gwx014 said:
No real updates. Fortunately, things are picking up at Jackson Ampworks, so that will enable to devote more resources to this new bass amp. I certainly have not forgotten the idea.
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Uncle GAS Needs You: Help Design an All Tube Amp!!!
- Thread starter jokerjkny
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No real updates. Fortunately, things are picking up at Jackson Ampworks, so that will enable to devote more resources to this new bass amp. I certainly have not forgotten the idea.
Man, see what happens when I step away from TalkBass for awhile?
Tubes should always be mounted base down, in my opinion. Heat rises. Especially in a bass amp, where you might be looking at not only 100W-400W or more of power dissipation, but each tube itself might be running at 50W-70W (for KT88's).
Keep the amp as simple as possible. Personally, I really don't see the need for such things as multi-channel preamps, output power selection, built-in compression, etc. Overdrive in a bass amp can be a useful effect, but it's hardly what I would consider a foundation tone. Bias adjusters? Probably useful, considering that tubes are what they are, but my V-Type does't have them, and neither do my Mesa (guitar) amps, but we get along just fine using matched sets of tubes (then of course, there's the whole debate over whether or not tubes even need to be matched, at all).
I'd like to see a 100W amp with a single pair of KT88's in as small a chassis as is feasible. I'd love to have a smaller, lighter, tube bass amp for quieter gigs.
I really like the idea of using the Baxandall tone circuit. That will help set you apart from the crowd. Speaking of tone stacks and output sections, a bass amp is not a guitar amp. The eq centers need to be quite different, and the power section needs to provide as much headroom (read, *big* power supply, *big* transformers) as is humanly possible to put in the thing, not to mention needing much higher plate voltages to run KT88's to such a high dissipation than you typically find even in KT88 guitar amps (see VHT).
Octal preamp tubes are cool, but not so easy to come by these days. Try to think in terms of modular design. That way, you can offer different people the options they want. Some may want octal preamps, some may want 9-pin; some may want a single pair of output tubes, some may want four pairs. More tubes=more cost to replace them...and they *all* need to be replaced, eventually. Some may want a tube-driven FX loop, some may not want one at all (I rarely use my loops anymore). If you design things in a modular fashion, you can mix and match building blocks to produce custom tailored amps.
Personally, if I could find a PTP wired version of my V-Type, especially if I could have one with a 100W output and one with a 2-400W output, I'd be all over that. I think the V-Type design is the ideal place to start when considering a new tube bass amp design, especially since they're not made anymore, and probably never will be.
I'd be building them myself if I knew enough, but I don't, yet...eventually I hope to join the ranks of the boutique amp builders.
Tubes should always be mounted base down, in my opinion. Heat rises. Especially in a bass amp, where you might be looking at not only 100W-400W or more of power dissipation, but each tube itself might be running at 50W-70W (for KT88's).
Keep the amp as simple as possible. Personally, I really don't see the need for such things as multi-channel preamps, output power selection, built-in compression, etc. Overdrive in a bass amp can be a useful effect, but it's hardly what I would consider a foundation tone. Bias adjusters? Probably useful, considering that tubes are what they are, but my V-Type does't have them, and neither do my Mesa (guitar) amps, but we get along just fine using matched sets of tubes (then of course, there's the whole debate over whether or not tubes even need to be matched, at all).
I'd like to see a 100W amp with a single pair of KT88's in as small a chassis as is feasible. I'd love to have a smaller, lighter, tube bass amp for quieter gigs.
I really like the idea of using the Baxandall tone circuit. That will help set you apart from the crowd. Speaking of tone stacks and output sections, a bass amp is not a guitar amp. The eq centers need to be quite different, and the power section needs to provide as much headroom (read, *big* power supply, *big* transformers) as is humanly possible to put in the thing, not to mention needing much higher plate voltages to run KT88's to such a high dissipation than you typically find even in KT88 guitar amps (see VHT).
Octal preamp tubes are cool, but not so easy to come by these days. Try to think in terms of modular design. That way, you can offer different people the options they want. Some may want octal preamps, some may want 9-pin; some may want a single pair of output tubes, some may want four pairs. More tubes=more cost to replace them...and they *all* need to be replaced, eventually. Some may want a tube-driven FX loop, some may not want one at all (I rarely use my loops anymore). If you design things in a modular fashion, you can mix and match building blocks to produce custom tailored amps.
Personally, if I could find a PTP wired version of my V-Type, especially if I could have one with a 100W output and one with a 2-400W output, I'd be all over that. I think the V-Type design is the ideal place to start when considering a new tube bass amp design, especially since they're not made anymore, and probably never will be.
I'd be building them myself if I knew enough, but I don't, yet...eventually I hope to join the ranks of the boutique amp builders.
JacksonAmpworks said:Oh! Man I was WAY off!!
01.) 6SL7 front end Channel 1
Channel 1 Controls
Volume
Treble
Bass
Ultra-Lo and Ultra-Hi Switches
Tone Stack Bypass
02.) 12AX7 front end Channel 2
Channel 2 Controls
Volume
Treble
Bass
Ultra-Lo and Ultra-Hi Switches
Tone Stack Bypass
Master
03.) 6550/KT88 power tubes (6x @ 300W)
04.) Resonance and Presence controls (Global)
05.) Direct Out (XLR) - Selectable PREAMP (post FX Loop) or SPEAKER Tap
06.) Tube Buffered FX Loop
07.) Fixed Biased with Bias Meter
08.) 2-4-8 Ohm Selector Switch
09.) Speakon Connectors (1/4" and Speakon)
10.) 100W/200W/300W Switch
11.) Cathode Disconnect Standby (silent recording!)
12.) Footswitchable FX Loop
13.) Channel Blending (still in development)
14.) Footswitchable Mute
15.) Tuner Out
16.) Level/Gain Boost
ahem...
That certainly is one amazing set of specs. If Brad builds that amp, it looks like it just might be the tube bass amp to end all tube bass amps...which is exactly why I don't think I'd buy one in that spec! I'd never be able to justify any others! 
Brad's web site is very impressive. I though many of the clips were a little on the dark side, but a little eq would brighten them right up. The basic tones were very sweet, though.
If I ever get to building my ideas, I'd be honored to stake out a booth at NAMM right next to Brad!
Brad's web site is very impressive. I though many of the clips were a little on the dark side, but a little eq would brighten them right up. The basic tones were very sweet, though.
If I ever get to building my ideas, I'd be honored to stake out a booth at NAMM right next to Brad!
This amp looks insanley amazing so far on paper. If I could justify a boutique amp I would go for it.
I love the vintage style of all the Jackson amps and expect this amp to be the most attractive of the fleet!
Now if you would go and start making 2x10s and 2x15s you would really start to move some hardware!
I love the vintage style of all the Jackson amps and expect this amp to be the most attractive of the fleet!
Now if you would go and start making 2x10s and 2x15s you would really start to move some hardware!
protoz said:
Thanks so much for the kind words.
If things continue to go as well for Jackson Ampworks in 2006 as they did in 2005, we should see this amp shortly. 
amper said:That certainly is one amazing set of specs. If Brad builds that amp, it looks like it just might be the tube bass amp to end all tube bass amps...which is exactly why I don't think I'd buy one in that spec! I'd never be able to justify any others!
That's the idea. BATEABA - "Bass Amp To End All Bass Amps"
Thanks for the complements on the site. I did it all myself.
That may be before you think.
- Apr 3, 2003
- 35,518
- 19,955
- Disclosures
- Editor-in-Chief, Bass Gear Magazine
JacksonAmpworks said:If things continue to go as well for Jackson Ampworks in 2006 as they did in 2005, we should see this amp shortly.
Fingers are crossed in anticipation!
JacksonAmpworks said:That may be before you think.
FWIW:
you asked me to get back to you on that electrosonic 8 to 9 pin adaptor.
Took me a couple months to get it cause Josh only makes them to order and doesn't keep a shelfstock. Usually done in downtime more or less from what I can gather. Holidays upcoming and said he was backed up some so I killed a month before I ship the cash off. So may have got faster turnaround time.
Anyway it works and does throw a warm fat tone to it, probably more so than any 9 pin tube I've had. 12AT7 5751 gain so no major drop there. I didn't know it but he sends a 6sl7 tube with it.
Pretty tall, 4 5/8" with tube and fairly heavy so clearance and inverted placement could be an issue - in fact he recommends to remove it for transport of inverted placement and I had to remove the cage on the THD cause it didn't quite clear with it on.
The tube does reportedly come out but that sucker is pretty hermetically sealed using my grip. Enough to where I'm not going to jack with pulling it till necessary. I didn't call him on it but I'm guessing he has a method that's not mentioned in the lit that came with it - maybe even a tool for all I know. At least that was my first thought.
Just figured i'd bump this one back up to the top to see if there's any new or info or dates. I'm putting off grabbing a SA200 to wait for one of the Jackson "_____" all tube bass amps
Well, having joined the forum only a few weeks ago, it looks like I'm the last guy on earth to have stumbled across this amazing thread. I've spent most of the afternoon trawling through it from one end to the other, and it's been a thrill. When it does emerge, the Jackson Bass Guitar Amplifier (that's my outrageous, left-field, off-the-wall suggestion for a name, by the way) will be a world-beater. As for the visuals, Brad, just stick with your trademark look: the contrasting chevron. Very cool! 
Yeh that was a recurring thought with GC getting Markbass on the shelf.
One just never know do one?
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