class AB amp. He offered to let me hear that amp in my system so that I could decide for myself (at a fee of $300.) The only problem is he doesn’t  have the 30 watt amp in stock but would have to demo the Pass sound with 60 watt monoblocks. He assured  me that with my very efficient GoldenEar Triton 1 speakers the 30 watt amp will almost have the the same quality.

Do you think I can honestly judge how the smaller amp will actually sound? Or should I cancel the demonstration (and save$300?)

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The problem is the slightest turn of the volume control brings a big difference in the sound. With the Benchmark, I didn’t need to change the control that often because one setting was fine for many recordings. Maybe the less powerful 30 watt amp would allow for greater range of control.

The gain on the 30.8 is the same as the monos so it would likely be the same with the volume control setting on your preamp. You are likely using the volume control closer to the 12-2 o’clock position with the Benchmark. Most amplifiers have gain of 26db or even more (was at one time the industry norm), so this volume situation will still occur. Volume attenuators (the kind used in the PV11, with wipers) are actually better when they are used at around the 12 o’clock position or higher (the higher you go the less resistance within the wipers). Your PV11 has 20db of gain, which is greater than most, ime. You can always have CJ, or a good tech, lower the gain, or even replace the attenuator with something like a Khozmo unit, but this is jumping ahead. Not sure what else I can say, but if this is a problem and is disconcerting, you might have your answer earlier than after the full weekend. Pass is not at fault here, but the gain issue seems to be, as suggested by yogiboy above. My best, MrD.

@mrdecibel Gave a great explanation of what I stated. The PV11 has way too much gain for that Pass amp. If you look at Pass preamps the gain is half (9db) of the PV11. The range of the volume control is useless if it is on the lower end of the dial!

PV11 SPECIFICATIONS Gain: High level 18 dB Output: Maximum 20V Phase: Line stage inverts phase of all inputs. Hum and noise (20Hz-20KHz): Line level:92 dB below 2.5V output Distortion: THD less than.25% IMD less than.25% Output impedance: less than 500 ohms Dimensions: 19"W x 3.5"H x 12.5"D

The sound at times is really quite good. The problem is it gets too loud too soon and there is a blurring of the sound, like it overwhelms the system.I’m going to experiment and listen this weekend with a positive attitude, but I’m afraid I might have to have to pass on buying the Pass.

Interestingly, pop and rock, due to the limited dynamic range, sound wonderful..

@mrdecibel 

Can you recommend a quality amp that will match well with my CJ?    
The Benchmark matches perfectly.   
 Maybe I should just leave well enough alone.