Quote:Dan, I don't think the ridges can be replicated easily so if they're there it's an Amperex.
I don't know...Lots of older inputs have the ridges and notched/stepped riser plate, and from many companies and countries...Right?
I have been thinking further about the track of my system, tube exploration and preferences, especially with the MKIV. I hope this might be useful to some folks.
I understand consensus about the more revered NOS tubes. I seem to need rarer inputs to get the most from the CSP3, though with a dirt cheap (but great sounding) GE labelled 5R4GY with double bottom D getters.
But the MKIV circuit....I find with the levels of revealing complexity it is capable of, the amp itself can make some decent tubes quite beautiful, and some of the "best" tubes
can be a bit overstated for me.
I think how well the MKIV can bring out tubes, and its amazing flexibility for tonal variations are remarkable design accomplishments. To get its best, we need very good room, source, tubes, cables, speakers etc, but then the amp's complex, revealing, and refined signature is capable of amazing variations of tonal synergy from a wide variety of tubes.
I inadvertently took this trait further with regular system tuning. This process revealed that my DAC was better than I thought, drawing even more musical complexity from it. And the Oppo was sort of even, fine for DVDs, but the comparison indicated it was not up to the MKIVs potential.
My MKIV needed over 600 hours to start showing its potential fully, and like source, all the system/room parts need to rise up to the amp to hear it fully (not hobbling it). This process taught me some about cables and power too! But finally, the amp circuit is so good, once the system is tuned to use it, ....not all, but many quality tubes can become extra good in my experience.
And this suits my preference well. I really enjoy changing things up now and then, helping to re-awaken my perceptions while pulling the beauty of the music in fresh ways. So for my love of exploring variations of beauty, the MKIVs capabilities and a nice variety of tubes are ideal.
I also understand more single-minded refinement.
I just like having a number of very good sounding rectifiers with different traits for fine-tuning. And with patience, most of mine were quite cheap, some ridiculously so. I could probably narrow this down to three rectifiers now if I had to, but then I also enjoy amazing bargains, taking exploration deeper. But I am in no hurry. I have plenty of nice tubes.
In this context, I found my Mazda GZ32 coke bottles on one of these exploratory tracks, and they are likely my current favs. BTW, they have horizontal (they look level), large, bottom D getters on both sides. Best I can tell from this not so good pic they look like the Mullards from a seller LS linked above.
http://valvetubes.com/gz32-mullard-british.html But my pair was about $78 delivered from Georgia! Not the one in the southern US.
AND LASTLY. My matched pair of Upscale Phillips 5R4GYSs have the original boxes (not perfect having a few dents and tears as I received them, but very clean otherwise). The tubes are in excellent shape, burned in, but not much more than that. I think less than 300 hours. I would take 130, my paying shipping to US addresses. PM if interested.
TUBES SOLD