Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
- Thread starter DTrane
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Edgecrusher
Well-known member
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
Sure it will. How exactly depends on how they are doing it. I'm not familiar with the inner workings of the HT20 but if say they are running the tubes triode instead of pentode that will effect the tone. Same with if they have dropped the voltage and are running less of a power transformer that will also effect the tone. But just cause it changes the tone doesnt mean its bad. Just different. If you dig the tone of the HT20 then have at it and enjoy.
Sure it will. How exactly depends on how they are doing it. I'm not familiar with the inner workings of the HT20 but if say they are running the tubes triode instead of pentode that will effect the tone. Same with if they have dropped the voltage and are running less of a power transformer that will also effect the tone. But just cause it changes the tone doesnt mean its bad. Just different. If you dig the tone of the HT20 then have at it and enjoy.
ItsaBass
New member
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
If they are getting 20W using two EL34's, I'm imagining they aren't using the whole tubes, but a portion of each. Interesting approach, using a portion of two larger tubes in a 20W amp, instead of smaller EL84's or 6V6's. So I'd say yes, it probably sounds quite a bit different than most EL34-powered amps. But in the end, it doesn't really matter. Just go try the amp. If you like it, then you like it.
If they are getting 20W using two EL34's, I'm imagining they aren't using the whole tubes, but a portion of each. Interesting approach, using a portion of two larger tubes in a 20W amp, instead of smaller EL84's or 6V6's. So I'd say yes, it probably sounds quite a bit different than most EL34-powered amps. But in the end, it doesn't really matter. Just go try the amp. If you like it, then you like it.
DTrane
New member
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
yeah, I used to have a Epiphone so-cal 50w head with the pentode triode switch. It didn't sound good at 25w.
Then I read about amps with adjustable wattage like the Rebel, and people say it just affects headroom. And they say it sounds best at full wattage.
Then Ive read about people using a Variac to lower the voltage, and it sounds good. Supposedly, VH used that for his brown sound. I wonder if BlackStar is doing something similar.
I plan on checking out the amp. Just want to know what to look for.
yeah, I used to have a Epiphone so-cal 50w head with the pentode triode switch. It didn't sound good at 25w.
Then I read about amps with adjustable wattage like the Rebel, and people say it just affects headroom. And they say it sounds best at full wattage.
Then Ive read about people using a Variac to lower the voltage, and it sounds good. Supposedly, VH used that for his brown sound. I wonder if BlackStar is doing something similar.
I plan on checking out the amp. Just want to know what to look for.
trevorus
Modsterbator
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
I would doubt they would use a variac. Those things are expensive and would likely double the price of the amp. Also, it can be dangerous for the amp, since dropping voltages can cause odd mismatches in the amp that can cause issues. Your bias supply could drop and make the tubes run overly "hot."
trevorus
Modsterbator
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
In that way, you may be a bit right, as in running the whole thing at lower voltages. The amp would be designed to do such, so bias and the like would be stable.
DTrane
New member
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
I did have an EL34 amp with a dying transformer. It was supposed to be 50w but it wasn't louder than 30w. Anyways, it sounded great until it finally died.
You could adjust the gain and volume for different tones. With the gain and volume set in the middle, the volume would flatten out. Running more gain or volume affected the tone more than loudness.
I did have an EL34 amp with a dying transformer. It was supposed to be 50w but it wasn't louder than 30w. Anyways, it sounded great until it finally died.
You could adjust the gain and volume for different tones. With the gain and volume set in the middle, the volume would flatten out. Running more gain or volume affected the tone more than loudness.
Edgecrusher
Well-known member
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
20 watts might also be 2 EL34's in class A. There are a lot of possibilities for how the 20 watts is being achieved. My guess though is triode and a smaller transformer.
20 watts might also be 2 EL34's in class A. There are a lot of possibilities for how the 20 watts is being achieved. My guess though is triode and a smaller transformer.
glassman
Electron Herder
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
The power supply dictates the output; the tubes only dictate the output (to a point) when the power supply is more capable than the tubes used.
If you want to drop output you can (1) reduce the voltage which will change the tone or (2) reduce the available current from the power supply which will not affect the tone.
My amps put out 25 watts no matter what power tubes are in them; 6V6, EL34, 6550, whatever. My plate voltage is around 495VDC when biased about middle of the road. The individual character of each tube type really shines through; 6V6s compress, EL34s crunch, 6550s are warm and clean and 6L6s are big and glassy. I tried lower voltages first and the outcome was disappointing; little tonal difference between tube types and pretty much one sound.
If they are maintaining a fairly high plate voltage and reducing current, the tone should sound pretty authentic to what you would expect an EL34 amp to sound like. The only major difference you would notice is that the tubes absolutely last forever. I have one of my 25 watters that I've never changed the tubes in...they've been in there for almost 18 years and probably have over 10,000 hours on them. These are the cheapest Chinese 6L6s that were available in the mid 90s for about $6.00 a piece. They still test very good.
There's more than one way to skin a cat.
The power supply dictates the output; the tubes only dictate the output (to a point) when the power supply is more capable than the tubes used.
If you want to drop output you can (1) reduce the voltage which will change the tone or (2) reduce the available current from the power supply which will not affect the tone.
My amps put out 25 watts no matter what power tubes are in them; 6V6, EL34, 6550, whatever. My plate voltage is around 495VDC when biased about middle of the road. The individual character of each tube type really shines through; 6V6s compress, EL34s crunch, 6550s are warm and clean and 6L6s are big and glassy. I tried lower voltages first and the outcome was disappointing; little tonal difference between tube types and pretty much one sound.
If they are maintaining a fairly high plate voltage and reducing current, the tone should sound pretty authentic to what you would expect an EL34 amp to sound like. The only major difference you would notice is that the tubes absolutely last forever. I have one of my 25 watters that I've never changed the tubes in...they've been in there for almost 18 years and probably have over 10,000 hours on them. These are the cheapest Chinese 6L6s that were available in the mid 90s for about $6.00 a piece. They still test very good.
There's more than one way to skin a cat.
DTrane
New member
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
yeah, youd think the tubes would last longer at lower watts.
Most of the lower wattage amps run a pair of el84's or 6v6's. I know very little about amps, and figured EL34's and 6L6's wouldn't sound right at lower watts.
GlassMan, how would you describe the tone of EL84's? Jet City 20w seems to get harsh when pushed. Maybe the Alnico Blues smooth this out on the AC30.
yeah, youd think the tubes would last longer at lower watts.
Most of the lower wattage amps run a pair of el84's or 6v6's. I know very little about amps, and figured EL34's and 6L6's wouldn't sound right at lower watts.
GlassMan, how would you describe the tone of EL84's? Jet City 20w seems to get harsh when pushed. Maybe the Alnico Blues smooth this out on the AC30.
glassman
Electron Herder
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
Generally I think of EL84s as warm and sparkly with a lot of punch...but hat's completely dependent on what amp they're in. Older designs (AC30s, older Gibsons, etc) had significantly lower filtering which really brings the character out in the tubes. Newer designs, like your Jet City, have excessive filtering (in my opinion) which nulls any tube character out of them. The harshness you experience really starts in the preamp and with an output that isn't designed to add any warmth, that harshness continues to the output. Less filtering would probably sweeten things up and give you a more dynamic feel...if that's really what you want.
Generally I think of EL84s as warm and sparkly with a lot of punch...but hat's completely dependent on what amp they're in. Older designs (AC30s, older Gibsons, etc) had significantly lower filtering which really brings the character out in the tubes. Newer designs, like your Jet City, have excessive filtering (in my opinion) which nulls any tube character out of them. The harshness you experience really starts in the preamp and with an output that isn't designed to add any warmth, that harshness continues to the output. Less filtering would probably sweeten things up and give you a more dynamic feel...if that's really what you want.
DTrane
New member
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
I have a pos crate vintage club 30w with el84's and it sounds great loud and like crap at low volume. Whereas the jetcity sounds good at most volumes, but not great at any volume.
That is the impression I get from modern tube amps.
I have a pos crate vintage club 30w with el84's and it sounds great loud and like crap at low volume. Whereas the jetcity sounds good at most volumes, but not great at any volume.
That is the impression I get from modern tube amps.
misterwhizzy
Well-known member
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
If I'm looking at the schematic right, the Jet City has a 47uF cap in parallel with two 22uF caps. What values would "tube it up" a bit? By the way, Jerry, I put a 330pF across the 47k negative feedback resistor as described here, and I think it solved a lot of the power-section harshness. I would do what you describe, but I'm worried I might lose a little bit of the punch that comes from those big, fully-charged caps. Any insight?
If I'm looking at the schematic right, the Jet City has a 47uF cap in parallel with two 22uF caps. What values would "tube it up" a bit? By the way, Jerry, I put a 330pF across the 47k negative feedback resistor as described here, and I think it solved a lot of the power-section harshness. I would do what you describe, but I'm worried I might lose a little bit of the punch that comes from those big, fully-charged caps. Any insight?
glassman
Electron Herder
Re: Does Running EL34 Tubes at 20W instead of 50w Affect the Tone?
Hey Will...I think that somewhere around 33uF of total capacitance on the main filter is just about optimum for bringing out tube character. Generally, it will increase the punch (attack) by speeding the recovery time (smaller value caps charge quicker). The trick is to time the depletion/recovery right. Bias current also plays into it as this sets the demand which alters the depletion/recovery timing. Truth be told, a change may or may not be an improvement to your ears. Plus, if the small value cap across the NFB resistor solved what you were aiming to solve, I wouldn't suggest making any major moves in the power supply unless there was something else about the amp that bugged you.
Hey Will...I think that somewhere around 33uF of total capacitance on the main filter is just about optimum for bringing out tube character. Generally, it will increase the punch (attack) by speeding the recovery time (smaller value caps charge quicker). The trick is to time the depletion/recovery right. Bias current also plays into it as this sets the demand which alters the depletion/recovery timing. Truth be told, a change may or may not be an improvement to your ears. Plus, if the small value cap across the NFB resistor solved what you were aiming to solve, I wouldn't suggest making any major moves in the power supply unless there was something else about the amp that bugged you.
