Sambob2
Well-known member
When listening to my turntable setup, I have a noticeable lower level of high frequencies, a high frequency roll-off as though there is a thin blanket over the speakers if you will. This has always persisted and is not something that just happened overnight or over a short period of time. The deficiency is most noticeable with cymbals and any sound with high frequency harmonics. All my other sources cassette, CD player, Reel to reel, play music fine which leads me to think something needs tweaking in the vinyl chain.
Here’s the setup chain, Benz Micro Glider M2 (moving coil cartridge – medium output at 0.8mV, internal impedance of 38Ω, fairly new with 50 to 60 hours on it), SME 3009 Series III tone arm, Audioquest diamondback interconnect, Audio Research PH3 Phono Preamp (Bought used, however serviced by Audio Research before I received shipment of the unit, complete with new ARC selected 6922 EH Electro-Harmonix Russian tubes also with about 50 to 60 hours on it), Audioquest Diamondback interconnect, Audio Research LS-15 Pre Amp with the high gain option 18dB in lieu of 12dB. Speakers are Martin Logan ReQuest purchased new October of 1999). By the way, the ReQuests are still singing clear and bright as other sources prove. I’ve tried changing the cartridge load resistors in the PH3 in the hopes that it would load the cartridge and transfer the signal to the pre amp better but did not notice a change at all in frequency, soundstage width, height or depth, bass level, articulation, extension, mids, highs, overall volume or level, noise, distortion, not anything. The load resistors from ARC included 30, 60, 100, 200, and 800 ohms. Apparently the Benz is fine with the ARC PH3 47K Ω input impedance. I’ve also swapped the Audioquest cables with MIT 6 interconnects without any change. I’ve played the same recordings of both the record and CD same label, company, year, and pressing with dramatic differences in the high end. I minimized all system differences outside of the load resistor or cable swap, by changing one thing at a time. I also played the same track during each of the changes noted above. Eventually, I tried other recordings just to rule out the record I was using as a standard reference, only to find the same result.
I’m open for suggestions. To me this only leaves a few things that could be at fault. The cartridge may still not be broken in, the PH3 has an inherent darker high end, or the tubes need to be rolled to something brighter. I am a little hesitant on using different tubes since the PH3 is “voiced” from ARC using the 6922’s, however if I can find someone with success at this issue by changing out to a different tube set then I would be interested in knowing that. My preference to the “sound” of the system is more forward, a bit more high frequency gain than what I am getting now in the phono section, with solid bass yet nice high end that does not sound like a blanket is covering the speakers. (do not confuse the high frequency gain with the cartridge output as I am fine with the medium output Benz in combination with the LS-15’s higher gain).
Perhaps I should consider a new pre amp altogether? Perhaps a solid state or newer ARC tube pre amp? How does the PH5 compare to the PH3? Does the PH5 also use the 6922 tubes? Anyone have the same experience with their setup and switch to another phono pre amp, if so what and what were your observations?
I have to mention that I am considering an upgrade path for the phono pre amp as well as the line stage pre amp. I would like to consider an ARC PH5 along with a LS-26 in black to replace the PH3 and LS-15 someday as the luxury funds allow. I am open to other makes or type of phono sections however. CD player stays as is for a log time, it is an ARC CD-7.
Thanks for reading and your comments or suggestions,
Sam
Here’s the setup chain, Benz Micro Glider M2 (moving coil cartridge – medium output at 0.8mV, internal impedance of 38Ω, fairly new with 50 to 60 hours on it), SME 3009 Series III tone arm, Audioquest diamondback interconnect, Audio Research PH3 Phono Preamp (Bought used, however serviced by Audio Research before I received shipment of the unit, complete with new ARC selected 6922 EH Electro-Harmonix Russian tubes also with about 50 to 60 hours on it), Audioquest Diamondback interconnect, Audio Research LS-15 Pre Amp with the high gain option 18dB in lieu of 12dB. Speakers are Martin Logan ReQuest purchased new October of 1999). By the way, the ReQuests are still singing clear and bright as other sources prove. I’ve tried changing the cartridge load resistors in the PH3 in the hopes that it would load the cartridge and transfer the signal to the pre amp better but did not notice a change at all in frequency, soundstage width, height or depth, bass level, articulation, extension, mids, highs, overall volume or level, noise, distortion, not anything. The load resistors from ARC included 30, 60, 100, 200, and 800 ohms. Apparently the Benz is fine with the ARC PH3 47K Ω input impedance. I’ve also swapped the Audioquest cables with MIT 6 interconnects without any change. I’ve played the same recordings of both the record and CD same label, company, year, and pressing with dramatic differences in the high end. I minimized all system differences outside of the load resistor or cable swap, by changing one thing at a time. I also played the same track during each of the changes noted above. Eventually, I tried other recordings just to rule out the record I was using as a standard reference, only to find the same result.
I’m open for suggestions. To me this only leaves a few things that could be at fault. The cartridge may still not be broken in, the PH3 has an inherent darker high end, or the tubes need to be rolled to something brighter. I am a little hesitant on using different tubes since the PH3 is “voiced” from ARC using the 6922’s, however if I can find someone with success at this issue by changing out to a different tube set then I would be interested in knowing that. My preference to the “sound” of the system is more forward, a bit more high frequency gain than what I am getting now in the phono section, with solid bass yet nice high end that does not sound like a blanket is covering the speakers. (do not confuse the high frequency gain with the cartridge output as I am fine with the medium output Benz in combination with the LS-15’s higher gain).
Perhaps I should consider a new pre amp altogether? Perhaps a solid state or newer ARC tube pre amp? How does the PH5 compare to the PH3? Does the PH5 also use the 6922 tubes? Anyone have the same experience with their setup and switch to another phono pre amp, if so what and what were your observations?
I have to mention that I am considering an upgrade path for the phono pre amp as well as the line stage pre amp. I would like to consider an ARC PH5 along with a LS-26 in black to replace the PH3 and LS-15 someday as the luxury funds allow. I am open to other makes or type of phono sections however. CD player stays as is for a log time, it is an ARC CD-7.
Thanks for reading and your comments or suggestions,
Sam
