Valve bass!

[umph]

i've been working on a valve preamp to put into a bass for a while now and i've finally settled on a design i like that sounds great and is reliable.

it uses one a russian 1zh1zb valve as the preamp, and currently i've only got it wired up with a volume pot for each pick up but i may add a tone control later on but as is i think it sound great without.

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i got around the problem of battery drain by powering it via a stereo cable which means it has to be powered via a floor box (kind've like phantom power but using a 1/4 cable) but the added bonus is you can have a DI etc in this floor box aswell i have a DI and valve buffered effects loop in mine, sounds great!

clip is bridge solo'd neck solo'd the both pick ups with fingers then the same again with a pick. and its recording going straight into the computer!

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and some pictures of the cheapo 30pounds bass i put the preamp into!



and the valve itself - exscuse the wiring its not the neatest i've done.

Edited August 25, 2009 by umph

[odub]

Thats a great idea, but it needs perpex so that you can see the valve glow!

[steve-soar]

Excellent.

[waynepunkdude]

Very,very smart. Good work.

[Machines]

Is there enough current for it to glow ?!

[MythSte]

Cracking idea buddy, but the only issue i see is that if you have to have a floorbox, Would people not be more inclined to just use a valve pedal? Unless you do indeed make it somehow visible, in which case it would be cool as funk...

[BigRedX]

So what's the advantage of having this in the bass and not in a stand-alone pre-amp?

[molan]

Are you going to vent the installation somewhere to let the heat out?

[umph]

[quote name='MythSte' post='576958' date='Aug 21 2009, 06:18 PM']Cracking idea buddy, but the only issue i see is that if you have to have a floorbox, Would people not be more inclined to just use a valve pedal? Unless you do indeed make it somehow visible, in which case it would be cool as funk...[/quote]
unfortunatly it doesn't glow, most of the subminis don't it only has 1.5v's on the heaters! well the floor box doesn't have to be very large at all just big enough to fit two jacks and a 9v input into it, so its not a huge draw back. It can still be powere off a battery if you wanted i just havn't tested the battery life yet i'm thinking it'll be about the same as a power hungry opamp though.

the only advantage of having this in the bass and not just a standalone preamp though would be so you could play around with it on the fly, with this version i've made it very basic i've made it so it runs very clean and just has volume controls, but you could always add a bit more control so that you could have the valve break up a bit more and produce some distortion and also add some tone controls.

think the main reason i did it though is just because i wanted a bass with a valve in it ;>

Edited August 21, 2009 by umph

[umph]

[quote name='molan' post='576987' date='Aug 21 2009, 06:38 PM']Are you going to vent the installation somewhere to let the heat out?[/quote]
it doesn't really produce much heat, subminis are different beasts to your average 12ax7!

[YouMa]

Have you got the pcb layout you used mate? I wont nick the idea or anything,i have been wanting to get into valves for a while and this looks a lot safer than messing round with mains voltage.

[umph]

[quote name='YouMa' post='577009' date='Aug 21 2009, 06:58 PM']Have you got the pcb layout you used mate? I wont nick the idea or anything,i have been wanting to get into valves for a while and this looks a lot safer than messing round with mains voltage.[/quote]

its on stripboard and i havn't made up a pcb for it just yet, i can draw up a schematic for you if you'd like though?

[Kiwi]

Sandberg did this a while back for one of their basses. There are also a couple of suppliers I've seen who do an after market valve based circuit but the valve isn't there for power, its running pretty cold so mostly for tone shaping. I had conversations with John East a long time ago about something similar too.

[BarnacleBob]

I was about to ask if this idea had ever been commercially marketed and I am surprised that Sandberg had done it.
I never quite grasped valves in the power vs tone area.
I know older amps have post and pre amp valve sections and the newer ones tend to have just pre-amp so I guess this is trying to emulate the latter.
Had been asking the troops for opinions on an 70s simms-watts all valve bass amp earlier.
You always associate miniatuarisation with ICs rather than valves - is this a recent developement?


BB

[Kiwi]

This is the Sandberg bass, called the 'Tube Machine'



Takamine have an onboard valve preamp called the Cool Tube used in some of their acoustic guitars. At one point it was available separately but I'm not sure thats the case now.

[BarnacleBob]

[quote name='Crazykiwi' post='577327' date='Aug 22 2009, 04:45 AM']This is the Sandberg bass, called the 'Tube Machine'

[/quote]

Interesting!You sure that isn't photoshopped!

A 3 pick-up case - not too many of them about, the MM Big Al (Marmite effect) and Stu Hamm Fender spring to mind.
The controls dont seem very accessible on that. Was/Is that commercially available do you know?

BB

[JimBobTTD]

[quote name='BarnacleBob' post='577322' date='Aug 22 2009, 03:52 AM'][...]
You always associate miniatuarisation with ICs rather than valves - is this a recent developement?


BB[/quote]

Depends on your perception of "recent" - I have some mini valves here (I can't remember the code right now) which are 50s West German military.

Based on my limited experience in life, trying to get things lighter and smaller has been going on since the first big heavy things existed!

[BigRedX]

[quote name='BarnacleBob' post='577329' date='Aug 22 2009, 04:54 AM']A 3 pick-up case - not too many of them about, the MM Big Al (Marmite effect) and Stu Hamm Fender spring to mind.

BB[/quote]

Actually German bass makers seem to be very keen on 3 PU configurations. Have a look at the Weird & Wonderful thread for more examples.

As for the valve pre-amp in the bass, while it's a neat idea, I'm not sure that the impracticality doesn't outweigh the usefulness, especially given the need for an external power supply. The more active basses I play, the more I find I'm a set it and forget it person when it comes to tone shaping. The only controls I ever use during performance on the the bass are volume and pickup balance. For me I can see the point of having of having other controls on the bass, if there was separate tone shaping for each PU, but even then it would only be to avoid the need for a custom lead to the amp.

[JanSpeeltBas]

Here's Bas-Extravaganza with a built-in 12AX7 preamp tube. Power is supplied through the XLR.[attachment=31381:Bas_Extr..._J_style.jpg]

[Shaggy]

That's immensely cool umph, I actually prefer your more discrete design to the Sanberg's.

My other big interest is vintage motorbikes; an occasional OTT custom project is to shoe-horn a V8 car engine into a bike - just wondering if you could do the same with a Mesa 400+ into a bass.......

[clauster]

[quote name='Shaggy' post='577395' date='Aug 22 2009, 10:04 AM']just wondering if you could do the same with a Mesa 400+ into a bass....... [/quote]

A double bass maybe?

[umph]

[quote name='BarnacleBob' post='577322' date='Aug 22 2009, 02:52 AM']I was about to ask if this idea had ever been commercially marketed and I am surprised that Sandberg had done it.
I never quite grasped valves in the power vs tone area.
I know older amps have post and pre amp valve sections and the newer ones tend to have just pre-amp so I guess this is trying to emulate the latter.
Had been asking the troops for opinions on an 70s simms-watts all valve bass amp earlier.
You always associate miniatuarisation with ICs rather than valves - is this a recent developement?


BB[/quote]

valves started getting very small and powerfully there was talk of IC style valves but then obviously transistors etc came along and won the race and all the research was scrapped bit of a shame really in one sense but IC's are alot easier to run

[JanSpeeltBas]

The german-made Hoyer 25 guitar (three were made in the mid '50s) had a built in full tube amp and speaker. There are several '60s makers who used built-in transistor amps but this one is the only one I know that uses tubes.

[umph]

[quote name='JanSpeeltBas' post='577545' date='Aug 22 2009, 01:31 PM']The german-made Hoyer 25 guitar (three were made in the mid '50s) had a built in full tube amp and speaker. There are several '60s makers who used built-in transistor amps but this one is the only one I know that uses tubes.[/quote]
bet that was a instant back breaker.

i've put up clips now, will have to do some more with distortion and when i've not got 2 year old strings on the bass also!

[henry norton]

[quote name='umph' post='577520' date='Aug 22 2009, 01:59 PM']IC's are alot easier to run[/quote]

Slightly off topic but on the odd occasion I've looked at on board pre amp bits all the very best quality, lowest noise ICs tend to draw a huge current. As most people don't want to change their batteries every other week most pre's use ICs chosen for their low energy use rather than performance. Maybe more use should be made of pedalboard mounted power supplies - Alembic is the only bass I can think of that uses them.