T_Evans

Ah, understood. So far as my ears can tell, zero loss in mids at all, and the highs seem just as nice also. I find the sound stage width expanded as well. So for me it sounds more like a solid state in terms of the bass, but the mids and highs have the beauty tube sound! It would be interesting to see it plotted, but to my hearing, I’m loving the power and the detail with the 150s. 👍

I didn’t look for charts or graphs for the 150, just went by what others have stated with their experience with them with the same amp and similar speakers. I’m no expert with this, but if PrimaLuna states in their material that the amp is fully capable of running the 150, I’m inclined to believe them. I installed them last night, and I can unequivocally concur with every else’s experience that they have a far more powerful low end, and they make the Cornwalls sound absolutely amazing, and that’s right out of the box! I’m looking forward to them being burned in after a few more days to see how they really open up! Maybe I’ll try the KT88s next once the 150s have served their time.

Sorry for the late update. Was able to totally illuminate the HT hum with this iso transformer from Amazon: Ancable Ground Loop Isolator,Isolation Transformer,Hum/Buzz/Noise Eliminator for Cable TV Applications https://www.amazon.ca/dp/B074KD8X6S/ref=cm_sw_r_cp_api_glt_i_Q650WMMX4X02AY7EEMP8?_encoding=UTF8&psc=1 Thanks @rebuy and everyone for the help! I’ve also pulled the trigger on the KT150s and have ordered a pair of RFT 12AU7s for the gain and two more Mullard 12AU7s for the remaining preamp sections. Excited for those to arrive! Anyone else running the 150s? Did you keep the speakers on the 4 ohm taps? Anything dangerous using those taps with the higher powered tubes? Was listening to The Wall last night, and it was blowing my mind how good it sounds. Hadn’t spun that album since getting the PL!

With regards to speaker wire connection to the Evo, how many are using bare wire wrapped around the post, or using spade connectors? I was recommended Furutech FP-201(G) connectors at about $24 Cdn each. I'm a fan of using bare wire connections, but I find without a hole in the pots, I'm nervous about stray wire strands after wrapping them around the post. Worth spending the $100 to have piece of mind not having a short, and a secure connection with the spade? Any degrade in the audio?

Haha no problem! Love seeing pics of everyone's set up! It appears the coax cable issue is a common one, so I just need to figure out how to ground it (or unground it maybe). I've found a few remedies like isolation transformers that I will try when I get back home in a couple weeks. I'll let you know when I have it sorted. Cheers!

Beautiful system! What are you using for a phono preamp?

Thanks, I’ll check that out. Unfortunately the ground loop is still present with the cable box. So I’ll keep working that issue. Thanks for the link!

Thanks! I'm definitely a PrimaLuna convert now too. You are absolutely right, they are a match made in heaven! I have a set of Mullard preamp tubes that I'll give a go in a little while. Just trying to take my time with it now that I have a properly functioning unit. Very cool to hear about the KT150s, that'll be the way I go eventually as well, but for now I'll just enjoy the EL34s. Thanks for the insight! Those big 150s look pretty cool too! PS, not sure why the photo I tried to upload didn't work, looks like its on there now!

UPDATE: Hey everyone, well the wait is over, the 400 arrived! All I can say is WOW. This is the sound I was expecting! Sounds incredible, so much power, bass, detail, airiness, and none of the noise and interference I was getting with the 300. I'm super excited, and happy that I wasn't way off the mark thinking I had a bad unit with the 300. This is now a noticeable difference from the Yamaha A-S2100, with better imaging and bass slam. Thanks for everyone's help and advice. Ive got my forever set up now with the 400 driving the Cornwall IVs. Perfect match! Again, shameless plug for Daniel at vinylsound.ca who was super patient, understanding, and genuinely concerned about the issues I had, and made the return and exchange super easy. Happy listening!

It’s brand new. But yes, my dealer is taking it back. 👍

The saga continues! After a while of rolling preamp tubes last night, I was still getting the faintest RFI hum through the speakers. After trying the lights off, lamps off, receiver unplugged, cable box unplugged from power and the coax, etc I looked at the red LED on my old PS3 sitting beside the tv (adjacent to the the PL). Thought “what the hell” and unplugged it. Holy crap, the hum disappeared! The friggin PS3 was causing something that the PL was picking up on HT bypass. So one more mystery solved. But I started to think, if I can’t have my cable box or anything electrical like a PS3 connected without noise, what good is this amp? In any case, finally with pure sweet silence coming from the Cornwalls I put on DSOTM and I think I finally revelled in the joy of tubes with the Cornwalls. It sounded glorious. Immersive, beautiful separation and sound stage. UNTIL I heard this really high frequency ringing coming from the left speaker! I thought it was coming from outside or I had sudden tinnitus, but no, sure enough it was coming from the speaker. Mute, volume up, volume down, turntable and preamp on, off, no difference. Just this ear splitting tone that immediately interrupted the wonderful music coming from the grooves. It was at this point I pretty much called it a night. I talked to my dealer today and told him I’m done with this unit, it’s not enjoyable, I’m not going to relax listening to it always on guard for something to be wrong, it’s defective and I want to return for refund or replacement. Completely apologetic and sympathetic, he offered a replacement with shipping (once again I can’t say enough good things about Daniel at Vinyl Sound; if you’re in Canada, get in touch with them because they are awesome). I feel bad because I believe this amp should be amazing, I think I just got unlucky and this one is faulty. So naturally, I asked him about the 400, and so for a little extra 💸💸💸 a new Evo 400 is on the way! In the meantime I’ll enjoy the Cornwalls with the Yamaha (which really does sound fantastic) and I’ll update here once the 400 arrives. Thanks for everyone’s suggestions, advice and insight. I’m confident the 400 will be a better experience, and I hope my experience hasn’t turned anyone off form PrimaLuna because I do think they are remarkable amps! Cheers, and happy Friday! 🍻

Update: after troubleshooting with Josh at upscale audio, he suggested I try to swap the 4 power tubes from left to right, and then do the same with the preamp tubes if the power tubes didn't fix anything. So swapped the left 2 power tubes with the right 2 power tubes, and no difference, same pop out of the left channel when selecting HT. Swapped the preamp tubes, and VOILA! No pop! So perhaps one of the preamp tubes is faulty. But I would have expected the pop to come from the right channel instead. When I purchased the amp, my dealer threw in a couple bonus Mullard 12AU7 tubes to try out. So now those are in the gain sockets, and I'm seeing if I can identify which of the PL preamp tubes are faulty by switching them out one at a time. Takes a long time to experiment letting the tubes cool off before I change them. So far no luck eliminating the noise floor, but happy the pop is gone. Confidence is slowly coming back with the amp.

Yeah I feel your pain! I'm not sure yet how to solve the cable box issue either, but I wonder if something like this might help? https://www.digikey.ca/en/products/detail/tdk-corporation/ZCAT1325-0530A-BK/761919?utm_adgroup=Ferrite Cores - Cables and Wiring&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Product_Filters_NEW&utm_term=&productid=761919&gclid=Cj0KCQjwvYSEBhDjARIsAJMn0ljv0G9zgisesyZ5dn4V074yCYPlYUs3kStwVTbPlEhn_c901u9b60IaAi__EALw_wcB

Interesting. Is it the same sound as in the video above? The ground loop I was getting with the cable box connected was excessively loud. As in I was afraid of speaker damage from it. That ground loop is eliminated when I disconnect the cable box (either the HDMI from the receiver, or the coax from the cable box). Also, if you disconnect your Marantz and then select HT on the PL, do you get the same buzz?

Here's the video with it connected to my B&W 606s.

Alright there's no way to reduce a video file to 2mb to allow it to be posted here, so here's the link to the YouTube post. The video shows the PL connected to my Pioneer Elite VSX-53 home theatre receiver, with the pop sounding from the speakers when I select the HT input on the PL. I move the phone close to the speaker to capture the noise floor while on HT. It can be heard from a normal seating position (i.e., not needing to bring my ear right next to the speaker like the phone). This pop and noise floor can be heard at all times; with the receiver connected, volume up, volume down, on mute, disconnected, downstairs with the Cornwalls or upstairs connected to my B&W 606 bookshelf's so its not a location issue picking up some random RF. I think I will call Kevin at upscale audio (thanks for the suggestion Fido!). Josh, who I have been communicating with via my dealer is an employee at upscale audio, so I would hope that he can help. So far, not yet. Please take a look at the video and let me know what you think! Thanks!

Thanks Fido, I hope so. I’m going to try attaching a video of the noise to compare. PrimaLuna rep is saying the noise I’m hearing is normal (besides the popping when selecting HT) but I’m skeptical since you’re saying it’s totally silent on HT with your 400. I’ll format the video so I can upload it, if you could take a listen and see if I’m out to lunch compared to yours.

Thanks Bruce, The volumes don't seem to have any effect on the quieter hum. The loud ground loop hum is eliminated now that I've discovered it was the cable box causing it. But, the HT input still has a relatively loud hum or noise floor, regardless if the receiver is connected, turned on, turned off, on mute, volume zero, or totally disconnected. So dealing with PrimaLuna directly now. I'll keep everyone updated as I move forward. Thanks again!

Thanks everyone for the advice a d suggestions. After spending some time on the phone yesterday with Daniel from Vinyl Sound who had me on a conference call with a PrimaLuna rep troubleshooting (again, great service from both Daniel and PrimaLuna! Really impressed), we thought that the problem was the long interconnect RCA between the receiver and amp. Pulled the receiver out of the cabinet and disconnected everything, we were able to get the receiver and the amp connected without the ground loop hum with the receiver and amp plugged into the same power conditioner (previously each were powered by different conditioners due to room set up). Hung up and re-connected everything. The hum was back. 🤬 More troubleshooting, I disconnected each HDMI cable from the receiver one by one, as I recall reading someone mention their cable box was causing RF interference. Well, it was the damn cable box! It seems the coax cable is causing it. What a pain! Happy it seems the amp is functioning properly, and I think I can relax about that and actually listen to it without worrying. I am still hearing a faint hiss on HT (which I think is just the noise floor, and it being louder than the Yamaha, took me off guard). Fido, can you hear your 400 noise floor on HT? It’s very quiet on any of the aux inputs, but louder on HT. Does anyone have any suggestions to eliminate the interference from the cable box coax? Thanks again!

Thank you, happy to be here! Nice to be a part of the Klipsch community! Yes, HT is for home theater. The PL has a HT bypass input where it bypasses the preamp section and basically becomes a power amp with the HT receiver acting as the preamp. Worked excellent with the Yamaha with the same feature. I think I understand what you’re saying about tube amps being more sensitive to electrical interference. The odd thing with this amp is when I select HT, it hums even with nothing connected to the input. So it seems the interference is coming from within the amp. It does intensify if I connect the receiver to it. Oddly, and a pretty drastic change from this morning, now the hum volume is pretty low and the pop when selecting that input is gone. The amp now has about 35 hours on it, so I’m thinking the power tubes are starting to break in? In any case, I will take a good look at the wiring tomorrow. I’m pretty OCD with that stuff, I have trunks of audio carrying cables bundled together, and keep the power cords as far as possible, crossing the audio cables at right angles and avoiding running them parallel to each other. But I will double check everything, thanks for the suggestion! And the hum is constant in both channels, so I think the tubes are ok 👍

Hi everyone, Brand new to this site, but have been referencing it a lot lately. I recently purchased a pair of Cornwall IVs, and wow, these speakers are awesome. I had been running them with a Yamaha A-S2100 which to my ear sounded great. But reading how well Klipsch speakers perform with tubes, I took the plunge and got a Primaluna Evo 300 integrated. The amp arrived a couple days ago. This is my first tube amp, so I’m learning as I go. I have a problem with it (already spoken with my dealer, Vinyl Sound in Richmond Hill, ON, and can’t say enough good things about Daniel there, top notch service!) and he is going to contact PL for me tomorrow. But figured I’d ask here if anyone else has these issues: First, and most concerning, the HT bypass has a nasty pop and a lot of hum when selected with nothing connected to the input. When I had connected the RCA from my HT reciever pre-out (as I did with the Yamaha with zero issue) the hum from the PL was excessively loud on HT, and could be heard through every other input as well. Additionally, as I’m in the process of breaking in the tubes, when playing a source through one of the Aux inputs, if I switch to HT I can faintly hear the aux source leaking through. It seems like a manufacturing fault to me, as the inputs are supposed to be totally isolated from one another. Second, as it’s my first tube amp, is it normal to hear a little hum and buzz as the amp is warming up after turning on the power? Third, I’m a little worried that I haven’t actually upgraded switching from my Yamaha. I listen to primarily vinyl, and the amp needs to double as a power amp for home theatre applications. Am I just paranoid given the issue I’m having (which will be taken care of under warrantee)? Haven’t given the PL enough time to break in? It sounds great, I’m just not sure I hear an upgrade over the Yamaha yet. Finally, what are other’s experience with 4ohm vs 8ohm with the Cornwalls? Initially connected to 8 ohm, and have switched them to 4 ohm this morning. Honestly I can’t hear a difference lol. Sorry for the long story for a first post! Love the Cornwalls! Hoping the PL can live up to the hype! Thanks in advance for any advice. Taylor