Valve caster option

[Mgt280y]

Sorry to start another but there is almost to much info in the monster thread and trying to get my head round tubes...
I'm looking at the original 9vdc design as it looks nice and easy to try tubes.

https://flic.kr/p/HQHK8i

What I'm trying to get my head round is there seams to be a popular opinion that 9v tube don't sound as good as they could, so with the above design am I right in thinking the above could have the charge pump added can't rember where the layout was to provide more to the tube.
How does the original design need to differ to do this if an option?
Thanks dan

[GibsonGM]

Hi Dan,

I'd go ahead and try it at 9V, see if you like it, find out what each part does, mod it, etc.  Then you might try 18V, which will increase headroom. 

Learn as much about tubes as you can from web sites, get the fundamentals...after which you might move into a 48V volt range, or even go 100V +.    There's (of course) reasons why most tube circuits run on HT, and why they sound "different" down at lower voltages.  It's good to understand them beforehand, and to also build safe work practices, because those high voltages can smoke you     Also, different tubes sound different/do different things at low voltage (12AU7 vs. 12AX7, for instance).   Read the threads!

To run a Valvy higher, you'd need to be sure your coupling caps are rated high enough for the supply (poly? 100V, maybe?), and at some point (as we approach 200V...) you'd need to switch your plate resistors for 1/2W components.    P= E * I, remember, and I think .25W resistors are only rated to 250V, IIRC...I use 1/2W plate resistors for anything over 100V, anyway, as they're right there in the box....

[rutabaga bob]

There are a few different layouts for voltage multipliers and charge pumps on the forum...Renegadrian (Adriano) has some in the layouts gallery, I think.

If you're starting with 9 volts, you might think about using a 9au7 tube - it's the same as a 12au7, only the heater runs on the standard stomp box 9 volts.

Larry

[Mgt280y]

Thanks fort the replies, Ill keep researching can anyone recommend brand of 9au7 or 12au7 and cheap source in the uk. I'll probably build on as per schematic then play around with values get a bit of experience, I deal with 11 kv mains all day so I have a healthy respect of hv but this work is still a learning curve

[PRR]

> I deal with 11 kv mains all day so I have a healthy respect

You don't stick your nose _IN_ 11KV gear. It's too big. You surely have covers, lock-out procedures, safety sign-off sessions, hotwork sticks, rubber gloves.

Tube audio invites a more intimate experience (ow!).

Anyway converting a 9V tube amp to "proper" 12V heat and 100V plate power is about like re-rigging a neighborhood from all 220V to a 240V line to homes and a 11KV to the factory. Figure which needs what, split the wires, connect to the appropriate supply.

And keep overall perspective. Guitar-cord signals are a Volt or less. A 100+V tube will pass this so clean you cudda used an opamp. To get "tube sound" you need several stages to boost-up to strain a tube, then massive cut-down so your amp input doesn't explode. Yes, power utilities do boost from 2KV generator to 11KV long-line and cut-down to 230V for homes. However that's overkill even for my 500-foot power line from the street. And is added work and complication for a "tube pedal".