Tube upgrades for Terror Bass?

[Mikal kHill]

I've seen folks mention a tube upgrade for a terror bass... have you done one? What tubes would you recommend for such a thing? I've swapped tubes on my ac30 previously but this is the first time I'd be opening up the Terror Bass for anything.

 

[WRM]

I've seen folks mention a tube upgrade for a terror bass... have you done one? What tubes would you recommend for such a thing? I've swapped tubes on my ac30 previously but this is the first time I'd be opening up the Terror Bass for anything.

Unless there is something wrong with the current tube(s), it's probably best to leave it be.

Just my opinion, and welcome to Talkbass!

 

[agedhorse]

Unless there is something wrong with the current tube(s), it's probably best to leave it be.

Just my opinion, and welcome to Talkbass!

Agreed.

 

[Wasnex]

I've seen folks mention a tube upgrade for a terror bass... have you done one? What tubes would you recommend for such a thing? I've swapped tubes on my ac30 previously but this is the first time I'd be opening up the Terror Bass for anything.

Is it an original Terror Bass or the current MkII?

Quite a few people rolled lower gain tube types in the original because they thought the preamp drive comes on too fast. My perception is essentially they wanted to be able to turn the gain higher before OD sets in. The MkII was designed with lower gain or more headroom, most likely in response to this concern.

A lower gain tube type may allow you to turn the gain up more before OD sets in, but AFAIK it won't actually give you more headroom. In fact it may actually reduce headroom, because the circuits are optimized for a certain tube type.

Some people suggest running lower gain preamp tubes in the Aguilar DB359. I tried it for myself and I preferred the tone and feel of the original tube types. The original tube tube seemed more musical and responsive to my ears.

The first thing for you to figure out IMHO is how responsive the amp is to tube rolling. At most you should expect minor changes when you sub like type tubes. Some circuits produce little to no perceivable change, so there is no point in spending money on a different tube.

If the circuits do respond to tube rolling, the next step is to figure out what sort of change you want to achieve. Then you can try and choose tubes with a reputation for producing the desired change. Some of the tube vendors have online guides that can give you some hints...but the way a tube sounds is somewhat dependent on the circuit it is running in...so actual results may vary. You may find that a given tube gives you a little of what you want, but takes away a little bit of something else that you find desirable.

My favorite combination in bass amps has been a current Production Mullard ECC83 in V1 and a JJ ECC803S pretty much everywhere else. But I don't always choose this combination for bass amps. It depends upon the amp's voicing and which direction I want to nudge the voicing.

Also, just because I think an amp sounds great with the Mullard/JJ combination does not mean you would choose the same tubes. You might think the amp sounds far better with a bunch of Tung Sols.

There is a certain amount of risk to tube rolling. So the advice to leave the tubes alone unless you have an actual problem is valid.

 

[markjazzbassist]

Which model do you have mkI or mkII?

mkI try 5751 instead of 12ax7 to tame the gain. It will smooth it out a bit too.

mkII I would try some JJ 12ax7 or something equivalent and see if there’s much difference. I don’t know what they ship with.

 

[Mikal kHill]

It's an MKII.

 

[Wasnex]

It's an MKII.

Per the website, the stock tubes are one 12AX7 and one 12AT7.

You may find this informative/useful:

 

[WRM]

Per the website, the stock tubes are one 12AX7 and one 12AT7.

You may find this informative/useful:

Nice comparison, but suspect some of the difference was player dynamics? They should have sent the same, recorded, signal as an input to eliminate that variable.

I still liked it!

 

[Super Bass]

Man I change preamp tubes like crazy and really there isn't much difference.. But for some reason I have my favorites!

 

[Lammchop93]

Per the website, the stock tubes are one 12AX7 and one 12AT7.

You may find this informative/useful:

that’s my video!

i didn’t have a looper pedal, so yes player dynamics are a variable. The difference is so subtle between tubes. I felt the EHX has a little more presence that I liked, but in a band setting or to a non-bassist, no one would hear the difference in these tubes.

 

[Wasnex]

that’s my video!

i didn’t have a looper pedal, so yes player dynamics are a variable. The difference is so subtle between tubes. I felt the EHX has a little more presence that I liked, but in a band setting or to a non-bassist, no one would hear the difference in these tubes.

I heard some clear but subtle differences on my laptop. I would consider rolling 12AX7s in this amp.

 

[Coot]

The only tubes I change out are output 6L6's for EL34's as per the manual recommendation by Traynor in the YBA 100. Its a push/pull set of 2 pairs and all 4 must be similar types ELs or 6L6's. There's a definite difference. The 6L6's are cleaner with more head room and the EL34's have a nice grit at lesser volumes. I bought a spare 12AT7 for the Mesa WD800 just to have around in an emergency but I doubt if it will really be necessary. 10 years ago, a hardware store in Gimli Manitoba( small beach town)went out of business after 80 years . I snagged a lot of the stock of 12ax7s but somebody else got there before me and got all the output tubes and the store's tube tester.

 

[Coot]

I never try switching out tubes unless they are specified by the manufacturer. Im concerned about damaging the components by trying tubes that aren't okayed for use. Good luck with the Orange . I have never played through any.. but I hear they are excellent. Just be careful with tube rolling.

 

[leonard]

I just changed the quartet of 6550 power tubes to EL34's on my Marshall Plexi clone. And all the preamp tubes too because the old ones were mostly microphonic. The new tubes don't arc, blow fuses and make weird noises. Other than that I can't hear much difference. I play bass with the amp.

But don't be discouraged. There's no harm in trying different preamp tubes. You might like the difference.

 

[Deleted member 271037]

Changing to a different type of tube (like 12AX7 to 12AT7) is rarely a good idea unless you have a specific problem and have reason to believe that such a change will solve the problem. As a general rule I will always recommend using the type of tube the amp is actually designed for.

As for upgrading the tube to a "better" tube... it depends. I personally find that upgrading current production tubes to good quality NOS tubes can make a noticable difference in vintage amps and studio mic preamps. With many modern guitar/bass amps I've noticed less difference, if any. The problem with NOS tubes is that they've gotten very expensive and most of the tubes that are sold as NOS aren't really NOS at all. The vast majority of "NOS" tubes for sale these days are used tubes. They may test ok and sound great but it's a lottery. Also, there is a wide range of different NOS manufacturers and they all sound a bit different. NOS doesn't necessarily mean great.

The NOS tubes that REALLY make a difference (IMO) are the long plate tubes from the late 50s/early 60s, but with a couple of exceptions they have gotten outrageously expensive. And the ones you will find for sale are most likely used, which is particularly bad with these old long plate tubes as they tend to go microphonic far more easily than later short plate designs.

Having said that, there are certain current production tubes that I like better than others. The "standard" JJ ECC83S is one of the worst IMO. I find this tube muddy sounding, with limited high AND low end extension in MOST amps. JJ have other ECC83-versions that I've liked better. Unfortunately I also find JJ tubes unreliable. Particularly their output tubes, although there have been rumours about bad batches so maybe I've simply had extremely poor luck with JJ.

As for other current production tubes, some of the Russian tubes from New Sensor are ok (although I'm not sure how they've managed to get around the current sanctions against Russia...???). I think their whole business model stinks though, using the brand names of EXCELLENT tube manufacurers from the past to sell COMPLETELY different tubes coming out of the factory that manufacture Sovtek tubes. If they had any pride in their product they should use their own brand rather than "Mullard", "Genalex", "Tung-Sol", "Svetlana". All great tube manufacturers that are long gone (well, Svetlana actually existed well into the 90s until their quality control went down the drain...").

I haven't tested the preamp tubes from TAD's new "Redbase" series. These are Chinese (I believe they are made by Psvane?). I have tested the TAD Redbase 6V6 and El34 though and they are great... so far. The jury is still out on long term reliability. TAD did a really great job with their previous series of Chinese tubes (made by Shuguang) so I have high hopes for these new Redbase series. They obviously won't be the same quality as NOS tubes from the 50s/60s but it's good to see that tube manufacturing isn't completely wiped out... yet.

 

[WRM]

that’s my video!

i didn’t have a looper pedal, so yes player dynamics are a variable. The difference is so subtle between tubes. I felt the EHX has a little more presence that I liked, but in a band setting or to a non-bassist, no one would hear the difference in these tubes.

It's no longer in production, but have a "Jam-Man" pedal that I use all the time. I recorded "The Star Spangled Banner" (Bass solo) on one of the tracks, and find it very handy to be able to adjust amp/pedal settings, or walk around the room to hear how it sounds, without having to play the bass at the same time. I can also record & play along with whatever songs I want to learn/practice, and since you can save 100 X ~9.5 minute tracks on an SD card, it's also a "juke box"....

Thanks for the video - I did enjoy it!

Cheers,

 

[Drredplate]

There isn’t actually that many tube manufacturers.
Tubes made in the same factory get labelled up differently.
So you are quite likely to find that swapping one 12ax7 for another “make” gives no significant difference.
I use JJ tubes personally. you can put lower gain tubes in if you want but I wouldn’t bother unless too much gain is actually a problem

 

[agedhorse]

We reject quote a few tubes due to noise and microphonics. They get returned to the source to be sold to other that have different requirements and standards. Some are perfectly fine for other uses, others I hope they discard.

 

[Drredplate]

I get my tubes from Hotrox UK. They test the tubes and reject as necessary. So the JJ tubes I buy from them are all tested.
They do this with all the “brands” they sell