Tube question for the gurus...Fender 6L6 in particular......

bungalowbill

bungalowbill

Luckybastidologist
I am trying to tighten up the low end on my HRDX to no avail....its flubby sounding.....I tried a new speaker and that is costly and you can't really try them out....very hit or miss.

Could it be that my power tubes are getting weak? I play about 7-8 gigs a month and these tubes are a year old.....I really don't remember the amp being this tubby when it was new.

What 6L6s would you recommend for more of an EL34 flavor? I do not use the drive or more drive channel on this amp...I use it like an old non-master volume Fender if that makes any difference.

Thanks
 
Re: Tube question for the gurus...Fender 6L6 in particular......

There is no EL34 flavor 6L6.

Also you need to decide to you want to correct the amps tone it has now by de-flubbing it or do you want to try and change the flavor by trying a new type of power tube.

FWIW, modding a 6L6 amp for EL34's is a simple mod but I'm not sure I'd do it on a PCB Fender amp...you might live to regret it.

As for the flub it could be the power tubes...what are they???
 
Re: Tube question for the gurus...Fender 6L6 in particular......

the guy who invented fire said:
There is no EL34 flavor 6L6.

Also you need to decide to you want to correct the amps tone it has now by de-flubbing it or do you want to try and change the flavor by trying a new type of power tube.

FWIW, modding a 6L6 amp for EL34's is a simple mod but I'm not sure I'd do it on a PCB Fender amp...you might live to regret it.

As for the flub it could be the power tubes...what are they???
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If I could get rid of the excessive low end, it would be great. The amp has the original Groove Tube 6l6s in it.
 
Re: Tube question for the gurus...Fender 6L6 in particular......

I would try some real 6L6GC's. The Groove tubes they put in them are actually a 5881WXT (as far as the ones I have seen). As far as speakers, what have you tried?
 
Re: Tube question for the gurus...Fender 6L6 in particular......

bungalowbill said:
If I could get rid of the excessive low end, it would be great. The amp has the original Groove Tube 6l6s in it.
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Try some fresh tubes...

However what I want to be clear on is your issue...

Is the low end flubby or is there too much low end??

Flubby could be a tube issue, if the amp makes a lot of low end and that is becoming flubby it could be a speaker...

That said I'd still start with a fresh set of power tubes.

Those amps run the tubes semi hard and new production tubes, in my experience are often toast in 6 months to a year in amps like that if they are actually getting used in gig situations.
 
Re: Tube question for the gurus...Fender 6L6 in particular......

trevorus said:
No need to inject speculation. (I sold those amps for years, and worked on them for more, and even owned a couple.) Also, 6L6's are not 6L6G's are not 6L6GC's are not 6L6WXT's.
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Who is speculating???

The lines between all these tube types are all blurred these days anyway not to mention many new makers build tubes and label them wrong anyway.

Like I said I was just trying to let the OP know that if he wanted to stick with GT tubes that he could get a more true 6L6 type.

Now if we can let's try and get this thread back on point for the OP...
 
Re: Tube question for the gurus...Fender 6L6 in particular......

The line is not "blurred." They have different specs. They can sometimes be substituted in the same circuit with no real ill effects (allowing for the bias to be adjusted for the tube type installed), but they are not the same. The plate dissipation for a 5881 series tube is 23 watts, and for a 6L6GC is 30 watts. That alone is enough of a difference, but lets look at the plate voltage ratings. a 5881 (by the spec) is rated to about 360 volts, yet a 6L6GC is rated to 500 volts. I would highly recommend an actual 6L6GC for these amps, because Fender tends to push the plate voltage a bit. Especially in the DeVilles, they were even worse about it. This is relevant to the question at hand. A 6L6GC is a better match for that amp than the 5881, even thought the 5881WXT is somewhat ruggedized, it's not a great tube for this amp.
 
Re: Tube question for the gurus...Fender 6L6 in particular......

If you aren't really utilizing the first gain stages, maybe try swapping the PI tube then. That tube can play a big role in how the power section sounds, responds and feels.
 
Re: Tube question for the gurus...Fender 6L6 in particular......

trevorus said:
I would highly recommend an actual 6L6GC for these amps, because Fender tends to push the plate voltage a bit. Especially in the DeVilles, they were even worse about it. This is relevant to the question at hand. A 6L6GC is a better match for that amp than the 5881, even thought the 5881WXT is somewhat ruggedized, it's not a great tube for this amp.
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+1

Visit the Groove Tubes website. Find the 6L6 page. You will be presented with offerings of widely varying price and quality.

I recently revalved both a PR246 HRDx and a PR247 HRDv410. Both amps perked up considerably. The Deluxe got the regular, thinly-disguised Sovtek 5881WXTs. I treated the DeVille to the pricier, round-ended 6L6GC with the longer envelope. I had to restyle the steel protective cage to get the new valves in.

*

Famously, the other thing that blurs the HRDx sound more than a little is its onboard reverb. There is a well-known, extremely simple mod that fixes this.
 
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Re: Tube question for the gurus...Fender 6L6 in particular......

trevorus said:
The line is not "blurred." They have different specs. They can sometimes be substituted in the same circuit with no real ill effects (allowing for the bias to be adjusted for the tube type installed), but they are not the same. The plate dissipation for a 5881 series tube is 23 watts, and for a 6L6GC is 30 watts. That alone is enough of a difference, but lets look at the plate voltage ratings. a 5881 (by the spec) is rated to about 360 volts, yet a 6L6GC is rated to 500 volts. I would highly recommend an actual 6L6GC for these amps, because Fender tends to push the plate voltage a bit. Especially in the DeVilles, they were even worse about it. This is relevant to the question at hand. A 6L6GC is a better match for that amp than the 5881, even thought the 5881WXT is somewhat ruggedized, it's not a great tube for this amp.
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What I'm saying is that tube types like 5881, 6L6, 6L6G, 6L6GC, etc don't always mean the same things they did when the books were written.

Most of todays tubes that are sold as 5881's are far more rugged than vintage 5881's in terms of the voltage they can take and the power they can create.

Look atr what some companies call a 6V6 (JJ for example)...it has almost nothing in common with a spec 6V6 sve for the pin out.

New Sensor sells a tube they call 6L6G and except for the "ST" shape it has nothing in common with a real 50's 6L6G, in fact it's almost the same exact innards as their 6L6GC so compared to spec based on the name it can take more voltage and create more wattage...

Like I said, today the lines are blurred...

Not that any of this matters much since the OP's question had nothing to do with this.
 
Re: Tube question for the gurus...Fender 6L6 in particular......

the guy who invented fire said:
What I'm saying is that tube types like 5881, 6L6, 6L6G, 6L6GC, etc don't always mean the same things they did when the books were written.

Most of todays tubes that are sold as 5881's are far more rugged than vintage 5881's in terms of the voltage they can take and the power they can create.

Look atr what some companies call a 6V6 (JJ for example)...it has almost nothing in common with a spec 6V6 sve for the pin out.

New Sensor sells a tube they call 6L6G and except for the "ST" shape it has nothing in common with a real 50's 6L6G, in fact it's almost the same exact innards as their 6L6GC so compared to spec based on the name it can take more voltage and create more wattage...

Like I said, today the lines are blurred...

Not that any of this matters much since the OP's question had nothing to do with this.
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Indeed, that is one case where the innards have been changed, and honestly it is no longer the same tube type. It's now just a 6L6GC in a fat bottle. My point still stands, actual 6L6GC tubes are the best for this amp.

More pertinent to the discussion here, another thing that can be done to rein in the low end is to mod the tone stack. The classic Fender tone stack has a mid control that is wired as a variable resistor. You can easily tell if your particular amp has this type by turning the T/M/B knobs all down. The amp should no longer make sound. The Hot Rod Deluxe/Devilles changed this to a voltage splitter, which changes how the tone stack operates a bit. A soldered connection about 1/4" is all it takes to turn the Dlx circuit back to the proper Fender tone stack. It makes a good bit of difference, and I did it to both the DeVilles I owned.

Basically, dump the stock Fender speaker, get something American voiced that works for an open back cab, pull the amp away from the wall or out of the corner (whatever your situation is), get some good 6L6GC tubes (The EHX ones are pretty good, labeled as a 6L6EH), bias it, and dump the Sovtek Preamp tubes if you haven't already.
 
Re: Tube question for the gurus...Fender 6L6 in particular......

I had new Groove Tubes put in my Mesa when I got it, power and preamp. I'd have to look to see which model 6L6 they are.

Bungalow, I had a Fender DRRI for a while. It sounded flubby when you would start getting the volume on up on it. I can't remember who, but someone on this forum recommended I try an Eminence Cannibis Rex. I did and it made the amp sound 100% better as far as the flubby sound.Kind of wish I had kept that amp.
 
Re: Tube question for the gurus...Fender 6L6 in particular......

Lucid_Lunatic said:
I had new Groove Tubes put in my Mesa when I got it, power and preamp. I'd have to look to see which model 6L6 they are.

Bungalow, I had a Fender DRRI for a while. It sounded flubby when you would start getting the volume on up on it. I can't remember who, but someone on this forum recommended I try an Eminence Cannibis Rex. I did and it made the amp sound 100% better as far as the flubby sound.Kind of wish I had kept that amp.
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:scratchch

Joe, isn't that the speaker you ordered?
 
Re: Tube question for the gurus...Fender 6L6 in particular......

dr.barlo said:
JJ KT77's?

B
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The heater amperage is about 1.6 amps per tube, whereas the 6L6GC is 0.9. I'd be a bit concerned about that, along with having to bias them cold so as not to overtax the power supply otherwise, and not blow out the output transformer. I jsut depends on how overspeced the amp has been built.
 
Re: Tube question for the gurus...Fender 6L6 in particular......

bungalowbill said:
I am trying to tighten up the low end on my HRDX to no avail....its flubby sounding.....I tried a new speaker and that is costly and you can't really try them out....very hit or miss.

Could it be that my power tubes are getting weak? I play about 7-8 gigs a month and these tubes are a year old.....I really don't remember the amp being this tubby when it was new.

What 6L6s would you recommend for more of an EL34 flavor? I do not use the drive or more drive channel on this amp...I use it like an old non-master volume Fender if that makes any difference.

Thanks
Click to expand...
low end mods on an HRD:
http://www.justinholton.com/hotrod/jvmods.html#bass
power tube reviews in a hot rod:
http://www.justinholton.com/hotrod/tubereview.html
biasing:
http://www.justinholton.com/hotrod/bias.html

Hopefully this all helps. I used an HRD for a few years. The twin stack mod and less splashy reverb mods are good and ridiculously easy. If you want tight low end you need headroom - jj's in the power section will fix this. I think your amp has probably done enough work to deserve a fresh set to work at its best if you remember to bias it too. You might also want to consider new preamp tubes, but see how you go with the power tube bias/change first. I think EH would probably be the best bet for you for two reasons: 1. That they can handle high gain and they are extremely low noise. 2. You said you wanted more of an el34 sound - which i would read as being less big in the lows and more firm in the mids. While preamp tubes are not power tubes, it think EH will give you more of that kind of tonality.
Last thing: we all know the stock speaker is pretty lame, but what did you replace it with? I know you dont want to swap it out again due to cost, and i would not recommend considering it at least until you have freshly biased power tubes in there, but it would be good to know, because it may be part of the problem.
 
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