I pretty much agree with SY, but it depends on what you're trying to do. In Class A triode, my preference is for the EL34, but I've built a couple of very nice 6L6 variants. In AB and/or terode/pentode the choice is less clear cut for me, but if you're not bothered by topcaps, there are a bazillion great old 807's out there that can be had really cheap. I like the look of the ST bottle too....
In the end, it depends on the circuit and implementation.
In the end, it depends on the circuit and implementation.
Depends on how adventurous you are and your willingness to chase NOS. In the NOS category, the "super" 6BG6s that have been around at attractive prices are a great choice. They like to see 6600 ohm plate-plate. 6JN6 and similar medium-power sweep tubes are also bargains that perform extremely well with the right circuit. EL38s can still be found. EL37s are spectacular, but fairly unobtainable. I'd look at paralleled EL84s, and (if they're actually reliable and meet spec) 7591s.
If I were doing a new commercial design today, I'd be using EL509s.
If I were doing a new commercial design today, I'd be using EL509s.
Hi resident,
There is nothing wrong with 6L6's or their variants. I own amplifiers using 6L6's, 7591's, EL34's and 6BQ5's. I'm sure I have others too. I'd worry more about the iron and the layout.
If you are thinking tube life, a 6L6GC is a 30W, EL34 is 25W and 7581A/KT-66 is 35W. 5881's are rated at 25W. Pushing a 25W tube into the 50W range may shorten tube life a bit, or increase distortion. This depends on your design.
Design away and enjoy, try another tube on your next design if you are curious.
-Chris
There is nothing wrong with 6L6's or their variants. I own amplifiers using 6L6's, 7591's, EL34's and 6BQ5's. I'm sure I have others too. I'd worry more about the iron and the layout.
If you are thinking tube life, a 6L6GC is a 30W, EL34 is 25W and 7581A/KT-66 is 35W. 5881's are rated at 25W. Pushing a 25W tube into the 50W range may shorten tube life a bit, or increase distortion. This depends on your design.
Design away and enjoy, try another tube on your next design if you are curious.
-Chris
My plan is to use 6L6 or EL34 in CFB P-P configuration. But I’d like to try them in UL, tetrode or pentode and triode P-P, too. You know, with the classic method by changing connections at taps of OPT. Just to see the difference with CFB! So, choose any tube I like? I like to drive them at 30watts. I think I’ll go with 6L6.
At Va = 400-450V, Ia=50-60mA and AB1 P-P.
@SY and Brett
I know that there are a lot of tubes out there with same size/power range. But, as a newbie I’d like to try some usual one. If I start to think about alternatives, I’ll go..
Even right now I can’t decide btw those two!
At Va = 400-450V, Ia=50-60mA and AB1 P-P.
@SY and Brett
I know that there are a lot of tubes out there with same size/power range. But, as a newbie I’d like to try some usual one. If I start to think about alternatives, I’ll go..
Even right now I can’t decide btw those two!
Hi resident,
I find that at 450V, cheap 6L6GC's may run into problems. I'm sure there are many good brands out there, but from personal experience I've started to use Electroharmonix 6L6EH. They have a plate area similar to KT-66 and survive Fender twins. Sovetek's will fail for sure in those, as do many others. No sound problems over NOS units I have either. If you are using 12AX7A's, you will find the 12AX7EH's to be very quiet on average. These are a pretty good place to start.
-Chris
I find that at 450V, cheap 6L6GC's may run into problems. I'm sure there are many good brands out there, but from personal experience I've started to use Electroharmonix 6L6EH. They have a plate area similar to KT-66 and survive Fender twins. Sovetek's will fail for sure in those, as do many others. No sound problems over NOS units I have either. If you are using 12AX7A's, you will find the 12AX7EH's to be very quiet on average. These are a pretty good place to start.
-Chris
Hi resident,
My own experience has been okay with Svetlana's products and okay with Sovtek at lower voltages. The Electroharmonix product has been a fair bit better than the Sovtek product. Same supplier (New Sensor in NY). I'd be deciding between Svetlana and Electroharmonix.
I think the most important things to buy are the output transformers, power transformer and the chassis. Make sure to leave room around the output tubes. Ventilation holes in the chassis will help cooling further. I prefer chassis mounted sockets. PCB's + heat + high voltage don't get along to well.
Start building with quality parts & enjoy!
-Chris
My own experience has been okay with Svetlana's products and okay with Sovtek at lower voltages. The Electroharmonix product has been a fair bit better than the Sovtek product. Same supplier (New Sensor in NY). I'd be deciding between Svetlana and Electroharmonix.
I think the most important things to buy are the output transformers, power transformer and the chassis. Make sure to leave room around the output tubes. Ventilation holes in the chassis will help cooling further. I prefer chassis mounted sockets. PCB's + heat + high voltage don't get along to well.
Start building with quality parts & enjoy!
-Chris
Hi anatech,
I'll go with Svetlana.Preamp tubes, I'll go with 6H8C (russian 6SN7).I found them at 10euro each.
About transformers I'll buy from a local winder that I believe are very good.Better than Hammond!At reasonable prices.
Chassis, 2.00-2.50mm aluminium with wooden base.
Of course, I'll go point-to-point wiring.I don't like PCBs.
About sovtek 6L6WXT+ aren't the same with 6L6EH?
My friend has two of them and he likes to build a P-P guitar amp.Maybe a Fender clone.
How much anode voltage do you believe is good to use with Sovteks?
I'll go with Svetlana.Preamp tubes, I'll go with 6H8C (russian 6SN7).I found them at 10euro each.
About transformers I'll buy from a local winder that I believe are very good.Better than Hammond!At reasonable prices.
Chassis, 2.00-2.50mm aluminium with wooden base.
Of course, I'll go point-to-point wiring.I don't like PCBs.
About sovtek 6L6WXT+ aren't the same with 6L6EH?
My friend has two of them and he likes to build a P-P guitar amp.Maybe a Fender clone.
How much anode voltage do you believe is good to use with Sovteks?
Hi resident,
No, Sovteks are not the same as Electroharmonix. Totally different tubes. The 6L6EH is one of the few tubes that will consistantly survive Fender Twins or Mesa Boogie Barons. I'd watch taking the Sovteks over 400V. This doesn't mean they can't go higher, it just means that you should approach those voltages with caution. I have tried many. I've seen too many plates turn red quickly.
You might consider a metal base for shielding, you can put wood over it. Hammond manufacturing is local in my provence, lucky me. Fred Hammond was a very helpful man, as all his staff has been.
Sounds like you are off to a good start.
-Chris
No, Sovteks are not the same as Electroharmonix. Totally different tubes. The 6L6EH is one of the few tubes that will consistantly survive Fender Twins or Mesa Boogie Barons. I'd watch taking the Sovteks over 400V. This doesn't mean they can't go higher, it just means that you should approach those voltages with caution. I have tried many. I've seen too many plates turn red quickly.
You might consider a metal base for shielding, you can put wood over it. Hammond manufacturing is local in my provence, lucky me. Fred Hammond was a very helpful man, as all his staff has been.
Sounds like you are off to a good start.
-Chris
EL34 vs 6L6
I note above that you intend to use Cathode Feedback - an excellent way to get good dampimg factor without resorting to large amounts of global feedback and suffering loss of image and crispness.
If you can beg, borrow or steal a copy of Menno van der Veen's "Modern High-End Valve Amplifiers" have a look at what he says about cathode feedback with real pentodes (the EL34) vs beam power tetrodes (the 6L6). The Ia vs Va curves (at each grid voltage) move to the left (that is you get higher Ia at the same Va) when using real pentodes - this doesn't happen with the beam power tetrode.
The EL34 is much easier to drive as you don't need such a low value grid 1 resistor. It also has a tidier turn on/off characteristic which helps if your design is Class AB1.
I believe that it also has a softer saturation which will help if you like things LOUD.
I'm part way down this track myself with a prototype amp built using VDV-2100-CFB/H Output Transformer - I settled on 4 x KT88 to drive it (a beam power tetrode) and cathode followers (6SN7) driving the KT88 grids.
Just another dabblers views - hope you find this useful.
Cheers,
gingertube
I note above that you intend to use Cathode Feedback - an excellent way to get good dampimg factor without resorting to large amounts of global feedback and suffering loss of image and crispness.
If you can beg, borrow or steal a copy of Menno van der Veen's "Modern High-End Valve Amplifiers" have a look at what he says about cathode feedback with real pentodes (the EL34) vs beam power tetrodes (the 6L6). The Ia vs Va curves (at each grid voltage) move to the left (that is you get higher Ia at the same Va) when using real pentodes - this doesn't happen with the beam power tetrode.
The EL34 is much easier to drive as you don't need such a low value grid 1 resistor. It also has a tidier turn on/off characteristic which helps if your design is Class AB1.
I believe that it also has a softer saturation which will help if you like things LOUD.
I'm part way down this track myself with a prototype amp built using VDV-2100-CFB/H Output Transformer - I settled on 4 x KT88 to drive it (a beam power tetrode) and cathode followers (6SN7) driving the KT88 grids.
Just another dabblers views - hope you find this useful.
Cheers,
gingertube
I'm still a little bit
I think I'll go with 6L6GC.More power dissipation.So lower THD.
I'll choose EHX or Sovtek WXT+ (very similar with EHX-maybe same) for my first project.I can get them about 10euro/each instead of 20 for Svetlana.
@anatech
See at New Sensor about Sovtek WXT+.It looks same with EHX.
I think I'll go with 6L6GC.More power dissipation.So lower THD.
I'll choose EHX or Sovtek WXT+ (very similar with EHX-maybe same) for my first project.I can get them about 10euro/each instead of 20 for Svetlana.
@anatech
See at New Sensor about Sovtek WXT+.It looks same with EHX.
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