The SOHA II Tube Thread
Oct 30, 2009 at 3:01 PM Post #31 of 99

TimJo

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Quote:

Originally Posted by regal /img/forum/go_quote.gif
Does JJ 12AU7 = EH 12AU7, same company ?


I don't think so. JJ is the new name for Tesla, whereas EH is Elctro-Harmonix. Two different manufactures as far as I know...
 
Oct 31, 2009 at 9:50 AM Post #32 of 99

regal

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I finished the amp today, started with RCA 5963's. I wasn't that impressed, sounded like a Millet Hybrid , some break-up distortion on complex loud passages. I turned up the tail current to 2.5 ma per tube and installed the NOS 8416's. Completely different amp, beautiful full rich sound with the detail to convey the ambience of the recording. I am very impressed with these tubes, it is cool to be able to own a true New Old Stock amperex 6(12)DJ8 for $50 a pair. I wish I had bought a dozen of these when they were selling for $10 a piece.
 
Oct 31, 2009 at 3:26 PM Post #33 of 99

TimJo

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Quote:

Originally Posted by regal /img/forum/go_quote.gif
I wish I had bought a dozen of these when they were selling for $10 a piece.


You and me both... It has been my standby for awhile in the CTH. I guess Amperex was the only manufacturer of these, and were made specifically for Tektronix scopes. The gentleman I bought mine from (who is certainly an expert) said that 8416 is also one of the only tube designations that was never officially registered, and has yet to come across a datasheet for it.

Sad story - A few weeks back, when crossing the room, my foot snagged my headphone cable and the CTH went flying - landing upside down - snapping the glass on one of these.
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Oct 31, 2009 at 3:39 PM Post #34 of 99

wolf18t

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Quote:

Originally Posted by regal /img/forum/go_quote.gif
I finished the amp today, started with RCA 5963's. I wasn't that impressed, sounded like a Millet Hybrid , some break-up distortion on complex loud passages. I turned up the tail current to 2.5 ma per tube and installed the NOS 8416's. Completely different amp, beautiful full rich sound with the detail to convey the ambience of the recording. I am very impressed with these tubes, it is cool to be able to own a true New Old Stock amperex 6(12)DJ8 for $50 a pair. I wish I had bought a dozen of these when they were selling for $10 a piece.


Actually, with all my headphones I've never been impressed by my Phillips 5963s. My favs are the Amperex 8416 with PS-1000 and Amperex Orange globe 6DJ8 with RS-1. I suppose 5963s sound better with Senns 6x0.
 
Nov 6, 2009 at 4:55 AM Post #36 of 99

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I just recently got some 1955 CBS Hytron 5814A Black Plate Square Getter. Wow, a gigantic improvement over my late 60's Sylvania 5814A. Where the Sylvania were almost harsh sounding in the midrange and veiled in the high end, the Hytron's are smooth throughout and crisp in the high-end. Deeper soundstage as well. I've been listening to these for about 4 hours straight now and I never get tired of these. I'll be sad when they go.
 
Nov 6, 2009 at 6:19 AM Post #37 of 99

TimJo

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I have some Hytron tubes as well, although not 5814's, and they are very high quality indeed. Hard to find I'd say, but really nice sound.
 
Nov 6, 2009 at 6:27 AM Post #38 of 99

TimJo

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Quote:

Originally Posted by regal /img/forum/go_quote.gif
I am very impressed with these tubes, it is cool to be able to own a true New Old Stock amperex 8416's.


I was able to find another pair of these last week.
smile.gif


These ones came in Tektronix boxes - p/n 154-0413-00. They must have been replacement tubes for whatever scopes these where used in at the time.
 
Nov 11, 2009 at 4:56 AM Post #40 of 99

TimJo

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Quote:

Originally Posted by regal /img/forum/go_quote.gif
The Mullard Blackburn 12AU7's sound marvelous, at least as good as the 8416's maybe better. Huge improvement over the RCA 5963's.


What time period are they from?

Have you ever watched that documentary filmed at the factory? Well, I guess it was more of a company informational film, but it is quite fascinating to watch what went in to building those tubes.
 
Nov 11, 2009 at 5:20 AM Post #41 of 99

regal

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Quote:

Originally Posted by TimJo /img/forum/go_quote.gif
What time period are they from?

Have you ever watched that documentary filmed at the factory? Well, I guess it was more of a company informational film, but it is quite fascinating to watch what went in to building those tubes.



top O getters. Lastly they have Gf2 B 4H1 and Gf2 B3A4 factory/date codes, meaning they were made in Mullard's Blackburn, Lancashire plant.
 
Nov 15, 2009 at 6:45 AM Post #43 of 99

regal

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I compared the Amperex 8416's to the Mullard 12AU7's. The 8416's have a smoother thicker midrange while the Mullards excell in having more bass. I'm a guitar listening freak so I'm sticking with the 8416's.

On another note this SOHA II is the first tube amp that has me completely impressed by Grados, never liked them till now, the Senns and AKG's are gathering dust after building this amp.
 
Nov 15, 2009 at 7:04 AM Post #44 of 99

dBel84

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lol , nothing smooths out a grado except for the original RS1's
biggrin.gif


you should try get your hands on some 6680's - I have some british made rebranded tubes which have great synergy with this amp. I still like the 8416 too but these have been getting more play ( actually the soha ii has been getting more play since my other amp is out on loan ) I forget just how well this amp performs overall.

..dB
 

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