Can I replace ECC83 pre amp tubes with 12AX7 pre amp tubes?

[daveyboyFTW]

I’m wanting to replace the tubes I currently have in my Marshall TSL60 but want a different tone. I love the peavey 6505+ amp but don’t have the money to buy one. Can I swap out the preamp tubes without damaging anything?

[DeepEnd]

First, hi and welcome to the Forum. Second, you know those are different names for the same tube, right? https://www.thetubestore.com/preamp-tubes/12ax7-ecc83-tube-types. So you won't hurt anything but you also won't change much. You can try different brands of tubes but I don't necessarily think you can get where you want to go by swapping tubes. Someone else may have an idea how to achieve what you want. Good luck.

[daveyboyFTW]

Thanks! I don’t know very much about tubes and what works with what. I’ve been playing for a while but never looked into tubes as themselves. I know I won’t be able to get the exact tone of a 6505+ without buying the amp itself. I’m curious as if I can get a tone closer to it.

[1001gear]

Actually, preamp tubes do make a difference in tone. They are the first to act on the input signal. Little bit goes a long way.

[t_e_l_e]

swapping tubes can change the sound, but what is it you want to change on your marshall, which should be more 6505 alike? more gain? less gain? the tone? too bright? too dark? more scooped mids?

 

ecc83/12ax7 tubes come in different flavours with less or more gain. but to be fair, less gain does not mean low(est) gain, and they will still distort and add the tube flavour. where more gain does not mean brutal high gain of your favourite metal band on its own...

 

lets say your amp has 3 preamp tubes, if you put 3 highgain 12ax7 in it, you get the highest possible gain from the preamp stage

if you put 3 lowergain tu es in it, you get the lowest possible gain preamp stage, which will also be the one with the most clean head room...

 

any other combination will vary the result.

in most amp the first tube is the most crucial in altering the "sound", putting the low (high) gain there will have the most effect, while you can keep the other two unchanged, so you can get one of each and experiment from there...

 

but first of all, make yourself clear about your goal, where do you want to go? and have the change i have done (e.g. swapping one tube) got me closer to my goal or am i farer away...

[daveyboyFTW]

Thanks for the reply! I’m not 100% on how to explain the tone I’m looking for so here it goes. I prefer the way the overdrive/distortion “breaks up” in the 6505. I also would like more bottom end with a bit less mid range than the Marshall is putting out. I hope that made sense lol

[WRGKMC]

ECC83 and 12AX7 are the same thing. ECC83 is the European version and the 12AX7 is the American name for the same tube.

 

Where you get tonal differences is in the build quality and some minor differences in how they are built.

 

The Tube store - https://www.thetubestore.com/preamp-tubes/12ax7-ecc83-tube-types Tube depot - https://tubedepot.com/t/tubes/preamp-tubes/12ax7-ecc83-7025-cv4004 and the Antique electronic supply - https://www.tubesandmore.com/products/vacuum_tubes and Amplified Parts - https://www.amplifiedparts.com/tech-corner/12ax7-comparison-current-made-tubes are the places I purchase tubes. They tend to have the best pricing and quality and you wont be buying someone else's used tubes stuck back in a box when you buy them like you might on EB and other shady sites.

 

All of these sites have tube comparison charts like this.

 

https://www.tubedepot.com/tube-comparison-tool Just use the preamp tube dropdown.

 

Here's the tubes I prefer in Marshalls. I'm old enough to have used all the old vintage tubes back in the day and I've tried nearly all new brands being made/ I did a first hand comparison of over a dozen different types awhile back on a mic preamp and the EH were the only set that were clearly better. They blow the doors off of anything else out there for the price. Loud, bright, low noise, great sensitivity and will put the guitar far in front of others using the same amp. Nearly twice as loud as JJ's too.

 

As you can see below, spending more for gold contacts doesn't do a dam thing tone wise. The only thing that extra $7 is good for its preventing the pins from oxidizing but a can of contact cleaner to clean the sockets does the same thing.

 

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https://www.amplifiedparts.com/tech-corner/12ax7-comparison-current-made-tubes will give you some idea of the tone differences the tubes can produce when compared in the same circuit. This can sometimes help if you know what tubes you have and want to shape the tone to match the amp better. differences in circuit designs are the other factor of course. You aren't going to make a Marshall sound like a Fender or vice versa by simply changing the tubes.

 

The circuits and tone stacks are vastly different and the differences tubes make are typically very small, some changes in tubes are undetectable. Many of the tubes you but are Branded and made by the same China or Russian companies so you shouldn't expect too much from a tube change, especially if the tubes are still relatively new. If the tubes are old and beat then any new set will sound better in comparison.

 

Marshall has used many tubes over the years before having Chinese Shuguang tubes branded with the Marshall Logo.

If you want matching quality then simply buy Shuguang. They aren't bad sounding tubes when new but from my experience they aren't as durable as some others. I wouldn't buy JJ's or Sovtek either. The gains aren't right and they wind up sounding dark. Groove tubes would be my second choice over EH or maybe something like the Tung Sol or Mullard's They cost a little more but you get whet you pay for.

 

Not sure if you amp has a 12AT7 as an inverter. If it does you can still buy NOS - JAN Tubes (Joint, Army Navy), military spec tubes which are excellent. These Phillips are as good as you're going to get at any price. https://www.tubedepot.com/products/12at7wc-jan-philips

 

[daddymack]

you can also change the characteristics by not using a 12AX7.... using a 12AT [ECC81], 12AU [ECC82], 12AY [6072] and so on will certainly garner different gain, headroom, warmth, etc, from the pre-amp stage.

That said, there are other considerations you mention which may be attributable to other components, like the speakers, the type of cabinet and the amp settings. If you run the amp 'wide open', with all the controls dimed, then you are going to get far more mids than you would like, which will bury some of the bottom end. Having also owned a couple of Marshalls over the the past 40+ years, I have to say bottom end was never a problem, even on an open backed combo [with a Celestion], so I think it is worth mentioning that what you are after may not be the fault of the amp, but in how you are setting it, and what guitar [and settings] and pedals [and settings] you are using as well. The TSL60 has its own midrange pot on each channel, so turning that down would be the right place to start...

[daveyboyFTW]

The cabinet I’m using is a Marshall MG slant cab loaded with celestion g12t-75s instead of the stock Marshall mgs. Ive maxed out the low end and cut some of the mids. Bass is at 10, mid is just below 2 and treble is at 6. The presence is at 8. I mentioned before that I loved the 6505 peavey amp head and was looking for something that would get me closer to that tone. I know I won’t get that exact tone without buying the amp. I loved the way the distorion broke up and it had plenty of low end so I’m seeing what I can do to get me in that direction.

[DeepEnd]

Have you tried all three channels? Adjusting the EQ? You mentioned you have the Presence at 8. Try backing it off. You'll get less upper mids. Used cabs are cheap compared with amps or maybe try different speakers in your existing cab.

 

Actually' date=' preamp tubes do make a difference in tone. They are the first to act on the input signal. Little bit goes a long way.[/quote']

Perhaps but I seriously doubt any amount of tube swapping can make a Marshall sound like a Peavey.

[daveyboyFTW]

Yes I did. I did notice that while on the clean channel it had more low end than the dirty channels. On the clean channel I have it as follows: bass10 middle5 trebble6 and presence8. Very clear sound with plenty of low end but as soon as I go to any dirty channel, the lows tend to not show up to the party. I borrowed a 6505+ a while back and it sounded amazing with the cab. Haven’t changed anything with the cab since then either.

[daddymack]

well, then there's the real answer: Nothing will change a Marshall to a Peavey, so, put the Marshall on Reverb/eBay, and start looking for a 6505.

[daveyboyFTW]

Pretty much. I had a gut feeling that I couldn’t get a peavey tone from my Marshall. I guess I’m going to experiment with tubes and see what comes of it. Any suggestions for tubes that are high gain and have a good amount of low end? I have a 89 epiphone les Paul custom loaded with Seymour duncans. Jazz in the neck and a JB in the bridge. I play in dropped C. Any suggestions for tubes will be appcriated.

[daveyboyFTW]

UPDATE: did some digging around and with a lot of research I’ve decided to take the amp in to a shop and had them replace the tubes. They told me the tubes were fairly old and it was time to replace them. They replaced the preamp tubes and power tubes and made sure the bias was on point. The amp sounds pretty damn good now. Thank you all for your help!

[DeepEnd]

Congratulations and Happy New Tubes Day. I hope you enjoy your amp now. Out of curiosity, do you know what tubes the shop installed?

[1001gear]

Did you get your old tubes back?

[daveyboyFTW]

I believe he said JJ

[daveyboyFTW]

No I didn’t. I didn’t see any need for them back. Should I have?

[1001gear]

No I didn’t. I didn’t see any need for them back. Should I have?

 

There's always the odd chance that some of the tubes were good (obviously they still worked) and/or had unique tonal properties.

 

 

[daddymack]

UPDATE: did some digging around and with a lot of research I’ve decided to take the amp in to a shop and had them replace the tubes. They told me the tubes were fairly old and it was time to replace them. They replaced the preamp tubes and power tubes and made sure the bias was on point. The amp sounds pretty damn good now. Thank you all for your help!

 

ah, well, there is a piece of information we didn't have. I'm guessing your power tubes were past their prime; preamp tubes don't get the same level of abuse as power tubes do, especially in a 'hi-gain' amp..

[daveyboyFTW]

Ah I see. I don’t miss them tho lol

[daveyboyFTW]

At the time I made the first post, i didn’t have any idea that power tubes affected tone. I thought it it just increased the volume and the preamps made the tone. I made the decision to just replace them all because I didn’t want to have to replace the other tubes shortly later.

[Daehtihs]

I look at amps the same way I look at guitars, a guitar that's optimized for jazz may not be the best choice for metal, you can change the strings, try different picks but that archtop jazz guitar is still optimized for one thing. in other words, just save up for a while and get that 6505 they'e not very expensive used, and let the Marshall be what it is.