Adding to the thoughts of using the 4 ohm vs. 8 ohm speaker leads a recent review of the Stereo 100 power amplifier shows the power output lower at the 4 ohm terminals. Testing showed the output at clipping to be 56 WPC from the 4 ohm terminals and 80 WPC from the 8 ohm terminals. Not certain of the CM III would perform the same or how this would translate into sound quality of a given set of speakers but the point is to definitely try each set of leads.
yes sir. FYI i'm currently running the Stereo 100 and it sounds amazing and a lot like the CM II! Rogue Audio Stereo 100 power amplifier
The store let me know that the CMIII should be arriving in the next couple days. Is it too late to cancel plans with my girlfriend this weekend?
Somewhat off-topic, but have been preparing my setup for the Cronus' arrival (sounds like it'll be Monday). I've had my Clear Audio Concept table for around a year and figure it's about time to use the included bearing oil. The manual doesn't explain their recommended procedure for lubing the bearing. If anyone has any advice or can point me in the right direction it would be greatly appreciated! I'm probably overthinking it but everyone here has been a fantastic resource so figure it can't hurt to ask.
So I have the amp and its arrived safe and sound. Store told me not to worry about bearing oil yet for what it's worth (not my area of expertise). I'm listening to Bonnie Raitt-Live in Philadelphia 1975 which is a fantastic sounding live album. Too early for me to really pass judgments on the amp just yet (I've only heard 1.5 records so far). Listening to the Triode mode predominantly thus far, though the difference appears subtle between Ultra-linear and Triode. The main takeaway thus far is that records are quieter. Looking forward to putting in some serious listening time and getting a better idea of the amp's character. Cheers! Thanks again for the help in this thread.
Hmm, was hoping it was a one-off occurrence but it's happened a few times now. I'm getting a random quick tapping-like sound out of the left speaker irrespective of input (Phono, AUX 1, 2, etc.) with volume at any position (including 0). Seems to happen for a few minutes at a time and then disappear. It doesn't get louder or quieter if I adjust the volume dial. Not sure what's going on there. If it's a weird wifi/cellular signal happening somehow (?) that didn't occur with prior CMII. Haven't changed anything in setup with regards to what's plugged in where. Hoping I'm missing something obvious here. Amp hum from transformers also seems louder than my CMII. Any suggestions welcome. Very overtired so that isn't helping; plan to give it a fresh look again tomorrow.
Going to post a few more thoughts (into the void? ) Troubleshooting concerns: · Repetition of both speakers making quiet tapping sound (kind of like a fast, repetitive, “heartbeat”). Occurred approximately 30 minutes after turning amp on. Switching Triode to UL during the sound appeared to stop it. Unsure if the issue is specifically with the Triode setting. Going to listen more today on UL mode only and see if it appears. · Hum from the amp is louder than before. Source seems to be front portion of the amp. In the past I had to have my CMII taken in for transformer hum but this sounds different. Sound: So far I think it sounds good, but somewhat underwhelmed. Not hearing a major upgrade listening to records thus far. As mentioned earlier in the thread, I requested Rogue to have the amp set to 4 ohms vs. 8 (like my CMII was), so perhaps I like the sound better with the 8. Will look into that later. Still, the phono section is meant to be decidedly nicer regardless so I'm not sure if there isn't something else at play here or I was just partial to the CMII I had (which my store noted sounded better than the other models they'd sold FWIW). I'm hoping there is user error involved here and this can be sorted out. Having to take back in or ship back to Rogue after 1 day is completely deflating.
I see your KEF speakers are rated at 8 ohms. Why did you have them switch it to 4 ohms? Hopefully your problem is easily sorted out. I would call Rogue right away. They are eager to help.
Thanks. Was a recommendation on here (with explanation) to try it out as they are rated at a minimum of 3.2. Still very early on in me trying to figure out what's going on. Currently listening and thinking it sounds good so could just be an adjustment period. But yeah, it may be a good idea to see how they sound with 8 ohms.
I used the 4 ohm terminals on my stereo 100 and the sound was slightly sweeter, less bassy but overall a significant loss of oomph that my speakers really liked. Definitely try the 8 ohm terminals ASAP.
try versing the tubes to see if the clicking follows (small signal then power tubes, one row at a time)
I will. Thank you. Re: the strange tapping issue, I've had the amp on UL mode for an hour now without it occurring. Not sure why that issue is occurring, but at least seemingly isolated it to the Triode mode. Go figure. And yeah, by no means does it sound *bad*, but oomph is nice succinct way to describe what feels like is missing.
I plan to open it up on the weekend and switch the taps. I've listened to it for a few hours today and no return of the tapping sound on UL mode. Sounding pretty good but need to compare how it sounds with 8 ohms to get better idea of how I like the new phono. It's generally clear and very quiet.
Remember what we said earlier about unplugging the amp and give it a couple hours(that enough?) to discharge before touching the inside.
For sure, thanks. I briefly took a look to confirm that the 4 ohms were selected but I didn't mess with it today as I didn't have right wrench on me. Going to have a friend come by on the weekend.
Some updated impressions: I think @avanti1960 's description of the amp (when set to 4 ohms) lacking some oomph, less bass, etc. is apt. Things sound good, albeit like there is a blanket over the sound. Both the lows and highs sound somewhat dulled compared to the CMII at 8 ohms. There's some less harshness, but also less bite and articulation to the highs. I find this most apparent in the tone of the bass as well as vocals. It doesn't sound *bad* but will be switching taps. Given my room isn't massive, there are arguably some benefits to the mellower bass. There's less boominess, but also less power and energy IMO. So, to some extent it's trying to determine the best compromise that works for the space. 8 Ohms was what my CMII was set to, so it might just be personal preference. I could see amp/speaker configurations where this sound would certainly be beneficial and preferable. For my tastes and in this configuration however, I think 8 ohms will wind up being the right way to go. Just for fun, I plugged in my laptop (Mac Book Pro 2016) and used iTunes. Hardly "audiophile" territory but I felt the improvements in the CMIII could even be felt listening through this configuration. It felt like a noticeable increase in detail compared to using this same configuration on the CMII. Not my main setup or preference for critical listening (don't have a nice dedicated digital setup at the moment), but speaks to the quality of the amp IMO. Also, *wow* is this thing quiet while playing records. Store is calling Rogue to inquire re: tapping sound on Triode and coming over on the weekend to switch taps.
FWIW, Rogue and Legacy exhibited the CMIII and Legacy Studio HD (rated 4 ohm) at the Capital Audio Fest. The retailer, Now Listen Hear, said Mark from Rogue said to leave the taps on 8. Everyone raved about the sound and one site named the combo best in show.
Generally using the 4 ohm taps will make the top end and upper mids darker, while allowing a fuller bottom end sound. That sounds like what you are hearing. The 8 ohm tap will have the opposite effect, leaving the bass lighter and tighter sounding, and the mids and highs more dynamic and sparkly. So if that's the resut you want, 8 ohms it is. The difference is more subtle than the description sounds, but there is some change there. The other tonal change is to replace the 12AU7 with a Gold Lion version. That will have a similar effect while retaining the subtle 4 ohm tap effects, or you'll get both cumulatively when you switch both. -Bill
Thanks for the info. I'll take a look at the Gold Lion. I'll certainly report back what I think after switching the taps. Hoping there isn't something else going on here to troubleshoot as so far I'd say the difference between how it sounds and the CMII isn't subtle (with regards to the above).
Really thoughtful of Decware to put a toggle on top of some of their amps to easily switch between 4 & 8 ohm speakers.
Update: Had store employee come by and change the taps to 8 ohms. 100 % improvement for me. Very pleased! Will share more thorough impressions later once I have some time to listen to it more. Will listen to Triode again and see if tapping issue reappears; store told me they'd ship it back to Rogue if needed.
