Tube Noob Question - EL34

[IndyWS6]

I've had several tube amps, but have never swapped tube types to see what change in tone I might get. The gigging amp I have now (H&K Switchblade 100W) uses EL34's. So.....

If I re-tube with EL34's, what brand would be a good choice? (H&K claims their tubes are thoroughly tested and matched and as good as anything you can get, but...)

What tubes (besides EL34's) will work in that amp?

If I go with something other than EL34, what would you suggest - and why (more gain, less gain, quicker breakup, smoother, fatter, better aroma, etc)

Will I run into any bias issues if I switch to something other than EL34's? I'll have to farm that job out - I don't have the tools/skill and I'm not a fan of electrocution...

On the pre-amp side, the Switchblade uses (2) 12ax7's. What brand / combination of replacement 12ax7's would be a good choice when I re-tube?

There is no immediate need to re-tube, but I'm curious and want to plan ahead. I apologize for the noob questions. Many of you have gone through more tubes than I will in a lifetime and I figured asking questions is cheaper than experimentation. Thanks in advance

 

[locoed]

I'm interested to know as well,i searched this topic earlier and get to many different responses from other websites.

 

[Ventura]

If you're running EL34s, you can 'typically' swap these out with KT77s, and that's about it. Nevertheless, H&K make some seriously sweet sounding amps, and I'd imagine they went with EL34s and in this case, you best be sticking with EL34s. If you want a rough guideline as to what different glass can produce tonally, check this site:

http://thetubestore.com/el34review.html

As for preamp glass - all depends what's in there right now. Again, H&K should have a baseline as to what it likes in there, and what they've voiced their amps with. Sometimes the very best amps in the world have the lowest priced Chinese/Shuguang preamps in them, this isn't a result of 'cheaping out', just so happens the B or C grade Chinese tubes have a terrific gain structure to them, an acceptable noise floor, and are reliable as anything else. Furthermore, if you blow one or six, they're cheap and readily available. Some preamp sockets and their respective glass will have IMMENSE impact on your overall amp flavour. Specifically your PI slot, your clean channel, your output buffer (at times), and all the bits that cascade in between. I've gone with the new Genalex Gold Lion ECC83 in my Mak4 preamp, it's absolutely mindblowing how rich that preamp sounds now - just sick. I've used Jan Philips in clean spots, terrific preamp tube. And I've gone with high grade Shuguang/Chinese in my Diezel and Bogner, primarily because a) Diezel works from the Chinese/Ruby preamp tube footprint, and b) Bogner comes stock with em, and one change in a Bogner's line up can change the entire character of the amp.

For lots of good information on preamps, check this:

http://thetubestore.com/12ax7review.html

And for changing the gain structure:

http://thetubestore.com/gainfactor.html

I know this business very well (thetubestore.com), I'm not sending links to their site as a press to have you buy from them, it's more just the fact there's some solid info on the site. Our local glass Lady Laura will help you out just fine. But if there's something on thetubestore.com's site that piques your interest, Jon will take good care of you.

Peace,
Mo

 

[mrkmas]

After reading the manual from the H&K site, they make zero mention of using different tubes besides EL-34's. From what I have heard KT 77's should be able to be used with any EL-34 amp ( not sure with/without a bias or not). Since your amp specifically has digital components (effects), I would personally be much more hesitant of changing tubes than a standard amp. I would contact an amp tech or contact H&K to get an official response, otherwise I would stick with EL-34's.

 

[IndyWS6]

If you're running EL34s, you can 'typically' swap these out with KT77s, and that's about it. Nevertheless, H&K make some seriously sweet sounding amps, and I'd imagine they went with EL34s and in this case, you best be sticking with EL34s. If you want a rough guideline as to what different glass can produce tonally, check this site:

http://thetubestore.com/el34review.html

As for preamp glass - all depends what's in there right now. Again, H&K should have a baseline as to what it likes in there, and what they've voiced their amps with. Sometimes the very best amps in the world have the lowest priced Chinese/Shuguang preamps in them, this isn't a result of 'cheaping out', just so happens the B or C grade Chinese tubes have a terrific gain structure to them, an acceptable noise floor, and are reliable as anything else. Furthermore, if you blow one or six, they're cheap and readily available. Some preamp sockets and their respective glass will have IMMENSE impact on your overall amp flavour. Specifically your PI slot, your clean channel, your output buffer (at times), and all the bits that cascade in between. I've gone with the new Genalex Gold Lion ECC83 in my Mak4 preamp, it's absolutely mindblowing how rich that preamp sounds now - just sick. I've used Jan Philips in clean spots, terrific preamp tube. And I've gone with high grade Shuguang/Chinese in my Diezel and Bogner, primarily because a) Diezel works from the Chinese/Ruby preamp tube footprint, and b) Bogner comes stock with em, and one change in a Bogner's line up can change the entire character of the amp.

For lots of good information on preamps, check this:

http://thetubestore.com/12ax7review.html

And for changing the gain structure:

http://thetubestore.com/gainfactor.html

I know this business very well (thetubestore.com), I'm not sending links to their site as a press to have you buy from them, it's more just the fact there's some solid info on the site. Our local glass Lady Laura will help you out just fine. But if there's something on thetubestore.com's site that piques your interest, Jon will take good care of you.

Peace,
Mo

Thank you, sir. The detailed response is much appreciated I'll take a look at the links and do a little research.

 

[IndyWS6]

After reading the manual from the H&K site, they make zero mention of using different tubes besides EL-34's. From what I have heard KT 77's should be able to be used with any EL-34 amp ( not sure with/without a bias or not). Since your amp specifically has digital components (effects), I would personally be much more hesitant of changing tubes than a standard amp. I would contact an amp tech or contact H&K to get an official response, otherwise I would stick with EL-34's.

Thanks for the response I thought that EL34's and KT77's were (more or less) interchangeable, but wasn't sure. Figured it was better to ask those who have done this a couple of times

The tubes in the amp are reasonably fresh and (to my ears) it sounds pretty darn good. Just wanted to see what the options were when it comes time.

Thanks again...

 

[jlbaxe]

Try E34Ls and that is not a miss type. I liked those.

 

[JTyson]

You would need to check the bias whatever you end up choosing, even staying with 34's. There are significant differences between even the same brand of whatever tube flavor you choose. Its too important not to do it. You could easily decide you dont like a particular brand of tube by not checking the bias because it could be colder than what you had before, and sound thinner and more sterile. The odds the ones you pick will land right in the sweet spot are not very good unless you have worked with a retailer who documents what you got last time, and exactly what they were rated, or done it yourself. The acceptable range seems to be between 25-40mA's on 34's, but there is a huge difference in my amps tone at 25 as opposed to 33-35. I rarely run them over 35mA
As far as the EL34/KT77 comparison, I have had both in the same heads for comparison's sake, I found the 77's to be slightly bigger sounding with slightly better bottom end, while the 34's had a little more snarl in the mids, which I ended up preferring. Mostly because I'm a mids guy to start with. Its all personal preferance
I think the SED =C='s are the best EL34 out there right now, but you do pay more for them. My understanding is that Laura has one of the better matching setups out there at the moment, I would much perfer to have them matched up as tight as possible.

 

[Giga]

The "H&K" powertubes that I've seen are actually Chinese BSTR types with a hardnessrating on them like GT and Mesa use.

Giga

 

[IndyWS6]

"BSTR"? "Hardness rating"?

Noob here

 

[Laura]

Ruby's come with PC and transconductance ratings stamped on a label on the tube base. New Sensor lists those numbers on the boxes. I don't go by them. Matched quads from the factory are not always matched. I burn tubes in and then re-match pairs, quads...

I have a couple guys that went from EL34's to KT77's in H&K amps with no problems. The BSTR's sound good in those amps though. The JJ E34 L's sound good but I have had issues with JJ power tubes recently and will probably stop selling those. SED's are awesome but there currently is no dealer pricing so I am not buying more right now.

As far as what tubes are best for each amp...tone is subjective...what I like, you may not like. I like JJ pre-amp tubes and most of the guys I know hate them. It really depends on what you are trying to achieve with your tone.

 

[IndyWS6]

JTyson -
Thanks for the response. Much appreciated... I realize that I need to check bias when changing tubes. I probably wasn't as clear as I could have been. What I wondered was whether a shift to another tube type (apparently KT77 is the only option...) would require a bias change that was outside the normal limits for that amp. If I understand correctly, some amps provide for a wide range of bias adjustment without changing any electrical components. I'm not sure if the H&K falls into that category.

Giga -
Thanks for the response. Much appreciated... What do you mean by "hardness rating"? I don't think I've ever heard that description relative to a tube.

Laura,
Thanks for the response! Tone is definitely subjective - and difficult to describe. Once again, I was probably not as clear as I could have been and probably should have said that I was curious what specific tonal characteristics a tube change would cause. For example, JTyson's comment that he felt the EL34's had more snarl in the mids than a KT77. That statement is subjective, but also helps me understand what I might be able to expect. Since it looks like those are my only power tube choices, I may not have to dig too deep. I think the amp sounds great the way it is - even though it's not a modded Marshall - so I may just stick with the "stock" tubes when it's time to replace them.

Speaking of which, H&K strongly recommends that you get replacement tubes from them. They are supposedly rigorously tested and inspected to match what was originally shipped. I know some (a lot?) of that is marketing and, I suspect, a way to drive another source of revenue, but it's not unlike what Mesa does. What are your thoughts? P.S. I'm right next door to you, so I'll probably be looking your way regardless...

 

[rupe]

EL34 = E34L = KT77 = 6CA7...they are all different versions of the same tube and are all interchangable. You really can't rely on the type of tube to tell you how it sounds as they vary (sometimes greatly) from one brand/manufacturer to the next. Additionally, different brands/types may work better with a particular amp than others (greatly subjective). Buy 'em and try 'em is really all you can do until you find "your" tube for your amp.

 

[Giga]

JTyson -
Thanks for the response. Much appreciated... I realize that I need to check bias when changing tubes. I probably wasn't as clear as I could have been. What I wondered was whether a shift to another tube type (apparently KT77 is the only option...) would require a bias change that was outside the normal limits for that amp. If I understand correctly, some amps provide for a wide range of bias adjustment without changing any electrical components. I'm not sure if the H&K falls into that category.

Giga -
Thanks for the response. Much appreciated... What do you mean by "hardness rating"? I don't think I've ever heard that description relative to a tube.

Laura,
Thanks for the response! Tone is definitely subjective - and difficult to describe. Once again, I was probably not as clear as I could have been and probably should have said that I was curious what specific tonal characteristics a tube change would cause. For example, JTyson's comment that he felt the EL34's had more snarl in the mids than a KT77. That statement is subjective, but also helps me understand what I might be able to expect. Since it looks like those are my only power tube choices, I may not have to dig too deep. I think the amp sounds great the way it is - even though it's not a modded Marshall - so I may just stick with the "stock" tubes when it's time to replace them.

Speaking of which, H&K strongly recommends that you get replacement tubes from them. They are supposedly rigorously tested and inspected to match what was originally shipped. I know some (a lot?) of that is marketing and, I suspect, a way to drive another source of revenue, but it's not unlike what Mesa does. What are your thoughts? P.S. I'm right next door to you, so I'll probably be looking your way regardless...

The hardness-rating is a way to differentiate tubes by the bias-range they fall in which also has it's effect on the headroom. As an example: In my Duotone are powertubes with a "4" rating and it's biased to 40 mA per tube. If the time comes to replace the tubes and I buy H&K tubes with the "4" rating again they will be very close to 40 mA again without a rebias.

FYI: I've tried a few different brands and types of powertubes in that amp and *I* liked the stock (Chinese) H&K tubes best. To my ears and in that amp they gave the best EL34 tone.

Giga

 

[IndyWS6]

EL34 = E34L = KT77 = 6CA7...they are all different versions of the same tube and are all interchangable. You really can't rely on the type of tube to tell you how it sounds as they vary (sometimes greatly) from one brand/manufacturer to the next. Additionally, different brands/types may work better with a particular amp than others (greatly subjective). Buy 'em and try 'em is really all you can do until you find "your" tube for your amp.

The "Buy 'em and Try 'em" approach was what I was hoping to avoid. Aside from the cost of the tubes, I would have to farm out the biasing chores (no tools / no experience). The closest place to me is about 50 miles away and I'm not completely sure of the quality of work I could expect. Having to do that more than a couple of times could be cost-prohibitive. There might not be a better solution, though...

 

[IndyWS6]

JTyson -
Thanks for the response. Much appreciated... I realize that I need to check bias when changing tubes. I probably wasn't as clear as I could have been. What I wondered was whether a shift to another tube type (apparently KT77 is the only option...) would require a bias change that was outside the normal limits for that amp. If I understand correctly, some amps provide for a wide range of bias adjustment without changing any electrical components. I'm not sure if the H&K falls into that category.

Giga -
Thanks for the response. Much appreciated... What do you mean by "hardness rating"? I don't think I've ever heard that description relative to a tube.

Laura,
Thanks for the response! Tone is definitely subjective - and difficult to describe. Once again, I was probably not as clear as I could have been and probably should have said that I was curious what specific tonal characteristics a tube change would cause. For example, JTyson's comment that he felt the EL34's had more snarl in the mids than a KT77. That statement is subjective, but also helps me understand what I might be able to expect. Since it looks like those are my only power tube choices, I may not have to dig too deep. I think the amp sounds great the way it is - even though it's not a modded Marshall - so I may just stick with the "stock" tubes when it's time to replace them.

Speaking of which, H&K strongly recommends that you get replacement tubes from them. They are supposedly rigorously tested and inspected to match what was originally shipped. I know some (a lot?) of that is marketing and, I suspect, a way to drive another source of revenue, but it's not unlike what Mesa does. What are your thoughts? P.S. I'm right next door to you, so I'll probably be looking your way regardless...

The hardness-rating is a way to differentiate tubes by the bias-range they fall in which also has it's effect on the headroom. As an example: In my Duotone are powertubes with a "4" rating and it's biased to 40 mA per tube. If the time comes to replace the tubes and I buy H&K tubes with the "4" rating again they will be very close to 40 mA again without a rebias.

FYI: I've tried a few different brands and types of powertubes in that amp and *I* liked the stock (Chinese) H&K tubes best. To my ears and in that amp they gave the best EL34 tone.

Giga

Thanks for the explanation - and the recommendation.

 

[Laura]

EL34 = E34L = KT77 = 6CA7...they are all different versions of the same tube and are all interchangable. You really can't rely on the type of tube to tell you how it sounds as they vary (sometimes greatly) from one brand/manufacturer to the next. Additionally, different brands/types may work better with a particular amp than others (greatly subjective). Buy 'em and try 'em is really all you can do until you find "your" tube for your amp.

The "Buy 'em and Try 'em" approach was what I was hoping to avoid. Aside from the cost of the tubes, I would have to farm out the biasing chores (no tools / no experience). The closest place to me is about 50 miles away and I'm not completely sure of the quality of work I could expect. Having to do that more than a couple of times could be cost-prohibitive. There might not be a better solution, though...

I used to buy different tubes just to try but I also bias my own amps so I did not have to worry about that part.

If you notice, even GT says to check your bias when changing tubes even when using the same hardness ratings. It is always the safest way to go.

 

[JTyson]

Ruby's come with PC and transconductance ratings stamped on a label on the tube base. New Sensor lists those numbers on the boxes. I don't go by them. Matched quads from the factory are not always matched. I burn tubes in and then re-match pairs, quads...

I have a couple guys that went from EL34's to KT77's in H&K amps with no problems. The BSTR's sound good in those amps though. The JJ E34 L's sound good but I have had issues with JJ power tubes recently and will probably stop selling those. SED's are awesome but there currently is no dealer pricing so I am not buying more right now.

As far as what tubes are best for each amp...tone is subjective...what I like, you may not like. I like JJ pre-amp tubes and most of the guys I know hate them. It really depends on what you are trying to achieve with your tone.

Jeesh, Laura, does that mean you have to pay retail on SED's?
I knew they had gone up, but I guess I thought you'd get some kind of volume price at least.. dam, that stinks
I gotta get with you on a quad of those if you have them, at this point, I'll still pay what they want for them. I've had really good luck with those

 

[Laura]

Ruby's come with PC and transconductance ratings stamped on a label on the tube base. New Sensor lists those numbers on the boxes. I don't go by them. Matched quads from the factory are not always matched. I burn tubes in and then re-match pairs, quads...

I have a couple guys that went from EL34's to KT77's in H&K amps with no problems. The BSTR's sound good in those amps though. The JJ E34 L's sound good but I have had issues with JJ power tubes recently and will probably stop selling those. SED's are awesome but there currently is no dealer pricing so I am not buying more right now.

As far as what tubes are best for each amp...tone is subjective...what I like, you may not like. I like JJ pre-amp tubes and most of the guys I know hate them. It really depends on what you are trying to achieve with your tone.

Jeesh, Laura, does that mean you have to pay retail on SED's?
I knew they had gone up, but I guess I thought you'd get some kind of volume price at least.. dam, that stinks
I gotta get with you on a quad of those if you have them, at this point, I'll still pay what they want for them. I've had really good luck with those

Pretty close to retail which is BS. I only have some pairs of EL34's right now. I will order more at some point but I won't be looking at stocking too many because of the cost. However, I use them in my own amps so I gotta keep some around.