[JonT]

Here is the Brimar 'Footscray' (made at the Standard Telephone & Cable Ltd Foots Cray plant in 1956). Langrex currently has 247 of them:

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 marginal improvements.

Noticeably, the tonal balance is much more balanced across the spectrum from low > mid > high frequencies. Despite the change in gain, listening volume on the pot is broadly positioned the same but with audible improvements in dynamics. I'm uncertain on this (after just one listening session) but if pressed I would say that the leading edge of transients slightly loses clarity versus the Brimar 12AX7 but detail is - if anything - improved whilst retaining fantastic timbre and texture.

I should state that I'm using new production tubes in the power section (Psvane CV181-T-MII) that have plenty of hours since October 2022.

My HP8 is also a Signature Edition with Mundorf caps.

I should also own up that I disagree with David Shaw regarding the effect of tube rolling in the HP8. Although my experience is limited, the first time - after about 24 months of use - that I swapped out the stock Treasure CV181s and EH 12AX7 it was like making a dramatic turn on tone controls; a radical change (not for the better).

Regarding the 12AT7, I should also mention that I am listening to wholly analogue chain. My cartridge (Dynavector DV XX2 MkII) is fairly low output and my phono stage always felt compromised with the either 60db or 70db gain options into the 12AX7. Conversely, 60db into the 12AT7 appears to have great synergy. On this basis, I make no generalist claims that 12AT7s improve on 12AX7s. Moreover, I'm listening on HD800S - soundstage and dynamics start from a great place; it is texture and tonality that is relied upon elsewhere in the chain.

As an aside, for about 18 months I have had an Icon Audio Stereo 30SE as my integrated in my speaker set up - I have been over the moon with it!

 

[geoffalter11]

Anyone?

https://www.ebay.com/itm/2856769832...3JX3T2&hash=item4283acd3c4:g:56MAAOSwtjZluIza
https://www.ebay.com/itm/2259343873...JBVMJD&hash=item349abd2896:g:cz0AAOSwxmJljOBS
https://www.ebay.com/itm/2259896611...3XMDVW&hash=item349e0891d3:g:J4UAAOSw6u9lwHAJ

 

[geoffalter11]

Anyone?

Just sent you 3 different VT-231s. Best tube seller I know, with the best tubes in the best condition and I have yet to meet anyone other than Brent Jesse who is of equal knowledge. They have a ton of 6SN7s. They have a pair of Hytron's for $175 that I would get.

I only buy from this seller. Even if it says pre-owned the testing will come out at like new. They will come in original boxes and they are the real McCoy.

 

[geoffalter11]

Anyone?

Always matched for the HP8. Gain, emissions, gas, etc. Unmatched won't hurt the amp according to David as the circuit is so stable, but I wouldn't mess with it. I sent you 3 different VT-231s. Expensive, but great tubes.

 

[infinity3914]

Just sent you 3 different VT-231s. Best tube seller I know, with the best tubes in the best condition and I have yet to meet anyone other than Brent Jesse who is of equal knowledge. They have a ton of 6SN7s. They have a pair of Hytron's for $175 that I would get.

I only buy from this seller. Even if it says pre-owned the testing will come out at like new. They will come in original boxes and they are the real McCoy.

I bought a pair of Westinghouse 6SN7GTB and they sang much better than the stock tubes. Though I didn’t get the Ken-Rad VT-231s from this seller, I’d still grab a pair here for being close to NOS and measuring so well.

 

[geoffalter11]

I bought a pair of Westinghouse 6SN7GTB and they sang much better than the stock tubes. Though I didn’t get the Ken-Rad VT-231s from this seller, I’d still grab a pair here for being close to NOS and measuring so well.

He is really an amazing seller. I got all of my 2A3s from him and probably half of the 6SN7s I had when I owned the HP8. He doesn't put up anything that doesn't measure as right around new. 3500 is new for 6SN7s on his rig. Anything over 3000 will give you thousands of hours of listening pleasure. Especially on that amp, as it is pulling very little from those tubes. That amp is like 90% the transformers. Good thing they are so good!

Glad you are enjoying those Westinghouse. I find them to be an amazing tube with great sonics.

 

[ardbeg1975]

https://www.ebay.com/itm/2856769832...3JX3T2&hash=item4283acd3c4:g:56MAAOSwtjZluIza
https://www.ebay.com/itm/2259343873...JBVMJD&hash=item349abd2896:g:cz0AAOSwxmJljOBS
https://www.ebay.com/itm/2259896611...3XMDVW&hash=item349e0891d3:g:J4UAAOSw6u9lwHAJ

I can vouch for this seller as well. I've acquired some pretty exotic stuff from them and the tubes have always been top notch.

 

[geoffalter11]

I bought a pair of Westinghouse 6SN7GTB and they sang much better than the stock tubes. Though I didn’t get the Ken-Rad VT-231s from this seller, I’d still grab a pair here for being close to NOS and measuring so well.

Honestly, those Westinghouse are just as good. There are some great 6SN7s on his page for less than $200. He has such amazing stuff...

 

[lauthoerer]

Thanks a lot @geoffalter11 and all for the tips and links. As said, I still only vaguely understand the multitudes of differences in these tubes. When 2 letters or numbers can make a $50-150 difference, I’m immediately realizing I’m not in a position to tell a good deal from a bad one

The exchange tube from my HP8 seller should hopefully arrive today, for me to confirm the amp works all fine as expected

Once done, I’ll trust your advice (and @infinity3914 ‘s own experience with them) and get the Ken-Rad, as I understand, the additional $200 to the Westinghouse and $150 to the Hytron will get me a significantly better experience. One day, I might understand the signs and numbers myself…

 

[geoffalter11]

Thanks a lot @geoffalter11 and all for the tips and links. As said, I still only vaguely understand the multitudes of differences in these tubes. When 2 letters or numbers can make a $50-150 difference, I’m immediately realizing I’m not in a position to tell a good deal from a bad one

The exchange tube from my HP8 seller should hopefully arrive today, for me to confirm the amp works all fine as expected

Once done, I’ll trust your advice (and @infinity3914 ‘s own experience with them) and get the Ken-Rad, as I understand, the additional $200 to the Westinghouse and $150 to the Hytron will get me a significantly better experience. One day, I might understand the signs and numbers myself…

Read all of Igolioto’s descriptions. VT-231s are prized for the length of time they last because they were built originally for wartime and are a rugged version of the tube. Meaning it can take a beating and still keep ticking. There are other small differences but nothing major.

If his description says “outstanding sonics” it will be a great tube for the HP8.

Because of how the circuit of the HP8 was made the differences between tubes isn’t huge. There are noticeable differences, but you aren’t going to see a monumental difference that will completely transform the amp. It isn’t that type of amp. That is why I said that I would start with the Hytron’s for $175. They will sound as close to a Ken Rad VT-231 as anything.

The actual replica of the KR VT-231 is a very rare RCA tube made for about an 18 month period called the Narrow Gaps. That tube is special and very rare.

I actually preferred the Raytheon VT-231 and the RCA VT-231s. I just love the RCA midrange and the Raytheon’s bass.

But I do love my Ken Rad Black Glass 2A3s. But totally different tube.

 

[lauthoerer]

So, the replacement tube arrived safely today.

EDIT All works fine now…

Will be back later…

 

[JerseyD]

So, the replacement tube arrived safely today.

I installed all tubes, connected the amp to my DAC, plugged in my GH2, but while I hear some faint music when I turn the volume, even when I’m all the way around, the sound stays very quiet and faint. I checked the cable, and the connection still works fine with my other amps, but not with the HP8.

Any idea what I’m doing wrong here?
Is there any pre-amplification needed with the HP8?

No preamp needed with the HP8. Maybe (when cool) remove and re-insert all 3 tubes. If your DAC is sending audio to your other amps, this is quite a mystery.

 

[jonathan c]

No preamp needed with the HP8. Maybe (when cool) remove and re-insert all 3 tubes. If your DAC is sending audio to your other amps, this is quite a mystery.

Is the DAC connected to the INPUT rca sockets in back of HP8?

 

[geoffalter11]

Is the DAC connected to the INPUT rca sockets in back of HP8?

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.

 

[Pharmaboy]

I bought a pair of Westinghouse 6SN7GTB and they sang much better than the stock tubes. Though I didn’t get the Ken-Rad VT-231s from this seller, I’d still grab a pair here for being close to NOS and measuring so well.

(Pharmaboy, breaking free of restraints again)

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