New tubes??

[fuzzyratfarts]

Hey I have a Fender Hot Rod Deluxe 40 watt amp, and it seems like since I bought it new (around 4 years ago), the volume has dropped...Like I used to play it on 1.5 or so and now I play it at around 2.5....Does this mean my tubes are fading, or what?

[fuzzyratfarts]

Re: New tubes??

The tubes in it are:

• Two 6L6 Groove Tube output tubes
• Three 12AX7 preamp tubes

[benjaturner]

Re: New tubes??

4 years is pretty good going for tubes. There's much debate about how often they should be changed. I've heard pretty strong agruements for changing every 6 months while some people swear that their 10 year old tubes sound as good as anything they could buy!

It's perfectly plausible that you've just grown accustomed to your amp and higher volumes don't seem so extreme to you anymore. I think the time to change tubes is when you think they start to sound worse, not quieter. If your amp still sounds as good to you as ever then why bother changing tubes at all? Does it really matter if you set your amp at 2.5 now? You've still got A LOT of headroom left, so why bother?

[mnbaseball91]

Re: New tubes??

Does it really matter if you set your amp at 2.5 now? You've still got A LOT of headroom left, so why bother?

You would if Fender didn't use those crazy volume pots! 2.5 is practically cranking it!

Personally, I'd just go ahead and swap out the tubes but save these as your backup set.

[Jeff_H]

Re: New tubes??

I personally think the HRDlx can benefit greatly from a tube change, expecially if the one's in it are stock. Some slightly softer rated GT's will take some of the edge of the OD (I used to own one), and then just play with some pre-amp tubes to find what you like best, since they are cheap. Try the GT12AX7-M's, the C's, some of the new Tungsol, try a few, since they usually run under $20 each, and many under $10. Also, try a 12 AT7 in the reverb slot, and don't forget a balanced 12AX7 in the PI slot.

Pre-amp tubes are the easiest way to shape the sound of your amp. Nothing is right or wrong, buy a bunch and find out what you like.

[fuzzyratfarts]

Re: New tubes??

Alright several questions for you amp knowers:

1. The current two power tubes are GT 6l6's, and if (as Jeff H suggested) I want slightly smoother 6l6's, which model should I look at?
2. If preamp tubes are what really shape the sound, and currently I have three 12AX7 preamp tubes, what preamp tubes should I get for a slightly jazzier, softer, smoother, cleaner tone, but totally changing the tone of the amp?
3. I, opposite of all other tube amp owners, wish my amp would sound "cranked" at a higher volume rather than a lower volume...I have several good overdrives to make it sound cranked (Barber LTD and Analogman Silver Mod Maxon Tubescreamer)... What tubes would stay cleaner at higher volumes? I love my clean tone but once you turn up the volume at all, it quickly overdrives, taking away the jazzy feel to it...
4. In Jeff H's post, I am confused about if there is another slot for a reverb tube, or is that one of the preamp tubes....and what does PI stand for?
Thanks!!

[fuzzyratfarts]

Re: New tubes??

How would JJ tubes works? The 6L6GC looks pretty cool...and when they say 'more headroom' does that mean it stays cleaner at higher volumes rather than overdriving quickly?

[adrian]

Re: New tubes??

JJ 6L6 would probably sound great, slightly darker and powerful. Svetlanas (SED) 6L6 perhaps smoother and more Fenderish. A GE 5751 in V1 (the first preamp tube, closest to the input jack: guess that´s what Jeff H meant) will probably give some more clean headroom. But ok, as we all know about pickup changes: it all sound different in different woods and guitars, and so on...

[fuzzyratfarts]

Re: New tubes??

more powerful? would this cause earlier tube overdrive, because i dont want that...

[Jeff_H]

Re: New tubes??

I'll answer the best I can here, I'm not a 6L6 expert.

Power Tubes

More headroom does in fact mean the amp stays clean longer, and at higher volumes. Groove Tubes rates their tubes in terms of "hardness" on a 1-10 scale. The higher the number, the longer it takes to breakup. Remember with a higher breakup point, the OD you get can sound harsh. You have to find a balance between headroom and tube distortion...it's always somewhat of a compromise. The JJ sounds like it may be a good choice, or a GT rated in the 7 range.

Pre-amp tubes

Each pre-amp tube is in fact 2 seperate tubes combined in one. Each side of the pre-amp tube can and normally is used in a different part of the tone stack. As an example here is how the tubes work in my modified Marshall:

V1a is first gain stage for clean channel. V1b is first gain stage for OD.

V2a is second gain stage for clean, V2b is second gain stage for OD.

V3a is third gain stage for OD, V3b is final gain stage for everything and is post effects loop.

V4 is reverb only

V5 is PI...you can use anything you want here so long as both sides are the same i.e 12Ax7, T7 or U7

Your amp will be similar, but I don't know the layout of how your tubes are used. My guess is V1 (the farthest small tube from the power tubes) controls your clean channel and maybe reverb. V2 then should control the OD channel and maybe effects loop. Again, I'm just guessing. The closest small tube to your power tubes is your PI, or Phase Inverter. Basically (if I remember) this takes your guitar signal at that point in the chain, and inverts it before slamming it into the power tubes. I don't pretend to understand exactly what it does, but I know it's important to have a closely matched or "balanced" tube in this spot. A "balanced" tube generally costs $5 more than a regular tube.

As for what brand or type of tube to use...that gets tougher. 12AX7's have the most gain, 12AT7's have roughly 70% of the gain of an AX7, and 12AU7's have even less gain. I've never really experimented with lower gain tubes except in a dedicated reverb spot since I'm a rock player, and gain is always needed.

JJ's are generally smoother in nature, so may be a good choice. Groove Tubes have been great to me lately, so I like them quite a bit. Sovtek LPS AX7's are also great tubes for rock, but I don't know about for smooth/jazz tones. Then you can delve into NOS tubes, which are unused tubes from the 50's thru 70's that are reputably of better quality than new. Some NOS tubes are very, very good, and up until the past few years I would have told you that they were much better than new tubes. Groove Tubes and a lot of other companies have improved quality so much in the last few years that now I don't spend the $$ on NOS tubes, because the difference is so much smaller.

Bottom line, you may need to spend $100 or so on 5-8 different 12AX7 or other type pre-amp tubes and experiment....what we think may not sound good to you. What you need to understand is how the tubes work, and then find what works best for you.

You can e-mail Bob at Eurotubes, and he will help you select tubes for the sound you want...but you will end up with JJ's since that's all he sells. That's not a bad thing, as JJ makes a bunch of different pre-amp and power tubes in a variety of ratings and sound. You can also e-mail Mike at KCANOSTUBES.com, and he will help you also. He carries the better selection of new tubes and almost all of the NOS tubes.

Hope this has helped a little.

[adrian]

Re: New tubes??

Ok, Jeff H, then I understand what you mean with P1. I´m used to the more common models of Fender amps, like Hot Rod Deluxe and Deville, which often has only 3 pre-amp tubes and 2 powertubes.

[fuzzyratfarts]

Re: New tubes??

I emailed Bob at Eurotubes and he reccomended me some models for what I want so I think I am set!