Tube Amp Headroom

[jamesnotjamie]

Hi Everyone,

I got myself a Fender Blues Deluxe Reissue. As you can imagine I'm very happy with the tone. It's my first valve amp and I obviously will never go back!

But, I played a smallish gig the other week and had the volume (clean channel) on about 5. Before the gig, the owner of the pub, a keen blues enthusiast and harp player told me to leave it on standby to 'heat the bastard up'. I did so. When I came to play, it sounded mean, BUT I lost my clean tone! It became too overdriven (which I would normally use the Tube Screamer or Blues Driver for).

The amp is 40 Watts and I have a biggish gig next Thursday, in which the amp will be mic'ed up...

So my general question is, is it normal for this to happen, on volume 5 out of 12? I know it's only 40 Watts, but it was only a pub gig. Would an extension cab give me the necessary head room?

Thanks in advance,

James

[surfoverb]

Originally Posted by jamesnotjamie

Hi Everyone,

I got myself a Fender Blues Deluxe Reissue. As you can imagine I'm very happy with the tone. It's my first valve amp and I obviously will never go back!

But, I played a smallish gig the other week and had the volume (clean channel) on about 5. Before the gig, the owner of the pub, a keen blues enthusiast and harp player told me to leave it on standby to 'heat the bastard up'. I did so. When I came to play, it sounded mean, BUT I lost my clean tone! It became too overdriven (which I would normally use the Tube Screamer or Blues Driver for).

The amp is 40 Watts and I have a biggish gig next Thursday, in which the amp will be mic'ed up...

So my general question is, is it normal for this to happen, on volume 5 out of 12? I know it's only 40 Watts, but it was only a pub gig. Would an extension cab give me the necessary head room?

Thanks in advance,

James

It goes to 12?
The name of the amp alone implies it's gonna break up nicely. If you want clean headroom you should have gotten a twin.

Maybe different speakers? Tubes? What pickups are you using?

[jamesnotjamie]

Yeah the volume goes to 12, as does every other dial...

I would love a twin if I had double the money, and being a student it's hard to come by...

Any ideas on speakers? I'm really unexperienced with that side of things...

My pickups are Fender Custom Shop 69's put through a Mexican Strat...

[Darcy Hoover]

Yeah, love my Blues Deluxe as well, but it does start breaking up below 4 on the clean channel with the bridge pup on my 52RI. I put a ceramic Weber 12F150 in mine. I am not a big advocate of modding amps but it did really tighten up the bass over 4. Much cleaner and articulate, but you still get the tube breakup overdrive starting pretty early. Sorry, can't answer your question about the extension cab, never tried one. I'm just bored at work and wanted to pipe in!

[surfoverb]

Weber 12f150T (ceramic)
Check out this place for tubes:http://kcanostubes.com/content/newsl...sp?ArticleID=5
Find out what's in it now and do some research...Also check out the Weber website it has a lot of info on speakers.

[jamesnotjamie]

Cheers for the input guys, i'll look into that speaker...

Any other views?

[Jeffscreamedcorn]

Try changing out the V1 position 12AX7 with a 12AT7.

[PhatTele]

Tube amps seem to go through a few of phases as they warm up:

1) Right after they're turned on, they sound a bit overdriven and kind of nasty IMO.

2) After about 15 to 20 minutes, they start to settle in and tighten up a bit into a tone and temperment that you can really work with.

3) After an hour or two, they are starting to really cook and you get to hear all of the subtleties of the amp.

If you're in the latter two stages and you don't have enough headroom, then you need to adapt. Plug into the second input (if there is one) to drop the input signal a bit, lay off the overdrive pedals or just send a minimum clean boost signal (let the amp do the work), turn the amp up but turn down on the guitar volume (turn up the guitar volume to drive the amp when you take a solo...instead of using the pedals), reduce the amp's midrange a bit...that sort of stuff. In the meantime, a second speaker in parallel will help. You'll be moving more air and you'll perceive it as having extra headroom. Your other choices are to mic your amp or find another amp that can handle the gig.

[ce24]

Originally Posted by Jeffscreamedcorn

Try changing out the V1 position 12AX7 with a 12AT7.

+1 for a quick and cheap start..

Cheers
ce24

[IronJoe]

I've played the Blues Deluxe a few times and always had the same observation. Seemed to break up around 3 for me. I think it's just the way it's designed. I would expect that a re-tube and bias would help some.

[jamesnotjamie]

Originally Posted by PhatTele

Tube amps seem to go through a few of phases as they warm up:

1) Right after they're turned on, they sound a bit overdriven and kind of nasty IMO.

2) After about 15 to 20 minutes, they start to settle in and tighten up a bit into a tone and temperment that you can really work with.

3) After an hour or two, they are starting to really cook and you get to hear all of the subtleties of the amp.

If you're in the latter two stages and you don't have enough headroom, then you need to adapt. Plug into the second input (if there is one) to drop the input signal a bit, lay off the overdrive pedals or just send a minimum clean boost signal (let the amp do the work), turn the amp up but turn down on the guitar volume (turn up the guitar volume to drive the amp when you take a solo...instead of using the pedals), reduce the amp's midrange a bit...that sort of stuff. In the meantime, a second speaker in parallel will help. You'll be moving more air and you'll perceive it as having extra headroom. Your other choices are to mic your amp or find another amp that can handle the gig.

That is exactly what I wanted to have done if my brain was working in any way during the gig! Unfortunately I had my mind on about 15 songs' lyrics!

Regardless, great advice, I think that's the cheapest option for me at the moment as buying the amp sucked most of my funds away so replacing tubes and speakers are not really an option right now...

Ta for all the input...

[ce24]

a 12AT7 is only about 6 buks...I've got a bunch..I'll send you one if you want to try it..pm me with an address...

ce24

[woodman]

i've never been a fan of 12AT7 in the driver slot ... they seem gutless to me. what about a 5751 or a 12AY7? both work well in the V1 position.

[Billm]

A 12AY7 will preserve your tone better than a 12AT7, which may make it a bit dark, and will give you plenty of clean headroom.

For clean tones, turn up the Master and leave the volume low, no higher than 4 or so with a 12AX7, 6-7 with a 12AY7.

There's a simple one-jumper mod on the mids control that will give you more clean headroom and less muddy tone in your amp. It's the same as the mids mod on the Hot Rod Deluxe:

http://studentweb.eku.edu/justin_hol...mods.html#bass

[ce24]

I agree with woodman...I like the 5751 but do have a bunch of ay7's so I can part with one of those easily enough.

Cheers

[Jeffscreamedcorn]

Originally Posted by woodman

i've never been a fan of 12AT7 in the driver slot ... they seem gutless to me. what about a 5751 or a 12AY7? both work well in the V1 position.

The AT7 does change the tone, but I've been able to tweek my way around it. I don't know about the 5751, but the AY7 does work.

[Gaber_771]

The early breakup is really due to the log type volume pot the amp uses. So when the amp is at the knob's 1/2 volume, you are really damn near close to full volume. you can try it. check out the difference in volume 6 and volume 12. The real output and breakup isn't that different. SO, yeah, 5751 in v1 i sprobobly where i'd start. i have the amp, and a 5751 i a blues deville. I can swap them out and check for you if you don't have a spare 5751.

Also biasing on the colder side might help, and pluging into the 2nd input, which i think is a 3 Db drop... Anyway, the aforementioned advice is all spot on.

[jefrs]

By all means swap tubes about, but if you need more of the same, get two amps.

[Jim L]

I can't add anything... just wanted to say +1 to the preamp tube swap ideas.

I would think that any 40 watt, two 6l6 powered Fender is going to give you a decent amount of clean headroom, especially in a small room. Has it been serviced lately? Any chance the bias needs to be checked? (are Blues Deluxe amps plug and play, or do you need to adjust the bias like most other Fender class AB amps?

[DH82c]

Ditto on the 5751 tubes! At that price do your taste test and enjoy :)

[marshman]

I used to use my Hot Rod Deluxe occasionally, and as well as the wonky volume pot, I had trouble getting good reaction from the master volume--but back then I knew squat about amps, it's a whole different world now.

I don't know a whole lot about the engineering side of amps, but I always thought that swapping preamp tubes wouldn't actually get you more headroom, just more control over your pots--eg: A 40 watt amp will make 40 watts wether there are 12AX7s or 12AU7s in the preamp. The difference is that the distortion will set in about 4 on your vol knob with the AX7s, but not until, say, 9 with the AU7. I don't think there's a REAL way to increase output without changing power tubes & output transformer, but you can get more control over the distortion level, which is really what most of us want, anyway.

Replacing that cruddy volume pot takes about an hour (and should only cost you a few bucks for the parts) if you're reasonably handy with a soldering iron and sure you can drain the caps without killin' yourself...otherwise, you'd better turn that over to a pro. I seem to recall reading somewhere that the BDx had a resistor in for it's bias, not a pot. Might not be true anymore.

Definitely read the Holton HRDx material--tons of good schtuff there.

[TexGoneNW]

Originally Posted by ce24

+1 for a quick and cheap start..

Cheers
ce24

Trying different preamp tubes would be the way to go, I think.

You might want to have a 5751 on hand as a "tweener" if the 12AT7 is plenty clean and the amp loses too much punch.

Oops, I see others already chimed in on that.

[jamesnotjamie]

Cheers for all the input everyone...

All this tube talk is getting me excited. I think I'm gonna have to seek the help of a pro TBH, as my soldering skills are basic...

It's late, I'm going to study this thread tomorrow!

Again, Thanks

[gpower]

There's no soldering required for any tube changes. Changing tubes will change the gain characteristic, making the signal out of the preamp cleaner or dirtier depending on the gain spec of the particular tube.. Pay attention to what BillM & woodman have to say, they're usually bang on.

I know the results in the case of Darcy's amp, (I jam with him). He retubed the amp with a set from Torres and replaced the speaker with the Weber he mentioned. The thing sounds absolutely delicious. I'd have to say 200 - 300% improvement.

Another guy who's opinion I value highly, is Bob at eurotubes.com. He sells jj's and puts together specific sets to match customer needs.

[marshman]

Some people say it's "illogical" to tinker with lower-gain preamp tubes in master volume amps, but you never know when your dream tone will be inexplicably found in some oddball Hungarian 12A_7 or some such.

So--tube gurus--any amp with 12A_7 or ECC8_ ok for these experiments? or are there some things that DON'T belong here?

[brotheradam]

Hey
Anyone have an opinion on the quality of a "Korean" built Tele? I just got a new American Standard. It's great. Howevr, I saw a really nice Tele at a shop and the grain and color was awesome. I don't choose my instruments based on looks, but this was particularly sweet! And cheap. Just wondering how the Korean ones are made up against the other cheaper ones. It seems to be old as well. Maybe 1990 or so. Just wondering if I'm gettin crap.
Thanks