[lauthoerer]

Look nice indeed, but I’m done for now

 

[geoffalter11]

Look nice indeed, but I’m done for now

good choice

 

[G8torbyte]

I was just gonna ask that. The input sockets are the ones closest to the middle of the amp if I remember correctly. Am I right Jonathan? Also, Icon's amps will pick up static from cell phones and other electronics like iPads, etc if close to the amp. David talks about this in his 205D description but not as much with the HP8. I learned to never keep my phone near the HP8 so I kept interference at bay.

I get a small amount of steady monotone hum when I turn on the HP8 that is persistent. I ruled out ground loop and I did try various sockets in the house away from my computer station and it does not change. The volume does not alter the hum but the impedance switch does increase it going from from low to high. Swapping tubes does not change the hum either. Someone earlier in the thread mentioned a similar issue and said capacitors could be the reason. The HP8 performs excellent otherwise so I am debating whether to change capacitors to get a more silent background. Since this is a UK based amp I was wondering if any shop in North America offers custom alterations?

 

[WorksUnit]

^No RF nasties since I swapped out the Chord C-link to QED performance.^
Couple of months in too, but appreciate there might be other forces at work in different cases.

 

[WorksUnit]

Since this is a UK based amp I was wondering if any shop in North America offers custom alterations?

You could look for a guitar amp specialist if you want a recap..
Once they understand nothing is broken and they can source the parts, pretty straightforward.

 

[jonathan c]

I was just gonna ask that. The input sockets are the ones closest to the middle of the amp if I remember correctly. Am I right Jonathan? Also, Icon's amps will pick up static from cell phones and other electronics like iPads, etc if close to the amp** David talks about this in his 205D description but not as much with the HP8. I learned to never keep my phone near the HP8 so I kept interference at bay.

** Also, have your audio gear plugged into different wall / power outlets from those of non-audio gear - preferably in a different room / different circuit. Do not have audio gear share 'power strips' with non-audio gear.

 

[jonathan c]

(Pharmaboy, breaking free of restraints again)

Exactly which Westinghouse 6SN7GTBs do you refer to ("asking for a friend")**

** Alter asking for ego...

 

[infinity3914]

I get a small amount of steady monotone hum when I turn on the HP8 that is persistent. I ruled out ground loop and I did try various sockets in the house away from my computer station and it does not change. The volume does not alter the hum but the impedance switch does increase it going from from low to high. Swapping tubes does not change the hum either. Someone earlier in the thread mentioned a similar issue and said capacitors could be the reason. The HP8 performs excellent otherwise so I am debating whether to change capacitors to get a more silent background. Since this is a UK based amp I was wondering if any shop in North America offers custom alterations?

It’s crazy that you’re having this problem because I did too for the first couple days! It was a persistent high-pitched hum/ring (> 12 KHz) that was got louder as I switched up the impedance. I know you said you’ve isolated the ground loop, but what worked best for me was a RCA ground loop noise isolator that sat between my DAC and HP8, tubes swapping (both the preamp and driver tubes), and playing pink noise for two nights. I can try to use the original CV181 again now and see if it was the tubes that caused the hum or it was just a burn-in issue.

Sorry that you’re dealing with this. I can imagine how frustrated you feel as I spent $200 for various solutions but nothing worked except … time.

 

[infinity3914]

I get a small amount of steady monotone hum when I turn on the HP8 that is persistent. I ruled out ground loop and I did try various sockets in the house away from my computer station and it does not change. The volume does not alter the hum but the impedance switch does increase it going from from low to high. Swapping tubes does not change the hum either. Someone earlier in the thread mentioned a similar issue and said capacitors could be the reason. The HP8 performs excellent otherwise so I am debating whether to change capacitors to get a more silent background. Since this is a UK based amp I was wondering if any shop in North America offers custom alterations?

This item: https://a.co/d/d2ItFb0

I remember how noticeably quieter it got when I connected this in. It’s worth a try given Amazon’s generous return policy.

 

[G8torbyte]

@infinity3914 and @WorksUnit Thank you for the recommendations. My hum is at a much lower frequency and not that intrusive except when nothing is playing. There are a couple vintage radio/electronics shops near me that I may ask them to take a listen. The other member I mentioned earlier said it was a power supply capacitor so it could be something isolated to that component. I appreciate it.

 

[geoffalter11]

I get a small amount of steady monotone hum when I turn on the HP8 that is persistent. I ruled out ground loop and I did try various sockets in the house away from my computer station and it does not change. The volume does not alter the hum but the impedance switch does increase it going from from low to high. Swapping tubes does not change the hum either. Someone earlier in the thread mentioned a similar issue and said capacitors could be the reason. The HP8 performs excellent otherwise so I am debating whether to change capacitors to get a more silent background. Since this is a UK based amp I was wondering if any shop in North America offers custom alterations?

Audio Arcan in Toronto is the North America dealer. Warren Lavender

 

[geoffalter11]

@infinity3914 and @WorksUnit Thank you for the recommendations. My hum is at a much lower frequency and not that intrusive except when nothing is playing. There are a couple vintage radio/electronics shops near me that I may ask them to take a listen. The other member I mentioned earlier said it was a power supply capacitor so it could be something isolated to that component. I appreciate it.

Dealing with this in my CFA3 and the builder and I isolated the issue to a biasing transistor. If it is a transistor it needs to be fixed.

But I don’t know my way thru anything electrical. I know the moment we realized it was a transistor I was told to turn it off and send it back to be fixed. That transistors are not to be messed with. I have no clue if the HP8 even has them.

 

[geoffalter11]

Audio Arcan in Toronto is the North America dealer. Warren Lavender

He has a team to fix all the equipment he reps. His team are certified to work with each of the brands he reps.

 

[geoffalter11]

@infinity3914 and @WorksUnit Thank you for the recommendations. My hum is at a much lower frequency and not that intrusive except when nothing is playing. There are a couple vintage radio/electronics shops near me that I may ask them to take a listen. The other member I mentioned earlier said it was a power supply capacitor so it could be something isolated to that component. I appreciate it.

Awesome collection of headphones, all of which are perfect for that HP8. Very cool!

 

[geoffalter11]

When I mentioned the sound from other electronics with my HP8 it would only happen when it was on and playing music and only my phone would cause interference if too close. A properly working HP8 will be dead silent with no music and I never heard a single headphone hit the noise floor. There is something you need checked out. Be careful. If it is a burned out transistor, which can happen, you do not want to mess with that. It will cause more issues with the circuit. I had both my CFA3 builder and Dr Jan Meier tell me to immediately stop using my CFA3.

I was getting a low hum out of the left channel with no music through the XLR inputs. The RCAs were dead silent, but we switched the left right of the wiring on my CFA3 of the XLR inputs into the volume attenuator and the hum persisted on the left side. So I switched them back and did what I was told and pulled it off my listening station. Which sucks as I have to send it to Munich to be fixed and it is no small amp. But, I would rather that then break it further. They both said it was a bad transistor. Fortunately, I have a Pure BiPolar so I am hardly without and my Aficionado sounds as good as ever, but I miss the treble nuance of my CFA3. It is just about perfect.

I have no idea if the HP8 has transistors, but that is my first guess having just gone through that exercise with two very talented builders. But, the Icon is not a SS amp and I have no clue if it has transistors. Just giving a warning from my experience as of late.