Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: 66Strat on May 05, 2018, 09:45:44 pm
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Looking for some insight on the timeline of changes/improvements in the EH 6V6GT.
The datasheet looks impressive.
https://www.newsensor.com/pdf/electro-harmonix/6v6eh.pdf (https://www.newsensor.com/pdf/electro-harmonix/6v6eh.pdf)
The tube pictured on the EH website is different from the tube pictured in Doug's store. The new tube looks like it has 4 support rods vs two in the earlier version. The plate structure resides in the lower part of the tube with the getters on top. In the older version, the plate structure was in the upper part of the tube and the getters on the bottom. This is a good looking tube.
https://shop.ehx.com/item/6v6eh/tubes-vacuum-electro-harmonix/ (https://shop.ehx.com/item/6v6eh/tubes-vacuum-electro-harmonix/)
When did these changes occur? The tube on the EH website has a production date of December 2014.
Does the newer version perform any better?
The platinum matching process looks to be very thorough.
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Not sure what you are looking at inside the tube?
Post an image with the parts you want to see circled
I will take a picture of the current stock I have on hand
My tubes from EH are all fresh because I only buy 20 platinum quads at a time
And they sell fast, so if EH's picture is new, that's what I have on hand
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Thanks for the reply.
I don't doubt that you have fresh stock. It certainly was not my intent to imply otherwise. I was just looking for some insight on the timing of changes/improvements made to the tube. It is not documented on the EH/New Sensor website. Attached are the pictures of the new and previous versions of the tube.
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Different production, for-sure.
Different sound? Quality? Reliability? Eh, I am not a 6V6 connoisseur. Many different things have been sold as "6V6", and work fine in many amps. I've never seen how a rod-count matters. The high/low guts is a compromise between what base-seal construction the factory favors and how much head-space to allow for gettering.
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I don't know what if any effect the changes would have on sonics. As to reliability, the two additional support rods, combined with lower component geometry may provide better vibration resistance. The newer version evidences much stronger getter flash than the previous version, which may provide for better vacuum. I don't know. :dontknow: Just guessing as to the possible improvements. I don't think that the changes would be made just for the sake of change, hence my questions here.
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I will look when I get to the shop
The tube on the left is what I think I have in stock
Probably time to look at all the EH tubes and see if the pictures match the tubes on my web site
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Sounds like good marketing. I want to buy one! :icon_biggrin:
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Just opened a box and took this pic
They look like this
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That's great..... That tube doesn't look like either of the first tubes. The plates look taller... Valve madness!
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Just opened a box and took this pic
They look like this
Thanks for the update.
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That's great..... That tube doesn't look like either of the first tubes. The plates look taller... Valve madness!
The plate structures look the same to me. If anything, there may be some difference in the bottle heights. New Sensor may have dropped the getter down a little closer to the top of the plate structure and put them in shorter bottles. It's hard to tell from the pictures.
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I don't know what if any effect the changes would have on sonics. As to reliability, the two additional support rods, combined with lower component geometry may provide better vibration resistance.
But what if they are mounted upside down (in a Fender-type amp)? :w2: :laugh:
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I don't know what if any effect the changes would have on sonics. As to reliability, the two additional support rods, combined with lower component geometry may provide better vibration resistance.
But what if they are mounted upside down (in a Fender-type amp)? :w2: :laugh:
Joking?
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Yes, was referring to the comparison photo. Rather than “lower component geometry” you may be better off thinking about lower center of gravity? Tube datasheets describe mounting orientations which tubes can be used in without adverse performance affects but never related to sonic qualities that I’m aware of.
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Lower center of gravity might be better terminology. The plate structure, situated lower in the tube on shorter rods, would have a smaller moment of inertia and thus be more resistant to sonic vibrations in a combo. It's been 40 years since Physics 202, so I may be mistaken and have my terminology confused. I hadn't really thought about the tube orientation. All in all, it looks like a more better, more ruggeder tube. :icon_biggrin:
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I like this thread. I really enjoy *trying* to research modern production tubes.
So many brands being made under so few roofs, yet there are considerable differences in visual *quality* (sloppy construction/ neat construction) , sound quality, etc.
BTW my new favorite 12ax7 is new production Mullard. Magical sounding.
And my set of Bugera relabeled (Chinese?) El34's with very sloppy looking internal construction sound like a million bucks !