Anyone had experience with the Mullard 12AT7 (ECC81) 10M Master Series - I know the sales case at the time of manufacture was about their longevity... ... but what about their sonics? Do they sound just 'meh' but last ages? Or do they have Mullard magic? How would one stand-up against a Brimar...

Dropped in the Ken-Rad VT-231s yesterday. Driver is the Brimar CV455 KB/FB Triple Mica Footscray 12AT7. Personally - disappointingly, to be honest - I couldn't detect any sonic differences whatsoever from the new production Psvane CV181-T MkII that were in immediately prior. I've owned the HP8...

Sunday evening (typical Sunday evening!) impulse buy: Ken-Rad 6SN7GT VT-231 Black Glass. UK eBay seller of 20 years standing. Reports same date codes and testing them on a recently calibrated AVO VCM 160: IA GM Valve 1: A1 9.2 2.75...

I sympathise - in 2020 I moved from south west to south east London, right in the shadow of several famous radio masts in Crystal Palace. I am sure you have tried this, but the permanent fix for me was moving to properly shielded interconnects (as in, old fashioned electrical theory inspired...

I'm sorry to hear this... I had forgotten about the 12AT7 Brimar Footscray that I had purchased from Langrex in October 2022 - until you guys revived the topic! When I dropped it into my HP8 about 11 days ago, it sounded fabulous out of the gate. No static or ringing. Impedance setting 'High'...

Listened this evening - finally - to the 12AT7 Brimar (purchased from Langrex) that has been sat on my shelf since October 2022. Wow! I swapped out a Brimar 'Red' 12AX7 purchased at the same time from Langrex, at more than twice the price. In my set up/ears, the 12AT7 brings more than...

I have no idea either - other than a tube needing to reach its operating envelope following switch on at the amp. I figure that if a tube really is the 'N' in NOS (apart from brief testing before sale) then there might be a period where manufacturing detritus settles and/or the properties of...

I bought one of these from Langrex in October 2022 - never got round to trying it! (I bought a Brimar 'Reds' 12AX7 in the same order and have had that in the HP8 ever since) All the excitement has prompted me to drop it into the HP8 - now warming up a few hours before listening tonight!

Thank-you so much @Slim1970 for sharing your experience with the Utopia and the HP8. Utopia now ordered!

Many thanks to both @geoffalter11 and @Jay Smith for your helpful replies - much appreciated! I exchanged a couple of emails with Icon Audio and - I have to say, despite my love for their products - I found it disappointing that they point blank refused to tell me what the output impedance(s)...

Has anyone seen anywhere the actual output impedance of the HP8 MkII at the three settings? I use mine with an HD800S but I'm considering a discounted pre-2022 Focal Utopia (80 Ohms) and - given the outlay - would like to be reasonably sure I can get a good impedance match. Thanks in advance.

Yes - more force than I was comfortable with to push the CV181s in, and the same worry getting them out.

I've had the same seating issues with the PSvane Ceramic Bottom David Shaws in my Stereo 30SE and similarly the Shuguang Treasures seated poorly in my HP8 - but the PSvane CV181-T-MkII seated rock solid.

I also had the signature edition supplied with Shuguang Black Treasure CV181s. I enjoyed the sound stock. Around two years in a tube went crackly. When I discussed tube rolling with David Shaw he was quite adamant that the HP8 circuit design as whole is responsible for the sound and that...

Apologies for taking the thread off topic, but as a delighted listener of the HP8 Mk2 SE for two-years I thought I'd briefly share my findings of trying an Icon Audio Stereo 30SE (Mundorf caps option) in my speaker system. I've listened for 12 hours or so - purely vinyl playback system -...