Re-Valving an Orange Bass Terror

[Waterboarder]

Nice one - I might give this ago. In a way, didn't see the point in having a 500W amp if the distortion kicks in at such low gain. Not that I don't like the sound...

I also wondered if the valve swap affects the actual tone, or there's any others that may be worth a try?

I love my amp, but the only bad point (apart from the gain as discussed) is it's so bloody bassy! I can get the sound I want, but with the treble almost full up and bass backed right off.

[karlfer]

Just come across this thread, brilliant work HJ.
Anybody know if this change gives more volume live (yes, I'm aware that is probably the dumbest question asked, but I only have the intelligence God gave me!)
Karl.

[Happy Jack]

More volume? I don't think so, and certainly that wasn't what I was trying to achieve!

The OTB kicks out so much, especially through a Barefaced cab, that what I wanted was more [b][i]control [/i][/b]of the sound.

With the original AX7's in place, at most pub gigs I had both Volume and Gain set to "9:00 o'clock" and they were almost On/Off switches.

I can now balance volume against gain to vary my tone as I wish, because I can use far more of each knob's range, while still turning out just as much volume as before.

The AT7s that I have used offer a slightly smoother, less raucous tone than the original fitment AX7s, but any time I want to max out on the grit I can turn the Gain to "3:00 o'clock" and the Volume back down to "9:00 o'clock".

[algmusic]

[quote name='Happy Jack' post='1241331' date='May 23 2011, 11:14 AM']More volume? I don't think so, and certainly that wasn't what I was trying to achieve!

The OTB kicks out so much, especially through a Barefaced cab, that what I wanted was more [b][i]control [/i][/b]of the sound.

With the original AX7's in place, at most pub gigs I had both Volume and Gain set to "9:00 o'clock" and they were almost On/Off switches.

I can now balance volume against gain to vary my tone as I wish, because I can use far more of each knob's range, while still turning out just as much volume as before.

The AT7s that I have used offer a slightly smoother, less raucous tone than the original fitment AX7s, but any time I want to max out on the grit I can turn the Gain to "3:00 o'clock" and the Volume back down to "9:00 o'clock".[/quote]


Not like the OTB has a any volume issues...

[umph]

[quote name='Happy Jack' post='1241331' date='May 23 2011, 11:14 AM']More volume? I don't think so, and certainly that wasn't what I was trying to achieve!

The OTB kicks out so much, especially through a Barefaced cab, that what I wanted was more [b][i]control [/i][/b]of the sound.

With the original AX7's in place, at most pub gigs I had both Volume and Gain set to "9:00 o'clock" and they were almost On/Off switches.

I can now balance volume against gain to vary my tone as I wish, because I can use far more of each knob's range, while still turning out just as much volume as before.

The AT7s that I have used offer a slightly smoother, less raucous tone than the original fitment AX7s, but any time I want to max out on the grit I can turn the Gain to "3:00 o'clock" and the Volume back down to "9:00 o'clock".[/quote]

You find you have less low end with the 81's? the lower plate resistance shifts the high pass filter up a fair bit so bigger caps may be required to retain the original sound

[Low End Bee]

The rig sounded great on Saturday HJ. Thanks for the loan.
My comments on the revalve are that there is still grit available but it's more defined and further around the dial. You really notice much more of a difference in the sound/tone from fingers to pick, different basses, etc.
Works a treat with the Barefaced stack.
Witout PA support I could hear the bass clearly from a fair old distance away.

Would I do the switch? Maybe not because I like the cheap valve sound and I don't need or desire versatility. If you want to sound less one dimensional than I do go for it.

[Happy Jack]

[quote name='umph' post='1241361' date='May 23 2011, 11:38 AM']You find you have less low end with the 81's? the lower plate resistance shifts the high pass filter up a fair bit so bigger caps may be required to retain the original sound[/quote]

Wouldn't this effect be offset by the internal crossover in the Big One?

[karlfer]

Thanks for that HJ.
As ever, expressed myself badly.
Like you, both dials are set at around 9 o'clock when gigging. I hate the sound with the gain much past that, when it starts to do that break up/farty kinda thing.
Guess I really meant more usable volume.
Anyway, thanks to your guide, which even this dumb sh*t can follow, gonna get me some of them there valves ordered at the werekend, and jolly well give it a go .
Cheers Jack,
Karl.

Edited May 23, 2011 by karlfer

[Raslee]

I would like to use more gain control in my sound but i still need to get that defined phat reggae sound, can anyone recommend any valves ?

[algmusic]

[quote name='karlfer' post='1247962' date='May 28 2011, 10:04 AM']Shame they are another company that can't be arsed to reply to emails .[/quote]

Give them a call, to be honest, I don't know any must store that's good at email. Mine were delivered very quickly too..

[Sibob]

Just ordered mine on eBay (same as jack), so looking forward to getting this done next week

Si

[Sibob]

And just fitted them....all seems good, plugged in and tried. Can't wait to gig it this weekend ....will report back

Si

[karlfer]

Got mine from Watford Valves last week.
Gigged it this weekend, much more flexibilty. Sounds great, really happy with it.

Many thanks HJ .
Karl.

[Jamesrt2004]

[quote name='KK Jale' post='1227493' date='May 11 2011, 01:29 PM']Nice work, Happy Jack.

Good advice about using a precisely-fitted crosshead screwdriver to remove the amp cover. The screws on mine were incredibly tight. In the end I had to lay the amp down, use a socket set with a foot-long extension and apply all my weight… that did it. Just!

One more idea, especially if anybody chooses to use secondhand replacement valves (though I used a new Sovtek for V2 I robbed a lovely General Electric 12AX7 from my Fender amp for V1). On removing the Chinese originals, lightly press the nine pins into a soft surface (eg plasticine) and check that the pins on your replacement line up perfectly before inserting. If not, tweak them carefully into shape with needle-nose pliers. Bending the connections on the TB500's valve holders may (*probably will*) necessitate entire circuit board replacement!!

I bought this 80mm PC fan – [url="http://www.quietpc.com/gb-en-gbp/products/casefans/x-rw-80r"]http://www.quietpc.com/gb-en-gbp/products/casefans/x-rw-80r[/url] - to reduce noise but my tech advised that at 19CFM it didn't push as much air as the original so we left the old one in place. A 30CFM fan would be better.[/quote]


No offence but you're techs a noob, what cools it is static pressure rather than cfm, and most cfm are lying anyways

[KK Jale]

[quote name='Jamesrt2004' post='1274440' date='Jun 19 2011, 09:45 AM']No offence but you're techs a noob, what cools it is static pressure rather than cfm, and most cfm are lying anyways [/quote]

Oh, I'm not offended, I couldn't tell 'static pressure' from a rolling doughnut, but I'll be sure to tell my guy he's a noob and shouldn't do stuff like this

[CPBassman]

Valves on their way

[Jamesrt2004]

[quote name='KK Jale' post='1274622' date='Jun 19 2011, 12:30 PM']Oh, I'm not offended, I couldn't tell 'static pressure' from a rolling doughnut, but I'll be sure to tell my guy he's a noob and shouldn't do stuff like this

[/quote]

sorry im a computer geek/nerd and have read pages and pages on 'fans' (lame I know) I hate miss-information thats all (:

+ a fan has nothing to do with the fact he can make an amp? I can show you cocktails I make as im a mixologist.. but doesnt really apply to what we are talking about.

[Mr. Foxen]

[quote name='KK Jale' post='1274622' date='Jun 19 2011, 12:30 PM']Oh, I'm not offended, I couldn't tell 'static pressure' from a rolling doughnut, but I'll be sure to tell my guy he's a noob and shouldn't do stuff like this

[/quote]

Cab manufacturers quote thermal watt ratings of their cabs, it is still meaningless. Same sort of thing. A fan is a 0hz driver, the enclosure matters.

[Low End Bee]

I've re-valved my Terror too now.

I had to drill out two screws. They're in tighter than a gnats chuff and are made of cheese. Anyway no real harm done. It was nice to get the case off and tighten up the flappy handle from inside. Why couldn't they tighten they handle on properly and leave the casing screws with some play rather than vice versa? Anyway back to the point. HJ donated me a couple of Electro Harmonix 12AX7's so I bunged them in. I love lots of gain on my bass so I was interested to see how it would change the overdriven sound from the Chinese cheapo originals in there. I didn't think of recording comparison sound clips because I'm not that organised.

The results? A more natural sounding overdrive with less harshness are the initial feelings. It seems to break up at just the same gain settings as the original valves did. It just sounds a bit smoother I guess. Turning the gain past 3 o'clock and it gets really filthy but you still get good note seperation. I'm not great at describing tones and they're very subjective anyway. But I'd say it was a very worthwhile mod.

Haven't tried to DI yet. Interested to see how that pans out.

[Chest Rockwell]

[quote name='Low End Bee' timestamp='1313143294' post='1337376']
They're in tighter than a gnats chuff and are made of cheese.
[/quote]

[Guest teamcoy]

Thanks very much for this guide, I bunged some Genalex Gold Lion 12AT7's in mine and quite pleased with the difference.

[Alfie]

I really don't know much about valves, but after having some problems in recording studios with the Terror Bass I am looking for something different.

Watford Valves sell a lot of different ECC81 and ECC83 valves, are there specific types that I should stick to, or will any work fine?

[Happy Jack]

[url="http://www.guitaramplifierblueprinting.com/12ax7.html"]http://www.guitaramplifierblueprinting.com/12ax7.html[/url]

Given how over-Gained the OTB is, putting in another AX7 will probably not be the solution which is why I chose to use the AT7 instead.

The DI Out on the OTB is simply dreadful. One solution is to use an attenuator to step the output down to more useable levels, but frankly I wouldn't choose to use an OTB for recording purposes unless I wanted to mic up my entire rig.

[tredders]

Thanks HJ. Ordered a couple of Philips AT7's from Watford Valves (who were incidentally very helpful), and followed your instructions & fitted the new valves this morning. Piece of cake, even to a ham fisted bloke like me. I'm really pleased with the results - same OTB sound, just a bit more controllable and bit more variety now.

Thanks for the guide - I'd never have thought of doing it myself until I read this.

[dannybuoy]

I've tried a Gold Lion 12AX7 in the V1 position (on the right) and a Jan Philips 5751 (which is somewhere inbetween a 12AT7 and 12AX7 in terms of gain). Definitely lower gain with the 5751, although the Gold Lions have slightly more gain than stock they still sound better. Still trying to decide what I prefer, limited by the fact that Hot Rox sent me an EHX valve in one of the Gold Lion boxes by mistake (I should have had two of em) - they are hopefully sending me a replacement.

I'm not sure if changing the V2 valve on the left to a lower gain tube will have the effect of limiting the maximum power out of the amp? Depends exactly how it's wired up but the schematic in the manual isn't detailed enough.

[url="http://www.orangeamps.com/images/Terror_Bass_manual_20100205.pdf"]http://www.orangeamps.com/images/Terror_Bass_manual_20100205.pdf[/url]