Suitable alternat for SED wing = c= ?

[bandit2013]

I am considering the Tung Sol ECC803S gold pin. From what I have read thus far as they good at reducing the hum associated with AC sourced heaters. I have the Tung Sol ECC83s (standard 12ax7), they work the best in the Mark IV. They were a bit noisy in the Mark V. So far the only preamp tubes that make a difference are my used Mesa Chinese tubes.

I will have to look into the Chinese versions of the GT. Are they generation 9? I may get a few and see if they sound the same.

I have tried Mullard re-issue and they are completely useless in a guitar amp. They easily translate any vibration into audible noise through the speaker. So far the only Long Plate (current production tube) that I have yet to have issues with is the Sovtek LPS, I only bought one of them and I have used it for almost a full year now. I wonder if that is the same tubes as the Gold Lion B759 (ECC83) but without the gold pins.

 

[DangerMoney]

FYI.

12AX7 comparison:
http://www.amplifiedparts.com/tech_corner/12ax7_comparison_of_current_made_tubes

6L6 comparison:
http://www.amplifiedparts.com/tech_corner/6l6gc-comparison-current-made-tubes

 

[shimmilou]

...the Chinese versions of the GT. Are they generation 9?...

I believe so. I like the GT better than Ruby, Penta or TAD.

 

[swbo101]

I have tried Mullard re-issue and they are completely useless in a guitar amp. They easily translate any vibration into audible noise through the speaker.

That's strange. I've been using them for about 5 years now in the PI slot, and I've yet to hear any noise. Did you use in a combo? I have it in a head on a 4X12 cab and I play pretty loud.

Just wondering.

 

[bandit2013]

FYI.

12AX7 comparison:
http://www.amplifiedparts.com/tech_corner/12ax7_comparison_of_current_made_tubes

6L6 comparison:
http://www.amplifiedparts.com/tech_corner/6l6gc-comparison-current-made-tubes

Danger Monkey, I have seen these charts many times. Especially the 12ax7 comparison. Unfortunately they do not do much for actual. They do not account for electrical noise such as heater hum. What would be better would be a frequency analysis of the guitar signal though a particular amp. The frequency analysis will reveal the fundamental frequencies of the guitar signal along with the harmonic content. Also a Bode plot of a frequency response would be better than the simple graph. They are good for simple comparison. If you read all of the details where the charts originated, there is a relation to the gain values but it is not clear what the actual gain is.

 

[bandit2013]

...the Chinese versions of the GT. Are they generation 9?...

I believe so. I like the GT better than Ruby, Penta or TAD.

I had three Penta Labs 12ax7 that I got in Doug's Tubes tone kit. They were terrible. One went completely microphonic, the others rattled. Out of the 7 preamp tubes that were original in the Mark V, 4 of them were mechanically noisy too. The getter design of the JJ style tube is probably the worse design which vibrates like a low frequency tuning fork. I will have to get some of the GT's to try out.

 

[bandit2013]

I have tried Mullard re-issue and they are completely useless in a guitar amp. They easily translate any vibration into audible noise through the speaker.

That's strange. I've been using them for about 5 years now in the PI slot, and I've yet to hear any noise. Did you use in a combo? I have it in a head on a 4X12 cab and I play pretty loud.

Just wondering.

I ordered three from "the Tube Store" to try out. My Mark V is a head. It is not inert of vibration since it is on top of the 412 cab. I typically play at moderate volume with the effects loop active. Master volume set at 10:00, all channels set to 90W (provides best balance on all the power tubes), that is enough to rattle just about anything in the room including me.
What I noticed without any input signal, I would hear a strange noise when channel changing. Sounds like a power tube rattle with low frequency, turns out to be the Mullard that I had in V1. As for use in the PI position, that would be fine since that circuit usually does not translate mechanical vibration into audible noise. Two of the Mullards made noise, only one was quiet. I was not impressed as it seemed to make the tone a bit muddy and less defined. The good Mullard had the same effect in my Mark IV combo. It may serve better as a PI tube than the primary gain tube. In my opinion, the Sovtek LPS is a better tube even though it looks identical to the Mullard, it just does not seem to have the same tone character. The LPS tube I have is quiet, hard to hear AC heater hum, and works quite well in V1 or the PI locations. There is a reason I will not get the Genalex Gold lion B759 (ECC83) at the $43.00 price tag, I believe it is the same tube as the Mullard with gold pins. Both would be more suitable for Hi Fi audio than guitar amp. Since my experience with the JJ6CA7, during my tube roll I discovered the issues with the TS 12ax7, and the EH 12ax7. AC heater hum. Most would probably ignor it as it is not very loud but is noticeable without input signal. The EH tubes were a bit more sensitive but they are the same tube as the TS 12ax7. They may be sorted tubes with different gain.

 

[jnoel64]

Bandit,
Just out of curiosity, what has been your experience with Tung Sol 12ax7s? I have them in the first three slots of my Dyne, and I haven't had any issues for almost a year.

 

[shimmilou]

bandit2013,

You sometimes have to look very closely at tubes to spot the differences, but none of the Russian tubes that you mentioned are the same tube relabeled, they are all quite different. Some of the differences are hard to spot, some differences can't even be seen, such as the grids underneath the Plates. Some Genalex are Chinese. As you've noted, the easiest way to tell the difference is by the sound.

Man, it really seems like your amp has some problems, it sure eats tubes like no other amp I've ever heard of.

 

[bandit2013]

Bandit,
Just out of curiosity, what has been your experience with Tung Sol 12ax7s? I have them in the first three slots of my Dyne, and I haven't had any issues for almost a year.

The medium plate sized Tung Sol 12ax7 are sweet. I love them in the Mark IV since I get the best sound in the clean channel with these tubes. I have also used the same tubes in the Mark V that I now have in the Mark IV. They are a good quality tube. The issue I have is tube related as well as amp related (probably more amp than the tube). The Mark V is a different animal when it comes to the preamp. The voltage jumps between channels is enough to hear annoying hum. CH1 clean may create some hum (almost not noticeable but I can hear it). Ch2 is usually noiseless but CH3 is where the issue reveals itself. There is nothing wrong with the tubes, however the TS 12AX7 and the similar tube EH 12AX7 seems to amplify the AC heater noise in the tube. They are quite better than the Mesa (JJ tubes) since the low level hum I can live with, JJ tubes generate lots of white noise (hiss). If I could not find a tube that eliminates the noise with no signal I would be praising the Tung Sol 12ax7 tubes as they are probably the most quiet tube when there is no input signal and the amp is set to deliver. Unfortunately they are not quiet in the Mark IV. The old Mesa 12ax7a (Chinese) tubes are extremely quiet under the same circumstances. Probably due to screening and perhaps design of the heater element. If I have 6L6GC power tubes, I barely hear the noise but it is there when the preamp is loaded with TS12ax7. When I run the EL34, there is considerable hum unless I use the old Mesa tubes. Perhaps I am picky. but when the hum is louder than palm muted playing it becomes annoying. It seems the most sensitive position is V3 followed by V6. The EH tubes (some claim to be the same, I beg to differ) are more susceptible to hum than the TS equivalent. Not all tubes are the same, and their characteristic can drift with use. So far I have not had any mechanical noise related issues with either TS or EH 12ax7. Same applies to the Sovtek LPS.

I am uncertain if the Mark IV uses AC heaters for the preamp tubes. The Mark IV is mixed. V3, V4, V6 and V7 are AC sourced where as V1, V2 and V5 are DC sourced. V4-V7 are drivers, with the exception of V6 as final gain stage CH3, V3 is all gain stage. I have tried mixing the preamp tubes, anything other than the Mesa Chinese tubes in the AC heated circuits generates hum.

 

[bandit2013]

bandit2013,

You sometimes have to look very closely at tubes to spot the differences, but none of the Russian tubes that you mentioned are the same tube relabeled, they are all quite different. Some of the differences are hard to spot, some differences can't even be seen, such as the grids underneath the Plates. Some Genalex are Chinese. As you've noted, the easiest way to tell the difference is by the sound.

Man, it really seems like your amp has some problems, it sure eats tubes like no other amp I've ever heard of.

My amp will eat power tubes, but I have only blown 3 sets so far.
Severely red plated one of the Mesa 6L6gc STR440 original tubes, in V8, V9 was also cherry red but did not get scorched. Happened in 45W mode, Effects loop Active, and Variac power.
Same tube positions but 13 year old and used Mesa 6L6GC STR 420 under same operating conditions. Took out both V8 and V9.
Lost one of the JJ6CA7 but in V10, 90W mode full power, Effects loop active.
The Mark IV toasted two of the remaining JJ6CA7. I believe the loss of the JJ tube in V10 was due to defect in the tube.

All the other tubes I have used in the Mark V are still in operating condition. I just did not care much for the tonal characteristics. May it be harsh, they just sounded terrible. What did not seem sound good (subjective ) in the Mark V sounds great in the Mark IV combo. What I found with the Mark V that is different is that only one tube is driven hard in the 45W mode. With effects loop active, V8 gets abuse, in hard bypass it is V9. The JJ6CA7 tubes revealed this due to the super hot glow of the grids and cathode was visible though the mica spacer and a signal applied. Looked like a incandescent light bulb on a dimmer control. 90W mode allows for parallel currents for V8 and V9 so the burden gets spread across all 4 tubes more evenly. So far only the SED tubes appear to be balanced but no proof since I do not have bias meter yet. The TAD6L6gc STR also do not seem to reveal hot spots at the plate seem. The SED tubes will glow slightly but not as much as the Svetlana or Tung Sol tubes (almost complete plate will get a slight orange glow but remains its natural color grey). This is of course with signal and moderate volume levels. They seem to cool down quickly as soon as the signal stops. I have also notices the hot spots with the same tubes in the Mark IV. I am assuming it is normal. Also it is not visible unless viewed in complete darkness.

Yes I would agree that all tubes that look similar are not identical. Case with the Reflektor (new sensor) preamp tubes. Sovtek LPS is identical in appearance to the Mullard re-issue, but they are not the same tube. Internals more than likely are different even if the plates appear to be the same design. TS 12ax7 also shares identical plates to the EH 12ax7 but are notably different in spacer design, and probably screen and cathode as well. Visual inspection cannot identify alloys used, plating, cathode thickness, etc.... Just based on visual cues, it is difficult to tell if it is the same tube. The Tung Sol 7581 looks identical to the Svetlana tube on plate design, they even sound similar but are not the same tube internals. I would expect to see similarities of different tubes made by the same manufacturer. However, if the Gold lion B759 tube is the same as the Mullard re-issue, I would be greatly disappointed. I may get one just for kicks. I do like the Sovtek LPS tube. I am considering getting a few to try out in the AC heated positions to hear if the Hum returns. I could always tube roll the one I have to hear if anything changes.

 

[jnoel64]

The RK1 I inherited came from my father. Apparently, he was going through tubes more frequently than he anticipated and contacted Mesa about it. According to what my father told me, Mesa told him that he would go through tubes rather quickly if he set his tone controls on the amp above 2 O'Clock. I personally find this a little difficult to believe. Why would a control set be physically available if it is known to cause issues? Kinda reminds me of Hendrix's experience with Sun amps.

 

[Chester]

The RK1 I inherited came from my father. Apparently, he was going through tubes more frequently than he anticipated and contacted Mesa about it. According to what my father told me, Mesa told him that he would go through tubes rather quickly if he set his tone controls on the amp above 2 O'Clock. I personally find this a little difficult to believe. Why would a control set be physically available if it is known to cause issues? Kinda reminds me of Hendrix's experience with Sun amps.

Not surprised to hear that

Mesa are always pointing out that the best tones (in their opinion) are found in middle settings of tone, gain & volume. That's the way the amp is designed, and seems to run most "efficiently". If I recall correctly, they also discuss extreme settings and increased tube wear in their manuals ..

 

[bandit2013]

After using the EH EL34 for a while, I put the SED 6L6GC back in the amp, I prefer the tone of the EL34. Now I have to get me some SED EL34 and hear the difference. First impressions on the EH tubes were low. After some use or abuse, they opened up in character. Probably better to get tubes that are burned in and matched. The EH I bought were off the shelf. They sounded thin but not any more. The only issue I have with them is they are noisy in mechanical terms. They tend to rattle with low frequency signals. At low volume that will get annoying. Not the best tube for a combo amp . I did notice that "the tube store" has a few questions regarding tubes and their use, what amp? is it a combo? I may say the amp is a combo to see if I get better tubes and not one's that rattle.

 

[swbo101]

bandit - I've heard good things about the Tung-Sol EL34B tubes. Maybe you should try them. The SED tubes have just gone up in price again. I purchased (which maybe my last if the price keeps going up) a mixed quad (6L6/EL34) of SEDs last week from Tube Depot for around $150. My max for a quad. They had a 10% off sale for just a few days. I caught it at the end.

Also based on the bias point ratings on the ones I got, I think they are runnning low on middle rating tubes (ones that Boogies generally use). In the past I got 6L6s rated at 21 and EL34s rated at 29. I got 6L6s rated at 20 (no big deal) and EL34s rated at 43. That maybe at the high end of the middle of the bell curve for Boogies, I'm looking into it.

Just a FYI.

 

[swbo101]

UPDATE:

Heard back from Tube Depot. They said that EL34 rated at 43 (instead of 29) will have a later break up. So does this mean it is running colder?
I still need to pop this in to test, but will it harm my amp? They consider middle rated for this tube from upper 20's to low 30's. So it's a bit out of range.

Just wondering.

Thanks.

 

[jnoel64]

The TS EL34Bs have been in my Dyne for almost a year. I don't even want to try anything else. I found the tone I have been hearing in my head forever and don't want to lose it. After installing new power tubes, I always leave my amp on for 24 hours with the volume turned down all the way. That solves the "burn in" test and cost.

 

[shimmilou]

...EL34 rated at 43 (instead of 29) will have a later break up. So does this mean it is running colder?...

The higher numbers mean a higher idle current for the tubes. Higher idle current means "stiffer" or cleaner sounding tubes with a later onset of breakup/distortion, as compared to the lower numbers which will have lower idle current and will have an earlier onset of breakup/distortion. :idea:

 

[swbo101]

...EL34 rated at 43 (instead of 29) will have a later break up. So does this mean it is running colder?...

The higher numbers mean a higher idle current for the tubes. Higher idle current means "stiffer" or cleaner sounding tubes with a later onset of breakup/distortion, as compared to the lower numbers which will have lower idle current and will have an earlier onset of breakup/distortion. :idea:

Thanks. One more question. Then a tube with later break up runs colder or hotter? Colder right?

Sorry to be so dense.

 

[shimmilou]

When referring to idle bias, I use the term "hotter" to mean a higher current through the output tubes, and "colder" to mean a lower current through the output tubes. At least one of the rating numbers on most tubes will indicate the current draw at a specific Plate voltage and specific bias voltage applied to the tube's grid, usually indicated by "Ip". So for my use of the terms, higher idle current rating would be hotter and later breakup, whereas lower idle current rating would be colder and earlier breakup. These numbers are used for comparison only, as the tubes can draw more or less current depending on the amp in which they are installed as well as the bias setting of that particular amp. So, a higher rated tube with later breakup rating runs hotter only as compared to another tube with a lower breakup rating used in the same amp at the same bias setting.

If that isn't confusing enough, in amps with adjustable bias, setting the bias hotter usually means earlier breakup. So, the numbers are just for comparison, as many amps have an adjustable bias. Meaning that basically, all else being equal, a tube with later breakup rating runs hotter, only as compared to a tube with earlier breakup rating, which runs cooler.