Brown Sound - Pulling two tubes for Class A

It’s gotta eat the power tubes up quicker doing that right? Any stress on the transformer?
 
EddyLenz said:
Then it looks like my store made a mistake, because this is what they say.
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Here's what JJ has on their spec sheet.
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Here they call it a beam pentode..........maybe it's some kind of hybrid now or it is a play on words, I just don't know. But your clips sound good nonetheless. The EH is just closer in construction and operation to the Sylvania Philips 6CA7 that you are going to find in new production these days was my only point. Having compared them directly to my Sylvania's in my 68 and 69 amps they are decent sounding and fairly close to what I get when I run my Slyvania fat bottle 6CA7's. I also have some NOS EI fat bottle 6CA7 that are in the same ballpark as well.
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EddyLenz said:
Thanks, but I don't want to risk anything with them. Pete Thorn did a video comparing tubes and there were Sylvania and EH 6CA7 in there. Really hard to hear a difference at all there.
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This is what I have found as well Eddy comparing the EH6ca7 and my collection of Sylvania 6ca7's. While not exact they are fairly close sounding and respond quite closely to what I hear in my Sylvanias, close enough that I don't feel the need to put my Sylvania's back in because I hear or feel the tone is missing something.

MGL AmpWorks said:
Eddy, None of the modern tubes labeled 6CA7 are remotely the same as the original US tubes that Ed used. I’ve got a bunch of originals. If you want to pay for the shipping back and forth, I’d send you a pair to try.
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While they aren't 100% exact... the construction and operation is as close as one is going to get in modern production tubes and they don't sound horrible and are close enough to my Sylvania's that I do not feel the need to pull them for my NOS which I still have a good number of which I have ran for years in my 68 amp. If they weren't close at all I would just run my NOS Sylvania's. I just replaced a pair of Sylvania's that I ran for almost 10 years in my 68 just to compare them and they sound and respond similar so I have kept them in my 68 amp. They Sylvanias still test good but the sound quality had noticably degraded and plates were ringing a bit..

Here's one of my 69 builds with 100% NOS parts except Heyboer OPT and MC Power transformer, Everything else was all era correct parts Iskras, NOS Mustards for 1969 specs except 820/.68uf on V1B, with EH6CA7's. This amp is 100% stock Marshall specs,(NO ed specs) except I did install a 50K midpot.
all era correct parts including the reddish fiber turret board from 69. Sorry for the Zoom clip it's what I had at the time.
 
Jccobb2 said:
It’s gotta eat the power tubes up quicker doing that right? Any stress on the transformer?
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Actually I watched a 2 hour interview with Jim Gaustad and Dave Friedman and Dave said he did not see an issue that would damage the Output transformer which suprised me but he did say it. Dave said it just sets up a strange operation mode in the amp but it will operate... I don't remember exactly how he phrased it. There was a guy called VHoholic on Metro amp that ran his 100 Watt Marshall plexi on ONE output tube and he claimed that was the tone. For me pulling V4 and V5 sounds good.....is it good enough to risk damaging my amp? I don't know....I guess if you feel it nails the tone for the 1978 album then so be it if you like it and Gaustad said he has not had any issues running the V4 V5 thing or just one power tube as well.

I will note that there is quite a difference between the 78 tone capture models and the 79 capture models in my IK Multimedia software but I was surprised that the differences were so tangible in a live amp. Kudos to Eddy Lenz for doing the experiment that I was hesitant to do myself.:2thumbsup:

 
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Cless357 said:
Is it possible to even use only one power tube ?
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It’s possible but will certainly stress out your amp. Whether or not it will be catastrophic or even damaging is on a case by case basis, but to me if this was the key to getting a sound, people would be designing amps to get it safely and consistently.
 
Another thing to consider is Edward’s favorite tubes were Telefunken EL34 tubes if you search back to the 78 Japan tour there are photos of the back of Edward’s 100 watt and 50 watt Marshall’s you can plainly see that they are EL34 tubes not 6ca7 tubes.i believe he switched to 6ca7 tubes during Van Halen II
 
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