#1
I've been looking on this forum and elsewhere on the internet for information about low gain, low distortion preamp tubes.

My Super Reverb gets preamp distortion at too low a volume for my taste. I'd like to be able to drive the power tubes harder before getting distortion. Right now I'm using a 12AX7. I put a 12AT7 in there, but it didn't sound any better.

I've seen 12AY7's recommended, and 5157's.

I need to cut the distortion about 40% or more.

Any suggestions as to tubes, or isn't there a tube that's capable of this?

I could lower distortion by not using a Tube Screamer, but then the tone is thin. I'm setting the drive to 0 and the level to 9:00 to 11:00.
#2
As far as my knowledge go, you can't, or at least not by swapping the tubes in the pre.
By any means verify this because I'm not really sure.

Lower gain tubes would work if you wanted to overdrive them at lower volumes.
What you actually want is a set of higher gain tubes.

12AX7s are the highest gain tubes in that category, and the lowest are 12AU7s.
The first ones will amplify your signal by a certain amount before distorting it, and the latter ones will amplify your signal by about a fifth before distorting it.

There are two things I'm not sure about now (apart from what I already wrote :P), which are
1. The super reverb doesn't even have a gain control, how in the world are you overdriving the pre?
2. What do you actually want to achieve, clean tones at higher volumes?
Name's Luca.

Quote by OliOsbourne
I don't know anything about this topic, but I just clicked on this thread because of your username :O
Quote by Cajundaddy
Clue: amplifiers amplify so don't turn it on if you need quiet.
Quote by chrismendiola
I guess spambots are now capable of reading minds.
#3
Use the 12AX7s, not the 12AY7s if you want to stay cleaner longer.

Talk to Bob at Eurotubes.
#4
Quote by Monkeyleg
My Super Reverb gets preamp distortion at too low a volume for my taste. I'd like to be able to drive the power tubes harder before getting distortion.

...I could lower distortion by not using a Tube Screamer, but then the tone is thin. I'm setting the drive to 0 and the level to 9:00 to 11:00.




you are looking for different preamp tubes because you want less preamp gain and you're running a tubescreamer in front of your amp?

i'd say changing the tubes is not going to help you. putting a lower gain preamp tube in your amp is just going to pretty much lower the volume output of your amp.

find some other way of making your amp less 'thin' sounding besides using a tubescreamer.

or maybe you need a EL84 amp if you really want power tube distortion.
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."
-ae
Last edited by gumbilicious at Jan 4, 2014,
#5
What you really need is a new amp.

Trade the TS for an EQ.
Spin 'round carousel when your horse isn't screwed in.

My band:
Fractured Instinct
(For fans of Death/Groove/Prog Metal)

Ibanez RGA42E
Ibanez S420
LTD H-301
Ibanez RG520
Peavey Predator USA
Douglas Grendel 725
Line 6 Pod HD500X
#6
what amp?

i disagree - if he uses a 12ay7, wont he have to turn the master up more, thus driving the power section harder?

another option is something like teh eminence attenuating speakers. they are going to drop the volume out of the speakers about 10 DB, which is quite significant. perhaps you can run a 12ay7, keep the gain down low, attenutate the eminence speaker, and then CRANK your master and you will really be pushing those power tubes hard. or any viarable in between for your taste.
Carvin CT624
Walden G630ce Acoustic
Carvin V3M, Avatar 2x12 WGS Reaper, vet 30
(crybaby, Fairfield circuitry Comp, GFS tuner, Vick Audio 73 Ram's Head, Xotic AC booster, lovepedal trem, TC Flashback, PGS Trinity Reverb, Walrus Audio Aetos power)
#7
Quote by ikey_
what amp?

i disagree - if he uses a 12ay7, wont he have to turn the master up more, thus driving the power section harder?


yeah, but i kinda get some mixed signals. he wants power amp distortion but is running a pedal that pushes the preamp, and he wants to cut the gain in the preamp in order to drive the preamp less?

my advice was mainly pointed to the desire for less preamp distortion, but you are correct in that the 12ay7 will make you run the amp louder which could provide more power amp distortion, but i don't see it cleaning up the preamp much or at all if he is still running a TS in front of the amp.

Quote by ikey_
another option is something like teh eminence attenuating speakers. they are going to drop the volume out of the speakers about 10 DB, which is quite significant. perhaps you can run a 12ay7, keep the gain down low, attenutate the eminence speaker, and then CRANK your master and you will really be pushing those power tubes hard. or any viarable in between for your taste.


holy crap, you could throw an attenuator in there too.

if he really wants power amp distortion i think it'd be easier to just get an amp where the power amp distorts much more easily. EL84's are great for that, get a vox ac4.
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."
-ae
#8
If a 12AY7 will push the power tubes harder, then I'll likely get the compression from them that I want at a lower volume setting. If that's the case, wouldn't I then get less preamp distortion?

It sounds messed up but this is what Doug at Doug's Tubes recommended. I'm just trying to make sense of it.

I have the sound I want right now, except that chords--especially high octave chords-- have too much distortion beyond what they deliver all on their own with electrics.

The alternative would be for me to use a compression pedal I have to compress the chords. They sound a bit muddy that way, though.
#9
Simply, anything you throw IN FRONT of your amp is going to push/affect your preamp, not your powreamp.

You're now making it very clear: what exactly do you want to do? Lay it out for us concisely.

Are you trying to get more poweramp breakup? At a lower volume, or at a higher volume? You're trying to get less preamp breakup (your amp doesn't have a master volume/gain knob? What does that mean?)?
Spin 'round carousel when your horse isn't screwed in.

My band:
Fractured Instinct
(For fans of Death/Groove/Prog Metal)

Ibanez RGA42E
Ibanez S420
LTD H-301
Ibanez RG520
Peavey Predator USA
Douglas Grendel 725
Line 6 Pod HD500X
#10
Quote by Monkeyleg
If a 12AY7 will push the power tubes harder


it doesn't push them harder. the gain factor on a 12ay7 is less than a 12ax7.

i am not really following on the reasoning on here, to me this actually doesn't sound like a preamp tube problem, a power tube distortion issue, a compression problem, a 40% less gain problem or most anything else that is getting brought up.

it just sounds to me like you need to tweak you tone a little bit. so get the 15 dollar preamp tube if you think it will help, but my advice is to take your whole setup to a guitar shop and try out some different pedals in front of your amp.

try a boost, an EQ or a different OD pedal and see if that gives you the tone you're after.
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."
-ae
#11
I've got my head stuck in the cupboard and my brain hurts.

Too many variables and not enough equations to solve it.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#12
Quote by Cathbard
I've got my head stuck in the cupboard and my brain hurts.

Too many variables and not enough equations to solve it.


You REALLY need to get new cupboards.
I'm tired of calling the fire department/rescue squad to pull your fat head of of them every week.
#13
Ok, let me try again. I'm sorry for sounding like an idiot, but this is all new to me.

I've been using the Super Reverb with the Tube Screamer or a Boss BD-2 for over a year. I've been making changes to the amp (speakers, trying out new tubes), and I have a nice warm tone that I like. The dynamic range is compressed a bit, so the treble doesn't shatter your ear. It sounds smooth. The mid range is nice and full. The lows aren't as bassy, but are still full. I'm sure there's distortion present in any single string notes.

It's just on chords where the distortion is noticeable. It's at rock levels, and I'm trying to get a nice blues tone, with just a bit less distortion on the chords.

I tried a 12AT7, but Doug at Doug's Tubes said that was a dirty tube not suited for what I want. He suggested a low gain tube, although I didn't ask him to be specific. I will on Monday.

What I don't know about all of this is obviously whether the power tubes can be driven harder through volume and pedal, but the preamp tube can be quieter while still putting out the same power. Is distortion merely a factor of preamp tube output, or are certain levels of distortion based upon the tube design? I see some tubes hawked as high distortion for heavy metal, etc.

Feel free to laugh at me.
#14
Wrong leg of the trousers, man.

Let me explain what you are actually talking about doing.

You are pushing a hot signal into the input and then trying to attenuate it inside the preamp with lower gain tubes. Just stop sending it a hot signal in the beginning.

Get yourself a nice EQ pedal and use it to adjust the signal to the correct level to drive the preamp tubes how you want it. You can also tailor your tone to what you like because it's an EQ.
You know what I'm about to say - MXR 10 band.

Stop boosting, man - unless you actually want a boosted, more distorted sound. Say, for solos. Go chasing unity and whatnot. Give your amp the right input and it will do what you want without all this "low gain tube" tomfoolery.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#15
That makes sense. I've been wondering about an equalizer for a long time, but figured they're expensive. I'll check.

Thanks.
#16
i think the issue is improper terminology. such as a 12ay7 driving harder. this is confusing.
___

if you want less preamp crunch, a cleaner tone, and trying to work your power amp harder, 12ay7s can be used for this. but really, this is all so variable on the amp, the guitar, playing style, pedals, etc etc.

you say too much distortion at low volume. so you want less distortion, and a cleaner amp, relying more on power tubes?

well first is turn the preamp down turn the master up. that is the first logical test. all variables in between. know your amp.

second, i think yes a tube swap is very logical. 5751s or 12ay7s are commonly used for this. 12ay7s have been used as some of the primary preamp tubes in fenders for decades. why not. its 15bucks. a EQ pedal is ... probably 40-150 bucks. you may change 1 or more preamp tubes to get the desired effect.

if you change the tubes in a fender super reverb and you still think the amp has "too much distortion" there is something wrong here. that amp should be LOUD and CLEAN.

i dont think the eminence speaker suggestion is realisitic since i think your amp is a combo with 4 speakers right? yeah that would be too expensive.

weber makes some affordable attenuators
http://www.tedweber.com/atten.htm

an attenuator can do many things. most people use it to get more POWER tube breakup at lower volumes since it allows you to drive it harder and mot make your ears bleed. this does not rule out the preamp, which you still need to stop providing so much gain. but you will be able to manipulate the power amp as you like.

it is all in the rig and the player. there are so many knobs and tweakable things. there is not 1 right answer.

if it were me?

i personalyl would start tweaking my preamp tubes. its simple, and if you pick correctly it will only help your tone. have friends with amps? maybe they have a tube to lend you. 12au7s are the lowest gain, but at times that is a bit drastic.
Carvin CT624
Walden G630ce Acoustic
Carvin V3M, Avatar 2x12 WGS Reaper, vet 30
(crybaby, Fairfield circuitry Comp, GFS tuner, Vick Audio 73 Ram's Head, Xotic AC booster, lovepedal trem, TC Flashback, PGS Trinity Reverb, Walrus Audio Aetos power)
#17
Call me crazy here, but have you considered turning down the volume knob on your guitar? In fact, you didn't even tell us what guitar you're playing. For all we know, you're running a guitar loaded with EMG 81/85's into this setup. It could be that your pickups have too much output for what you play.

The second thing I would try is turning down the level down some more on your Tubescreamer.

If your tone is too thin and weak and the Tubescreamer is solving that issue, my guess is that the mid-boost that TS-type pedals are known for is what's giving you your "thickness", especially since that amp has no mid control on the normal channel. If this is the case, then an EQ pedal could definitely do wonders for you, since you could control exactly what frequencies you want boosted/cut.

It might also help to try a different brand of tubes. That amp ships with Groove Tubes, which are all rebrands except for one that I know of, so they're probably Chinese Shuguangs or something similar. If you put something like JJ's in your preamp, it might give you the change you want also. Put a lower-gain tube in V1 and then normal 12AX7's in everything but the Phase Inverter, which would probably benefit the most from a 5751. Swapping the Power Tubes for JJ's or SED =C= 6L6's might help some, too.

I would definitely start with just tweaking the Volume levels in your guitar and Tubescreamer, though, seeing as how that's the cheapest and easiest
#18
Thanks for the replies again.

Guitar: Fender American Standard Strat with Klein 59 pickups.

Speakers: 2 Weber 10F150 & 2 Weber 10A125

Weber Attenuator (no way I could use the amp without it).

The sweet spot for the amp is between 5 and a bit below 7 on volume. That's where the sound is the fullest before getting some grit. Without the attenuator, I have to go into another room to listen to the amp without my ears bleeding.

Turning down the volume on the guitar changes the tone. I have turned it down to 8 because sometimes I like that tone, as it takes a bit off the highs. Turn it down too much and it sounds muddy.

Turning the Tube Screamer down below the point where the volume is the same with it on or off makes for a muddier sound. At first I thought it sounded compressed that way, but it's really not. Right now I'm actually set a little bit above the point where on/off volume is the same.

I have things dialed in pretty well, but I think a warmer preamp tube would sound better. If it's possible to do this while decreasing preamp distortion, that would be great.

you say too much distortion at low volume. so you want less distortion, and a cleaner amp, relying more on power tubes?


Yep. I'm going to call Doug's and see what he recommends. If nothing else, I can get along with the Fender 12AX7's. It's not like I'm doing an album.
#19
Jj Ecc83s
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#20
Thanks, Cathbard. I'll order one of those, along with the Tung-Sol 12AW7 that Doug recommended.
#21
The TungSols are quite bright. I don't think that's what you want. The JJ is darker with bucketloads of midrange.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band