my friend, thats the whole point of the jj E83CC. you see, the jj E83CC frame grid is a direct copy of the tesla E83CC frame grid, which is a direct copy of the TF ECC803S frame grid.
to make it a little wackier, the jj ECC803S is a copy of the tesla ECC803S, which is a long plate 12AX7 and bears no resemblance to the above frame grid lineage.
theyre $29 apiece from eurotubes. last time i bought em coulda sworn it was $23
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Has anyone submitted the JJ to a curve tracer. I don't have any of them to hand anymore, but did test the Tesla's and was surprised how much more linear they were compared the some USA long plates. There was a lack of matching in the Tesla's between the the two triodes / samples.
No, mine is real. Stepped from -4 to -0,5
In addition a quick test of the same tube.
Guess I haven't figured out how to use all the features in the software. How did you get it to produce curves in different colours like that ?
I used default settings , I may come back with the setup file for this measurment ( it's on a seldom used winXP computer)
Have used quite a few different 12AX7 over the years. From quite cheap and bad versions to Telefunken ECC803S.
One that have impressed me a lot is Sovtek 12AX7 LPS.
Surprizingly good sounding with a clear, neutral tone.
Prefer this tube to for example Mullard M8137 which are supposed to be the best version of Mullard 12AX7.
Have some RCA 7025 I like a lot too.
One that have impressed me a lot is Sovtek 12AX7 LPS.
Surprizingly good sounding with a clear, neutral tone.
Prefer this tube to for example Mullard M8137 which are supposed to be the best version of Mullard 12AX7.
Have some RCA 7025 I like a lot too.
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This is ( i think) a copy of the setup file used
This stupid webserver does object to the suffix .uts
I will instead open in a decent text editor and cut-and-paste the contents
<quote>
19500 external heater voltage (*1000)
0 external heater flag
0 system variable 3
0 system variable 4
0 system variable 5
0 system variable 6
0 system variable 7
0 system variable 8
0 system variable 9
0 system variable 10
4 measurement type
2000 Variable 1 Start (*1000)
350000 Variable 1 Stop (*1000)
40 Variable 1 number of intervals
0 Variable 1 log/lin
6300 Constant 1 (*1000)
6300 Constant 2 (*1000)
0 Delay (*1000)
8 number of stepping variables
-4000 stepping variable: 1
-3500 stepping variable: 2
-3000 stepping variable: 3
-2500 stepping variable: 4
-2000 stepping variable: 5
-1500 stepping variable: 6
-1000 stepping variable: 7
-500 stepping variable: 8
8 Ia Range
8 Is Range
6 no. Averagings
0 Compliance
0 to Beep or not to Beep
0 spare measurement variable 2
0 spare measurement variable 3
0 spare measurement variable 4
0 spare measurement variable 5
1 Y1 axis variable
2 Y2 axis variable
1 Y1 marker
3 Y2 marker
1 Y1 line style
2 Y2 line style
0 X axis scaling
1 Y1 axis scaling
1 Y2 axis scaling
0 Xmin (*1000)
0 Y1min (*1000)
0 Y2min (*1000)
350000 Xmax (*1000)
5000 Y1max (*1000)
5000 Y2max (*1000)
7 number of X-ticks
10 number of Y1-ticks
10 number of Y2-ticks
3 degree of polynom
1000 Pmax
0 spare variable
0 Keep Plot check box
1 Color check box
1 Grid check box
0 title off flag
1 title top flag
0 title top flag
E83CC
0 spare graph variable 1
0 spare graph variable 2
0 spare graph variable 3
0 spare graph variable 4
0 spare graph variable 5
0 pinning position 0
0 pinning position 1
0 pinning position 2
0 pinning position 3
0 pinning position 4
0 pinning position 5
0 pinning position 6
0 pinning position 7
0 pinning position 8
0 pinning position 9
0 pinning position 10
0 pinning position 11
0 pinning position 12
0 pinning position 13
0 pinning position 14
0 pinning position 15
0 pinning position 16
0 pinning position 17
0 pinning position 18
0 pinning position 19
0 pinning position 20
0 spare variable 1
0 spare variable 2
0 spare variable 3
0 spare variable 4
0 spare variable 5
0 spare variable 6
0 spare variable 7
0 spare variable 8
0 spare variable 9
0 spare variable 10
0 spare variable 11
0 spare variable 12
0 spare variable 13
0 spare variable 14
0 spare variable 15
0 spare variable 16
0 spare variable 17
0 spare variable 18
0 spare variable 19
0 spare variable 20
0 0 means this is not yet the end of file
1 Quick Test: triode of pentode flag
252000 Quick Test: triode anode voltage setpoint (*1000)
10000 Quick Test: triode anode voltage step in procenten (*1000)
252000 Quick Test: triode screen voltage setpoint (*1000)
10000 Quick Test: triode screen voltage step in procenten (*1000)
-2000 Quick Test: triode grid voltage setpoint (*1000)
10000 Quick Test: triode grid voltage step in procenten (*1000)
1200 Quick Test: triode nominal anode1 current (*1000)
1200 Quick Test: triode nominal anode2 current (*1000)
250000 Quick Test: pentode anode voltage setpoint (*1000)
10000 Quick Test: pentode anode voltage step in procenten (*1000)
250000 Quick Test: pentode screen voltage setpoint (*1000)
10000 Quick Test: pentode screen voltage step in procenten (*1000)
-10000 Quick Test: pentode grid voltage setpoint (*1000)
10000 Quick Test: pentode grid voltage step in procenten (*1000)
1000 Quick Test: pentode nominal anode current (*1000)
1 Quick Test: pentode nominal screen current (*1000)
2 Quick Test: pentode nominal anode resistance (*1000)
3 Quick Test: pentode nominal transconductance (*1000)
4 Quick Test: pentode nominal Mu (*1000)
62500 Quick Test: triode nominal anode resistance (*1000)
1600 Quick Test: triode nominal tranconductance (*1000)
100000 Quick Test: triode nominal Mu (*1000)
0
0
0 spare variable 1
0 spare variable 2
0 spare variable 3
0 spare variable 4
0 spare variable 5
0 spare variable 6
0 spare variable 7
0 spare variable 8
0 spare variable 9
0 spare variable 10
0 spare variable 11
0 0 means this is not yet end of file
1 number of points in stored curve
-1 0 0 0 0 0 0
0 0 means this is not yet end of file
1 number of points in actual curve
-1 1 7 6300 -4000 2000 2000
-1 -1 means this is the end of file
</quote>
This stupid webserver does object to the suffix .uts
I will instead open in a decent text editor and cut-and-paste the contents
<quote>
19500 external heater voltage (*1000)
0 external heater flag
0 system variable 3
0 system variable 4
0 system variable 5
0 system variable 6
0 system variable 7
0 system variable 8
0 system variable 9
0 system variable 10
4 measurement type
2000 Variable 1 Start (*1000)
350000 Variable 1 Stop (*1000)
40 Variable 1 number of intervals
0 Variable 1 log/lin
6300 Constant 1 (*1000)
6300 Constant 2 (*1000)
0 Delay (*1000)
8 number of stepping variables
-4000 stepping variable: 1
-3500 stepping variable: 2
-3000 stepping variable: 3
-2500 stepping variable: 4
-2000 stepping variable: 5
-1500 stepping variable: 6
-1000 stepping variable: 7
-500 stepping variable: 8
8 Ia Range
8 Is Range
6 no. Averagings
0 Compliance
0 to Beep or not to Beep
0 spare measurement variable 2
0 spare measurement variable 3
0 spare measurement variable 4
0 spare measurement variable 5
1 Y1 axis variable
2 Y2 axis variable
1 Y1 marker
3 Y2 marker
1 Y1 line style
2 Y2 line style
0 X axis scaling
1 Y1 axis scaling
1 Y2 axis scaling
0 Xmin (*1000)
0 Y1min (*1000)
0 Y2min (*1000)
350000 Xmax (*1000)
5000 Y1max (*1000)
5000 Y2max (*1000)
7 number of X-ticks
10 number of Y1-ticks
10 number of Y2-ticks
3 degree of polynom
1000 Pmax
0 spare variable
0 Keep Plot check box
1 Color check box
1 Grid check box
0 title off flag
1 title top flag
0 title top flag
E83CC
0 spare graph variable 1
0 spare graph variable 2
0 spare graph variable 3
0 spare graph variable 4
0 spare graph variable 5
0 pinning position 0
0 pinning position 1
0 pinning position 2
0 pinning position 3
0 pinning position 4
0 pinning position 5
0 pinning position 6
0 pinning position 7
0 pinning position 8
0 pinning position 9
0 pinning position 10
0 pinning position 11
0 pinning position 12
0 pinning position 13
0 pinning position 14
0 pinning position 15
0 pinning position 16
0 pinning position 17
0 pinning position 18
0 pinning position 19
0 pinning position 20
0 spare variable 1
0 spare variable 2
0 spare variable 3
0 spare variable 4
0 spare variable 5
0 spare variable 6
0 spare variable 7
0 spare variable 8
0 spare variable 9
0 spare variable 10
0 spare variable 11
0 spare variable 12
0 spare variable 13
0 spare variable 14
0 spare variable 15
0 spare variable 16
0 spare variable 17
0 spare variable 18
0 spare variable 19
0 spare variable 20
0 0 means this is not yet the end of file
1 Quick Test: triode of pentode flag
252000 Quick Test: triode anode voltage setpoint (*1000)
10000 Quick Test: triode anode voltage step in procenten (*1000)
252000 Quick Test: triode screen voltage setpoint (*1000)
10000 Quick Test: triode screen voltage step in procenten (*1000)
-2000 Quick Test: triode grid voltage setpoint (*1000)
10000 Quick Test: triode grid voltage step in procenten (*1000)
1200 Quick Test: triode nominal anode1 current (*1000)
1200 Quick Test: triode nominal anode2 current (*1000)
250000 Quick Test: pentode anode voltage setpoint (*1000)
10000 Quick Test: pentode anode voltage step in procenten (*1000)
250000 Quick Test: pentode screen voltage setpoint (*1000)
10000 Quick Test: pentode screen voltage step in procenten (*1000)
-10000 Quick Test: pentode grid voltage setpoint (*1000)
10000 Quick Test: pentode grid voltage step in procenten (*1000)
1000 Quick Test: pentode nominal anode current (*1000)
1 Quick Test: pentode nominal screen current (*1000)
2 Quick Test: pentode nominal anode resistance (*1000)
3 Quick Test: pentode nominal transconductance (*1000)
4 Quick Test: pentode nominal Mu (*1000)
62500 Quick Test: triode nominal anode resistance (*1000)
1600 Quick Test: triode nominal tranconductance (*1000)
100000 Quick Test: triode nominal Mu (*1000)
0
0
0 spare variable 1
0 spare variable 2
0 spare variable 3
0 spare variable 4
0 spare variable 5
0 spare variable 6
0 spare variable 7
0 spare variable 8
0 spare variable 9
0 spare variable 10
0 spare variable 11
0 0 means this is not yet end of file
1 number of points in stored curve
-1 0 0 0 0 0 0
0 0 means this is not yet end of file
1 number of points in actual curve
-1 1 7 6300 -4000 2000 2000
-1 -1 means this is the end of file
</quote>
12AX7 LPS is probably the nicest tube Sovtek makes IMO.
I'm surprised nobody has mentioned the good 'ol Sylvania 7025/12AX7A, a very balanced tube with great tone and detail.
I would absolutely love to see your measurements, the test setup configuration, and the equipment you used to arrive at this conclusion 🙂
I tend to be of the opinion that the sound of the tube is dependent on the circuit and operating points it works in, the role in the system, the music being played and the kind of day the listener has had at the office. You get my drift. I've tried heaps of 12ax7 and 6sl7 in both preamp and power amp stages and my "make my head swirl with delight" is an old brown base mullard ECC35 I got years ago. Probably because of a super strong valve with a gain advantage, but who knows? At the end of the day, just because of anti-modern world nostalgia, I'll stick with the NOS stuff.
Someone kindly sent me some JJs for distortion testing; here are the results. Distortion is consistent with other ECC83 brands I have tested, falling right in the middle of the range, e.g. these JJs are lower distortion than Mullard, higher than Sovtek.
Attachments
They are clearly labeled Valvo. May have started life in the Philips Heerlen factory but emerged as Valvo tubes.
they are clearly labeled/re-labeled and re-branded valvo, yet they are just as clearly not valvo.. LMK if youd like to know what they are.